Merge remote-tracking branch 'upstream/master' into fix-stream-compression-config-interface

172 files changed, 1441 insertions, 825 deletions

diff --git a/src/core/ext/census/base_resources.c b/src/core/ext/census/base_resources.cc
index 1f2bb39fe0..3697c6f0e0 100644
--- a/src/core/ext/census/base_resources.c
+++ b/src/core/ext/census/base_resources.cc
@@ -45,12 +45,12 @@ void define_base_resources() {
                 0,                                        // n_denominators
                 NULL};                                    // denominators
   define_resource(&r);
-  r = (resource){(char *)"server_rpc_latency",             // name
-                 (char *)"Server RPC latency in seconds",  // description
-                 0,                                        // prefix
-                 1,                                        // n_numerators
-                 &numerator,                               // numerators
-                 0,                                        // n_denominators
-                 NULL};                                    // denominators
+  r = {(char *)"server_rpc_latency",             // name
+       (char *)"Server RPC latency in seconds",  // description
+       0,                                        // prefix
+       1,                                        // n_numerators
+       &numerator,                               // numerators
+       0,                                        // n_denominators
+       NULL};                                    // denominators
   define_resource(&r);
 }
diff --git a/src/core/ext/census/base_resources.h b/src/core/ext/census/base_resources.h
index 78a4d1fae5..4b1b988e3f 100644
--- a/src/core/ext/census/base_resources.h
+++ b/src/core/ext/census/base_resources.h
@@ -18,7 +18,15 @@
 #ifndef GRPC_CORE_EXT_CENSUS_BASE_RESOURCES_H
 #define GRPC_CORE_EXT_CENSUS_BASE_RESOURCES_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Define all base resources. This should be called by census initialization. */
 void define_base_resources();
 
-#endif /* GRPC_CORE_EXT_CENSUS_BASE_RESOURCES_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_CENSUS_BASE_RESOURCES_H */
\ No newline at end of file
diff --git a/src/core/ext/census/census_init.c b/src/core/ext/census/census_init.cc
index d7f719ff8c..d7f719ff8c 100644
--- a/src/core/ext/census/census_init.c
+++ b/src/core/ext/census/census_init.cc
diff --git a/src/core/ext/census/census_interface.h b/src/core/ext/census/census_interface.h
index a42b68ad65..12438e3c0a 100644
--- a/src/core/ext/census/census_interface.h
+++ b/src/core/ext/census/census_interface.h
@@ -24,6 +24,10 @@
 /* Maximum length of an individual census trace annotation. */
 #define CENSUS_MAX_ANNOTATION_LENGTH 200
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Structure of a census op id. Define as structure because 64bit integer is not
    available on every platform for C89. */
 typedef struct census_op_id {
@@ -58,4 +62,8 @@ census_op_id census_tracing_start_op(void);
 /* Ends tracing. Calling this function will invalidate the input op_id. */
 void census_tracing_end_op(census_op_id op_id);
 
-#endif /* GRPC_CORE_EXT_CENSUS_CENSUS_INTERFACE_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_CENSUS_CENSUS_INTERFACE_H */
\ No newline at end of file
diff --git a/src/core/ext/census/census_log.c b/src/core/ext/census/census_log.cc
index 100047f12b..100047f12b 100644
--- a/src/core/ext/census/census_log.c
+++ b/src/core/ext/census/census_log.cc
diff --git a/src/core/ext/census/census_log.h b/src/core/ext/census/census_log.h
index 6b68b6bd37..cc9e008907 100644
--- a/src/core/ext/census/census_log.h
+++ b/src/core/ext/census/census_log.h
@@ -25,6 +25,10 @@
 #define CENSUS_LOG_2_MAX_RECORD_SIZE 14 /* 2^14 = 16KB */
 #define CENSUS_LOG_MAX_RECORD_SIZE (1 << CENSUS_LOG_2_MAX_RECORD_SIZE)
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Initialize the statistics logging subsystem with the given log size. A log
    size of 0 will result in the smallest possible log for the platform
    (approximately CENSUS_LOG_MAX_RECORD_SIZE * gpr_cpu_num_cores()). If
@@ -73,4 +77,8 @@ size_t census_log_remaining_space(void);
    out-of-space. */
 int census_log_out_of_space_count(void);
 
-#endif /* GRPC_CORE_EXT_CENSUS_CENSUS_LOG_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_CENSUS_CENSUS_LOG_H */
\ No newline at end of file
diff --git a/src/core/ext/census/census_rpc_stats.c b/src/core/ext/census/census_rpc_stats.cc
index 0aca1f109e..0aca1f109e 100644
--- a/src/core/ext/census/census_rpc_stats.c
+++ b/src/core/ext/census/census_rpc_stats.cc
diff --git a/src/core/ext/census/census_tracing.c b/src/core/ext/census/census_tracing.cc
index 199b260dd1..199b260dd1 100644
--- a/src/core/ext/census/census_tracing.c
+++ b/src/core/ext/census/census_tracing.cc
diff --git a/src/core/ext/census/context.c b/src/core/ext/census/context.cc
index 9b25a32e36..9b25a32e36 100644
--- a/src/core/ext/census/context.c
+++ b/src/core/ext/census/context.cc
diff --git a/src/core/ext/census/grpc_context.c b/src/core/ext/census/grpc_context.cc
index 0bfba63a5e..0bfba63a5e 100644
--- a/src/core/ext/census/grpc_context.c
+++ b/src/core/ext/census/grpc_context.cc
diff --git a/src/core/ext/census/grpc_filter.c b/src/core/ext/census/grpc_filter.cc
index b37ab90389..b37ab90389 100644
--- a/src/core/ext/census/grpc_filter.c
+++ b/src/core/ext/census/grpc_filter.cc
diff --git a/src/core/ext/census/grpc_filter.h b/src/core/ext/census/grpc_filter.h
index baa7bb931a..7940363061 100644
--- a/src/core/ext/census/grpc_filter.h
+++ b/src/core/ext/census/grpc_filter.h
@@ -21,9 +21,17 @@
 
 #include "src/core/lib/channel/channel_stack.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Census filters: provides tracing and stats collection functionalities. It
    needs to reside right below the surface filter in the channel stack. */
 extern const grpc_channel_filter grpc_client_census_filter;
 extern const grpc_channel_filter grpc_server_census_filter;
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_CENSUS_GRPC_FILTER_H */
diff --git a/src/core/ext/census/grpc_plugin.c b/src/core/ext/census/grpc_plugin.cc
index c0efe5afb8..22b16c6c63 100644
--- a/src/core/ext/census/grpc_plugin.c
+++ b/src/core/ext/census/grpc_plugin.cc
@@ -50,7 +50,7 @@ static bool maybe_add_census_filter(grpc_exec_ctx *exec_ctx,
   return true;
 }
 
-void census_grpc_plugin_init(void) {
+extern "C" void census_grpc_plugin_init(void) {
   /* Only initialize census if no one else has and some features are
    * available. */
   if (census_enabled() == CENSUS_FEATURE_NONE &&
@@ -67,4 +67,4 @@ void census_grpc_plugin_init(void) {
                                    (void *)&grpc_server_census_filter);
 }
 
-void census_grpc_plugin_shutdown(void) { census_shutdown(); }
+extern "C" void census_grpc_plugin_shutdown(void) { census_shutdown(); }
diff --git a/src/core/ext/census/hash_table.c b/src/core/ext/census/hash_table.cc
index 545b0857c7..545b0857c7 100644
--- a/src/core/ext/census/hash_table.c
+++ b/src/core/ext/census/hash_table.cc
diff --git a/src/core/ext/census/hash_table.h b/src/core/ext/census/hash_table.h
index 75770641c5..c22ba8df9d 100644
--- a/src/core/ext/census/hash_table.h
+++ b/src/core/ext/census/hash_table.h
@@ -23,6 +23,10 @@
 
 #include <grpc/support/port_platform.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* A chain based hash table with fixed number of buckets.
    Your probably shouldn't use this code directly. It is implemented for the
    use case in census trace store and stats store, where number of entries in
@@ -113,4 +117,8 @@ typedef void (*census_ht_itr_cb)(census_ht_key key, const void *val_ptr,
    should not invalidate data entries. */
 uint64_t census_ht_for_all(const census_ht *ht, census_ht_itr_cb);
 
-#endif /* GRPC_CORE_EXT_CENSUS_HASH_TABLE_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_CENSUS_HASH_TABLE_H */
\ No newline at end of file
diff --git a/src/core/ext/census/initialize.c b/src/core/ext/census/initialize.cc
index 165a1221d4..165a1221d4 100644
--- a/src/core/ext/census/initialize.c
+++ b/src/core/ext/census/initialize.cc
diff --git a/src/core/ext/census/intrusive_hash_map.c b/src/core/ext/census/intrusive_hash_map.cc
index 7930486963..7930486963 100644
--- a/src/core/ext/census/intrusive_hash_map.c
+++ b/src/core/ext/census/intrusive_hash_map.cc
diff --git a/src/core/ext/census/intrusive_hash_map.h b/src/core/ext/census/intrusive_hash_map.h
index f50de4fab4..2c7baa31fb 100644
--- a/src/core/ext/census/intrusive_hash_map.h
+++ b/src/core/ext/census/intrusive_hash_map.h
@@ -21,6 +21,10 @@
 
 #include "src/core/ext/census/intrusive_hash_map_internal.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* intrusive_hash_map is a fast chained hash table. This hash map is faster than
  * a dense hash map when the application calls insert and erase more often than
  * find. When the workload is dominated by find() a dense hash map may be
@@ -149,4 +153,8 @@ void intrusive_hash_map_clear(intrusive_hash_map *hash_map,
 void intrusive_hash_map_free(intrusive_hash_map *hash_map,
                              void (*free_object)(void *));
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_CENSUS_INTRUSIVE_HASH_MAP_H */
diff --git a/src/core/ext/census/mlog.c b/src/core/ext/census/mlog.cc
index 4b8c8466b3..4b8c8466b3 100644
--- a/src/core/ext/census/mlog.c
+++ b/src/core/ext/census/mlog.cc
diff --git a/src/core/ext/census/mlog.h b/src/core/ext/census/mlog.h
index 6f3125944f..7b4d39272b 100644
--- a/src/core/ext/census/mlog.h
+++ b/src/core/ext/census/mlog.h
@@ -28,6 +28,10 @@
 #define CENSUS_LOG_2_MAX_RECORD_SIZE 14 /* 2^14 = 16KB */
 #define CENSUS_LOG_MAX_RECORD_SIZE (1 << CENSUS_LOG_2_MAX_RECORD_SIZE)
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Initialize the statistics logging subsystem with the given log size. A log
    size of 0 will result in the smallest possible log for the platform
    (approximately CENSUS_LOG_MAX_RECORD_SIZE * gpr_cpu_num_cores()). If
@@ -77,4 +81,8 @@ size_t census_log_remaining_space(void);
    out-of-space. */
 int64_t census_log_out_of_space_count(void);
 
-#endif /* GRPC_CORE_EXT_CENSUS_MLOG_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_CENSUS_MLOG_H */
\ No newline at end of file
diff --git a/src/core/ext/census/operation.c b/src/core/ext/census/operation.cc
index be88ac74e6..be88ac74e6 100644
--- a/src/core/ext/census/operation.c
+++ b/src/core/ext/census/operation.cc
diff --git a/src/core/ext/census/placeholders.c b/src/core/ext/census/placeholders.cc
index bed9837ee3..bed9837ee3 100644
--- a/src/core/ext/census/placeholders.c
+++ b/src/core/ext/census/placeholders.cc
diff --git a/src/core/ext/census/resource.c b/src/core/ext/census/resource.cc
index 44a887231c..44a887231c 100644
--- a/src/core/ext/census/resource.c
+++ b/src/core/ext/census/resource.cc
diff --git a/src/core/ext/census/resource.h b/src/core/ext/census/resource.h
index b8bda2c72e..5f7ac2ad27 100644
--- a/src/core/ext/census/resource.h
+++ b/src/core/ext/census/resource.h
@@ -23,6 +23,10 @@
 #include <grpc/grpc.h>
 #include "src/core/ext/census/gen/census.pb.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Internal representation of a resource. */
 typedef struct {
   char *name;
@@ -45,4 +49,8 @@ void shutdown_resources(void);
    from configuration files. */
 int32_t define_resource(const resource *base);
 
-#endif /* GRPC_CORE_EXT_CENSUS_RESOURCE_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_CENSUS_RESOURCE_H */
\ No newline at end of file
diff --git a/src/core/ext/census/trace_context.c b/src/core/ext/census/trace_context.cc
index af92ae6d9e..af92ae6d9e 100644
--- a/src/core/ext/census/trace_context.c
+++ b/src/core/ext/census/trace_context.cc
diff --git a/src/core/ext/census/trace_context.h b/src/core/ext/census/trace_context.h
index a7233e6a2b..c707c63263 100644
--- a/src/core/ext/census/trace_context.h
+++ b/src/core/ext/census/trace_context.h
@@ -39,6 +39,10 @@
 1 byte for is_sampled (bool) */
 #define TRACE_MAX_CONTEXT_SIZE 31
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Encode a trace context (ctxt) into proto format to the buffer provided.  The
 size of buffer must be at least TRACE_MAX_CONTEXT_SIZE.  On success, returns the
 number of bytes successfully encoded into buffer.  On failure, returns 0. */
@@ -53,4 +57,8 @@ of these do not exist. On success, returns true and false otherwise. */
 bool decode_trace_context(google_trace_TraceContext *ctxt, uint8_t *buffer,
                           const size_t nbytes);
 
-#endif /* GRPC_CORE_EXT_CENSUS_TRACE_CONTEXT_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_CENSUS_TRACE_CONTEXT_H */
\ No newline at end of file
diff --git a/src/core/ext/census/trace_propagation.h b/src/core/ext/census/trace_propagation.h
index eecfcb7d01..3394e9e0fd 100644
--- a/src/core/ext/census/trace_propagation.h
+++ b/src/core/ext/census/trace_propagation.h
@@ -21,6 +21,10 @@
 
 #include "src/core/ext/census/tracing.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Encoding and decoding functions for receiving and sending trace contexts
    over the wire.  Only RPC libraries should be calling these
    functions.  These functions return the number of bytes encoded/decoded
@@ -45,4 +49,8 @@ size_t trace_span_context_to_http_format(const trace_span_context *ctxt,
 size_t http_format_to_trace_span_context(const char *buf, size_t buf_size,
                                          trace_span_context *ctxt);
 
-#endif /* GRPC_CORE_EXT_CENSUS_TRACE_PROPAGATION_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_CENSUS_TRACE_PROPAGATION_H */
\ No newline at end of file
diff --git a/src/core/ext/census/tracing.c b/src/core/ext/census/tracing.cc
index 823c681abf..823c681abf 100644
--- a/src/core/ext/census/tracing.c
+++ b/src/core/ext/census/tracing.cc
diff --git a/src/core/ext/census/tracing.h b/src/core/ext/census/tracing.h
index 038c9e2790..5fcbb1e1f7 100644
--- a/src/core/ext/census/tracing.h
+++ b/src/core/ext/census/tracing.h
@@ -25,6 +25,10 @@
 #include "src/core/ext/census/trace_label.h"
 #include "src/core/ext/census/trace_status.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* This is the low level tracing API that other languages will interface with.
    This is not intended to be accessed by the end-user, therefore it has been
    designed with performance in mind rather than ease of use. */
@@ -106,4 +110,8 @@ free to ignore all further calls using the Span. EndSpanOptions can
 optionally be NULL. */
 void trace_end_span(const trace_status *status, trace_span_context *span_ctxt);
 
-#endif /* GRPC_CORE_EXT_CENSUS_TRACING_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_CENSUS_TRACING_H */
\ No newline at end of file
diff --git a/src/core/ext/census/window_stats.c b/src/core/ext/census/window_stats.cc
index 0058e4bf9c..0058e4bf9c 100644
--- a/src/core/ext/census/window_stats.c
+++ b/src/core/ext/census/window_stats.cc
diff --git a/src/core/ext/census/window_stats.h b/src/core/ext/census/window_stats.h
index ebe3732008..3b1d197f76 100644
--- a/src/core/ext/census/window_stats.h
+++ b/src/core/ext/census/window_stats.h
@@ -21,6 +21,10 @@
 
 #include <grpc/support/time.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Keep rolling sums of a user-defined statistic (containing a number of
    measurements) over a a number of time intervals ("windows"). For example,
    you can use a window_stats object to answer questions such as
@@ -155,4 +159,8 @@ void census_window_stats_get_sums(const struct census_window_stats *wstats,
    assertion failure). This function is thread-compatible. */
 void census_window_stats_destroy(struct census_window_stats *wstats);
 
-#endif /* GRPC_CORE_EXT_CENSUS_WINDOW_STATS_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_CENSUS_WINDOW_STATS_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/channel_connectivity.c b/src/core/ext/filters/client_channel/channel_connectivity.cc
index 3844b98021..31a8fc39ce 100644
--- a/src/core/ext/filters/client_channel/channel_connectivity.c
+++ b/src/core/ext/filters/client_channel/channel_connectivity.cc
@@ -18,6 +18,8 @@
 
 #include "src/core/lib/surface/channel.h"
 
+#include <inttypes.h>
+
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
@@ -186,8 +188,8 @@ static void watcher_timer_init(grpc_exec_ctx *exec_ctx, void *arg,
   watcher_timer_init_arg *wa = (watcher_timer_init_arg *)arg;
 
   grpc_timer_init(exec_ctx, &wa->w->alarm,
-                  gpr_convert_clock_type(wa->deadline, GPR_CLOCK_MONOTONIC),
-                  &wa->w->on_timeout, gpr_now(GPR_CLOCK_MONOTONIC));
+                  grpc_timespec_to_millis_round_up(wa->deadline),
+                  &wa->w->on_timeout);
   gpr_free(wa);
 }
 
diff --git a/src/core/ext/filters/client_channel/client_channel.c b/src/core/ext/filters/client_channel/client_channel.cc
index 016199b1f4..22c2bc8880 100644
--- a/src/core/ext/filters/client_channel/client_channel.c
+++ b/src/core/ext/filters/client_channel/client_channel.cc
@@ -16,8 +16,11 @@
  *
  */
 
+#include <grpc/support/port_platform.h>
+
 #include "src/core/ext/filters/client_channel/client_channel.h"
 
+#include <inttypes.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <string.h>
@@ -68,7 +71,7 @@ typedef enum {
 
 typedef struct {
   gpr_refcount refs;
-  gpr_timespec timeout;
+  grpc_millis timeout;
   wait_for_ready_value wait_for_ready;
 } method_parameters;
 
@@ -98,17 +101,18 @@ static bool parse_wait_for_ready(grpc_json *field,
   return true;
 }
 
-static bool parse_timeout(grpc_json *field, gpr_timespec *timeout) {
+static bool parse_timeout(grpc_json *field, grpc_millis *timeout) {
   if (field->type != GRPC_JSON_STRING) return false;
   size_t len = strlen(field->value);
   if (field->value[len - 1] != 's') return false;
   char *buf = gpr_strdup(field->value);
   buf[len - 1] = '\0';  // Remove trailing 's'.
   char *decimal_point = strchr(buf, '.');
+  int nanos = 0;
   if (decimal_point != NULL) {
     *decimal_point = '\0';
-    timeout->tv_nsec = gpr_parse_nonnegative_int(decimal_point + 1);
-    if (timeout->tv_nsec == -1) {
+    nanos = gpr_parse_nonnegative_int(decimal_point + 1);
+    if (nanos == -1) {
       gpr_free(buf);
       return false;
     }
@@ -127,24 +131,25 @@ static bool parse_timeout(grpc_json *field, gpr_timespec *timeout) {
         gpr_free(buf);
         return false;
     }
-    timeout->tv_nsec *= multiplier;
+    nanos *= multiplier;
   }
-  timeout->tv_sec = gpr_parse_nonnegative_int(buf);
+  int seconds = gpr_parse_nonnegative_int(buf);
   gpr_free(buf);
-  if (timeout->tv_sec == -1) return false;
+  if (seconds == -1) return false;
+  *timeout = seconds * GPR_MS_PER_SEC + nanos / GPR_NS_PER_MS;
   return true;
 }
 
 static void *method_parameters_create_from_json(const grpc_json *json) {
   wait_for_ready_value wait_for_ready = WAIT_FOR_READY_UNSET;
-  gpr_timespec timeout = {0, 0, GPR_TIMESPAN};
+  grpc_millis timeout = 0;
   for (grpc_json *field = json->child; field != NULL; field = field->next) {
     if (field->key == NULL) continue;
     if (strcmp(field->key, "waitForReady") == 0) {
       if (wait_for_ready != WAIT_FOR_READY_UNSET) return NULL;  // Duplicate.
       if (!parse_wait_for_ready(field, &wait_for_ready)) return NULL;
     } else if (strcmp(field->key, "timeout") == 0) {
-      if (timeout.tv_sec > 0 || timeout.tv_nsec > 0) return NULL;  // Duplicate.
+      if (timeout > 0) return NULL;  // Duplicate.
       if (!parse_timeout(field, &timeout)) return NULL;
     }
   }
@@ -823,7 +828,7 @@ typedef struct client_channel_call_data {
 
   grpc_slice path;  // Request path.
   gpr_timespec call_start_time;
-  gpr_timespec deadline;
+  grpc_millis deadline;
   gpr_arena *arena;
   grpc_call_stack *owning_call;
   grpc_call_combiner *call_combiner;
@@ -976,11 +981,11 @@ static void apply_service_config_to_call_locked(grpc_exec_ctx *exec_ctx,
       // If the deadline from the service config is shorter than the one
       // from the client API, reset the deadline timer.
       if (chand->deadline_checking_enabled &&
-          gpr_time_cmp(calld->method_params->timeout,
-                       gpr_time_0(GPR_TIMESPAN)) != 0) {
-        const gpr_timespec per_method_deadline =
-            gpr_time_add(calld->call_start_time, calld->method_params->timeout);
-        if (gpr_time_cmp(per_method_deadline, calld->deadline) < 0) {
+          calld->method_params->timeout != 0) {
+        const grpc_millis per_method_deadline =
+            grpc_timespec_to_millis_round_up(calld->call_start_time) +
+            calld->method_params->timeout;
+        if (per_method_deadline < calld->deadline) {
           calld->deadline = per_method_deadline;
           grpc_deadline_state_reset(exec_ctx, elem, calld->deadline);
         }
@@ -995,13 +1000,14 @@ static void create_subchannel_call_locked(grpc_exec_ctx *exec_ctx,
   channel_data *chand = (channel_data *)elem->channel_data;
   call_data *calld = (call_data *)elem->call_data;
   const grpc_connected_subchannel_call_args call_args = {
-      .pollent = calld->pollent,
-      .path = calld->path,
-      .start_time = calld->call_start_time,
-      .deadline = calld->deadline,
-      .arena = calld->arena,
-      .context = calld->subchannel_call_context,
-      .call_combiner = calld->call_combiner};
+      calld->pollent,                  // pollent
+      calld->path,                     // path
+      calld->call_start_time,          // start_time
+      calld->deadline,                 // deadline
+      calld->arena,                    // arena
+      calld->subchannel_call_context,  // context
+      calld->call_combiner             // call_combiner
+  };
   grpc_error *new_error = grpc_connected_subchannel_create_call(
       exec_ctx, calld->connected_subchannel, &call_args,
       &calld->subchannel_call);
@@ -1418,7 +1424,7 @@ static grpc_error *cc_init_call_elem(grpc_exec_ctx *exec_ctx,
   // Initialize data members.
   calld->path = grpc_slice_ref_internal(args->path);
   calld->call_start_time = args->start_time;
-  calld->deadline = gpr_convert_clock_type(args->deadline, GPR_CLOCK_MONOTONIC);
+  calld->deadline = args->deadline;
   calld->arena = args->arena;
   calld->owning_call = args->call_stack;
   calld->call_combiner = args->call_combiner;
diff --git a/src/core/ext/filters/client_channel/client_channel.h b/src/core/ext/filters/client_channel/client_channel.h
index c99f0092e9..b32f378c6c 100644
--- a/src/core/ext/filters/client_channel/client_channel.h
+++ b/src/core/ext/filters/client_channel/client_channel.h
@@ -28,6 +28,10 @@ extern grpc_tracer_flag grpc_client_channel_trace;
 // Channel arg key for server URI string.
 #define GRPC_ARG_SERVER_URI "grpc.server_uri"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* A client channel is a channel that begins disconnected, and can connect
    to some endpoint on demand. If that endpoint disconnects, it will be
    connected to again later.
@@ -52,4 +56,8 @@ void grpc_client_channel_watch_connectivity_state(
 grpc_subchannel_call *grpc_client_channel_get_subchannel_call(
     grpc_call_element *elem);
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/client_channel_factory.c b/src/core/ext/filters/client_channel/client_channel_factory.cc
index 57eac8f875..57eac8f875 100644
--- a/src/core/ext/filters/client_channel/client_channel_factory.c
+++ b/src/core/ext/filters/client_channel/client_channel_factory.cc
diff --git a/src/core/ext/filters/client_channel/client_channel_factory.h b/src/core/ext/filters/client_channel/client_channel_factory.h
index ce6266c769..bad8b97042 100644
--- a/src/core/ext/filters/client_channel/client_channel_factory.h
+++ b/src/core/ext/filters/client_channel/client_channel_factory.h
@@ -27,6 +27,10 @@
 // Channel arg key for client channel factory.
 #define GRPC_ARG_CLIENT_CHANNEL_FACTORY "grpc.client_channel_factory"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct grpc_client_channel_factory grpc_client_channel_factory;
 typedef struct grpc_client_channel_factory_vtable
     grpc_client_channel_factory_vtable;
@@ -74,4 +78,8 @@ grpc_channel *grpc_client_channel_factory_create_channel(
 grpc_arg grpc_client_channel_factory_create_channel_arg(
     grpc_client_channel_factory *factory);
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/client_channel_plugin.c b/src/core/ext/filters/client_channel/client_channel_plugin.cc
index 1f71c5a7f9..4431d11519 100644
--- a/src/core/ext/filters/client_channel/client_channel_plugin.c
+++ b/src/core/ext/filters/client_channel/client_channel_plugin.cc
@@ -65,7 +65,7 @@ static bool set_default_host_if_unset(grpc_exec_ctx *exec_ctx,
   return true;
 }
 
-void grpc_client_channel_init(void) {
+extern "C" void grpc_client_channel_init(void) {
   grpc_lb_policy_registry_init();
   grpc_resolver_registry_init();
   grpc_retry_throttle_map_init();
@@ -84,7 +84,7 @@ void grpc_client_channel_init(void) {
 #endif
 }
 
-void grpc_client_channel_shutdown(void) {
+extern "C" void grpc_client_channel_shutdown(void) {
   grpc_subchannel_index_shutdown();
   grpc_channel_init_shutdown();
   grpc_proxy_mapper_registry_shutdown();
diff --git a/src/core/ext/filters/client_channel/connector.c b/src/core/ext/filters/client_channel/connector.cc
index c258468e58..c258468e58 100644
--- a/src/core/ext/filters/client_channel/connector.c
+++ b/src/core/ext/filters/client_channel/connector.cc
diff --git a/src/core/ext/filters/client_channel/connector.h b/src/core/ext/filters/client_channel/connector.h
index 7f3d4a1cc0..b91c93e446 100644
--- a/src/core/ext/filters/client_channel/connector.h
+++ b/src/core/ext/filters/client_channel/connector.h
@@ -23,6 +23,10 @@
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/transport/transport.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct grpc_connector grpc_connector;
 typedef struct grpc_connector_vtable grpc_connector_vtable;
 
@@ -34,7 +38,7 @@ typedef struct {
   /** set of pollsets interested in this connection */
   grpc_pollset_set *interested_parties;
   /** deadline for connection */
-  gpr_timespec deadline;
+  grpc_millis deadline;
   /** channel arguments (to be passed to transport) */
   const grpc_channel_args *channel_args;
 } grpc_connect_in_args;
@@ -70,4 +74,8 @@ void grpc_connector_connect(grpc_exec_ctx *exec_ctx, grpc_connector *connector,
 void grpc_connector_shutdown(grpc_exec_ctx *exec_ctx, grpc_connector *connector,
                              grpc_error *why);
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CONNECTOR_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CONNECTOR_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/http_connect_handshaker.c b/src/core/ext/filters/client_channel/http_connect_handshaker.cc
index 418bb41ef6..418bb41ef6 100644
--- a/src/core/ext/filters/client_channel/http_connect_handshaker.c
+++ b/src/core/ext/filters/client_channel/http_connect_handshaker.cc
diff --git a/src/core/ext/filters/client_channel/http_connect_handshaker.h b/src/core/ext/filters/client_channel/http_connect_handshaker.h
index 928a23dc93..5042c61bec 100644
--- a/src/core/ext/filters/client_channel/http_connect_handshaker.h
+++ b/src/core/ext/filters/client_channel/http_connect_handshaker.h
@@ -28,7 +28,15 @@
 /// seperated by colons.
 #define GRPC_ARG_HTTP_CONNECT_HEADERS "grpc.http_connect_headers"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /// Registers handshaker factory.
 void grpc_http_connect_register_handshaker_factory();
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_CONNECT_HANDSHAKER_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_CONNECT_HANDSHAKER_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/http_proxy.c b/src/core/ext/filters/client_channel/http_proxy.cc
index c507a2750e..a16b44d3dc 100644
--- a/src/core/ext/filters/client_channel/http_proxy.c
+++ b/src/core/ext/filters/client_channel/http_proxy.cc
@@ -91,6 +91,7 @@ static bool proxy_mapper_map_name(grpc_exec_ctx* exec_ctx,
   char* user_cred = NULL;
   *name_to_resolve = get_http_proxy_server(exec_ctx, &user_cred);
   if (*name_to_resolve == NULL) return false;
+  char* no_proxy_str = NULL;
   grpc_uri* uri =
       grpc_uri_parse(exec_ctx, server_uri, false /* suppress_errors */);
   if (uri == NULL || uri->path[0] == '\0') {
@@ -98,20 +99,14 @@ static bool proxy_mapper_map_name(grpc_exec_ctx* exec_ctx,
             "'http_proxy' environment variable set, but cannot "
             "parse server URI '%s' -- not using proxy",
             server_uri);
-    if (uri != NULL) {
-      gpr_free(user_cred);
-      grpc_uri_destroy(uri);
-    }
-    return false;
+    goto no_use_proxy;
   }
   if (strcmp(uri->scheme, "unix") == 0) {
     gpr_log(GPR_INFO, "not using proxy for Unix domain socket '%s'",
             server_uri);
-    gpr_free(user_cred);
-    grpc_uri_destroy(uri);
-    return false;
+    goto no_use_proxy;
   }
-  char* no_proxy_str = gpr_getenv("no_proxy");
+  no_proxy_str = gpr_getenv("no_proxy");
   if (no_proxy_str != NULL) {
     static const char* NO_PROXY_SEPARATOR = ",";
     bool use_proxy = true;
@@ -147,12 +142,7 @@ static bool proxy_mapper_map_name(grpc_exec_ctx* exec_ctx,
       gpr_free(no_proxy_hosts);
       gpr_free(server_host);
       gpr_free(server_port);
-      if (!use_proxy) {
-        grpc_uri_destroy(uri);
-        gpr_free(*name_to_resolve);
-        *name_to_resolve = NULL;
-        return false;
-      }
+      if (!use_proxy) goto no_use_proxy;
     }
   }
   grpc_arg args_to_add[2];
@@ -173,9 +163,15 @@ static bool proxy_mapper_map_name(grpc_exec_ctx* exec_ctx,
   } else {
     *new_args = grpc_channel_args_copy_and_add(args, args_to_add, 1);
   }
-  gpr_free(user_cred);
   grpc_uri_destroy(uri);
+  gpr_free(user_cred);
   return true;
+no_use_proxy:
+  if (uri != NULL) grpc_uri_destroy(uri);
+  gpr_free(*name_to_resolve);
+  *name_to_resolve = NULL;
+  gpr_free(user_cred);
+  return false;
 }
 
 static bool proxy_mapper_map_address(grpc_exec_ctx* exec_ctx,
diff --git a/src/core/ext/filters/client_channel/http_proxy.h b/src/core/ext/filters/client_channel/http_proxy.h
index 34694931d0..65d52334af 100644
--- a/src/core/ext/filters/client_channel/http_proxy.h
+++ b/src/core/ext/filters/client_channel/http_proxy.h
@@ -19,6 +19,14 @@
 #ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_PROXY_H
 #define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_PROXY_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 void grpc_register_http_proxy_mapper();
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_PROXY_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_PROXY_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/lb_policy.c b/src/core/ext/filters/client_channel/lb_policy.cc
index 8e6673d737..8e6673d737 100644
--- a/src/core/ext/filters/client_channel/lb_policy.c
+++ b/src/core/ext/filters/client_channel/lb_policy.cc
diff --git a/src/core/ext/filters/client_channel/lb_policy.h b/src/core/ext/filters/client_channel/lb_policy.h
index 645d51e138..010299c2f4 100644
--- a/src/core/ext/filters/client_channel/lb_policy.h
+++ b/src/core/ext/filters/client_channel/lb_policy.h
@@ -23,6 +23,10 @@
 #include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** A load balancing policy: specified by a vtable and a struct (which
     is expected to be extended to contain some parameters) */
 typedef struct grpc_lb_policy grpc_lb_policy;
@@ -204,4 +208,8 @@ void grpc_lb_policy_update_locked(grpc_exec_ctx *exec_ctx,
                                   grpc_lb_policy *policy,
                                   const grpc_lb_policy_args *lb_policy_args);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_H */
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.cc
index 7ad322902b..7ad322902b 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.cc
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.h b/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.h
index 51e30b20b8..c6a0d69c3f 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.h
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.h
@@ -21,7 +21,15 @@
 
 #include "src/core/lib/channel/channel_stack.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 extern const grpc_channel_filter grpc_client_load_reporting_filter;
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_CLIENT_LOAD_REPORTING_FILTER_H \
           */
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
index 85ef7894ea..53fa0fff04 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
@@ -80,6 +80,7 @@
    headers. Therefore, sockaddr.h must always be included first */
 #include "src/core/lib/iomgr/sockaddr.h"
 
+#include <inttypes.h>
 #include <limits.h>
 #include <string.h>
 
@@ -102,6 +103,7 @@
 #include "src/core/ext/filters/client_channel/parse_address.h"
 #include "src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h"
 #include "src/core/ext/filters/client_channel/subchannel_index.h"
+#include "src/core/lib/backoff/backoff.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/channel_stack.h"
 #include "src/core/lib/iomgr/combiner.h"
@@ -111,7 +113,6 @@
 #include "src/core/lib/slice/slice_hash_table.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
-#include "src/core/lib/support/backoff.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/surface/channel.h"
@@ -123,6 +124,7 @@
 #define GRPC_GRPCLB_RECONNECT_BACKOFF_MULTIPLIER 1.6
 #define GRPC_GRPCLB_RECONNECT_MAX_BACKOFF_SECONDS 120
 #define GRPC_GRPCLB_RECONNECT_JITTER 0.2
+#define GRPC_GRPCLB_DEFAULT_FALLBACK_TIMEOUT_MS 10000
 
 grpc_tracer_flag grpc_lb_glb_trace = GRPC_TRACER_INITIALIZER(false, "glb");
 
@@ -299,6 +301,10 @@ typedef struct glb_lb_policy {
   /** timeout in milliseconds for the LB call. 0 means no deadline. */
   int lb_call_timeout_ms;
 
+  /** timeout in milliseconds for before using fallback backend addresses.
+   * 0 means not using fallback. */
+  int lb_fallback_timeout_ms;
+
   /** for communicating with the LB server */
   grpc_channel *lb_channel;
 
@@ -325,6 +331,9 @@ typedef struct glb_lb_policy {
    * Otherwise, we delegate to the RR policy. */
   size_t serverlist_index;
 
+  /** stores the backend addresses from the resolver */
+  grpc_lb_addresses *fallback_backend_addresses;
+
   /** list of picks that are waiting on RR's policy connectivity */
   pending_pick *pending_picks;
 
@@ -345,6 +354,9 @@ typedef struct glb_lb_policy {
   /** is \a lb_call_retry_timer active? */
   bool retry_timer_active;
 
+  /** is \a lb_fallback_timer active? */
+  bool fallback_timer_active;
+
   /** called upon changes to the LB channel's connectivity. */
   grpc_closure lb_channel_on_connectivity_changed;
 
@@ -354,9 +366,6 @@ typedef struct glb_lb_policy {
   /************************************************************/
   /*  client data associated with the LB server communication */
   /************************************************************/
-  /* Finished sending initial request. */
-  grpc_closure lb_on_sent_initial_request;
-
   /* Status from the LB server has been received. This signals the end of the LB
    * call. */
   grpc_closure lb_on_server_status_received;
@@ -367,6 +376,9 @@ typedef struct glb_lb_policy {
   /* LB call retry timer callback. */
   grpc_closure lb_on_call_retry;
 
+  /* LB fallback timer callback. */
+  grpc_closure lb_on_fallback;
+
   grpc_call *lb_call; /* streaming call to the LB server, */
 
   grpc_metadata_array lb_initial_metadata_recv; /* initial MD from LB server */
@@ -385,19 +397,21 @@ typedef struct glb_lb_policy {
   grpc_slice lb_call_status_details;
 
   /** LB call retry backoff state */
-  gpr_backoff lb_call_backoff_state;
+  grpc_backoff lb_call_backoff_state;
 
   /** LB call retry timer */
   grpc_timer lb_call_retry_timer;
 
-  bool initial_request_sent;
+  /** LB fallback timer */
+  grpc_timer lb_fallback_timer;
+
   bool seen_initial_response;
 
   /* Stats for client-side load reporting. Should be unreffed and
    * recreated whenever lb_call is replaced. */
   grpc_grpclb_client_stats *client_stats;
   /* Interval and timer for next client load report. */
-  gpr_timespec client_stats_report_interval;
+  grpc_millis client_stats_report_interval;
   grpc_timer client_load_report_timer;
   bool client_load_report_timer_pending;
   bool last_client_load_report_counters_were_zero;
@@ -443,11 +457,11 @@ static bool is_server_valid(const grpc_grpclb_server *server, size_t idx,
 static void *lb_token_copy(void *token) {
   return token == NULL
              ? NULL
-             : (void *)GRPC_MDELEM_REF((grpc_mdelem){(uintptr_t)token}).payload;
+             : (void *)GRPC_MDELEM_REF(grpc_mdelem{(uintptr_t)token}).payload;
 }
 static void lb_token_destroy(grpc_exec_ctx *exec_ctx, void *token) {
   if (token != NULL) {
-    GRPC_MDELEM_UNREF(exec_ctx, (grpc_mdelem){(uintptr_t)token});
+    GRPC_MDELEM_UNREF(exec_ctx, grpc_mdelem{(uintptr_t)token});
   }
 }
 static int lb_token_cmp(void *token1, void *token2) {
@@ -536,6 +550,32 @@ static grpc_lb_addresses *process_serverlist_locked(
   return lb_addresses;
 }
 
+/* Returns the backend addresses extracted from the given addresses */
+static grpc_lb_addresses *extract_backend_addresses_locked(
+    grpc_exec_ctx *exec_ctx, const grpc_lb_addresses *addresses) {
+  /* first pass: count the number of backend addresses */
+  size_t num_backends = 0;
+  for (size_t i = 0; i < addresses->num_addresses; ++i) {
+    if (!addresses->addresses[i].is_balancer) {
+      ++num_backends;
+    }
+  }
+  /* second pass: actually populate the addresses and (empty) LB tokens */
+  grpc_lb_addresses *backend_addresses =
+      grpc_lb_addresses_create(num_backends, &lb_token_vtable);
+  size_t num_copied = 0;
+  for (size_t i = 0; i < addresses->num_addresses; ++i) {
+    if (addresses->addresses[i].is_balancer) continue;
+    const grpc_resolved_address *addr = &addresses->addresses[i].address;
+    grpc_lb_addresses_set_address(backend_addresses, num_copied, &addr->addr,
+                                  addr->len, false /* is_balancer */,
+                                  NULL /* balancer_name */,
+                                  (void *)GRPC_MDELEM_LB_TOKEN_EMPTY.payload);
+    ++num_copied;
+  }
+  return backend_addresses;
+}
+
 static void update_lb_connectivity_status_locked(
     grpc_exec_ctx *exec_ctx, glb_lb_policy *glb_policy,
     grpc_connectivity_state rr_state, grpc_error *rr_state_error) {
@@ -603,35 +643,38 @@ static bool pick_from_internal_rr_locked(
     grpc_exec_ctx *exec_ctx, glb_lb_policy *glb_policy,
     const grpc_lb_policy_pick_args *pick_args, bool force_async,
     grpc_connected_subchannel **target, wrapped_rr_closure_arg *wc_arg) {
-  // Look at the index into the serverlist to see if we should drop this call.
-  grpc_grpclb_server *server =
-      glb_policy->serverlist->servers[glb_policy->serverlist_index++];
-  if (glb_policy->serverlist_index == glb_policy->serverlist->num_servers) {
-    glb_policy->serverlist_index = 0;  // Wrap-around.
-  }
-  if (server->drop) {
-    // Not using the RR policy, so unref it.
-    if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
-      gpr_log(GPR_INFO, "Unreffing RR for drop (0x%" PRIxPTR ")",
-              (intptr_t)wc_arg->rr_policy);
+  // Check for drops if we are not using fallback backend addresses.
+  if (glb_policy->serverlist != NULL) {
+    // Look at the index into the serverlist to see if we should drop this call.
+    grpc_grpclb_server *server =
+        glb_policy->serverlist->servers[glb_policy->serverlist_index++];
+    if (glb_policy->serverlist_index == glb_policy->serverlist->num_servers) {
+      glb_policy->serverlist_index = 0;  // Wrap-around.
     }
-    GRPC_LB_POLICY_UNREF(exec_ctx, wc_arg->rr_policy, "glb_pick_sync");
-    // Update client load reporting stats to indicate the number of
-    // dropped calls.  Note that we have to do this here instead of in
-    // the client_load_reporting filter, because we do not create a
-    // subchannel call (and therefore no client_load_reporting filter)
-    // for dropped calls.
-    grpc_grpclb_client_stats_add_call_dropped_locked(server->load_balance_token,
-                                                     wc_arg->client_stats);
-    grpc_grpclb_client_stats_unref(wc_arg->client_stats);
-    if (force_async) {
-      GPR_ASSERT(wc_arg->wrapped_closure != NULL);
-      GRPC_CLOSURE_SCHED(exec_ctx, wc_arg->wrapped_closure, GRPC_ERROR_NONE);
+    if (server->drop) {
+      // Not using the RR policy, so unref it.
+      if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
+        gpr_log(GPR_INFO, "Unreffing RR for drop (0x%" PRIxPTR ")",
+                (intptr_t)wc_arg->rr_policy);
+      }
+      GRPC_LB_POLICY_UNREF(exec_ctx, wc_arg->rr_policy, "glb_pick_sync");
+      // Update client load reporting stats to indicate the number of
+      // dropped calls.  Note that we have to do this here instead of in
+      // the client_load_reporting filter, because we do not create a
+      // subchannel call (and therefore no client_load_reporting filter)
+      // for dropped calls.
+      grpc_grpclb_client_stats_add_call_dropped_locked(
+          server->load_balance_token, wc_arg->client_stats);
+      grpc_grpclb_client_stats_unref(wc_arg->client_stats);
+      if (force_async) {
+        GPR_ASSERT(wc_arg->wrapped_closure != NULL);
+        GRPC_CLOSURE_SCHED(exec_ctx, wc_arg->wrapped_closure, GRPC_ERROR_NONE);
+        gpr_free(wc_arg->free_when_done);
+        return false;
+      }
       gpr_free(wc_arg->free_when_done);
-      return false;
+      return true;
     }
-    gpr_free(wc_arg->free_when_done);
-    return true;
   }
   // Pick via the RR policy.
   const bool pick_done = grpc_lb_policy_pick_locked(
@@ -669,8 +712,18 @@ static bool pick_from_internal_rr_locked(
 
 static grpc_lb_policy_args *lb_policy_args_create(grpc_exec_ctx *exec_ctx,
                                                   glb_lb_policy *glb_policy) {
-  grpc_lb_addresses *addresses =
-      process_serverlist_locked(exec_ctx, glb_policy->serverlist);
+  grpc_lb_addresses *addresses;
+  if (glb_policy->serverlist != NULL) {
+    GPR_ASSERT(glb_policy->serverlist->num_servers > 0);
+    addresses = process_serverlist_locked(exec_ctx, glb_policy->serverlist);
+  } else {
+    // If rr_handover_locked() is invoked when we haven't received any
+    // serverlist from the balancer, we use the fallback backends returned by
+    // the resolver. Note that the fallback backend list may be empty, in which
+    // case the new round_robin policy will keep the requested picks pending.
+    GPR_ASSERT(glb_policy->fallback_backend_addresses != NULL);
+    addresses = grpc_lb_addresses_copy(glb_policy->fallback_backend_addresses);
+  }
   GPR_ASSERT(addresses != NULL);
   grpc_lb_policy_args *args = (grpc_lb_policy_args *)gpr_zalloc(sizeof(*args));
   args->client_channel_factory = glb_policy->cc_factory;
@@ -776,8 +829,6 @@ static void create_rr_locked(grpc_exec_ctx *exec_ctx, glb_lb_policy *glb_policy,
 /* glb_policy->rr_policy may be NULL (initial handover) */
 static void rr_handover_locked(grpc_exec_ctx *exec_ctx,
                                glb_lb_policy *glb_policy) {
-  GPR_ASSERT(glb_policy->serverlist != NULL &&
-             glb_policy->serverlist->num_servers > 0);
   if (glb_policy->shutting_down) return;
   grpc_lb_policy_args *args = lb_policy_args_create(exec_ctx, glb_policy);
   GPR_ASSERT(args != NULL);
@@ -926,6 +977,9 @@ static void glb_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   if (glb_policy->serverlist != NULL) {
     grpc_grpclb_destroy_serverlist(glb_policy->serverlist);
   }
+  if (glb_policy->fallback_backend_addresses != NULL) {
+    grpc_lb_addresses_destroy(exec_ctx, glb_policy->fallback_backend_addresses);
+  }
   grpc_fake_resolver_response_generator_unref(glb_policy->response_generator);
   grpc_subchannel_index_unref();
   if (glb_policy->pending_update_args != NULL) {
@@ -956,6 +1010,10 @@ static void glb_shutdown_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
     grpc_timer_cancel(exec_ctx, &glb_policy->lb_call_retry_timer);
     glb_policy->retry_timer_active = false;
   }
+  if (glb_policy->fallback_timer_active) {
+    grpc_timer_cancel(exec_ctx, &glb_policy->lb_fallback_timer);
+    glb_policy->fallback_timer_active = false;
+  }
 
   pending_pick *pp = glb_policy->pending_picks;
   glb_policy->pending_picks = NULL;
@@ -1067,12 +1125,28 @@ static void glb_cancel_picks_locked(grpc_exec_ctx *exec_ctx,
   GRPC_ERROR_UNREF(error);
 }
 
+static void lb_on_fallback_timer_locked(grpc_exec_ctx *exec_ctx, void *arg,
+                                        grpc_error *error);
 static void query_for_backends_locked(grpc_exec_ctx *exec_ctx,
                                       glb_lb_policy *glb_policy);
 static void start_picking_locked(grpc_exec_ctx *exec_ctx,
                                  glb_lb_policy *glb_policy) {
+  /* start a timer to fall back */
+  if (glb_policy->lb_fallback_timeout_ms > 0 &&
+      glb_policy->serverlist == NULL && !glb_policy->fallback_timer_active) {
+    grpc_millis deadline =
+        grpc_exec_ctx_now(exec_ctx) + glb_policy->lb_fallback_timeout_ms;
+    GRPC_LB_POLICY_WEAK_REF(&glb_policy->base, "grpclb_fallback_timer");
+    GRPC_CLOSURE_INIT(&glb_policy->lb_on_fallback, lb_on_fallback_timer_locked,
+                      glb_policy,
+                      grpc_combiner_scheduler(glb_policy->base.combiner));
+    glb_policy->fallback_timer_active = true;
+    grpc_timer_init(exec_ctx, &glb_policy->lb_fallback_timer, deadline,
+                    &glb_policy->lb_on_fallback);
+  }
+
   glb_policy->started_picking = true;
-  gpr_backoff_reset(&glb_policy->lb_call_backoff_state);
+  grpc_backoff_reset(&glb_policy->lb_call_backoff_state);
   query_for_backends_locked(exec_ctx, glb_policy);
 }
 
@@ -1173,20 +1247,69 @@ static void glb_notify_on_state_change_locked(grpc_exec_ctx *exec_ctx,
       exec_ctx, &glb_policy->state_tracker, current, notify);
 }
 
+static void lb_call_on_retry_timer_locked(grpc_exec_ctx *exec_ctx, void *arg,
+                                          grpc_error *error) {
+  glb_lb_policy *glb_policy = (glb_lb_policy *)arg;
+  glb_policy->retry_timer_active = false;
+  if (!glb_policy->shutting_down && error == GRPC_ERROR_NONE) {
+    if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
+      gpr_log(GPR_INFO, "Restaring call to LB server (grpclb %p)",
+              (void *)glb_policy);
+    }
+    GPR_ASSERT(glb_policy->lb_call == NULL);
+    query_for_backends_locked(exec_ctx, glb_policy);
+  }
+  GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base, "grpclb_retry_timer");
+}
+
+static void maybe_restart_lb_call(grpc_exec_ctx *exec_ctx,
+                                  glb_lb_policy *glb_policy) {
+  if (glb_policy->started_picking && glb_policy->updating_lb_call) {
+    if (glb_policy->retry_timer_active) {
+      grpc_timer_cancel(exec_ctx, &glb_policy->lb_call_retry_timer);
+    }
+    if (!glb_policy->shutting_down) start_picking_locked(exec_ctx, glb_policy);
+    glb_policy->updating_lb_call = false;
+  } else if (!glb_policy->shutting_down) {
+    /* if we aren't shutting down, restart the LB client call after some time */
+    grpc_millis next_try =
+        grpc_backoff_step(exec_ctx, &glb_policy->lb_call_backoff_state);
+    if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
+      gpr_log(GPR_DEBUG, "Connection to LB server lost (grpclb: %p)...",
+              (void *)glb_policy);
+      grpc_millis timeout = next_try - grpc_exec_ctx_now(exec_ctx);
+      if (timeout > 0) {
+        gpr_log(GPR_DEBUG, "... retry_timer_active in %" PRIdPTR "ms.",
+                timeout);
+      } else {
+        gpr_log(GPR_DEBUG, "... retry_timer_active immediately.");
+      }
+    }
+    GRPC_LB_POLICY_WEAK_REF(&glb_policy->base, "grpclb_retry_timer");
+    GRPC_CLOSURE_INIT(&glb_policy->lb_on_call_retry,
+                      lb_call_on_retry_timer_locked, glb_policy,
+                      grpc_combiner_scheduler(glb_policy->base.combiner));
+    glb_policy->retry_timer_active = true;
+    grpc_timer_init(exec_ctx, &glb_policy->lb_call_retry_timer, next_try,
+                    &glb_policy->lb_on_call_retry);
+  }
+  GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
+                            "lb_on_server_status_received_locked");
+}
+
 static void send_client_load_report_locked(grpc_exec_ctx *exec_ctx, void *arg,
                                            grpc_error *error);
 
 static void schedule_next_client_load_report(grpc_exec_ctx *exec_ctx,
                                              glb_lb_policy *glb_policy) {
-  const gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-  const gpr_timespec next_client_load_report_time =
-      gpr_time_add(now, glb_policy->client_stats_report_interval);
+  const grpc_millis next_client_load_report_time =
+      grpc_exec_ctx_now(exec_ctx) + glb_policy->client_stats_report_interval;
   GRPC_CLOSURE_INIT(&glb_policy->client_load_report_closure,
                     send_client_load_report_locked, glb_policy,
                     grpc_combiner_scheduler(glb_policy->base.combiner));
   grpc_timer_init(exec_ctx, &glb_policy->client_load_report_timer,
                   next_client_load_report_time,
-                  &glb_policy->client_load_report_closure, now);
+                  &glb_policy->client_load_report_closure);
 }
 
 static void client_load_report_done_locked(grpc_exec_ctx *exec_ctx, void *arg,
@@ -1203,21 +1326,6 @@ static void client_load_report_done_locked(grpc_exec_ctx *exec_ctx, void *arg,
   schedule_next_client_load_report(exec_ctx, glb_policy);
 }
 
-static void do_send_client_load_report_locked(grpc_exec_ctx *exec_ctx,
-                                              glb_lb_policy *glb_policy) {
-  grpc_op op;
-  memset(&op, 0, sizeof(op));
-  op.op = GRPC_OP_SEND_MESSAGE;
-  op.data.send_message.send_message = glb_policy->client_load_report_payload;
-  GRPC_CLOSURE_INIT(&glb_policy->client_load_report_closure,
-                    client_load_report_done_locked, glb_policy,
-                    grpc_combiner_scheduler(glb_policy->base.combiner));
-  grpc_call_error call_error = grpc_call_start_batch_and_execute(
-      exec_ctx, glb_policy->lb_call, &op, 1,
-      &glb_policy->client_load_report_closure);
-  GPR_ASSERT(GRPC_CALL_OK == call_error);
-}
-
 static bool load_report_counters_are_zero(grpc_grpclb_request *request) {
   grpc_grpclb_dropped_call_counts *drop_entries =
       (grpc_grpclb_dropped_call_counts *)
@@ -1237,6 +1345,9 @@ static void send_client_load_report_locked(grpc_exec_ctx *exec_ctx, void *arg,
     glb_policy->client_load_report_timer_pending = false;
     GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
                               "client_load_report");
+    if (glb_policy->lb_call == NULL) {
+      maybe_restart_lb_call(exec_ctx, glb_policy);
+    }
     return;
   }
   // Construct message payload.
@@ -1260,17 +1371,23 @@ static void send_client_load_report_locked(grpc_exec_ctx *exec_ctx, void *arg,
       grpc_raw_byte_buffer_create(&request_payload_slice, 1);
   grpc_slice_unref_internal(exec_ctx, request_payload_slice);
   grpc_grpclb_request_destroy(request);
-  // If we've already sent the initial request, then we can go ahead and
-  // sent the load report.  Otherwise, we need to wait until the initial
-  // request has been sent to send this
-  // (see lb_on_sent_initial_request_locked() below).
-  if (glb_policy->initial_request_sent) {
-    do_send_client_load_report_locked(exec_ctx, glb_policy);
+  // Send load report message.
+  grpc_op op;
+  memset(&op, 0, sizeof(op));
+  op.op = GRPC_OP_SEND_MESSAGE;
+  op.data.send_message.send_message = glb_policy->client_load_report_payload;
+  GRPC_CLOSURE_INIT(&glb_policy->client_load_report_closure,
+                    client_load_report_done_locked, glb_policy,
+                    grpc_combiner_scheduler(glb_policy->base.combiner));
+  grpc_call_error call_error = grpc_call_start_batch_and_execute(
+      exec_ctx, glb_policy->lb_call, &op, 1,
+      &glb_policy->client_load_report_closure);
+  if (call_error != GRPC_CALL_OK) {
+    gpr_log(GPR_ERROR, "call_error=%d", call_error);
+    GPR_ASSERT(GRPC_CALL_OK == call_error);
   }
 }
 
-static void lb_on_sent_initial_request_locked(grpc_exec_ctx *exec_ctx,
-                                              void *arg, grpc_error *error);
 static void lb_on_server_status_received_locked(grpc_exec_ctx *exec_ctx,
                                                 void *arg, grpc_error *error);
 static void lb_on_response_received_locked(grpc_exec_ctx *exec_ctx, void *arg,
@@ -1286,12 +1403,10 @@ static void lb_call_init_locked(grpc_exec_ctx *exec_ctx,
    * glb_policy->base.interested_parties, which is comprised of the polling
    * entities from \a client_channel. */
   grpc_slice host = grpc_slice_from_copied_string(glb_policy->server_name);
-  gpr_timespec deadline =
+  grpc_millis deadline =
       glb_policy->lb_call_timeout_ms == 0
-          ? gpr_inf_future(GPR_CLOCK_MONOTONIC)
-          : gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),
-                         gpr_time_from_millis(glb_policy->lb_call_timeout_ms,
-                                              GPR_TIMESPAN));
+          ? GRPC_MILLIS_INF_FUTURE
+          : grpc_exec_ctx_now(exec_ctx) + glb_policy->lb_call_timeout_ms;
   glb_policy->lb_call = grpc_channel_create_pollset_set_call(
       exec_ctx, glb_policy->lb_channel, NULL, GRPC_PROPAGATE_DEFAULTS,
       glb_policy->base.interested_parties,
@@ -1315,9 +1430,6 @@ static void lb_call_init_locked(grpc_exec_ctx *exec_ctx,
   grpc_slice_unref_internal(exec_ctx, request_payload_slice);
   grpc_grpclb_request_destroy(request);
 
-  GRPC_CLOSURE_INIT(&glb_policy->lb_on_sent_initial_request,
-                    lb_on_sent_initial_request_locked, glb_policy,
-                    grpc_combiner_scheduler(glb_policy->base.combiner));
   GRPC_CLOSURE_INIT(&glb_policy->lb_on_server_status_received,
                     lb_on_server_status_received_locked, glb_policy,
                     grpc_combiner_scheduler(glb_policy->base.combiner));
@@ -1325,14 +1437,13 @@ static void lb_call_init_locked(grpc_exec_ctx *exec_ctx,
                     lb_on_response_received_locked, glb_policy,
                     grpc_combiner_scheduler(glb_policy->base.combiner));
 
-  gpr_backoff_init(&glb_policy->lb_call_backoff_state,
-                   GRPC_GRPCLB_INITIAL_CONNECT_BACKOFF_SECONDS,
-                   GRPC_GRPCLB_RECONNECT_BACKOFF_MULTIPLIER,
-                   GRPC_GRPCLB_RECONNECT_JITTER,
-                   GRPC_GRPCLB_MIN_CONNECT_TIMEOUT_SECONDS * 1000,
-                   GRPC_GRPCLB_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
+  grpc_backoff_init(&glb_policy->lb_call_backoff_state,
+                    GRPC_GRPCLB_INITIAL_CONNECT_BACKOFF_SECONDS,
+                    GRPC_GRPCLB_RECONNECT_BACKOFF_MULTIPLIER,
+                    GRPC_GRPCLB_RECONNECT_JITTER,
+                    GRPC_GRPCLB_MIN_CONNECT_TIMEOUT_SECONDS * 1000,
+                    GRPC_GRPCLB_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
 
-  glb_policy->initial_request_sent = false;
   glb_policy->seen_initial_response = false;
   glb_policy->last_client_load_report_counters_were_zero = false;
 }
@@ -1349,7 +1460,7 @@ static void lb_call_destroy_locked(grpc_exec_ctx *exec_ctx,
   grpc_byte_buffer_destroy(glb_policy->lb_request_payload);
   grpc_slice_unref_internal(exec_ctx, glb_policy->lb_call_status_details);
 
-  if (!glb_policy->client_load_report_timer_pending) {
+  if (glb_policy->client_load_report_timer_pending) {
     grpc_timer_cancel(exec_ctx, &glb_policy->client_load_report_timer);
   }
 }
@@ -1373,7 +1484,7 @@ static void query_for_backends_locked(grpc_exec_ctx *exec_ctx,
   GPR_ASSERT(glb_policy->lb_call != NULL);
 
   grpc_call_error call_error;
-  grpc_op ops[4];
+  grpc_op ops[3];
   memset(ops, 0, sizeof(ops));
 
   grpc_op *op = ops;
@@ -1394,13 +1505,8 @@ static void query_for_backends_locked(grpc_exec_ctx *exec_ctx,
   op->flags = 0;
   op->reserved = NULL;
   op++;
-  /* take a weak ref (won't prevent calling of \a glb_shutdown if the strong ref
-   * count goes to zero) to be unref'd in lb_on_sent_initial_request_locked() */
-  GRPC_LB_POLICY_WEAK_REF(&glb_policy->base,
-                          "lb_on_sent_initial_request_locked");
-  call_error = grpc_call_start_batch_and_execute(
-      exec_ctx, glb_policy->lb_call, ops, (size_t)(op - ops),
-      &glb_policy->lb_on_sent_initial_request);
+  call_error = grpc_call_start_batch_and_execute(exec_ctx, glb_policy->lb_call,
+                                                 ops, (size_t)(op - ops), NULL);
   GPR_ASSERT(GRPC_CALL_OK == call_error);
 
   op = ops;
@@ -1437,19 +1543,6 @@ static void query_for_backends_locked(grpc_exec_ctx *exec_ctx,
   GPR_ASSERT(GRPC_CALL_OK == call_error);
 }
 
-static void lb_on_sent_initial_request_locked(grpc_exec_ctx *exec_ctx,
-                                              void *arg, grpc_error *error) {
-  glb_lb_policy *glb_policy = (glb_lb_policy *)arg;
-  glb_policy->initial_request_sent = true;
-  // If we attempted to send a client load report before the initial
-  // request was sent, send the load report now.
-  if (glb_policy->client_load_report_payload != NULL) {
-    do_send_client_load_report_locked(exec_ctx, glb_policy);
-  }
-  GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
-                            "lb_on_sent_initial_request_locked");
-}
-
 static void lb_on_response_received_locked(grpc_exec_ctx *exec_ctx, void *arg,
                                            grpc_error *error) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)arg;
@@ -1457,7 +1550,7 @@ static void lb_on_response_received_locked(grpc_exec_ctx *exec_ctx, void *arg,
   memset(ops, 0, sizeof(ops));
   grpc_op *op = ops;
   if (glb_policy->lb_response_payload != NULL) {
-    gpr_backoff_reset(&glb_policy->lb_call_backoff_state);
+    grpc_backoff_reset(&glb_policy->lb_call_backoff_state);
     /* Received data from the LB server. Look inside
      * glb_policy->lb_response_payload, for a serverlist. */
     grpc_byte_buffer_reader bbr;
@@ -1471,16 +1564,14 @@ static void lb_on_response_received_locked(grpc_exec_ctx *exec_ctx, void *arg,
         (response = grpc_grpclb_initial_response_parse(response_slice)) !=
             NULL) {
       if (response->has_client_stats_report_interval) {
-        glb_policy->client_stats_report_interval =
-            gpr_time_max(gpr_time_from_seconds(1, GPR_TIMESPAN),
-                         grpc_grpclb_duration_to_timespec(
-                             &response->client_stats_report_interval));
+        glb_policy->client_stats_report_interval = GPR_MAX(
+            GPR_MS_PER_SEC, grpc_grpclb_duration_to_millis(
+                                &response->client_stats_report_interval));
         if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
           gpr_log(GPR_INFO,
                   "received initial LB response message; "
-                  "client load reporting interval = %" PRId64 ".%09d sec",
-                  glb_policy->client_stats_report_interval.tv_sec,
-                  glb_policy->client_stats_report_interval.tv_nsec);
+                  "client load reporting interval = %" PRIdPTR " milliseconds",
+                  glb_policy->client_stats_report_interval);
         }
         /* take a weak ref (won't prevent calling of \a glb_shutdown() if the
          * strong ref count goes to zero) to be unref'd in
@@ -1525,6 +1616,15 @@ static void lb_on_response_received_locked(grpc_exec_ctx *exec_ctx, void *arg,
             if (glb_policy->serverlist != NULL) {
               /* dispose of the old serverlist */
               grpc_grpclb_destroy_serverlist(glb_policy->serverlist);
+            } else {
+              /* or dispose of the fallback */
+              grpc_lb_addresses_destroy(exec_ctx,
+                                        glb_policy->fallback_backend_addresses);
+              glb_policy->fallback_backend_addresses = NULL;
+              if (glb_policy->fallback_timer_active) {
+                grpc_timer_cancel(exec_ctx, &glb_policy->lb_fallback_timer);
+                glb_policy->fallback_timer_active = false;
+              }
             }
             /* and update the copy in the glb_lb_policy instance. This
              * serverlist instance will be destroyed either upon the next
@@ -1535,9 +1635,7 @@ static void lb_on_response_received_locked(grpc_exec_ctx *exec_ctx, void *arg,
           }
         } else {
           if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
-            gpr_log(GPR_INFO,
-                    "Received empty server list. Picks will stay pending until "
-                    "a response with > 0 servers is received");
+            gpr_log(GPR_INFO, "Received empty server list, ignoring.");
           }
           grpc_grpclb_destroy_serverlist(serverlist);
         }
@@ -1572,19 +1670,25 @@ static void lb_on_response_received_locked(grpc_exec_ctx *exec_ctx, void *arg,
   }
 }
 
-static void lb_call_on_retry_timer_locked(grpc_exec_ctx *exec_ctx, void *arg,
-                                          grpc_error *error) {
+static void lb_on_fallback_timer_locked(grpc_exec_ctx *exec_ctx, void *arg,
+                                        grpc_error *error) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)arg;
-  glb_policy->retry_timer_active = false;
-  if (!glb_policy->shutting_down && error == GRPC_ERROR_NONE) {
-    if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
-      gpr_log(GPR_INFO, "Restaring call to LB server (grpclb %p)",
-              (void *)glb_policy);
+  glb_policy->fallback_timer_active = false;
+  /* If we receive a serverlist after the timer fires but before this callback
+   * actually runs, don't fall back. */
+  if (glb_policy->serverlist == NULL) {
+    if (!glb_policy->shutting_down && error == GRPC_ERROR_NONE) {
+      if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
+        gpr_log(GPR_INFO,
+                "Falling back to use backends from resolver (grpclb %p)",
+                (void *)glb_policy);
+      }
+      GPR_ASSERT(glb_policy->fallback_backend_addresses != NULL);
+      rr_handover_locked(exec_ctx, glb_policy);
     }
-    GPR_ASSERT(glb_policy->lb_call == NULL);
-    query_for_backends_locked(exec_ctx, glb_policy);
   }
-  GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base, "grpclb_retry_timer");
+  GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
+                            "grpclb_fallback_timer");
 }
 
 static void lb_on_server_status_received_locked(grpc_exec_ctx *exec_ctx,
@@ -1603,66 +1707,30 @@ static void lb_on_server_status_received_locked(grpc_exec_ctx *exec_ctx,
   }
   /* We need to perform cleanups no matter what. */
   lb_call_destroy_locked(exec_ctx, glb_policy);
-  if (glb_policy->started_picking && glb_policy->updating_lb_call) {
-    if (glb_policy->retry_timer_active) {
-      grpc_timer_cancel(exec_ctx, &glb_policy->lb_call_retry_timer);
-    }
-    if (!glb_policy->shutting_down) start_picking_locked(exec_ctx, glb_policy);
-    glb_policy->updating_lb_call = false;
-  } else if (!glb_policy->shutting_down) {
-    /* if we aren't shutting down, restart the LB client call after some time */
-    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-    gpr_timespec next_try =
-        gpr_backoff_step(&glb_policy->lb_call_backoff_state, now);
-    if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
-      gpr_log(GPR_DEBUG, "Connection to LB server lost (grpclb: %p)...",
-              (void *)glb_policy);
-      gpr_timespec timeout = gpr_time_sub(next_try, now);
-      if (gpr_time_cmp(timeout, gpr_time_0(timeout.clock_type)) > 0) {
-        gpr_log(GPR_DEBUG,
-                "... retry_timer_active in %" PRId64 ".%09d seconds.",
-                timeout.tv_sec, timeout.tv_nsec);
-      } else {
-        gpr_log(GPR_DEBUG, "... retry_timer_active immediately.");
-      }
-    }
-    GRPC_LB_POLICY_WEAK_REF(&glb_policy->base, "grpclb_retry_timer");
-    GRPC_CLOSURE_INIT(&glb_policy->lb_on_call_retry,
-                      lb_call_on_retry_timer_locked, glb_policy,
-                      grpc_combiner_scheduler(glb_policy->base.combiner));
-    glb_policy->retry_timer_active = true;
-    grpc_timer_init(exec_ctx, &glb_policy->lb_call_retry_timer, next_try,
-                    &glb_policy->lb_on_call_retry, now);
+  // If the load report timer is still pending, we wait for it to be
+  // called before restarting the call.  Otherwise, we restart the call
+  // here.
+  if (!glb_policy->client_load_report_timer_pending) {
+    maybe_restart_lb_call(exec_ctx, glb_policy);
+  }
+}
+
+static void fallback_update_locked(grpc_exec_ctx *exec_ctx,
+                                   glb_lb_policy *glb_policy,
+                                   const grpc_lb_addresses *addresses) {
+  GPR_ASSERT(glb_policy->fallback_backend_addresses != NULL);
+  grpc_lb_addresses_destroy(exec_ctx, glb_policy->fallback_backend_addresses);
+  glb_policy->fallback_backend_addresses =
+      extract_backend_addresses_locked(exec_ctx, addresses);
+  if (glb_policy->lb_fallback_timeout_ms > 0 &&
+      !glb_policy->fallback_timer_active) {
+    rr_handover_locked(exec_ctx, glb_policy);
   }
-  GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &glb_policy->base,
-                            "lb_on_server_status_received_locked");
 }
 
 static void glb_update_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
                               const grpc_lb_policy_args *args) {
   glb_lb_policy *glb_policy = (glb_lb_policy *)policy;
-  if (glb_policy->updating_lb_channel) {
-    if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
-      gpr_log(GPR_INFO,
-              "Update already in progress for grpclb %p. Deferring update.",
-              (void *)glb_policy);
-    }
-    if (glb_policy->pending_update_args != NULL) {
-      grpc_channel_args_destroy(exec_ctx,
-                                glb_policy->pending_update_args->args);
-      gpr_free(glb_policy->pending_update_args);
-    }
-    glb_policy->pending_update_args = (grpc_lb_policy_args *)gpr_zalloc(
-        sizeof(*glb_policy->pending_update_args));
-    glb_policy->pending_update_args->client_channel_factory =
-        args->client_channel_factory;
-    glb_policy->pending_update_args->args = grpc_channel_args_copy(args->args);
-    glb_policy->pending_update_args->combiner = args->combiner;
-    return;
-  }
-
-  glb_policy->updating_lb_channel = true;
-  // Propagate update to lb_channel (pick first).
   const grpc_arg *arg =
       grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
   if (arg == NULL || arg->type != GRPC_ARG_POINTER) {
@@ -1680,13 +1748,43 @@ static void glb_update_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
               "ignoring.",
               (void *)glb_policy);
     }
+    return;
   }
   const grpc_lb_addresses *addresses =
       (const grpc_lb_addresses *)arg->value.pointer.p;
+
+  if (glb_policy->serverlist == NULL) {
+    // If a non-empty serverlist hasn't been received from the balancer,
+    // propagate the update to fallback_backend_addresses.
+    fallback_update_locked(exec_ctx, glb_policy, addresses);
+  } else if (glb_policy->updating_lb_channel) {
+    // If we have recieved serverlist from the balancer, we need to defer update
+    // when there is an in-progress one.
+    if (GRPC_TRACER_ON(grpc_lb_glb_trace)) {
+      gpr_log(GPR_INFO,
+              "Update already in progress for grpclb %p. Deferring update.",
+              (void *)glb_policy);
+    }
+    if (glb_policy->pending_update_args != NULL) {
+      grpc_channel_args_destroy(exec_ctx,
+                                glb_policy->pending_update_args->args);
+      gpr_free(glb_policy->pending_update_args);
+    }
+    glb_policy->pending_update_args = (grpc_lb_policy_args *)gpr_zalloc(
+        sizeof(*glb_policy->pending_update_args));
+    glb_policy->pending_update_args->client_channel_factory =
+        args->client_channel_factory;
+    glb_policy->pending_update_args->args = grpc_channel_args_copy(args->args);
+    glb_policy->pending_update_args->combiner = args->combiner;
+    return;
+  }
+
+  glb_policy->updating_lb_channel = true;
   GPR_ASSERT(glb_policy->lb_channel != NULL);
   grpc_channel_args *lb_channel_args = build_lb_channel_args(
       exec_ctx, addresses, glb_policy->response_generator, args->args);
-  /* Propagate updates to the LB channel through the fake resolver */
+  /* Propagate updates to the LB channel (pick first) through the fake resolver
+   */
   grpc_fake_resolver_response_generator_set_response(
       exec_ctx, glb_policy->response_generator, lb_channel_args);
   grpc_channel_args_destroy(exec_ctx, lb_channel_args);
@@ -1789,13 +1887,7 @@ static const grpc_lb_policy_vtable glb_lb_policy_vtable = {
 static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
                                   grpc_lb_policy_factory *factory,
                                   grpc_lb_policy_args *args) {
-  /* Count the number of gRPC-LB addresses. There must be at least one.
-   * TODO(roth): For now, we ignore non-balancer addresses, but in the
-   * future, we may change the behavior such that we fall back to using
-   * the non-balancer addresses if we cannot reach any balancers. In the
-   * fallback case, we should use the LB policy indicated by
-   * GRPC_ARG_LB_POLICY_NAME (although if that specifies grpclb or is
-   * unset, we should default to pick_first). */
+  /* Count the number of gRPC-LB addresses. There must be at least one. */
   const grpc_arg *arg =
       grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
   if (arg == NULL || arg->type != GRPC_ARG_POINTER) {
@@ -1829,7 +1921,11 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
 
   arg = grpc_channel_args_find(args->args, GRPC_ARG_GRPCLB_CALL_TIMEOUT_MS);
   glb_policy->lb_call_timeout_ms =
-      grpc_channel_arg_get_integer(arg, (grpc_integer_options){0, 0, INT_MAX});
+      grpc_channel_arg_get_integer(arg, {0, 0, INT_MAX});
+
+  arg = grpc_channel_args_find(args->args, GRPC_ARG_GRPCLB_FALLBACK_TIMEOUT_MS);
+  glb_policy->lb_fallback_timeout_ms = grpc_channel_arg_get_integer(
+      arg, {GRPC_GRPCLB_DEFAULT_FALLBACK_TIMEOUT_MS, 0, INT_MAX});
 
   // Make sure that GRPC_ARG_LB_POLICY_NAME is set in channel args,
   // since we use this to trigger the client_load_reporting filter.
@@ -1839,6 +1935,11 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
   glb_policy->args = grpc_channel_args_copy_and_add_and_remove(
       args->args, args_to_remove, GPR_ARRAY_SIZE(args_to_remove), &new_arg, 1);
 
+  /* Extract the backend addresses (may be empty) from the resolver for
+   * fallback. */
+  glb_policy->fallback_backend_addresses =
+      extract_backend_addresses_locked(exec_ctx, addresses);
+
   /* Create a client channel over them to communicate with a LB service */
   glb_policy->response_generator =
       grpc_fake_resolver_response_generator_create();
@@ -1900,7 +2001,7 @@ static bool maybe_add_client_load_reporting_filter(
   return true;
 }
 
-void grpc_lb_policy_grpclb_init() {
+extern "C" void grpc_lb_policy_grpclb_init() {
   grpc_register_lb_policy(grpc_glb_lb_factory_create());
   grpc_register_tracer(&grpc_lb_glb_trace);
 #ifndef NDEBUG
@@ -1912,4 +2013,4 @@ void grpc_lb_policy_grpclb_init() {
                                    (void *)&grpc_client_load_reporting_filter);
 }
 
-void grpc_lb_policy_grpclb_shutdown() {}
+extern "C" void grpc_lb_policy_grpclb_shutdown() {}
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h
index 63ad66c5e9..c67df609fc 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h
@@ -21,9 +21,17 @@
 
 #include "src/core/ext/filters/client_channel/lb_policy_factory.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** Returns a load balancing factory for the glb policy, which tries to connect
  * to a load balancing server to decide the next successfully connected
  * subchannel to pick. */
 grpc_lb_policy_factory *grpc_glb_lb_factory_create();
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.cc
index f2967182e2..f2967182e2 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.cc
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h
index 6120bf53f7..e8599d1f51 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h
@@ -23,6 +23,10 @@
 #include "src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h"
 #include "src/core/lib/slice/slice_hash_table.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** Create the channel used for communicating with an LB service.
  * Note that an LB *service* may be comprised of several LB *servers*.
  *
@@ -40,5 +44,9 @@ grpc_channel_args *grpc_lb_policy_grpclb_build_lb_channel_args(
     grpc_fake_resolver_response_generator *response_generator,
     const grpc_channel_args *args);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_CHANNEL_H \
           */
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel_secure.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel_secure.cc
index 2681b2a079..2681b2a079 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel_secure.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel_secure.cc
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_client_stats.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_client_stats.cc
index 903120ca7d..903120ca7d 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_client_stats.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_client_stats.cc
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_client_stats.h b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_client_stats.h
index c51e2a431a..b38c076f38 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_client_stats.h
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_client_stats.h
@@ -23,6 +23,10 @@
 
 #include <grpc/impl/codegen/grpc_types.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct grpc_grpclb_client_stats grpc_grpclb_client_stats;
 
 typedef struct {
@@ -61,5 +65,9 @@ void grpc_grpclb_client_stats_get_locked(
 void grpc_grpclb_dropped_call_counts_destroy(
     grpc_grpclb_dropped_call_counts* drop_entries);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_CLIENT_STATS_H \
           */
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.cc
index 8ef6dfc6f4..4d5fb2081c 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.cc
@@ -299,13 +299,10 @@ int grpc_grpclb_duration_compare(const grpc_grpclb_duration *lhs,
   return 0;
 }
 
-gpr_timespec grpc_grpclb_duration_to_timespec(
-    grpc_grpclb_duration *duration_pb) {
-  gpr_timespec duration;
-  duration.tv_sec = duration_pb->has_seconds ? duration_pb->seconds : 0;
-  duration.tv_nsec = duration_pb->has_nanos ? duration_pb->nanos : 0;
-  duration.clock_type = GPR_TIMESPAN;
-  return duration;
+grpc_millis grpc_grpclb_duration_to_millis(grpc_grpclb_duration *duration_pb) {
+  return (grpc_millis)(
+      (duration_pb->has_seconds ? duration_pb->seconds : 0) * GPR_MS_PER_SEC +
+      (duration_pb->has_nanos ? duration_pb->nanos : 0) / GPR_NS_PER_MS);
 }
 
 void grpc_grpclb_initial_response_destroy(
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.h b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.h
index c4a98492c9..56b9c096d0 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.h
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.h
@@ -81,8 +81,7 @@ void grpc_grpclb_destroy_serverlist(grpc_grpclb_serverlist *serverlist);
 int grpc_grpclb_duration_compare(const grpc_grpclb_duration *lhs,
                                  const grpc_grpclb_duration *rhs);
 
-gpr_timespec grpc_grpclb_duration_to_timespec(
-    grpc_grpclb_duration *duration_pb);
+grpc_millis grpc_grpclb_duration_to_millis(grpc_grpclb_duration *duration_pb);
 
 /** Destroy \a initial_response */
 void grpc_grpclb_initial_response_destroy(
diff --git a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
index d20cbb8388..b07fc3b720 100644
--- a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c
+++ b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
@@ -706,9 +706,9 @@ static grpc_lb_policy_factory *pick_first_lb_factory_create() {
 
 /* Plugin registration */
 
-void grpc_lb_policy_pick_first_init() {
+extern "C" void grpc_lb_policy_pick_first_init() {
   grpc_register_lb_policy(pick_first_lb_factory_create());
   grpc_register_tracer(&grpc_lb_pick_first_trace);
 }
 
-void grpc_lb_policy_pick_first_shutdown() {}
+extern "C" void grpc_lb_policy_pick_first_shutdown() {}
diff --git a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.c b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
index a3a62e9f3c..6812bb50cd 100644
--- a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.c
+++ b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
@@ -916,9 +916,9 @@ static grpc_lb_policy_factory *round_robin_lb_factory_create() {
 
 /* Plugin registration */
 
-void grpc_lb_policy_round_robin_init() {
+extern "C" void grpc_lb_policy_round_robin_init() {
   grpc_register_lb_policy(round_robin_lb_factory_create());
   grpc_register_tracer(&grpc_lb_round_robin_trace);
 }
 
-void grpc_lb_policy_round_robin_shutdown() {}
+extern "C" void grpc_lb_policy_round_robin_shutdown() {}
diff --git a/src/core/ext/filters/client_channel/lb_policy_factory.c b/src/core/ext/filters/client_channel/lb_policy_factory.cc
index 4d1405454c..05ab43d0b6 100644
--- a/src/core/ext/filters/client_channel/lb_policy_factory.c
+++ b/src/core/ext/filters/client_channel/lb_policy_factory.cc
@@ -56,7 +56,7 @@ grpc_lb_addresses* grpc_lb_addresses_copy(const grpc_lb_addresses* addresses) {
 }
 
 void grpc_lb_addresses_set_address(grpc_lb_addresses* addresses, size_t index,
-                                   void* address, size_t address_len,
+                                   const void* address, size_t address_len,
                                    bool is_balancer, const char* balancer_name,
                                    void* user_data) {
   GPR_ASSERT(index < addresses->num_addresses);
diff --git a/src/core/ext/filters/client_channel/lb_policy_factory.h b/src/core/ext/filters/client_channel/lb_policy_factory.h
index 9d9fb143df..69bcba4232 100644
--- a/src/core/ext/filters/client_channel/lb_policy_factory.h
+++ b/src/core/ext/filters/client_channel/lb_policy_factory.h
@@ -29,6 +29,10 @@
 // Channel arg key for grpc_lb_addresses.
 #define GRPC_ARG_LB_ADDRESSES "grpc.lb_addresses"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct grpc_lb_policy_factory grpc_lb_policy_factory;
 typedef struct grpc_lb_policy_factory_vtable grpc_lb_policy_factory_vtable;
 
@@ -73,7 +77,7 @@ grpc_lb_addresses *grpc_lb_addresses_copy(const grpc_lb_addresses *addresses);
  * \a address is a socket address of length \a address_len.
  * Takes ownership of \a balancer_name. */
 void grpc_lb_addresses_set_address(grpc_lb_addresses *addresses, size_t index,
-                                   void *address, size_t address_len,
+                                   const void *address, size_t address_len,
                                    bool is_balancer, const char *balancer_name,
                                    void *user_data);
 
@@ -130,4 +134,8 @@ grpc_lb_policy *grpc_lb_policy_factory_create_lb_policy(
     grpc_exec_ctx *exec_ctx, grpc_lb_policy_factory *factory,
     grpc_lb_policy_args *args);
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_FACTORY_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_FACTORY_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/lb_policy_registry.c b/src/core/ext/filters/client_channel/lb_policy_registry.cc
index f2460f8304..f2460f8304 100644
--- a/src/core/ext/filters/client_channel/lb_policy_registry.c
+++ b/src/core/ext/filters/client_channel/lb_policy_registry.cc
diff --git a/src/core/ext/filters/client_channel/lb_policy_registry.h b/src/core/ext/filters/client_channel/lb_policy_registry.h
index f5995687cf..0867844c37 100644
--- a/src/core/ext/filters/client_channel/lb_policy_registry.h
+++ b/src/core/ext/filters/client_channel/lb_policy_registry.h
@@ -22,6 +22,10 @@
 #include "src/core/ext/filters/client_channel/lb_policy_factory.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** Initialize the registry and set \a default_factory as the factory to be
  * returned when no name is provided in a lookup */
 void grpc_lb_policy_registry_init(void);
@@ -37,4 +41,8 @@ void grpc_register_lb_policy(grpc_lb_policy_factory *factory);
 grpc_lb_policy *grpc_lb_policy_create(grpc_exec_ctx *exec_ctx, const char *name,
                                       grpc_lb_policy_args *args);
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_REGISTRY_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_REGISTRY_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/parse_address.c b/src/core/ext/filters/client_channel/parse_address.cc
index 2152b5a1e9..2152b5a1e9 100644
--- a/src/core/ext/filters/client_channel/parse_address.c
+++ b/src/core/ext/filters/client_channel/parse_address.cc
diff --git a/src/core/ext/filters/client_channel/parse_address.h b/src/core/ext/filters/client_channel/parse_address.h
index c90a827da5..742df380b7 100644
--- a/src/core/ext/filters/client_channel/parse_address.h
+++ b/src/core/ext/filters/client_channel/parse_address.h
@@ -24,6 +24,10 @@
 #include "src/core/ext/filters/client_channel/uri_parser.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** Populate \a resolved_addr from \a uri, whose path is expected to contain a
  * unix socket path. Returns true upon success. */
 bool grpc_parse_unix(const grpc_uri *uri, grpc_resolved_address *resolved_addr);
@@ -45,4 +49,8 @@ bool grpc_parse_ipv4_hostport(const char *hostport, grpc_resolved_address *addr,
 bool grpc_parse_ipv6_hostport(const char *hostport, grpc_resolved_address *addr,
                               bool log_errors);
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PARSE_ADDRESS_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PARSE_ADDRESS_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/proxy_mapper.c b/src/core/ext/filters/client_channel/proxy_mapper.cc
index c6ea5fc680..c6ea5fc680 100644
--- a/src/core/ext/filters/client_channel/proxy_mapper.c
+++ b/src/core/ext/filters/client_channel/proxy_mapper.cc
diff --git a/src/core/ext/filters/client_channel/proxy_mapper.h b/src/core/ext/filters/client_channel/proxy_mapper.h
index a13861ccaf..1325a9f1f6 100644
--- a/src/core/ext/filters/client_channel/proxy_mapper.h
+++ b/src/core/ext/filters/client_channel/proxy_mapper.h
@@ -25,6 +25,10 @@
 
 #include "src/core/lib/iomgr/resolve_address.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct grpc_proxy_mapper grpc_proxy_mapper;
 
 typedef struct {
@@ -71,4 +75,8 @@ bool grpc_proxy_mapper_map_address(grpc_exec_ctx* exec_ctx,
 
 void grpc_proxy_mapper_destroy(grpc_proxy_mapper* mapper);
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PROXY_MAPPER_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PROXY_MAPPER_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/proxy_mapper_registry.c b/src/core/ext/filters/client_channel/proxy_mapper_registry.cc
index 09967eea3c..09967eea3c 100644
--- a/src/core/ext/filters/client_channel/proxy_mapper_registry.c
+++ b/src/core/ext/filters/client_channel/proxy_mapper_registry.cc
diff --git a/src/core/ext/filters/client_channel/proxy_mapper_registry.h b/src/core/ext/filters/client_channel/proxy_mapper_registry.h
index 99e54d1a78..2d389f1c21 100644
--- a/src/core/ext/filters/client_channel/proxy_mapper_registry.h
+++ b/src/core/ext/filters/client_channel/proxy_mapper_registry.h
@@ -21,6 +21,10 @@
 
 #include "src/core/ext/filters/client_channel/proxy_mapper.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 void grpc_proxy_mapper_registry_init();
 void grpc_proxy_mapper_registry_shutdown();
 
@@ -41,4 +45,8 @@ bool grpc_proxy_mappers_map_address(grpc_exec_ctx* exec_ctx,
                                     grpc_resolved_address** new_address,
                                     grpc_channel_args** new_args);
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PROXY_MAPPER_REGISTRY_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PROXY_MAPPER_REGISTRY_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/resolver.c b/src/core/ext/filters/client_channel/resolver.cc
index 8401504fcf..8401504fcf 100644
--- a/src/core/ext/filters/client_channel/resolver.c
+++ b/src/core/ext/filters/client_channel/resolver.cc
diff --git a/src/core/ext/filters/client_channel/resolver.h b/src/core/ext/filters/client_channel/resolver.h
index ae9c8f66fe..73fbbbbc3b 100644
--- a/src/core/ext/filters/client_channel/resolver.h
+++ b/src/core/ext/filters/client_channel/resolver.h
@@ -22,6 +22,10 @@
 #include "src/core/ext/filters/client_channel/subchannel.h"
 #include "src/core/lib/iomgr/iomgr.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct grpc_resolver grpc_resolver;
 typedef struct grpc_resolver_vtable grpc_resolver_vtable;
 
@@ -87,4 +91,8 @@ void grpc_resolver_next_locked(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
                                grpc_channel_args **result,
                                grpc_closure *on_complete);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_H */
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.c b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
index 9bb229ad95..5f7ab987cb 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.c
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
@@ -32,13 +32,13 @@
 #include "src/core/ext/filters/client_channel/lb_policy_registry.h"
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
 #include "src/core/ext/filters/client_channel/resolver_registry.h"
+#include "src/core/lib/backoff/backoff.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/gethostname.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/json/json.h"
-#include "src/core/lib/support/backoff.h"
 #include "src/core/lib/support/env.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/transport/service_config.h"
@@ -89,7 +89,7 @@ typedef struct {
   bool have_retry_timer;
   grpc_timer retry_timer;
   /** retry backoff state */
-  gpr_backoff backoff_state;
+  grpc_backoff backoff_state;
 
   /** currently resolving addresses */
   grpc_lb_addresses *lb_addresses;
@@ -137,7 +137,7 @@ static void dns_ares_channel_saw_error_locked(grpc_exec_ctx *exec_ctx,
                                               grpc_resolver *resolver) {
   ares_dns_resolver *r = (ares_dns_resolver *)resolver;
   if (!r->resolving) {
-    gpr_backoff_reset(&r->backoff_state);
+    grpc_backoff_reset(&r->backoff_state);
     dns_ares_start_resolving_locked(exec_ctx, r);
   }
 }
@@ -271,22 +271,20 @@ static void dns_ares_on_resolved_locked(grpc_exec_ctx *exec_ctx, void *arg,
   } else {
     const char *msg = grpc_error_string(error);
     gpr_log(GPR_DEBUG, "dns resolution failed: %s", msg);
-    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-    gpr_timespec next_try = gpr_backoff_step(&r->backoff_state, now);
-    gpr_timespec timeout = gpr_time_sub(next_try, now);
+    grpc_millis next_try = grpc_backoff_step(exec_ctx, &r->backoff_state);
+    grpc_millis timeout = next_try - grpc_exec_ctx_now(exec_ctx);
     gpr_log(GPR_INFO, "dns resolution failed (will retry): %s",
             grpc_error_string(error));
     GPR_ASSERT(!r->have_retry_timer);
     r->have_retry_timer = true;
     GRPC_RESOLVER_REF(&r->base, "retry-timer");
-    if (gpr_time_cmp(timeout, gpr_time_0(timeout.clock_type)) > 0) {
-      gpr_log(GPR_DEBUG, "retrying in %" PRId64 ".%09d seconds", timeout.tv_sec,
-              timeout.tv_nsec);
+    if (timeout > 0) {
+      gpr_log(GPR_DEBUG, "retrying in %" PRIdPTR " milliseconds", timeout);
     } else {
       gpr_log(GPR_DEBUG, "retrying immediately");
     }
     grpc_timer_init(exec_ctx, &r->retry_timer, next_try,
-                    &r->dns_ares_on_retry_timer_locked, now);
+                    &r->dns_ares_on_retry_timer_locked);
   }
   if (r->resolved_result != NULL) {
     grpc_channel_args_destroy(exec_ctx, r->resolved_result);
@@ -307,7 +305,7 @@ static void dns_ares_next_locked(grpc_exec_ctx *exec_ctx,
   r->next_completion = on_complete;
   r->target_result = target_result;
   if (r->resolved_version == 0 && !r->resolving) {
-    gpr_backoff_reset(&r->backoff_state);
+    grpc_backoff_reset(&r->backoff_state);
     dns_ares_start_resolving_locked(exec_ctx, r);
   } else {
     dns_ares_maybe_finish_next_locked(exec_ctx, r);
@@ -381,11 +379,11 @@ static grpc_resolver *dns_ares_create(grpc_exec_ctx *exec_ctx,
     grpc_pollset_set_add_pollset_set(exec_ctx, r->interested_parties,
                                      args->pollset_set);
   }
-  gpr_backoff_init(&r->backoff_state, GRPC_DNS_INITIAL_CONNECT_BACKOFF_SECONDS,
-                   GRPC_DNS_RECONNECT_BACKOFF_MULTIPLIER,
-                   GRPC_DNS_RECONNECT_JITTER,
-                   GRPC_DNS_MIN_CONNECT_TIMEOUT_SECONDS * 1000,
-                   GRPC_DNS_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
+  grpc_backoff_init(&r->backoff_state, GRPC_DNS_INITIAL_CONNECT_BACKOFF_SECONDS,
+                    GRPC_DNS_RECONNECT_BACKOFF_MULTIPLIER,
+                    GRPC_DNS_RECONNECT_JITTER,
+                    GRPC_DNS_MIN_CONNECT_TIMEOUT_SECONDS * 1000,
+                    GRPC_DNS_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
   GRPC_CLOSURE_INIT(&r->dns_ares_on_retry_timer_locked,
                     dns_ares_on_retry_timer_locked, r,
                     grpc_combiner_scheduler(r->base.combiner));
@@ -425,7 +423,7 @@ static grpc_resolver_factory *dns_ares_resolver_factory_create() {
   return &dns_resolver_factory;
 }
 
-void grpc_resolver_dns_ares_init(void) {
+extern "C" void grpc_resolver_dns_ares_init(void) {
   char *resolver = gpr_getenv("GRPC_DNS_RESOLVER");
   /* TODO(zyc): Turn on c-ares based resolver by default after the address
      sorter and the CNAME support are added. */
@@ -441,7 +439,7 @@ void grpc_resolver_dns_ares_init(void) {
   gpr_free(resolver);
 }
 
-void grpc_resolver_dns_ares_shutdown(void) {
+extern "C" void grpc_resolver_dns_ares_shutdown(void) {
   char *resolver = gpr_getenv("GRPC_DNS_RESOLVER");
   if (resolver != NULL && gpr_stricmp(resolver, "ares") == 0) {
     grpc_ares_cleanup();
@@ -451,8 +449,8 @@ void grpc_resolver_dns_ares_shutdown(void) {
 
 #else /* GRPC_ARES == 1 && !defined(GRPC_UV) */
 
-void grpc_resolver_dns_ares_init(void) {}
+extern "C" void grpc_resolver_dns_ares_init(void) {}
 
-void grpc_resolver_dns_ares_shutdown(void) {}
+extern "C" void grpc_resolver_dns_ares_shutdown(void) {}
 
 #endif /* GRPC_ARES == 1 && !defined(GRPC_UV) */
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h
index 386012d2ed..3d4309f2fa 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h
@@ -22,6 +22,10 @@
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/iomgr/pollset_set.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct grpc_ares_ev_driver grpc_ares_ev_driver;
 
 /* Start \a ev_driver. It will keep working until all IO on its ares_channel is
@@ -49,5 +53,9 @@ void grpc_ares_ev_driver_destroy(grpc_ares_ev_driver *ev_driver);
 void grpc_ares_ev_driver_shutdown(grpc_exec_ctx *exec_ctx,
                                   grpc_ares_ev_driver *ev_driver);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H \
           */
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc
index c30cc93b6f..c30cc93b6f 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.c b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
index 04379975e1..04379975e1 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.c
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h
index 108333047d..38fbea9aac 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h
@@ -25,6 +25,10 @@
 #include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct grpc_ares_request grpc_ares_request;
 
 /* Asynchronously resolve \a name. Use \a default_port if a port isn't
@@ -65,5 +69,9 @@ grpc_error *grpc_ares_init(void);
    it has been called the same number of times as grpc_ares_init(). */
 void grpc_ares_cleanup(void);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_H \
           */
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.c b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc
index f2587c4520..f2587c4520 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.c
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc
diff --git a/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.c b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
index 5ea75f0554..e669b6dfc7 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.c
+++ b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
@@ -16,6 +16,9 @@
  *
  */
 
+#include <grpc/support/port_platform.h>
+
+#include <inttypes.h>
 #include <string.h>
 
 #include <grpc/support/alloc.h>
@@ -24,11 +27,11 @@
 
 #include "src/core/ext/filters/client_channel/lb_policy_registry.h"
 #include "src/core/ext/filters/client_channel/resolver_registry.h"
+#include "src/core/lib/backoff/backoff.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/timer.h"
-#include "src/core/lib/support/backoff.h"
 #include "src/core/lib/support/env.h"
 #include "src/core/lib/support/string.h"
 
@@ -67,7 +70,7 @@ typedef struct {
   grpc_timer retry_timer;
   grpc_closure on_retry;
   /** retry backoff state */
-  gpr_backoff backoff_state;
+  grpc_backoff backoff_state;
 
   /** currently resolving addresses */
   grpc_resolved_addresses *addresses;
@@ -110,7 +113,7 @@ static void dns_channel_saw_error_locked(grpc_exec_ctx *exec_ctx,
                                          grpc_resolver *resolver) {
   dns_resolver *r = (dns_resolver *)resolver;
   if (!r->resolving) {
-    gpr_backoff_reset(&r->backoff_state);
+    grpc_backoff_reset(&r->backoff_state);
     dns_start_resolving_locked(exec_ctx, r);
   }
 }
@@ -123,7 +126,7 @@ static void dns_next_locked(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
   r->next_completion = on_complete;
   r->target_result = target_result;
   if (r->resolved_version == 0 && !r->resolving) {
-    gpr_backoff_reset(&r->backoff_state);
+    grpc_backoff_reset(&r->backoff_state);
     dns_start_resolving_locked(exec_ctx, r);
   } else {
     dns_maybe_finish_next_locked(exec_ctx, r);
@@ -150,6 +153,9 @@ static void dns_on_resolved_locked(grpc_exec_ctx *exec_ctx, void *arg,
   grpc_channel_args *result = NULL;
   GPR_ASSERT(r->resolving);
   r->resolving = false;
+  GRPC_ERROR_REF(error);
+  error = grpc_error_set_str(error, GRPC_ERROR_STR_TARGET_ADDRESS,
+                             grpc_slice_from_copied_string(r->name_to_resolve));
   if (r->addresses != NULL) {
     grpc_lb_addresses *addresses = grpc_lb_addresses_create(
         r->addresses->naddrs, NULL /* user_data_vtable */);
@@ -164,23 +170,21 @@ static void dns_on_resolved_locked(grpc_exec_ctx *exec_ctx, void *arg,
     grpc_resolved_addresses_destroy(r->addresses);
     grpc_lb_addresses_destroy(exec_ctx, addresses);
   } else {
-    gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-    gpr_timespec next_try = gpr_backoff_step(&r->backoff_state, now);
-    gpr_timespec timeout = gpr_time_sub(next_try, now);
+    grpc_millis next_try = grpc_backoff_step(exec_ctx, &r->backoff_state);
+    grpc_millis timeout = next_try - grpc_exec_ctx_now(exec_ctx);
     gpr_log(GPR_INFO, "dns resolution failed (will retry): %s",
             grpc_error_string(error));
     GPR_ASSERT(!r->have_retry_timer);
     r->have_retry_timer = true;
     GRPC_RESOLVER_REF(&r->base, "retry-timer");
-    if (gpr_time_cmp(timeout, gpr_time_0(timeout.clock_type)) > 0) {
-      gpr_log(GPR_DEBUG, "retrying in %" PRId64 ".%09d seconds", timeout.tv_sec,
-              timeout.tv_nsec);
+    if (timeout > 0) {
+      gpr_log(GPR_DEBUG, "retrying in %" PRIdPTR " milliseconds", timeout);
     } else {
       gpr_log(GPR_DEBUG, "retrying immediately");
     }
     GRPC_CLOSURE_INIT(&r->on_retry, dns_on_retry_timer_locked, r,
                       grpc_combiner_scheduler(r->base.combiner));
-    grpc_timer_init(exec_ctx, &r->retry_timer, next_try, &r->on_retry, now);
+    grpc_timer_init(exec_ctx, &r->retry_timer, next_try, &r->on_retry);
   }
   if (r->resolved_result != NULL) {
     grpc_channel_args_destroy(exec_ctx, r->resolved_result);
@@ -188,6 +192,7 @@ static void dns_on_resolved_locked(grpc_exec_ctx *exec_ctx, void *arg,
   r->resolved_result = result;
   r->resolved_version++;
   dns_maybe_finish_next_locked(exec_ctx, r);
+  GRPC_ERROR_UNREF(error);
 
   GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "dns-resolving");
 }
@@ -251,11 +256,11 @@ static grpc_resolver *dns_create(grpc_exec_ctx *exec_ctx,
     grpc_pollset_set_add_pollset_set(exec_ctx, r->interested_parties,
                                      args->pollset_set);
   }
-  gpr_backoff_init(&r->backoff_state, GRPC_DNS_INITIAL_CONNECT_BACKOFF_SECONDS,
-                   GRPC_DNS_RECONNECT_BACKOFF_MULTIPLIER,
-                   GRPC_DNS_RECONNECT_JITTER,
-                   GRPC_DNS_MIN_CONNECT_TIMEOUT_SECONDS * 1000,
-                   GRPC_DNS_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
+  grpc_backoff_init(&r->backoff_state, GRPC_DNS_INITIAL_CONNECT_BACKOFF_SECONDS,
+                    GRPC_DNS_RECONNECT_BACKOFF_MULTIPLIER,
+                    GRPC_DNS_RECONNECT_JITTER,
+                    GRPC_DNS_MIN_CONNECT_TIMEOUT_SECONDS * 1000,
+                    GRPC_DNS_RECONNECT_MAX_BACKOFF_SECONDS * 1000);
   return &r->base;
 }
 
@@ -289,7 +294,7 @@ static grpc_resolver_factory *dns_resolver_factory_create() {
   return &dns_resolver_factory;
 }
 
-void grpc_resolver_dns_native_init(void) {
+extern "C" void grpc_resolver_dns_native_init(void) {
   char *resolver = gpr_getenv("GRPC_DNS_RESOLVER");
   if (resolver != NULL && gpr_stricmp(resolver, "native") == 0) {
     gpr_log(GPR_DEBUG, "Using native dns resolver");
@@ -307,4 +312,4 @@ void grpc_resolver_dns_native_init(void) {
   gpr_free(resolver);
 }
 
-void grpc_resolver_dns_native_shutdown(void) {}
+extern "C" void grpc_resolver_dns_native_shutdown(void) {}
diff --git a/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.c b/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc
index 69ea440ae6..ed5b1011fb 100644
--- a/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.c
+++ b/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc
@@ -258,8 +258,8 @@ static const grpc_resolver_factory_vtable fake_resolver_factory_vtable = {
 static grpc_resolver_factory fake_resolver_factory = {
     &fake_resolver_factory_vtable};
 
-void grpc_resolver_fake_init(void) {
+extern "C" void grpc_resolver_fake_init(void) {
   grpc_register_resolver_type(&fake_resolver_factory);
 }
 
-void grpc_resolver_fake_shutdown(void) {}
+extern "C" void grpc_resolver_fake_shutdown(void) {}
diff --git a/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h b/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h
index c084ef2a58..95c3bafed8 100644
--- a/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h
+++ b/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h
@@ -21,6 +21,10 @@
 #include "src/core/ext/filters/client_channel/uri_parser.h"
 #include "src/core/lib/channel/channel_args.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR \
   "grpc.fake_resolver.response_generator"
 
@@ -56,5 +60,9 @@ grpc_fake_resolver_response_generator_ref(
 void grpc_fake_resolver_response_generator_unref(
     grpc_fake_resolver_response_generator* generator);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_FAKE_FAKE_RESOLVER_H \
           */
diff --git a/src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.c b/src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc
index 7ceb8f40a1..dda9542325 100644
--- a/src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.c
+++ b/src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc
@@ -211,7 +211,7 @@ DECL_FACTORY(unix);
 DECL_FACTORY(ipv4);
 DECL_FACTORY(ipv6);
 
-void grpc_resolver_sockaddr_init(void) {
+extern "C" void grpc_resolver_sockaddr_init(void) {
   grpc_register_resolver_type(&ipv4_resolver_factory);
   grpc_register_resolver_type(&ipv6_resolver_factory);
 #ifdef GRPC_HAVE_UNIX_SOCKET
@@ -219,4 +219,4 @@ void grpc_resolver_sockaddr_init(void) {
 #endif
 }
 
-void grpc_resolver_sockaddr_shutdown(void) {}
+extern "C" void grpc_resolver_sockaddr_shutdown(void) {}
diff --git a/src/core/ext/filters/client_channel/resolver_factory.c b/src/core/ext/filters/client_channel/resolver_factory.cc
index 6f0a7c1e36..6f0a7c1e36 100644
--- a/src/core/ext/filters/client_channel/resolver_factory.c
+++ b/src/core/ext/filters/client_channel/resolver_factory.cc
diff --git a/src/core/ext/filters/client_channel/resolver_factory.h b/src/core/ext/filters/client_channel/resolver_factory.h
index 6bd7929d4e..6e533e3248 100644
--- a/src/core/ext/filters/client_channel/resolver_factory.h
+++ b/src/core/ext/filters/client_channel/resolver_factory.h
@@ -24,6 +24,10 @@
 #include "src/core/ext/filters/client_channel/uri_parser.h"
 #include "src/core/lib/iomgr/pollset_set.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct grpc_resolver_factory grpc_resolver_factory;
 typedef struct grpc_resolver_factory_vtable grpc_resolver_factory_vtable;
 
@@ -67,4 +71,8 @@ grpc_resolver *grpc_resolver_factory_create_resolver(
 char *grpc_resolver_factory_get_default_authority(
     grpc_resolver_factory *factory, grpc_uri *uri);
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_FACTORY_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_FACTORY_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/resolver_registry.c b/src/core/ext/filters/client_channel/resolver_registry.cc
index 1a0fb0bc3c..1a0fb0bc3c 100644
--- a/src/core/ext/filters/client_channel/resolver_registry.c
+++ b/src/core/ext/filters/client_channel/resolver_registry.cc
diff --git a/src/core/ext/filters/client_channel/resolver_registry.h b/src/core/ext/filters/client_channel/resolver_registry.h
index 692490543d..eb08d887b1 100644
--- a/src/core/ext/filters/client_channel/resolver_registry.h
+++ b/src/core/ext/filters/client_channel/resolver_registry.h
@@ -22,6 +22,10 @@
 #include "src/core/ext/filters/client_channel/resolver_factory.h"
 #include "src/core/lib/iomgr/pollset_set.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 void grpc_resolver_registry_init();
 void grpc_resolver_registry_shutdown(void);
 
@@ -66,4 +70,8 @@ char *grpc_get_default_authority(grpc_exec_ctx *exec_ctx, const char *target);
 char *grpc_resolver_factory_add_default_prefix_if_needed(
     grpc_exec_ctx *exec_ctx, const char *target);
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_REGISTRY_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_REGISTRY_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/retry_throttle.c b/src/core/ext/filters/client_channel/retry_throttle.cc
index 09dcade089..09dcade089 100644
--- a/src/core/ext/filters/client_channel/retry_throttle.c
+++ b/src/core/ext/filters/client_channel/retry_throttle.cc
diff --git a/src/core/ext/filters/client_channel/retry_throttle.h b/src/core/ext/filters/client_channel/retry_throttle.h
index bf99297e98..3b849475b9 100644
--- a/src/core/ext/filters/client_channel/retry_throttle.h
+++ b/src/core/ext/filters/client_channel/retry_throttle.h
@@ -21,6 +21,10 @@
 
 #include <stdbool.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /// Tracks retry throttling data for an individual server name.
 typedef struct grpc_server_retry_throttle_data grpc_server_retry_throttle_data;
 
@@ -47,4 +51,8 @@ void grpc_retry_throttle_map_shutdown();
 grpc_server_retry_throttle_data* grpc_retry_throttle_map_get_data_for_server(
     const char* server_name, int max_milli_tokens, int milli_token_ratio);
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RETRY_THROTTLE_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RETRY_THROTTLE_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/subchannel.c b/src/core/ext/filters/client_channel/subchannel.cc
index 40a51c72d6..5710a22178 100644
--- a/src/core/ext/filters/client_channel/subchannel.c
+++ b/src/core/ext/filters/client_channel/subchannel.cc
@@ -18,6 +18,7 @@
 
 #include "src/core/ext/filters/client_channel/subchannel.h"
 
+#include <inttypes.h>
 #include <limits.h>
 #include <string.h>
 
@@ -30,6 +31,7 @@
 #include "src/core/ext/filters/client_channel/proxy_mapper_registry.h"
 #include "src/core/ext/filters/client_channel/subchannel_index.h"
 #include "src/core/ext/filters/client_channel/uri_parser.h"
+#include "src/core/lib/backoff/backoff.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/connected_channel.h"
 #include "src/core/lib/debug/stats.h"
@@ -37,7 +39,6 @@
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/support/backoff.h"
 #include "src/core/lib/surface/channel.h"
 #include "src/core/lib/surface/channel_init.h"
 #include "src/core/lib/transport/connectivity_state.h"
@@ -117,9 +118,9 @@ struct grpc_subchannel {
   external_state_watcher root_external_state_watcher;
 
   /** next connect attempt time */
-  gpr_timespec next_attempt;
+  grpc_millis next_attempt;
   /** backoff state */
-  gpr_backoff backoff_state;
+  grpc_backoff backoff_state;
   /** do we have an active alarm? */
   bool have_alarm;
   /** have we started the backoff loop */
@@ -343,31 +344,27 @@ grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
                       "grpc.testing.fixed_reconnect_backoff_ms")) {
         fixed_reconnect_backoff = true;
         initial_backoff_ms = min_backoff_ms = max_backoff_ms =
-            grpc_channel_arg_get_integer(
-                &c->args->args[i],
-                (grpc_integer_options){initial_backoff_ms, 100, INT_MAX});
+            grpc_channel_arg_get_integer(&c->args->args[i],
+                                         {initial_backoff_ms, 100, INT_MAX});
       } else if (0 == strcmp(c->args->args[i].key,
                              GRPC_ARG_MIN_RECONNECT_BACKOFF_MS)) {
         fixed_reconnect_backoff = false;
         min_backoff_ms = grpc_channel_arg_get_integer(
-            &c->args->args[i],
-            (grpc_integer_options){min_backoff_ms, 100, INT_MAX});
+            &c->args->args[i], {min_backoff_ms, 100, INT_MAX});
       } else if (0 == strcmp(c->args->args[i].key,
                              GRPC_ARG_MAX_RECONNECT_BACKOFF_MS)) {
         fixed_reconnect_backoff = false;
         max_backoff_ms = grpc_channel_arg_get_integer(
-            &c->args->args[i],
-            (grpc_integer_options){max_backoff_ms, 100, INT_MAX});
+            &c->args->args[i], {max_backoff_ms, 100, INT_MAX});
       } else if (0 == strcmp(c->args->args[i].key,
                              GRPC_ARG_INITIAL_RECONNECT_BACKOFF_MS)) {
         fixed_reconnect_backoff = false;
         initial_backoff_ms = grpc_channel_arg_get_integer(
-            &c->args->args[i],
-            (grpc_integer_options){initial_backoff_ms, 100, INT_MAX});
+            &c->args->args[i], {initial_backoff_ms, 100, INT_MAX});
       }
     }
   }
-  gpr_backoff_init(
+  grpc_backoff_init(
       &c->backoff_state, initial_backoff_ms,
       fixed_reconnect_backoff ? 1.0
                               : GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER,
@@ -431,8 +428,7 @@ static void on_alarm(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
   }
   if (error == GRPC_ERROR_NONE) {
     gpr_log(GPR_INFO, "Failed to connect to channel, retrying");
-    c->next_attempt =
-        gpr_backoff_step(&c->backoff_state, gpr_now(GPR_CLOCK_MONOTONIC));
+    c->next_attempt = grpc_backoff_step(exec_ctx, &c->backoff_state);
     continue_connect_locked(exec_ctx, c);
     gpr_mu_unlock(&c->mu);
   } else {
@@ -467,24 +463,22 @@ static void maybe_start_connecting_locked(grpc_exec_ctx *exec_ctx,
   c->connecting = true;
   GRPC_SUBCHANNEL_WEAK_REF(c, "connecting");
 
-  gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
   if (!c->backoff_begun) {
     c->backoff_begun = true;
-    c->next_attempt = gpr_backoff_begin(&c->backoff_state, now);
+    c->next_attempt = grpc_backoff_begin(exec_ctx, &c->backoff_state);
     continue_connect_locked(exec_ctx, c);
   } else {
     GPR_ASSERT(!c->have_alarm);
     c->have_alarm = true;
-    gpr_timespec time_til_next = gpr_time_sub(c->next_attempt, now);
-    if (gpr_time_cmp(time_til_next, gpr_time_0(time_til_next.clock_type)) <=
-        0) {
+    const grpc_millis time_til_next =
+        c->next_attempt - grpc_exec_ctx_now(exec_ctx);
+    if (time_til_next <= 0) {
       gpr_log(GPR_INFO, "Retry immediately");
     } else {
-      gpr_log(GPR_INFO, "Retry in %" PRId64 ".%09d seconds",
-              time_til_next.tv_sec, time_til_next.tv_nsec);
+      gpr_log(GPR_INFO, "Retry in %" PRIdPTR " milliseconds", time_til_next);
     }
     GRPC_CLOSURE_INIT(&c->on_alarm, on_alarm, c, grpc_schedule_on_exec_ctx);
-    grpc_timer_init(exec_ctx, &c->alarm, c->next_attempt, &c->on_alarm, now);
+    grpc_timer_init(exec_ctx, &c->alarm, c->next_attempt, &c->on_alarm);
   }
 }
 
@@ -759,14 +753,15 @@ grpc_error *grpc_connected_subchannel_create_call(
   grpc_call_stack *callstk = SUBCHANNEL_CALL_TO_CALL_STACK(*call);
   (*call)->connection = GRPC_CONNECTED_SUBCHANNEL_REF(con, "subchannel_call");
   const grpc_call_element_args call_args = {
-      .call_stack = callstk,
-      .server_transport_data = NULL,
-      .context = args->context,
-      .path = args->path,
-      .start_time = args->start_time,
-      .deadline = args->deadline,
-      .arena = args->arena,
-      .call_combiner = args->call_combiner};
+      callstk,            /* call_stack */
+      NULL,               /* server_transport_data */
+      args->context,      /* context */
+      args->path,         /* path */
+      args->start_time,   /* start_time */
+      args->deadline,     /* deadline */
+      args->arena,        /* arena */
+      args->call_combiner /* call_combiner */
+  };
   grpc_error *error = grpc_call_stack_init(
       exec_ctx, chanstk, 1, subchannel_call_destroy, *call, &call_args);
   if (error != GRPC_ERROR_NONE) {
diff --git a/src/core/ext/filters/client_channel/subchannel.h b/src/core/ext/filters/client_channel/subchannel.h
index 51d712f6a7..46b29f1fe0 100644
--- a/src/core/ext/filters/client_channel/subchannel.h
+++ b/src/core/ext/filters/client_channel/subchannel.h
@@ -26,6 +26,10 @@
 #include "src/core/lib/transport/connectivity_state.h"
 #include "src/core/lib/transport/metadata.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 // Channel arg containing a grpc_resolved_address to connect to.
 #define GRPC_ARG_SUBCHANNEL_ADDRESS "grpc.subchannel_address"
 
@@ -103,7 +107,7 @@ typedef struct {
   grpc_polling_entity *pollent;
   grpc_slice path;
   gpr_timespec start_time;
-  gpr_timespec deadline;
+  grpc_millis deadline;
   gpr_arena *arena;
   grpc_call_context_element *context;
   grpc_call_combiner *call_combiner;
@@ -188,4 +192,8 @@ const char *grpc_get_subchannel_address_uri_arg(const grpc_channel_args *args);
 /// Caller is responsible for freeing the string.
 grpc_arg grpc_create_subchannel_address_arg(const grpc_resolved_address *addr);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_SUBCHANNEL_H */
diff --git a/src/core/ext/filters/client_channel/subchannel_index.c b/src/core/ext/filters/client_channel/subchannel_index.cc
index d7a51f3899..1f466ec0b8 100644
--- a/src/core/ext/filters/client_channel/subchannel_index.c
+++ b/src/core/ext/filters/client_channel/subchannel_index.cc
@@ -114,11 +114,12 @@ static void *scv_avl_copy(void *p, void *unused) {
 }
 
 static const gpr_avl_vtable subchannel_avl_vtable = {
-    .destroy_key = sck_avl_destroy,
-    .copy_key = sck_avl_copy,
-    .compare_keys = sck_avl_compare,
-    .destroy_value = scv_avl_destroy,
-    .copy_value = scv_avl_copy};
+    sck_avl_destroy,  // destroy_key
+    sck_avl_copy,     // copy_key
+    sck_avl_compare,  // compare_keys
+    scv_avl_destroy,  // destroy_value
+    scv_avl_copy      // copy_value
+};
 
 void grpc_subchannel_index_init(void) {
   g_subchannel_index = gpr_avl_create(&subchannel_avl_vtable);
diff --git a/src/core/ext/filters/client_channel/subchannel_index.h b/src/core/ext/filters/client_channel/subchannel_index.h
index 92e36d5283..09bac3592c 100644
--- a/src/core/ext/filters/client_channel/subchannel_index.h
+++ b/src/core/ext/filters/client_channel/subchannel_index.h
@@ -21,6 +21,10 @@
 
 #include "src/core/ext/filters/client_channel/subchannel.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** \file Provides an index of active subchannels so that they can be
     shared amongst channels */
 
@@ -78,4 +82,8 @@ void grpc_subchannel_index_unref(void);
  * force_creation set. */
 void grpc_subchannel_index_test_only_set_force_creation(bool force_creation);
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_SUBCHANNEL_INDEX_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_SUBCHANNEL_INDEX_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/client_channel/uri_parser.c b/src/core/ext/filters/client_channel/uri_parser.cc
index fb4fb8e694..fb4fb8e694 100644
--- a/src/core/ext/filters/client_channel/uri_parser.c
+++ b/src/core/ext/filters/client_channel/uri_parser.cc
diff --git a/src/core/ext/filters/client_channel/uri_parser.h b/src/core/ext/filters/client_channel/uri_parser.h
index 05ca2e00e4..43e8ae64e0 100644
--- a/src/core/ext/filters/client_channel/uri_parser.h
+++ b/src/core/ext/filters/client_channel/uri_parser.h
@@ -22,6 +22,10 @@
 #include <stddef.h>
 #include "src/core/lib/iomgr/exec_ctx.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct {
   char *scheme;
   char *authority;
@@ -47,4 +51,8 @@ const char *grpc_uri_get_query_arg(const grpc_uri *uri, const char *key);
 /** destroy a uri */
 void grpc_uri_destroy(grpc_uri *uri);
 
-#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_URI_PARSER_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_URI_PARSER_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/deadline/deadline_filter.c b/src/core/ext/filters/deadline/deadline_filter.cc
index 1aed488077..dc194ec068 100644
--- a/src/core/ext/filters/deadline/deadline_filter.c
+++ b/src/core/ext/filters/deadline/deadline_filter.cc
@@ -86,9 +86,8 @@ static void timer_callback(grpc_exec_ctx* exec_ctx, void* arg,
 // synchronized.
 static void start_timer_if_needed(grpc_exec_ctx* exec_ctx,
                                   grpc_call_element* elem,
-                                  gpr_timespec deadline) {
-  deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
-  if (gpr_time_cmp(deadline, gpr_inf_future(GPR_CLOCK_MONOTONIC)) == 0) {
+                                  grpc_millis deadline) {
+  if (deadline == GRPC_MILLIS_INF_FUTURE) {
     return;
   }
   grpc_deadline_state* deadline_state = (grpc_deadline_state*)elem->call_data;
@@ -114,8 +113,7 @@ static void start_timer_if_needed(grpc_exec_ctx* exec_ctx,
   }
   GPR_ASSERT(closure != NULL);
   GRPC_CALL_STACK_REF(deadline_state->call_stack, "deadline_timer");
-  grpc_timer_init(exec_ctx, &deadline_state->timer, deadline, closure,
-                  gpr_now(GPR_CLOCK_MONOTONIC));
+  grpc_timer_init(exec_ctx, &deadline_state->timer, deadline, closure);
 }
 
 // Cancels the deadline timer.
@@ -155,7 +153,7 @@ static void inject_on_complete_cb(grpc_deadline_state* deadline_state,
 struct start_timer_after_init_state {
   bool in_call_combiner;
   grpc_call_element* elem;
-  gpr_timespec deadline;
+  grpc_millis deadline;
   grpc_closure closure;
 };
 static void start_timer_after_init(grpc_exec_ctx* exec_ctx, void* arg,
@@ -182,14 +180,13 @@ static void start_timer_after_init(grpc_exec_ctx* exec_ctx, void* arg,
 void grpc_deadline_state_init(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
                               grpc_call_stack* call_stack,
                               grpc_call_combiner* call_combiner,
-                              gpr_timespec deadline) {
+                              grpc_millis deadline) {
   grpc_deadline_state* deadline_state = (grpc_deadline_state*)elem->call_data;
   deadline_state->call_stack = call_stack;
   deadline_state->call_combiner = call_combiner;
   // Deadline will always be infinite on servers, so the timer will only be
   // set on clients with a finite deadline.
-  deadline = gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC);
-  if (gpr_time_cmp(deadline, gpr_inf_future(GPR_CLOCK_MONOTONIC)) != 0) {
+  if (deadline != GRPC_MILLIS_INF_FUTURE) {
     // When the deadline passes, we indicate the failure by sending down
     // an op with cancel_error set.  However, we can't send down any ops
     // until after the call stack is fully initialized.  If we start the
@@ -214,7 +211,7 @@ void grpc_deadline_state_destroy(grpc_exec_ctx* exec_ctx,
 }
 
 void grpc_deadline_state_reset(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
-                               gpr_timespec new_deadline) {
+                               grpc_millis new_deadline) {
   grpc_deadline_state* deadline_state = (grpc_deadline_state*)elem->call_data;
   cancel_timer_if_needed(exec_ctx, deadline_state);
   start_timer_if_needed(exec_ctx, elem, new_deadline);
@@ -385,7 +382,7 @@ static bool maybe_add_deadline_filter(grpc_exec_ctx* exec_ctx,
              : true;
 }
 
-void grpc_deadline_filter_init(void) {
+extern "C" void grpc_deadline_filter_init(void) {
   grpc_channel_init_register_stage(
       GRPC_CLIENT_DIRECT_CHANNEL, GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
       maybe_add_deadline_filter, (void*)&grpc_client_deadline_filter);
@@ -394,4 +391,4 @@ void grpc_deadline_filter_init(void) {
       maybe_add_deadline_filter, (void*)&grpc_server_deadline_filter);
 }
 
-void grpc_deadline_filter_shutdown(void) {}
+extern "C" void grpc_deadline_filter_shutdown(void) {}
diff --git a/src/core/ext/filters/deadline/deadline_filter.h b/src/core/ext/filters/deadline/deadline_filter.h
index 3eb102ad28..4a80535b14 100644
--- a/src/core/ext/filters/deadline/deadline_filter.h
+++ b/src/core/ext/filters/deadline/deadline_filter.h
@@ -20,6 +20,10 @@
 #include "src/core/lib/channel/channel_stack.h"
 #include "src/core/lib/iomgr/timer.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef enum grpc_deadline_timer_state {
   GRPC_DEADLINE_STATE_INITIAL,
   GRPC_DEADLINE_STATE_PENDING,
@@ -52,7 +56,8 @@ typedef struct grpc_deadline_state {
 void grpc_deadline_state_init(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
                               grpc_call_stack* call_stack,
                               grpc_call_combiner* call_combiner,
-                              gpr_timespec deadline);
+                              grpc_millis deadline);
+
 void grpc_deadline_state_destroy(grpc_exec_ctx* exec_ctx,
                                  grpc_call_element* elem);
 
@@ -66,7 +71,7 @@ void grpc_deadline_state_destroy(grpc_exec_ctx* exec_ctx,
 //
 // Note: Must be called while holding the call combiner.
 void grpc_deadline_state_reset(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
-                               gpr_timespec new_deadline);
+                               grpc_millis new_deadline);
 
 // To be called from the client-side filter's start_transport_stream_op_batch()
 // method.  Ensures that the deadline timer is cancelled when the call
@@ -89,4 +94,8 @@ bool grpc_deadline_checking_enabled(const grpc_channel_args* args);
 extern const grpc_channel_filter grpc_client_deadline_filter;
 extern const grpc_channel_filter grpc_server_deadline_filter;
 
-#endif /* GRPC_CORE_EXT_FILTERS_DEADLINE_DEADLINE_FILTER_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_DEADLINE_DEADLINE_FILTER_H */
\ No newline at end of file
diff --git a/src/core/ext/filters/http/client/http_client_filter.c b/src/core/ext/filters/http/client/http_client_filter.cc
index 6208089f2e..6208089f2e 100644
--- a/src/core/ext/filters/http/client/http_client_filter.c
+++ b/src/core/ext/filters/http/client/http_client_filter.cc
diff --git a/src/core/ext/filters/http/client/http_client_filter.h b/src/core/ext/filters/http/client/http_client_filter.h
index ec8177c436..9ed8e76915 100644
--- a/src/core/ext/filters/http/client/http_client_filter.h
+++ b/src/core/ext/filters/http/client/http_client_filter.h
@@ -20,10 +20,18 @@
 
 #include "src/core/lib/channel/channel_stack.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Processes metadata on the client side for HTTP2 transports */
 extern const grpc_channel_filter grpc_http_client_filter;
 
 /* Channel arg to determine maximum size of payload eligable for GET request */
 #define GRPC_ARG_MAX_PAYLOAD_SIZE_FOR_GET "grpc.max_payload_size_for_get"
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_HTTP_CLIENT_HTTP_CLIENT_FILTER_H */
diff --git a/src/core/ext/filters/http/http_filters_plugin.c b/src/core/ext/filters/http/http_filters_plugin.cc
index 88bd2250f9..8f5b856317 100644
--- a/src/core/ext/filters/http/http_filters_plugin.c
+++ b/src/core/ext/filters/http/http_filters_plugin.cc
@@ -64,7 +64,7 @@ static bool maybe_add_required_filter(grpc_exec_ctx *exec_ctx,
              : true;
 }
 
-void grpc_http_filters_init(void) {
+extern "C" void grpc_http_filters_init(void) {
   grpc_register_tracer(&grpc_compression_trace);
   grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL,
                                    GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
@@ -86,4 +86,4 @@ void grpc_http_filters_init(void) {
       maybe_add_required_filter, (void *)&grpc_http_server_filter);
 }
 
-void grpc_http_filters_shutdown(void) {}
+extern "C" void grpc_http_filters_shutdown(void) {}
diff --git a/src/core/ext/filters/http/message_compress/message_compress_filter.c b/src/core/ext/filters/http/message_compress/message_compress_filter.cc
index b7c50fdc3a..b7c50fdc3a 100644
--- a/src/core/ext/filters/http/message_compress/message_compress_filter.c
+++ b/src/core/ext/filters/http/message_compress/message_compress_filter.cc
diff --git a/src/core/ext/filters/http/message_compress/message_compress_filter.h b/src/core/ext/filters/http/message_compress/message_compress_filter.h
index c121a391eb..92771d9858 100644
--- a/src/core/ext/filters/http/message_compress/message_compress_filter.h
+++ b/src/core/ext/filters/http/message_compress/message_compress_filter.h
@@ -23,6 +23,10 @@
 
 #include "src/core/lib/channel/channel_stack.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** Compression filter for outgoing data.
  *
  * See <grpc/compression.h> for the available compression settings.
@@ -47,5 +51,9 @@
 
 extern const grpc_channel_filter grpc_message_compress_filter;
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_HTTP_MESSAGE_COMPRESS_MESSAGE_COMPRESS_FILTER_H \
           */
diff --git a/src/core/ext/filters/http/server/http_server_filter.c b/src/core/ext/filters/http/server/http_server_filter.cc
index 03958136b4..03958136b4 100644
--- a/src/core/ext/filters/http/server/http_server_filter.c
+++ b/src/core/ext/filters/http/server/http_server_filter.cc
diff --git a/src/core/ext/filters/http/server/http_server_filter.h b/src/core/ext/filters/http/server/http_server_filter.h
index c0f678a329..4b38cc5bf7 100644
--- a/src/core/ext/filters/http/server/http_server_filter.h
+++ b/src/core/ext/filters/http/server/http_server_filter.h
@@ -21,7 +21,15 @@
 
 #include "src/core/lib/channel/channel_stack.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Processes metadata on the client side for HTTP2 transports */
 extern const grpc_channel_filter grpc_http_server_filter;
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_HTTP_SERVER_HTTP_SERVER_FILTER_H */
diff --git a/src/core/ext/filters/load_reporting/server_load_reporting_filter.c b/src/core/ext/filters/load_reporting/server_load_reporting_filter.cc
index ca8a3b2a13..ca8a3b2a13 100644
--- a/src/core/ext/filters/load_reporting/server_load_reporting_filter.c
+++ b/src/core/ext/filters/load_reporting/server_load_reporting_filter.cc
diff --git a/src/core/ext/filters/load_reporting/server_load_reporting_filter.h b/src/core/ext/filters/load_reporting/server_load_reporting_filter.h
index 9527868c9f..94d19cc249 100644
--- a/src/core/ext/filters/load_reporting/server_load_reporting_filter.h
+++ b/src/core/ext/filters/load_reporting/server_load_reporting_filter.h
@@ -22,7 +22,15 @@
 #include "src/core/ext/filters/load_reporting/server_load_reporting_plugin.h"
 #include "src/core/lib/channel/channel_stack.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 extern const grpc_channel_filter grpc_server_load_reporting_filter;
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_LOAD_REPORTING_SERVER_LOAD_REPORTING_FILTER_H \
           */
diff --git a/src/core/ext/filters/load_reporting/server_load_reporting_plugin.c b/src/core/ext/filters/load_reporting/server_load_reporting_plugin.cc
index 2486ead427..223fb3ee8b 100644
--- a/src/core/ext/filters/load_reporting/server_load_reporting_plugin.c
+++ b/src/core/ext/filters/load_reporting/server_load_reporting_plugin.cc
@@ -61,10 +61,10 @@ grpc_arg grpc_load_reporting_enable_arg() {
 
 /* Plugin registration */
 
-void grpc_server_load_reporting_plugin_init(void) {
+extern "C" void grpc_server_load_reporting_plugin_init(void) {
   grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL, INT_MAX,
                                    maybe_add_server_load_reporting_filter,
                                    (void *)&grpc_server_load_reporting_filter);
 }
 
-void grpc_server_load_reporting_plugin_shutdown() {}
+extern "C" void grpc_server_load_reporting_plugin_shutdown() {}
diff --git a/src/core/ext/filters/load_reporting/server_load_reporting_plugin.h b/src/core/ext/filters/load_reporting/server_load_reporting_plugin.h
index 65a6d0900e..65e254eb53 100644
--- a/src/core/ext/filters/load_reporting/server_load_reporting_plugin.h
+++ b/src/core/ext/filters/load_reporting/server_load_reporting_plugin.h
@@ -23,6 +23,10 @@
 
 #include "src/core/lib/channel/channel_stack.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** Identifiers for the invocation point of the users LR callback */
 typedef enum grpc_load_reporting_source {
   GRPC_LR_POINT_UNKNOWN = 0,
@@ -55,5 +59,9 @@ typedef struct grpc_load_reporting_call_data {
 /** Return a \a grpc_arg enabling load reporting */
 grpc_arg grpc_load_reporting_enable_arg();
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_LOAD_REPORTING_SERVER_LOAD_REPORTING_PLUGIN_H \
           */
diff --git a/src/core/ext/filters/max_age/max_age_filter.c b/src/core/ext/filters/max_age/max_age_filter.cc
index 0ac803ed41..ade2e5bc82 100644
--- a/src/core/ext/filters/max_age/max_age_filter.c
+++ b/src/core/ext/filters/max_age/max_age_filter.cc
@@ -33,9 +33,9 @@
 #define MAX_CONNECTION_AGE_JITTER 0.1
 
 #define MAX_CONNECTION_AGE_INTEGER_OPTIONS \
-  (grpc_integer_options) { DEFAULT_MAX_CONNECTION_AGE_MS, 1, INT_MAX }
+  { DEFAULT_MAX_CONNECTION_AGE_MS, 1, INT_MAX }
 #define MAX_CONNECTION_IDLE_INTEGER_OPTIONS \
-  (grpc_integer_options) { DEFAULT_MAX_CONNECTION_IDLE_MS, 1, INT_MAX }
+  { DEFAULT_MAX_CONNECTION_IDLE_MS, 1, INT_MAX }
 
 typedef struct channel_data {
   /* We take a reference to the channel stack for the timer callback */
@@ -56,11 +56,11 @@ typedef struct channel_data {
      max_connection_idle */
   grpc_timer max_idle_timer;
   /* Allowed max time a channel may have no outstanding rpcs */
-  gpr_timespec max_connection_idle;
+  grpc_millis max_connection_idle;
   /* Allowed max time a channel may exist */
-  gpr_timespec max_connection_age;
+  grpc_millis max_connection_age;
   /* Allowed grace period after the channel reaches its max age */
-  gpr_timespec max_connection_age_grace;
+  grpc_millis max_connection_age_grace;
   /* Closure to run when the channel's idle duration reaches max_connection_idle
      and should be closed gracefully */
   grpc_closure close_max_idle_channel;
@@ -99,10 +99,9 @@ static void increase_call_count(grpc_exec_ctx* exec_ctx, channel_data* chand) {
 static void decrease_call_count(grpc_exec_ctx* exec_ctx, channel_data* chand) {
   if (gpr_atm_full_fetch_add(&chand->call_count, -1) == 1) {
     GRPC_CHANNEL_STACK_REF(chand->channel_stack, "max_age max_idle_timer");
-    grpc_timer_init(
-        exec_ctx, &chand->max_idle_timer,
-        gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), chand->max_connection_idle),
-        &chand->close_max_idle_channel, gpr_now(GPR_CLOCK_MONOTONIC));
+    grpc_timer_init(exec_ctx, &chand->max_idle_timer,
+                    grpc_exec_ctx_now(exec_ctx) + chand->max_connection_idle,
+                    &chand->close_max_idle_channel);
   }
 }
 
@@ -123,10 +122,9 @@ static void start_max_age_timer_after_init(grpc_exec_ctx* exec_ctx, void* arg,
   gpr_mu_lock(&chand->max_age_timer_mu);
   chand->max_age_timer_pending = true;
   GRPC_CHANNEL_STACK_REF(chand->channel_stack, "max_age max_age_timer");
-  grpc_timer_init(
-      exec_ctx, &chand->max_age_timer,
-      gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), chand->max_connection_age),
-      &chand->close_max_age_channel, gpr_now(GPR_CLOCK_MONOTONIC));
+  grpc_timer_init(exec_ctx, &chand->max_age_timer,
+                  grpc_exec_ctx_now(exec_ctx) + chand->max_connection_age,
+                  &chand->close_max_age_channel);
   gpr_mu_unlock(&chand->max_age_timer_mu);
   grpc_transport_op* op = grpc_make_transport_op(NULL);
   op->on_connectivity_state_change = &chand->channel_connectivity_changed,
@@ -144,11 +142,12 @@ static void start_max_age_grace_timer_after_goaway_op(grpc_exec_ctx* exec_ctx,
   gpr_mu_lock(&chand->max_age_timer_mu);
   chand->max_age_grace_timer_pending = true;
   GRPC_CHANNEL_STACK_REF(chand->channel_stack, "max_age max_age_grace_timer");
-  grpc_timer_init(exec_ctx, &chand->max_age_grace_timer,
-                  gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),
-                               chand->max_connection_age_grace),
-                  &chand->force_close_max_age_channel,
-                  gpr_now(GPR_CLOCK_MONOTONIC));
+  grpc_timer_init(
+      exec_ctx, &chand->max_age_grace_timer,
+      chand->max_connection_age_grace == GRPC_MILLIS_INF_FUTURE
+          ? GRPC_MILLIS_INF_FUTURE
+          : grpc_exec_ctx_now(exec_ctx) + chand->max_connection_age_grace,
+      &chand->force_close_max_age_channel);
   gpr_mu_unlock(&chand->max_age_timer_mu);
   GRPC_CHANNEL_STACK_UNREF(exec_ctx, chand->channel_stack,
                            "max_age start_max_age_grace_timer_after_goaway_op");
@@ -249,7 +248,8 @@ static void channel_connectivity_changed(grpc_exec_ctx* exec_ctx, void* arg,
    connection storms. Note that the MAX_CONNECTION_AGE option without jitter
    would not create connection storms by itself, but if there happened to be a
    connection storm it could cause it to repeat at a fixed period. */
-static int add_random_max_connection_age_jitter(int value) {
+static grpc_millis
+add_random_max_connection_age_jitter_and_convert_to_grpc_millis(int value) {
   /* generate a random number between 1 - MAX_CONNECTION_AGE_JITTER and
      1 + MAX_CONNECTION_AGE_JITTER */
   double multiplier = rand() * MAX_CONNECTION_AGE_JITTER * 2.0 / RAND_MAX +
@@ -257,7 +257,9 @@ static int add_random_max_connection_age_jitter(int value) {
   double result = multiplier * value;
   /* INT_MAX - 0.5 converts the value to float, so that result will not be
      cast to int implicitly before the comparison. */
-  return result > INT_MAX - 0.5 ? INT_MAX : (int)result;
+  return result > ((double)GRPC_MILLIS_INF_FUTURE) - 0.5
+             ? GRPC_MILLIS_INF_FUTURE
+             : (grpc_millis)result;
 }
 
 /* Constructor for call_data. */
@@ -287,46 +289,36 @@ static grpc_error* init_channel_elem(grpc_exec_ctx* exec_ctx,
   chand->max_age_grace_timer_pending = false;
   chand->channel_stack = args->channel_stack;
   chand->max_connection_age =
-      DEFAULT_MAX_CONNECTION_AGE_MS == INT_MAX
-          ? gpr_inf_future(GPR_TIMESPAN)
-          : gpr_time_from_millis(add_random_max_connection_age_jitter(
-                                     DEFAULT_MAX_CONNECTION_AGE_MS),
-                                 GPR_TIMESPAN);
+      add_random_max_connection_age_jitter_and_convert_to_grpc_millis(
+          DEFAULT_MAX_CONNECTION_AGE_MS);
   chand->max_connection_age_grace =
       DEFAULT_MAX_CONNECTION_AGE_GRACE_MS == INT_MAX
-          ? gpr_inf_future(GPR_TIMESPAN)
-          : gpr_time_from_millis(DEFAULT_MAX_CONNECTION_AGE_GRACE_MS,
-                                 GPR_TIMESPAN);
-  chand->max_connection_idle =
-      DEFAULT_MAX_CONNECTION_IDLE_MS == INT_MAX
-          ? gpr_inf_future(GPR_TIMESPAN)
-          : gpr_time_from_millis(DEFAULT_MAX_CONNECTION_IDLE_MS, GPR_TIMESPAN);
+          ? GRPC_MILLIS_INF_FUTURE
+          : DEFAULT_MAX_CONNECTION_AGE_GRACE_MS;
+  chand->max_connection_idle = DEFAULT_MAX_CONNECTION_IDLE_MS == INT_MAX
+                                   ? GRPC_MILLIS_INF_FUTURE
+                                   : DEFAULT_MAX_CONNECTION_IDLE_MS;
   for (size_t i = 0; i < args->channel_args->num_args; ++i) {
     if (0 == strcmp(args->channel_args->args[i].key,
                     GRPC_ARG_MAX_CONNECTION_AGE_MS)) {
       const int value = grpc_channel_arg_get_integer(
           &args->channel_args->args[i], MAX_CONNECTION_AGE_INTEGER_OPTIONS);
       chand->max_connection_age =
-          value == INT_MAX
-              ? gpr_inf_future(GPR_TIMESPAN)
-              : gpr_time_from_millis(
-                    add_random_max_connection_age_jitter(value), GPR_TIMESPAN);
+          add_random_max_connection_age_jitter_and_convert_to_grpc_millis(
+              value);
     } else if (0 == strcmp(args->channel_args->args[i].key,
                            GRPC_ARG_MAX_CONNECTION_AGE_GRACE_MS)) {
       const int value = grpc_channel_arg_get_integer(
           &args->channel_args->args[i],
-          (grpc_integer_options){DEFAULT_MAX_CONNECTION_AGE_GRACE_MS, 0,
-                                 INT_MAX});
+          {DEFAULT_MAX_CONNECTION_AGE_GRACE_MS, 0, INT_MAX});
       chand->max_connection_age_grace =
-          value == INT_MAX ? gpr_inf_future(GPR_TIMESPAN)
-                           : gpr_time_from_millis(value, GPR_TIMESPAN);
+          value == INT_MAX ? GRPC_MILLIS_INF_FUTURE : value;
     } else if (0 == strcmp(args->channel_args->args[i].key,
                            GRPC_ARG_MAX_CONNECTION_IDLE_MS)) {
       const int value = grpc_channel_arg_get_integer(
           &args->channel_args->args[i], MAX_CONNECTION_IDLE_INTEGER_OPTIONS);
       chand->max_connection_idle =
-          value == INT_MAX ? gpr_inf_future(GPR_TIMESPAN)
-                           : gpr_time_from_millis(value, GPR_TIMESPAN);
+          value == INT_MAX ? GRPC_MILLIS_INF_FUTURE : value;
     }
   }
   GRPC_CLOSURE_INIT(&chand->close_max_idle_channel, close_max_idle_channel,
@@ -349,8 +341,7 @@ static grpc_error* init_channel_elem(grpc_exec_ctx* exec_ctx,
                     channel_connectivity_changed, chand,
                     grpc_schedule_on_exec_ctx);
 
-  if (gpr_time_cmp(chand->max_connection_age, gpr_inf_future(GPR_TIMESPAN)) !=
-      0) {
+  if (chand->max_connection_age != GRPC_MILLIS_INF_FUTURE) {
     /* When the channel reaches its max age, we send down an op with
        goaway_error set.  However, we can't send down any ops until after the
        channel stack is fully initialized.  If we start the timer here, we have
@@ -367,8 +358,7 @@ static grpc_error* init_channel_elem(grpc_exec_ctx* exec_ctx,
   /* Initialize the number of calls as 1, so that the max_idle_timer will not
      start until start_max_idle_timer_after_init is invoked. */
   gpr_atm_rel_store(&chand->call_count, 1);
-  if (gpr_time_cmp(chand->max_connection_idle, gpr_inf_future(GPR_TIMESPAN)) !=
-      0) {
+  if (chand->max_connection_idle != GRPC_MILLIS_INF_FUTURE) {
     GRPC_CHANNEL_STACK_REF(chand->channel_stack,
                            "max_age start_max_idle_timer_after_init");
     GRPC_CLOSURE_SCHED(exec_ctx, &chand->start_max_idle_timer_after_init,
@@ -414,10 +404,10 @@ static bool maybe_add_max_age_filter(grpc_exec_ctx* exec_ctx,
   }
 }
 
-void grpc_max_age_filter_init(void) {
+extern "C" void grpc_max_age_filter_init(void) {
   grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL,
                                    GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
                                    maybe_add_max_age_filter, NULL);
 }
 
-void grpc_max_age_filter_shutdown(void) {}
+extern "C" void grpc_max_age_filter_shutdown(void) {}
diff --git a/src/core/ext/filters/max_age/max_age_filter.h b/src/core/ext/filters/max_age/max_age_filter.h
index 68fb4a4ca5..eeeefd695e 100644
--- a/src/core/ext/filters/max_age/max_age_filter.h
+++ b/src/core/ext/filters/max_age/max_age_filter.h
@@ -19,6 +19,14 @@
 
 #include "src/core/lib/channel/channel_stack.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 extern const grpc_channel_filter grpc_max_age_filter;
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_MAX_AGE_MAX_AGE_FILTER_H */
diff --git a/src/core/ext/filters/message_size/message_size_filter.c b/src/core/ext/filters/message_size/message_size_filter.cc
index 47763b1deb..5dc131b9f6 100644
--- a/src/core/ext/filters/message_size/message_size_filter.c
+++ b/src/core/ext/filters/message_size/message_size_filter.cc
@@ -288,7 +288,7 @@ static bool maybe_add_message_size_filter(grpc_exec_ctx* exec_ctx,
   }
 }
 
-void grpc_message_size_filter_init(void) {
+extern "C" void grpc_message_size_filter_init(void) {
   grpc_channel_init_register_stage(GRPC_CLIENT_SUBCHANNEL,
                                    GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
                                    maybe_add_message_size_filter, NULL);
@@ -300,4 +300,4 @@ void grpc_message_size_filter_init(void) {
                                    maybe_add_message_size_filter, NULL);
 }
 
-void grpc_message_size_filter_shutdown(void) {}
+extern "C" void grpc_message_size_filter_shutdown(void) {}
diff --git a/src/core/ext/filters/message_size/message_size_filter.h b/src/core/ext/filters/message_size/message_size_filter.h
index d3667f7003..da325d6f89 100644
--- a/src/core/ext/filters/message_size/message_size_filter.h
+++ b/src/core/ext/filters/message_size/message_size_filter.h
@@ -19,6 +19,14 @@
 
 #include "src/core/lib/channel/channel_stack.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 extern const grpc_channel_filter grpc_message_size_filter;
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_MESSAGE_SIZE_MESSAGE_SIZE_FILTER_H */
diff --git a/src/core/ext/filters/workarounds/workaround_cronet_compression_filter.c b/src/core/ext/filters/workarounds/workaround_cronet_compression_filter.cc
index c8b2fe5f99..f77ed02421 100644
--- a/src/core/ext/filters/workarounds/workaround_cronet_compression_filter.c
+++ b/src/core/ext/filters/workarounds/workaround_cronet_compression_filter.cc
@@ -196,7 +196,7 @@ static bool register_workaround_cronet_compression(
       builder, &grpc_workaround_cronet_compression_filter, NULL, NULL);
 }
 
-void grpc_workaround_cronet_compression_filter_init(void) {
+extern "C" void grpc_workaround_cronet_compression_filter_init(void) {
   grpc_channel_init_register_stage(
       GRPC_SERVER_CHANNEL, GRPC_WORKAROUND_PRIORITY_HIGH,
       register_workaround_cronet_compression, NULL);
@@ -204,4 +204,4 @@ void grpc_workaround_cronet_compression_filter_init(void) {
                            parse_user_agent);
 }
 
-void grpc_workaround_cronet_compression_filter_shutdown(void) {}
+extern "C" void grpc_workaround_cronet_compression_filter_shutdown(void) {}
diff --git a/src/core/ext/filters/workarounds/workaround_cronet_compression_filter.h b/src/core/ext/filters/workarounds/workaround_cronet_compression_filter.h
index 9dae4f0734..c8b07df63e 100644
--- a/src/core/ext/filters/workarounds/workaround_cronet_compression_filter.h
+++ b/src/core/ext/filters/workarounds/workaround_cronet_compression_filter.h
@@ -19,7 +19,15 @@
 
 #include "src/core/lib/channel/channel_stack.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 extern const grpc_channel_filter grpc_workaround_cronet_compression_filter;
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_FILTERS_WORKAROUNDS_WORKAROUND_CRONET_COMPRESSION_FILTER_H \
         */
diff --git a/src/core/ext/filters/workarounds/workaround_utils.c b/src/core/ext/filters/workarounds/workaround_utils.cc
index e600fbee67..e600fbee67 100644
--- a/src/core/ext/filters/workarounds/workaround_utils.c
+++ b/src/core/ext/filters/workarounds/workaround_utils.cc
diff --git a/src/core/ext/filters/workarounds/workaround_utils.h b/src/core/ext/filters/workarounds/workaround_utils.h
index 2ad7a876d5..afd5291333 100644
--- a/src/core/ext/filters/workarounds/workaround_utils.h
+++ b/src/core/ext/filters/workarounds/workaround_utils.h
@@ -24,6 +24,10 @@
 #define GRPC_WORKAROUND_PRIORITY_HIGH 10001
 #define GRPC_WORKAROUND_PROIRITY_LOW 9999
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct grpc_workaround_user_agent_md {
   bool workaround_active[GRPC_MAX_WORKAROUND_ID];
 } grpc_workaround_user_agent_md;
@@ -34,4 +38,8 @@ typedef bool (*user_agent_parser)(grpc_mdelem);
 
 void grpc_register_workaround(uint32_t id, user_agent_parser parser);
 
-#endif /* GRPC_CORE_EXT_FILTERS_WORKAROUNDS_WORKAROUND_UTILS_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_FILTERS_WORKAROUNDS_WORKAROUND_UTILS_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/alpn/alpn.c b/src/core/ext/transport/chttp2/alpn/alpn.cc
index ca2e801ec8..ca2e801ec8 100644
--- a/src/core/ext/transport/chttp2/alpn/alpn.c
+++ b/src/core/ext/transport/chttp2/alpn/alpn.cc
diff --git a/src/core/ext/transport/chttp2/alpn/alpn.h b/src/core/ext/transport/chttp2/alpn/alpn.h
index 379af4b24c..5842204c20 100644
--- a/src/core/ext/transport/chttp2/alpn/alpn.h
+++ b/src/core/ext/transport/chttp2/alpn/alpn.h
@@ -21,6 +21,10 @@
 
 #include <string.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Retuns 1 if the version is supported, 0 otherwise. */
 int grpc_chttp2_is_alpn_version_supported(const char *version, size_t size);
 
@@ -31,4 +35,8 @@ size_t grpc_chttp2_num_alpn_versions(void);
  * grpc_chttp2_num_alpn_versions()) */
 const char *grpc_chttp2_get_alpn_version_index(size_t i);
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_ALPN_ALPN_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_ALPN_ALPN_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/client/chttp2_connector.c b/src/core/ext/transport/chttp2/client/chttp2_connector.cc
index 202bcd47f5..202bcd47f5 100644
--- a/src/core/ext/transport/chttp2/client/chttp2_connector.c
+++ b/src/core/ext/transport/chttp2/client/chttp2_connector.cc
diff --git a/src/core/ext/transport/chttp2/client/chttp2_connector.h b/src/core/ext/transport/chttp2/client/chttp2_connector.h
index e258892cfc..63f264e0ef 100644
--- a/src/core/ext/transport/chttp2/client/chttp2_connector.h
+++ b/src/core/ext/transport/chttp2/client/chttp2_connector.h
@@ -19,8 +19,16 @@
 #ifndef GRPC_CORE_EXT_TRANSPORT_CHTTP2_CLIENT_CHTTP2_CONNECTOR_H
 #define GRPC_CORE_EXT_TRANSPORT_CHTTP2_CLIENT_CHTTP2_CONNECTOR_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include "src/core/ext/filters/client_channel/connector.h"
 
 grpc_connector* grpc_chttp2_connector_create();
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_CLIENT_CHTTP2_CONNECTOR_H */
diff --git a/src/core/ext/transport/chttp2/client/insecure/channel_create.c b/src/core/ext/transport/chttp2/client/insecure/channel_create.cc
index 6410a6043d..6410a6043d 100644
--- a/src/core/ext/transport/chttp2/client/insecure/channel_create.c
+++ b/src/core/ext/transport/chttp2/client/insecure/channel_create.cc
diff --git a/src/core/ext/transport/chttp2/client/insecure/channel_create_posix.c b/src/core/ext/transport/chttp2/client/insecure/channel_create_posix.cc
index dd88136f7b..dd88136f7b 100644
--- a/src/core/ext/transport/chttp2/client/insecure/channel_create_posix.c
+++ b/src/core/ext/transport/chttp2/client/insecure/channel_create_posix.cc
diff --git a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.cc
index d4580f15f5..fe296cf4ff 100644
--- a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
+++ b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.cc
@@ -86,7 +86,8 @@ static grpc_subchannel_args *get_secure_naming_subchannel_args(
     if (target_uri->path[0] != '\0') {  // "path" may be empty
       const grpc_slice key = grpc_slice_from_static_string(
           target_uri->path[0] == '/' ? target_uri->path + 1 : target_uri->path);
-      const char *value = grpc_slice_hash_table_get(targets_info, key);
+      const char *value =
+          (const char *)grpc_slice_hash_table_get(targets_info, key);
       if (value != NULL) target_name_to_check = gpr_strdup(value);
       grpc_slice_unref_internal(exec_ctx, key);
     }
@@ -127,7 +128,8 @@ static grpc_subchannel_args *get_secure_naming_subchannel_args(
   if (new_args_from_connector != NULL) {
     grpc_channel_args_destroy(exec_ctx, new_args_from_connector);
   }
-  grpc_subchannel_args *final_sc_args = gpr_malloc(sizeof(*final_sc_args));
+  grpc_subchannel_args *final_sc_args =
+      (grpc_subchannel_args *)gpr_malloc(sizeof(*final_sc_args));
   memcpy(final_sc_args, args, sizeof(*args));
   final_sc_args->args = new_args;
   return final_sc_args;
@@ -164,7 +166,7 @@ static grpc_channel *client_channel_factory_create_channel(
   }
   // Add channel arg containing the server URI.
   grpc_arg arg = grpc_channel_arg_string_create(
-      GRPC_ARG_SERVER_URI,
+      (char *)GRPC_ARG_SERVER_URI,
       grpc_resolver_factory_add_default_prefix_if_needed(exec_ctx, target));
   const char *to_remove[] = {GRPC_ARG_SERVER_URI};
   grpc_channel_args *new_args =
diff --git a/src/core/ext/transport/chttp2/server/chttp2_server.c b/src/core/ext/transport/chttp2/server/chttp2_server.cc
index 60244e163b..7ac7f4ece8 100644
--- a/src/core/ext/transport/chttp2/server/chttp2_server.c
+++ b/src/core/ext/transport/chttp2/server/chttp2_server.cc
@@ -20,6 +20,7 @@
 
 #include <grpc/grpc.h>
 
+#include <inttypes.h>
 #include <string.h>
 
 #include <grpc/support/alloc.h>
@@ -133,8 +134,8 @@ static void on_accept(grpc_exec_ctx *exec_ctx, void *arg, grpc_endpoint *tcp,
                        connection_state->handshake_mgr);
   // TODO(roth): We should really get this timeout value from channel
   // args instead of hard-coding it.
-  const gpr_timespec deadline = gpr_time_add(
-      gpr_now(GPR_CLOCK_MONOTONIC), gpr_time_from_seconds(120, GPR_TIMESPAN));
+  const grpc_millis deadline =
+      grpc_exec_ctx_now(exec_ctx) + 120 * GPR_MS_PER_SEC;
   grpc_handshake_manager_do_handshake(exec_ctx, connection_state->handshake_mgr,
                                       tcp, state->args, deadline, acceptor,
                                       on_handshake_done, connection_state);
diff --git a/src/core/ext/transport/chttp2/server/chttp2_server.h b/src/core/ext/transport/chttp2/server/chttp2_server.h
index ed968496f9..e1df28ed11 100644
--- a/src/core/ext/transport/chttp2/server/chttp2_server.h
+++ b/src/core/ext/transport/chttp2/server/chttp2_server.h
@@ -23,10 +23,18 @@
 
 #include "src/core/lib/iomgr/exec_ctx.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /// Adds a port to \a server.  Sets \a port_num to the port number.
 /// Takes ownership of \a args.
 grpc_error *grpc_chttp2_server_add_port(grpc_exec_ctx *exec_ctx,
                                         grpc_server *server, const char *addr,
                                         grpc_channel_args *args, int *port_num);
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_SERVER_CHTTP2_SERVER_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_SERVER_CHTTP2_SERVER_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/server/insecure/server_chttp2.c b/src/core/ext/transport/chttp2/server/insecure/server_chttp2.cc
index d42b2d123e..d42b2d123e 100644
--- a/src/core/ext/transport/chttp2/server/insecure/server_chttp2.c
+++ b/src/core/ext/transport/chttp2/server/insecure/server_chttp2.cc
diff --git a/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.c b/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.cc
index e647067f73..e647067f73 100644
--- a/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.c
+++ b/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.cc
diff --git a/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c b/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.cc
index 5ad63aaf1f..e74a138d23 100644
--- a/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c
+++ b/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.cc
@@ -40,6 +40,8 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr,
   grpc_error *err = GRPC_ERROR_NONE;
   grpc_server_security_connector *sc = NULL;
   int port_num = 0;
+  grpc_security_status status;
+  grpc_channel_args *args = NULL;
   GRPC_API_TRACE(
       "grpc_server_add_secure_http2_port("
       "server=%p, addr=%s, creds=%p)",
@@ -50,7 +52,7 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr,
         "No credentials specified for secure server port (creds==NULL)");
     goto done;
   }
-  grpc_security_status status =
+  status =
       grpc_server_credentials_create_security_connector(&exec_ctx, creds, &sc);
   if (status != GRPC_SECURITY_OK) {
     char *msg;
@@ -66,7 +68,7 @@ int grpc_server_add_secure_http2_port(grpc_server *server, const char *addr,
   grpc_arg args_to_add[2];
   args_to_add[0] = grpc_server_credentials_to_arg(creds);
   args_to_add[1] = grpc_security_connector_to_arg(&sc->base);
-  grpc_channel_args *args =
+  args =
       grpc_channel_args_copy_and_add(grpc_server_get_channel_args(server),
                                      args_to_add, GPR_ARRAY_SIZE(args_to_add));
   // Add server port.
diff --git a/src/core/ext/transport/chttp2/transport/bin_decoder.c b/src/core/ext/transport/chttp2/transport/bin_decoder.cc
index 5a99cbeffc..5a99cbeffc 100644
--- a/src/core/ext/transport/chttp2/transport/bin_decoder.c
+++ b/src/core/ext/transport/chttp2/transport/bin_decoder.cc
diff --git a/src/core/ext/transport/chttp2/transport/bin_decoder.h b/src/core/ext/transport/chttp2/transport/bin_decoder.h
index 047b33d587..f50e0a8ac4 100644
--- a/src/core/ext/transport/chttp2/transport/bin_decoder.h
+++ b/src/core/ext/transport/chttp2/transport/bin_decoder.h
@@ -22,6 +22,10 @@
 #include <grpc/slice.h>
 #include <stdbool.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 struct grpc_base64_decode_context {
   /* input/output: */
   uint8_t *input_cur;
@@ -49,4 +53,8 @@ grpc_slice grpc_chttp2_base64_decode_with_length(grpc_exec_ctx *exec_ctx,
                                                  grpc_slice input,
                                                  size_t output_length);
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_BIN_DECODER_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_BIN_DECODER_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/transport/bin_encoder.c b/src/core/ext/transport/chttp2/transport/bin_encoder.cc
index 42d481b3c0..42d481b3c0 100644
--- a/src/core/ext/transport/chttp2/transport/bin_encoder.c
+++ b/src/core/ext/transport/chttp2/transport/bin_encoder.cc
diff --git a/src/core/ext/transport/chttp2/transport/bin_encoder.h b/src/core/ext/transport/chttp2/transport/bin_encoder.h
index a8f36a345a..ae8219c5ce 100644
--- a/src/core/ext/transport/chttp2/transport/bin_encoder.h
+++ b/src/core/ext/transport/chttp2/transport/bin_encoder.h
@@ -21,6 +21,10 @@
 
 #include <grpc/slice.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* base64 encode a slice. Returns a new slice, does not take ownership of the
    input */
 grpc_slice grpc_chttp2_base64_encode(grpc_slice input);
@@ -36,4 +40,8 @@ grpc_slice grpc_chttp2_huffman_compress(grpc_slice input);
    return y; */
 grpc_slice grpc_chttp2_base64_encode_and_huffman_compress(grpc_slice input);
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_BIN_ENCODER_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_BIN_ENCODER_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_plugin.c b/src/core/ext/transport/chttp2/transport/chttp2_plugin.cc
index 6d09953830..ac9ae5c395 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_plugin.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_plugin.cc
@@ -20,7 +20,7 @@
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/transport/metadata.h"
 
-void grpc_chttp2_plugin_init(void) {
+extern "C" void grpc_chttp2_plugin_init(void) {
   grpc_register_tracer(&grpc_http_trace);
   grpc_register_tracer(&grpc_flowctl_trace);
   grpc_register_tracer(&grpc_trace_http2_stream_state);
@@ -29,4 +29,4 @@ void grpc_chttp2_plugin_init(void) {
 #endif
 }
 
-void grpc_chttp2_plugin_shutdown(void) {}
+extern "C" void grpc_chttp2_plugin_shutdown(void) {}
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
index acf49632ff..e4b19a2c4a 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
@@ -18,6 +18,9 @@
 
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 
+#include <grpc/support/port_platform.h>
+
+#include <inttypes.h>
 #include <limits.h>
 #include <math.h>
 #include <stdio.h>
@@ -156,11 +159,9 @@ static void finish_bdp_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
 
 static void cancel_pings(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                          grpc_error *error);
-static void send_ping_locked(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-    grpc_chttp2_ping_type ping_type, grpc_closure *on_initiate,
-    grpc_closure *on_complete,
-    grpc_chttp2_initiate_write_reason initiate_write_reason);
+static void send_ping_locked(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                             grpc_closure *on_initiate,
+                             grpc_closure *on_complete);
 static void retry_initiate_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
                                        grpc_error *error);
 
@@ -276,6 +277,7 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   t->is_client = is_client;
   t->flow_control.remote_window = DEFAULT_WINDOW;
   t->flow_control.announced_window = DEFAULT_WINDOW;
+  t->flow_control.target_initial_window_size = DEFAULT_WINDOW;
   t->flow_control.t = t;
   t->deframe_state = is_client ? GRPC_DTS_FH_0 : GRPC_DTS_CLIENT_PREFIX_0;
   t->is_first_frame = true;
@@ -314,16 +316,6 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                     grpc_combiner_scheduler(t->combiner));
 
   grpc_bdp_estimator_init(&t->flow_control.bdp_estimator, t->peer_string);
-  t->flow_control.last_pid_update = gpr_now(GPR_CLOCK_MONOTONIC);
-  grpc_pid_controller_init(
-      &t->flow_control.pid_controller,
-      (grpc_pid_controller_args){.gain_p = 4,
-                                 .gain_i = 8,
-                                 .gain_d = 0,
-                                 .initial_control_value = log2(DEFAULT_WINDOW),
-                                 .min_control_value = -1,
-                                 .max_control_value = 25,
-                                 .integral_range = 10});
 
   grpc_chttp2_goaway_parser_init(&t->goaway_parser);
   grpc_chttp2_hpack_parser_init(exec_ctx, &t->hpack_parser);
@@ -362,43 +354,33 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
     queue_setting_update(exec_ctx, t,
                          GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS, 0);
   }
-  queue_setting_update(exec_ctx, t, GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE,
-                       DEFAULT_WINDOW);
   queue_setting_update(exec_ctx, t, GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE,
                        DEFAULT_MAX_HEADER_LIST_SIZE);
   queue_setting_update(exec_ctx, t,
                        GRPC_CHTTP2_SETTINGS_GRPC_ALLOW_TRUE_BINARY_METADATA, 1);
 
   t->ping_policy.max_pings_without_data = g_default_max_pings_without_data;
-  t->ping_policy.min_sent_ping_interval_without_data = gpr_time_from_millis(
-      g_default_min_sent_ping_interval_without_data_ms, GPR_TIMESPAN);
+  t->ping_policy.min_sent_ping_interval_without_data =
+      g_default_min_sent_ping_interval_without_data_ms;
   t->ping_policy.max_ping_strikes = g_default_max_ping_strikes;
-  t->ping_policy.min_recv_ping_interval_without_data = gpr_time_from_millis(
-      g_default_min_recv_ping_interval_without_data_ms, GPR_TIMESPAN);
+  t->ping_policy.min_recv_ping_interval_without_data =
+      g_default_min_recv_ping_interval_without_data_ms;
 
   /* Keepalive setting */
   if (t->is_client) {
-    t->keepalive_time =
-        g_default_client_keepalive_time_ms == INT_MAX
-            ? gpr_inf_future(GPR_TIMESPAN)
-            : gpr_time_from_millis(g_default_client_keepalive_time_ms,
-                                   GPR_TIMESPAN);
-    t->keepalive_timeout =
-        g_default_client_keepalive_timeout_ms == INT_MAX
-            ? gpr_inf_future(GPR_TIMESPAN)
-            : gpr_time_from_millis(g_default_client_keepalive_timeout_ms,
-                                   GPR_TIMESPAN);
+    t->keepalive_time = g_default_client_keepalive_time_ms == INT_MAX
+                            ? GRPC_MILLIS_INF_FUTURE
+                            : g_default_client_keepalive_time_ms;
+    t->keepalive_timeout = g_default_client_keepalive_timeout_ms == INT_MAX
+                               ? GRPC_MILLIS_INF_FUTURE
+                               : g_default_client_keepalive_timeout_ms;
   } else {
-    t->keepalive_time =
-        g_default_server_keepalive_time_ms == INT_MAX
-            ? gpr_inf_future(GPR_TIMESPAN)
-            : gpr_time_from_millis(g_default_server_keepalive_time_ms,
-                                   GPR_TIMESPAN);
-    t->keepalive_timeout =
-        g_default_server_keepalive_timeout_ms == INT_MAX
-            ? gpr_inf_future(GPR_TIMESPAN)
-            : gpr_time_from_millis(g_default_server_keepalive_timeout_ms,
-                                   GPR_TIMESPAN);
+    t->keepalive_time = g_default_server_keepalive_time_ms == INT_MAX
+                            ? GRPC_MILLIS_INF_FUTURE
+                            : g_default_server_keepalive_time_ms;
+    t->keepalive_timeout = g_default_server_keepalive_timeout_ms == INT_MAX
+                               ? GRPC_MILLIS_INF_FUTURE
+                               : g_default_server_keepalive_timeout_ms;
   }
   t->keepalive_permit_without_calls = g_default_keepalive_permit_without_calls;
 
@@ -433,73 +415,63 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                              GRPC_ARG_HTTP2_MAX_PINGS_WITHOUT_DATA)) {
         t->ping_policy.max_pings_without_data = grpc_channel_arg_get_integer(
             &channel_args->args[i],
-            (grpc_integer_options){g_default_max_pings_without_data, 0,
-                                   INT_MAX});
+            {g_default_max_pings_without_data, 0, INT_MAX});
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_HTTP2_MAX_PING_STRIKES)) {
         t->ping_policy.max_ping_strikes = grpc_channel_arg_get_integer(
-            &channel_args->args[i],
-            (grpc_integer_options){g_default_max_ping_strikes, 0, INT_MAX});
+            &channel_args->args[i], {g_default_max_ping_strikes, 0, INT_MAX});
       } else if (0 ==
                  strcmp(
                      channel_args->args[i].key,
                      GRPC_ARG_HTTP2_MIN_SENT_PING_INTERVAL_WITHOUT_DATA_MS)) {
         t->ping_policy.min_sent_ping_interval_without_data =
-            gpr_time_from_millis(
-                grpc_channel_arg_get_integer(
-                    &channel_args->args[i],
-                    (grpc_integer_options){
-                        g_default_min_sent_ping_interval_without_data_ms, 0,
-                        INT_MAX}),
-                GPR_TIMESPAN);
+            grpc_channel_arg_get_integer(
+                &channel_args->args[i],
+                grpc_integer_options{
+                    g_default_min_sent_ping_interval_without_data_ms, 0,
+                    INT_MAX});
       } else if (0 ==
                  strcmp(
                      channel_args->args[i].key,
                      GRPC_ARG_HTTP2_MIN_RECV_PING_INTERVAL_WITHOUT_DATA_MS)) {
         t->ping_policy.min_recv_ping_interval_without_data =
-            gpr_time_from_millis(
-                grpc_channel_arg_get_integer(
-                    &channel_args->args[i],
-                    (grpc_integer_options){
-                        g_default_min_recv_ping_interval_without_data_ms, 0,
-                        INT_MAX}),
-                GPR_TIMESPAN);
+            grpc_channel_arg_get_integer(
+                &channel_args->args[i],
+                grpc_integer_options{
+                    g_default_min_recv_ping_interval_without_data_ms, 0,
+                    INT_MAX});
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_HTTP2_WRITE_BUFFER_SIZE)) {
         t->write_buffer_size = (uint32_t)grpc_channel_arg_get_integer(
-            &channel_args->args[i],
-            (grpc_integer_options){0, 0, MAX_WRITE_BUFFER_SIZE});
+            &channel_args->args[i], {0, 0, MAX_WRITE_BUFFER_SIZE});
       } else if (0 ==
                  strcmp(channel_args->args[i].key, GRPC_ARG_HTTP2_BDP_PROBE)) {
-        t->flow_control.enable_bdp_probe = grpc_channel_arg_get_integer(
-            &channel_args->args[i], (grpc_integer_options){1, 0, 1});
+        t->flow_control.enable_bdp_probe =
+            grpc_channel_arg_get_integer(&channel_args->args[i], {1, 0, 1});
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_KEEPALIVE_TIME_MS)) {
         const int value = grpc_channel_arg_get_integer(
             &channel_args->args[i],
-            (grpc_integer_options){t->is_client
-                                       ? g_default_client_keepalive_time_ms
-                                       : g_default_server_keepalive_time_ms,
-                                   1, INT_MAX});
-        t->keepalive_time = value == INT_MAX
-                                ? gpr_inf_future(GPR_TIMESPAN)
-                                : gpr_time_from_millis(value, GPR_TIMESPAN);
+            grpc_integer_options{t->is_client
+                                     ? g_default_client_keepalive_time_ms
+                                     : g_default_server_keepalive_time_ms,
+                                 1, INT_MAX});
+        t->keepalive_time = value == INT_MAX ? GRPC_MILLIS_INF_FUTURE : value;
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_KEEPALIVE_TIMEOUT_MS)) {
         const int value = grpc_channel_arg_get_integer(
             &channel_args->args[i],
-            (grpc_integer_options){t->is_client
-                                       ? g_default_client_keepalive_timeout_ms
-                                       : g_default_server_keepalive_timeout_ms,
-                                   0, INT_MAX});
-        t->keepalive_timeout = value == INT_MAX
-                                   ? gpr_inf_future(GPR_TIMESPAN)
-                                   : gpr_time_from_millis(value, GPR_TIMESPAN);
+            grpc_integer_options{t->is_client
+                                     ? g_default_client_keepalive_timeout_ms
+                                     : g_default_server_keepalive_timeout_ms,
+                                 0, INT_MAX});
+        t->keepalive_timeout =
+            value == INT_MAX ? GRPC_MILLIS_INF_FUTURE : value;
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_KEEPALIVE_PERMIT_WITHOUT_CALLS)) {
         t->keepalive_permit_without_calls =
-            (uint32_t)grpc_channel_arg_get_integer(
-                &channel_args->args[i], (grpc_integer_options){0, 0, 1});
+            (uint32_t)grpc_channel_arg_get_integer(&channel_args->args[i],
+                                                   {0, 0, 1});
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_OPTIMIZATION_TARGET)) {
         if (channel_args->args[i].type != GRPC_ARG_STRING) {
@@ -574,23 +546,27 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   t->ping_state.pings_before_data_required = 0;
   t->ping_state.is_delayed_ping_timer_set = false;
 
-  t->ping_recv_state.last_ping_recv_time = gpr_inf_past(GPR_CLOCK_MONOTONIC);
+  t->ping_recv_state.last_ping_recv_time = GRPC_MILLIS_INF_PAST;
   t->ping_recv_state.ping_strikes = 0;
 
   /* Start keepalive pings */
-  if (gpr_time_cmp(t->keepalive_time, gpr_inf_future(GPR_TIMESPAN)) != 0) {
+  if (t->keepalive_time != GRPC_MILLIS_INF_FUTURE) {
     t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_WAITING;
     GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
-    grpc_timer_init(
-        exec_ctx, &t->keepalive_ping_timer,
-        gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), t->keepalive_time),
-        &t->init_keepalive_ping_locked, gpr_now(GPR_CLOCK_MONOTONIC));
+    grpc_timer_init(exec_ctx, &t->keepalive_ping_timer,
+                    grpc_exec_ctx_now(exec_ctx) + t->keepalive_time,
+                    &t->init_keepalive_ping_locked);
   } else {
     /* Use GRPC_CHTTP2_KEEPALIVE_STATE_DISABLED to indicate there are no
        inflight keeaplive timers */
     t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_DISABLED;
   }
 
+  grpc_chttp2_act_on_flowctl_action(
+      exec_ctx,
+      grpc_chttp2_flowctl_get_action(exec_ctx, &t->flow_control, NULL), t,
+      NULL);
+
   grpc_chttp2_initiate_write(exec_ctx, t,
                              GRPC_CHTTP2_INITIATE_WRITE_INITIAL_WRITE);
   post_benign_reclaimer(exec_ctx, t);
@@ -701,7 +677,7 @@ static int init_stream(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
   grpc_chttp2_incoming_metadata_buffer_init(&s->metadata_buffer[1], arena);
   grpc_chttp2_data_parser_init(&s->data_parser);
   grpc_slice_buffer_init(&s->flow_controlled_buffer);
-  s->deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  s->deadline = GRPC_MILLIS_INF_FUTURE;
   GRPC_CLOSURE_INIT(&s->complete_fetch_locked, complete_fetch_locked, s,
                     grpc_schedule_on_exec_ctx);
   grpc_slice_buffer_init(&s->unprocessed_incoming_frames_buffer);
@@ -905,9 +881,6 @@ static void inc_initiate_write_reason(
     case GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS:
       GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_SEND_SETTINGS(exec_ctx);
       break;
-    case GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING:
-      GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_BDP_ESTIMATOR_PING(exec_ctx);
-      break;
     case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING:
       GRPC_STATS_INC_HTTP2_INITIATE_WRITE_DUE_TO_FLOW_CONTROL_UNSTALLED_BY_SETTING(
           exec_ctx);
@@ -1045,6 +1018,7 @@ static void write_action_begin_locked(grpc_exec_ctx *exec_ctx, void *gt,
                                                    write_action, t, scheduler),
                        GRPC_ERROR_NONE);
   } else {
+    GRPC_STATS_INC_HTTP2_SPURIOUS_WRITES_BEGUN(exec_ctx);
     set_write_state(exec_ctx, t, GRPC_CHTTP2_WRITE_STATE_IDLE,
                     "begin writing nothing");
     GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "writing");
@@ -1143,14 +1117,12 @@ void grpc_chttp2_add_incoming_goaway(grpc_exec_ctx *exec_ctx,
     gpr_log(GPR_ERROR,
             "Received a GOAWAY with error code ENHANCE_YOUR_CALM and debug "
             "data equal to \"too_many_pings\"");
-    double current_keepalive_time_ms =
-        gpr_timespec_to_micros(t->keepalive_time) / 1000;
+    double current_keepalive_time_ms = (double)t->keepalive_time;
     t->keepalive_time =
         current_keepalive_time_ms > INT_MAX / KEEPALIVE_TIME_BACKOFF_MULTIPLIER
-            ? gpr_inf_future(GPR_TIMESPAN)
-            : gpr_time_from_millis((int64_t)(current_keepalive_time_ms *
-                                             KEEPALIVE_TIME_BACKOFF_MULTIPLIER),
-                                   GPR_TIMESPAN);
+            ? GRPC_MILLIS_INF_FUTURE
+            : (grpc_millis)(current_keepalive_time_ms *
+                            KEEPALIVE_TIME_BACKOFF_MULTIPLIER);
   }
 
   /* lie: use transient failure from the transport to indicate goaway has been
@@ -1464,8 +1436,7 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
         t->settings[GRPC_PEER_SETTINGS]
                    [GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE];
     if (t->is_client) {
-      s->deadline =
-          gpr_time_min(s->deadline, s->send_initial_metadata->deadline);
+      s->deadline = GPR_MIN(s->deadline, s->send_initial_metadata->deadline);
     }
     if (metadata_size > metadata_peer_limit) {
       grpc_chttp2_cancel_stream(
@@ -1649,8 +1620,8 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
             &t->flow_control, &s->flow_control, GRPC_HEADER_SIZE_IN_BYTES,
             already_received);
         grpc_chttp2_act_on_flowctl_action(
-            exec_ctx,
-            grpc_chttp2_flowctl_get_action(&t->flow_control, &s->flow_control),
+            exec_ctx, grpc_chttp2_flowctl_get_action(exec_ctx, &t->flow_control,
+                                                     &s->flow_control),
             t, s);
       }
     }
@@ -1683,16 +1654,14 @@ static void perform_stream_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
 
   if (!t->is_client) {
     if (op->send_initial_metadata) {
-      gpr_timespec deadline =
+      grpc_millis deadline =
           op->payload->send_initial_metadata.send_initial_metadata->deadline;
-      GPR_ASSERT(0 ==
-                 gpr_time_cmp(gpr_inf_future(deadline.clock_type), deadline));
+      GPR_ASSERT(deadline == GRPC_MILLIS_INF_FUTURE);
     }
     if (op->send_trailing_metadata) {
-      gpr_timespec deadline =
+      grpc_millis deadline =
           op->payload->send_trailing_metadata.send_trailing_metadata->deadline;
-      GPR_ASSERT(0 ==
-                 gpr_time_cmp(gpr_inf_future(deadline.clock_type), deadline));
+      GPR_ASSERT(deadline == GRPC_MILLIS_INF_FUTURE);
     }
   }
 
@@ -1716,28 +1685,21 @@ static void cancel_pings(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                          grpc_error *error) {
   /* callback remaining pings: they're not allowed to call into the transpot,
      and maybe they hold resources that need to be freed */
-  for (size_t i = 0; i < GRPC_CHTTP2_PING_TYPE_COUNT; i++) {
-    grpc_chttp2_ping_queue *pq = &t->ping_queues[i];
-    for (size_t j = 0; j < GRPC_CHTTP2_PCL_COUNT; j++) {
-      grpc_closure_list_fail_all(&pq->lists[j], GRPC_ERROR_REF(error));
-      GRPC_CLOSURE_LIST_SCHED(exec_ctx, &pq->lists[j]);
-    }
+  grpc_chttp2_ping_queue *pq = &t->ping_queue;
+  for (size_t j = 0; j < GRPC_CHTTP2_PCL_COUNT; j++) {
+    grpc_closure_list_fail_all(&pq->lists[j], GRPC_ERROR_REF(error));
+    GRPC_CLOSURE_LIST_SCHED(exec_ctx, &pq->lists[j]);
   }
   GRPC_ERROR_UNREF(error);
 }
 
-static void send_ping_locked(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-    grpc_chttp2_ping_type ping_type, grpc_closure *on_initiate,
-    grpc_closure *on_ack,
-    grpc_chttp2_initiate_write_reason initiate_write_reason) {
-  grpc_chttp2_ping_queue *pq = &t->ping_queues[ping_type];
+static void send_ping_locked(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                             grpc_closure *on_initiate, grpc_closure *on_ack) {
+  grpc_chttp2_ping_queue *pq = &t->ping_queue;
   grpc_closure_list_append(&pq->lists[GRPC_CHTTP2_PCL_INITIATE], on_initiate,
                            GRPC_ERROR_NONE);
-  if (grpc_closure_list_append(&pq->lists[GRPC_CHTTP2_PCL_NEXT], on_ack,
-                               GRPC_ERROR_NONE)) {
-    grpc_chttp2_initiate_write(exec_ctx, t, initiate_write_reason);
-  }
+  grpc_closure_list_append(&pq->lists[GRPC_CHTTP2_PCL_NEXT], on_ack,
+                           GRPC_ERROR_NONE);
 }
 
 static void retry_initiate_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
@@ -1752,8 +1714,7 @@ static void retry_initiate_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
 
 void grpc_chttp2_ack_ping(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                           uint64_t id) {
-  grpc_chttp2_ping_queue *pq =
-      &t->ping_queues[id % GRPC_CHTTP2_PING_TYPE_COUNT];
+  grpc_chttp2_ping_queue *pq = &t->ping_queue;
   if (pq->inflight_id != id) {
     char *from = grpc_endpoint_get_peer(t->ep);
     gpr_log(GPR_DEBUG, "Unknown ping response from %s: %" PRIx64, from, id);
@@ -1772,8 +1733,8 @@ static void send_goaway(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   t->sent_goaway_state = GRPC_CHTTP2_GOAWAY_SEND_SCHEDULED;
   grpc_http2_error_code http_error;
   grpc_slice slice;
-  grpc_error_get_status(error, gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL,
-                        &slice, &http_error);
+  grpc_error_get_status(exec_ctx, error, GRPC_MILLIS_INF_FUTURE, NULL, &slice,
+                        &http_error);
   grpc_chttp2_goaway_append(t->last_new_stream_id, (uint32_t)http_error,
                             grpc_slice_ref_internal(slice), &t->qbuf);
   grpc_chttp2_initiate_write(exec_ctx, t,
@@ -1783,7 +1744,7 @@ static void send_goaway(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
 
 void grpc_chttp2_add_ping_strike(grpc_exec_ctx *exec_ctx,
                                  grpc_chttp2_transport *t) {
-  gpr_log(GPR_DEBUG, "PING strike");
+  t->ping_recv_state.ping_strikes++;
   if (++t->ping_recv_state.ping_strikes > t->ping_policy.max_ping_strikes &&
       t->ping_policy.max_ping_strikes != 0) {
     send_goaway(exec_ctx, t,
@@ -1823,9 +1784,9 @@ static void perform_transport_op_locked(grpc_exec_ctx *exec_ctx,
   }
 
   if (op->send_ping) {
-    send_ping_locked(exec_ctx, t, GRPC_CHTTP2_PING_ON_NEXT_WRITE, NULL,
-                     op->send_ping,
-                     GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING);
+    send_ping_locked(exec_ctx, t, NULL, op->send_ping);
+    grpc_chttp2_initiate_write(exec_ctx, t,
+                               GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING);
   }
 
   if (op->on_connectivity_state_change != NULL) {
@@ -1901,7 +1862,9 @@ void grpc_chttp2_maybe_complete_recv_message(grpc_exec_ctx *exec_ctx,
                                  &s->frame_storage);
           s->unprocessed_incoming_frames_decompressed = false;
         }
-        if (!s->unprocessed_incoming_frames_decompressed) {
+        if (!s->unprocessed_incoming_frames_decompressed &&
+            s->stream_decompression_method !=
+                GRPC_STREAM_COMPRESSION_IDENTITY_DECOMPRESS) {
           GPR_ASSERT(s->decompressed_data_buffer.length == 0);
           bool end_of_context;
           if (!s->stream_decompression_ctx) {
@@ -2070,7 +2033,8 @@ void grpc_chttp2_cancel_stream(grpc_exec_ctx *exec_ctx,
   if (!s->read_closed || !s->write_closed) {
     if (s->id != 0) {
       grpc_http2_error_code http_error;
-      grpc_error_get_status(due_to_error, s->deadline, NULL, NULL, &http_error);
+      grpc_error_get_status(exec_ctx, due_to_error, s->deadline, NULL, NULL,
+                            &http_error);
       grpc_slice_buffer_add(
           &t->qbuf, grpc_chttp2_rst_stream_create(s->id, (uint32_t)http_error,
                                                   &s->stats.outgoing));
@@ -2088,7 +2052,7 @@ void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                              grpc_chttp2_stream *s, grpc_error *error) {
   grpc_status_code status;
   grpc_slice slice;
-  grpc_error_get_status(error, s->deadline, &status, &slice, NULL);
+  grpc_error_get_status(exec_ctx, error, s->deadline, &status, &slice, NULL);
 
   if (status != GRPC_STATUS_OK) {
     s->seen_error = true;
@@ -2253,7 +2217,8 @@ static void close_from_api(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   uint32_t len = 0;
   grpc_status_code grpc_status;
   grpc_slice slice;
-  grpc_error_get_status(error, s->deadline, &grpc_status, &slice, NULL);
+  grpc_error_get_status(exec_ctx, error, s->deadline, &grpc_status, &slice,
+                        NULL);
 
   GPR_ASSERT(grpc_status >= 0 && (int)grpc_status < 100);
 
@@ -2470,10 +2435,8 @@ void grpc_chttp2_act_on_flowctl_action(grpc_exec_ctx *exec_ctx,
   if (action.need_ping) {
     GRPC_CHTTP2_REF_TRANSPORT(t, "bdp_ping");
     grpc_bdp_estimator_schedule_ping(&t->flow_control.bdp_estimator);
-    send_ping_locked(exec_ctx, t,
-                     GRPC_CHTTP2_PING_BEFORE_TRANSPORT_WINDOW_UPDATE,
-                     &t->start_bdp_ping_locked, &t->finish_bdp_ping_locked,
-                     GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING);
+    send_ping_locked(exec_ctx, t, &t->start_bdp_ping_locked,
+                     &t->finish_bdp_ping_locked);
   }
 }
 
@@ -2581,7 +2544,8 @@ static void read_action_locked(grpc_exec_ctx *exec_ctx, void *tp,
     grpc_endpoint_read(exec_ctx, t->ep, &t->read_buffer,
                        &t->read_action_locked);
     grpc_chttp2_act_on_flowctl_action(
-        exec_ctx, grpc_chttp2_flowctl_get_bdp_action(&t->flow_control), t,
+        exec_ctx,
+        grpc_chttp2_flowctl_get_action(exec_ctx, &t->flow_control, NULL), t,
         NULL);
     GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "keep_reading");
   } else {
@@ -2614,7 +2578,7 @@ static void finish_bdp_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
   if (GRPC_TRACER_ON(grpc_http_trace)) {
     gpr_log(GPR_DEBUG, "%s: Complete BDP ping", t->peer_string);
   }
-  grpc_bdp_estimator_complete_ping(&t->flow_control.bdp_estimator);
+  grpc_bdp_estimator_complete_ping(exec_ctx, &t->flow_control.bdp_estimator);
 
   GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "bdp_ping");
 }
@@ -2626,9 +2590,7 @@ void grpc_chttp2_config_default_keepalive_args(grpc_channel_args *args,
     for (i = 0; i < args->num_args; i++) {
       if (0 == strcmp(args->args[i].key, GRPC_ARG_KEEPALIVE_TIME_MS)) {
         const int value = grpc_channel_arg_get_integer(
-            &args->args[i],
-            (grpc_integer_options){g_default_client_keepalive_time_ms, 1,
-                                   INT_MAX});
+            &args->args[i], {g_default_client_keepalive_time_ms, 1, INT_MAX});
         if (is_client) {
           g_default_client_keepalive_time_ms = value;
         } else {
@@ -2638,8 +2600,7 @@ void grpc_chttp2_config_default_keepalive_args(grpc_channel_args *args,
                  strcmp(args->args[i].key, GRPC_ARG_KEEPALIVE_TIMEOUT_MS)) {
         const int value = grpc_channel_arg_get_integer(
             &args->args[i],
-            (grpc_integer_options){g_default_client_keepalive_timeout_ms, 0,
-                                   INT_MAX});
+            {g_default_client_keepalive_timeout_ms, 0, INT_MAX});
         if (is_client) {
           g_default_client_keepalive_timeout_ms = value;
         } else {
@@ -2650,18 +2611,15 @@ void grpc_chttp2_config_default_keepalive_args(grpc_channel_args *args,
         g_default_keepalive_permit_without_calls =
             (uint32_t)grpc_channel_arg_get_integer(
                 &args->args[i],
-                (grpc_integer_options){g_default_keepalive_permit_without_calls,
-                                       0, 1});
+                {g_default_keepalive_permit_without_calls, 0, 1});
       } else if (0 ==
                  strcmp(args->args[i].key, GRPC_ARG_HTTP2_MAX_PING_STRIKES)) {
         g_default_max_ping_strikes = grpc_channel_arg_get_integer(
-            &args->args[i],
-            (grpc_integer_options){g_default_max_ping_strikes, 0, INT_MAX});
+            &args->args[i], {g_default_max_ping_strikes, 0, INT_MAX});
       } else if (0 == strcmp(args->args[i].key,
                              GRPC_ARG_HTTP2_MAX_PINGS_WITHOUT_DATA)) {
         g_default_max_pings_without_data = grpc_channel_arg_get_integer(
-            &args->args[i], (grpc_integer_options){
-                                g_default_max_pings_without_data, 0, INT_MAX});
+            &args->args[i], {g_default_max_pings_without_data, 0, INT_MAX});
       } else if (0 ==
                  strcmp(
                      args->args[i].key,
@@ -2669,9 +2627,7 @@ void grpc_chttp2_config_default_keepalive_args(grpc_channel_args *args,
         g_default_min_sent_ping_interval_without_data_ms =
             grpc_channel_arg_get_integer(
                 &args->args[i],
-                (grpc_integer_options){
-                    g_default_min_sent_ping_interval_without_data_ms, 0,
-                    INT_MAX});
+                {g_default_min_sent_ping_interval_without_data_ms, 0, INT_MAX});
       } else if (0 ==
                  strcmp(
                      args->args[i].key,
@@ -2679,9 +2635,7 @@ void grpc_chttp2_config_default_keepalive_args(grpc_channel_args *args,
         g_default_min_recv_ping_interval_without_data_ms =
             grpc_channel_arg_get_integer(
                 &args->args[i],
-                (grpc_integer_options){
-                    g_default_min_recv_ping_interval_without_data_ms, 0,
-                    INT_MAX});
+                {g_default_min_recv_ping_interval_without_data_ms, 0, INT_MAX});
       }
     }
   }
@@ -2698,24 +2652,22 @@ static void init_keepalive_ping_locked(grpc_exec_ctx *exec_ctx, void *arg,
         grpc_chttp2_stream_map_size(&t->stream_map) > 0) {
       t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_PINGING;
       GRPC_CHTTP2_REF_TRANSPORT(t, "keepalive ping end");
-      send_ping_locked(exec_ctx, t, GRPC_CHTTP2_PING_ON_NEXT_WRITE,
-                       &t->start_keepalive_ping_locked,
-                       &t->finish_keepalive_ping_locked,
-                       GRPC_CHTTP2_INITIATE_WRITE_KEEPALIVE_PING);
+      send_ping_locked(exec_ctx, t, &t->start_keepalive_ping_locked,
+                       &t->finish_keepalive_ping_locked);
+      grpc_chttp2_initiate_write(exec_ctx, t,
+                                 GRPC_CHTTP2_INITIATE_WRITE_KEEPALIVE_PING);
     } else {
       GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
-      grpc_timer_init(
-          exec_ctx, &t->keepalive_ping_timer,
-          gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), t->keepalive_time),
-          &t->init_keepalive_ping_locked, gpr_now(GPR_CLOCK_MONOTONIC));
+      grpc_timer_init(exec_ctx, &t->keepalive_ping_timer,
+                      grpc_exec_ctx_now(exec_ctx) + t->keepalive_time,
+                      &t->init_keepalive_ping_locked);
     }
   } else if (error == GRPC_ERROR_CANCELLED) {
     /* The keepalive ping timer may be cancelled by bdp */
     GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
-    grpc_timer_init(
-        exec_ctx, &t->keepalive_ping_timer,
-        gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), t->keepalive_time),
-        &t->init_keepalive_ping_locked, gpr_now(GPR_CLOCK_MONOTONIC));
+    grpc_timer_init(exec_ctx, &t->keepalive_ping_timer,
+                    grpc_exec_ctx_now(exec_ctx) + t->keepalive_time,
+                    &t->init_keepalive_ping_locked);
   }
   GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "init keepalive ping");
 }
@@ -2724,10 +2676,9 @@ static void start_keepalive_ping_locked(grpc_exec_ctx *exec_ctx, void *arg,
                                         grpc_error *error) {
   grpc_chttp2_transport *t = (grpc_chttp2_transport *)arg;
   GRPC_CHTTP2_REF_TRANSPORT(t, "keepalive watchdog");
-  grpc_timer_init(
-      exec_ctx, &t->keepalive_watchdog_timer,
-      gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), t->keepalive_timeout),
-      &t->keepalive_watchdog_fired_locked, gpr_now(GPR_CLOCK_MONOTONIC));
+  grpc_timer_init(exec_ctx, &t->keepalive_watchdog_timer,
+                  grpc_exec_ctx_now(exec_ctx) + t->keepalive_time,
+                  &t->keepalive_watchdog_fired_locked);
 }
 
 static void finish_keepalive_ping_locked(grpc_exec_ctx *exec_ctx, void *arg,
@@ -2738,10 +2689,9 @@ static void finish_keepalive_ping_locked(grpc_exec_ctx *exec_ctx, void *arg,
       t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_WAITING;
       grpc_timer_cancel(exec_ctx, &t->keepalive_watchdog_timer);
       GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
-      grpc_timer_init(
-          exec_ctx, &t->keepalive_ping_timer,
-          gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), t->keepalive_time),
-          &t->init_keepalive_ping_locked, gpr_now(GPR_CLOCK_MONOTONIC));
+      grpc_timer_init(exec_ctx, &t->keepalive_ping_timer,
+                      grpc_exec_ctx_now(exec_ctx) + t->keepalive_time,
+                      &t->init_keepalive_ping_locked);
     }
   }
   GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "keepalive ping end");
@@ -2841,9 +2791,9 @@ static void incoming_byte_stream_next_locked(grpc_exec_ctx *exec_ctx,
                                            bs->next_action.max_size_hint,
                                            cur_length);
     grpc_chttp2_act_on_flowctl_action(
-        exec_ctx,
-        grpc_chttp2_flowctl_get_action(&t->flow_control, &s->flow_control), t,
-        s);
+        exec_ctx, grpc_chttp2_flowctl_get_action(exec_ctx, &t->flow_control,
+                                                 &s->flow_control),
+        t, s);
   }
   GPR_ASSERT(s->unprocessed_incoming_frames_buffer.length == 0);
   if (s->frame_storage.length > 0) {
@@ -3191,8 +3141,6 @@ const char *grpc_chttp2_initiate_write_reason_string(
       return "TRANSPORT_FLOW_CONTROL";
     case GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS:
       return "SEND_SETTINGS";
-    case GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING:
-      return "BDP_ESTIMATOR_PING";
     case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING:
       return "FLOW_CONTROL_UNSTALLED_BY_SETTING";
     case GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE:
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.h b/src/core/ext/transport/chttp2/transport/chttp2_transport.h
index 55fb1a8343..321fca4c82 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.h
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.h
@@ -23,6 +23,10 @@
 #include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/transport/transport.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 extern grpc_tracer_flag grpc_http_trace;
 extern grpc_tracer_flag grpc_flowctl_trace;
 extern grpc_tracer_flag grpc_trace_http2_stream_state;
@@ -41,4 +45,8 @@ void grpc_chttp2_transport_start_reading(grpc_exec_ctx *exec_ctx,
                                          grpc_transport *transport,
                                          grpc_slice_buffer *read_buffer);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_CHTTP2_TRANSPORT_H */
diff --git a/src/core/ext/transport/chttp2/transport/flow_control.c b/src/core/ext/transport/chttp2/transport/flow_control.cc
index 569a6349d3..639e51da70 100644
--- a/src/core/ext/transport/chttp2/transport/flow_control.c
+++ b/src/core/ext/transport/chttp2/transport/flow_control.cc
@@ -18,6 +18,7 @@
 
 #include "src/core/ext/transport/chttp2/transport/internal.h"
 
+#include <inttypes.h>
 #include <limits.h>
 #include <math.h>
 #include <string.h>
@@ -86,7 +87,7 @@ static char* fmt_uint32_diff_str(uint32_t old_val, uint32_t new_val) {
 
 static void posttrace(shadow_flow_control* shadow_fc,
                       grpc_chttp2_transport_flowctl* tfc,
-                      grpc_chttp2_stream_flowctl* sfc, char* reason) {
+                      grpc_chttp2_stream_flowctl* sfc, const char* reason) {
   uint32_t acked_local_window =
       tfc->t->settings[GRPC_SENT_SETTINGS]
                       [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE];
@@ -128,7 +129,7 @@ static void posttrace(shadow_flow_control* shadow_fc,
   gpr_free(saw_str);
 }
 
-static char* urgency_to_string(grpc_chttp2_flowctl_urgency urgency) {
+static const char* urgency_to_string(grpc_chttp2_flowctl_urgency urgency) {
   switch (urgency) {
     case GRPC_CHTTP2_FLOWCTL_NO_ACTION_NEEDED:
       return "no action";
@@ -175,11 +176,9 @@ static void trace_action(grpc_chttp2_transport_flowctl* tfc,
 /* How many bytes of incoming flow control would we like to advertise */
 static uint32_t grpc_chttp2_target_announced_window(
     const grpc_chttp2_transport_flowctl* tfc) {
-  return (uint32_t)GPR_MIN(
-      (int64_t)((1u << 31) - 1),
-      tfc->announced_stream_total_over_incoming_window +
-          tfc->t->settings[GRPC_SENT_SETTINGS]
-                          [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE]);
+  return (uint32_t)GPR_MIN((int64_t)((1u << 31) - 1),
+                           tfc->announced_stream_total_over_incoming_window +
+                               tfc->target_initial_window_size);
 }
 
 // we have sent data on the wire, we must track this in our bookkeeping for the
@@ -281,13 +280,14 @@ grpc_error* grpc_chttp2_flowctl_recv_data(grpc_chttp2_transport_flowctl* tfc,
 // Returns a non zero announce integer if we should send a transport window
 // update
 uint32_t grpc_chttp2_flowctl_maybe_send_transport_update(
-    grpc_chttp2_transport_flowctl* tfc) {
+    grpc_chttp2_transport_flowctl* tfc, bool writing_anyway) {
   PRETRACE(tfc, NULL);
   uint32_t target_announced_window = grpc_chttp2_target_announced_window(tfc);
   uint32_t threshold_to_send_transport_window_update =
       tfc->t->outbuf.count > 0 ? 3 * target_announced_window / 4
                                : target_announced_window / 2;
-  if (tfc->announced_window <= threshold_to_send_transport_window_update &&
+  if ((writing_anyway ||
+       tfc->announced_window <= threshold_to_send_transport_window_update) &&
       tfc->announced_window != target_announced_window) {
     uint32_t announce = (uint32_t)GPR_CLAMP(
         target_announced_window - tfc->announced_window, 0, UINT32_MAX);
@@ -392,15 +392,26 @@ static grpc_chttp2_flowctl_urgency delta_is_significant(
 
 // Takes in a target and uses the pid controller to return a stabilized
 // guess at the new bdp.
-static double get_pid_controller_guess(grpc_chttp2_transport_flowctl* tfc,
+static double get_pid_controller_guess(grpc_exec_ctx* exec_ctx,
+                                       grpc_chttp2_transport_flowctl* tfc,
                                        double target) {
-  double bdp_error = target - grpc_pid_controller_last(&tfc->pid_controller);
-  gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-  gpr_timespec dt_timespec = gpr_time_sub(now, tfc->last_pid_update);
-  double dt = (double)dt_timespec.tv_sec + dt_timespec.tv_nsec * 1e-9;
-  if (dt > 0.1) {
-    dt = 0.1;
+  grpc_millis now = grpc_exec_ctx_now(exec_ctx);
+  if (!tfc->pid_controller_initialized) {
+    tfc->last_pid_update = now;
+    tfc->pid_controller_initialized = true;
+    grpc_pid_controller_init(
+        &tfc->pid_controller,
+        (grpc_pid_controller_args){.gain_p = 4,
+                                   .gain_i = 8,
+                                   .gain_d = 0,
+                                   .initial_control_value = target,
+                                   .min_control_value = -1,
+                                   .max_control_value = 25,
+                                   .integral_range = 10});
+    return pow(2, target);
   }
+  double bdp_error = target - grpc_pid_controller_last(&tfc->pid_controller);
+  double dt = (double)(now - tfc->last_pid_update) * 1e-3;
   double log2_bdp_guess =
       grpc_pid_controller_update(&tfc->pid_controller, bdp_error, dt);
   tfc->last_pid_update = now;
@@ -413,20 +424,25 @@ static double get_target_under_memory_pressure(
   // do not increase window under heavy memory pressure.
   double memory_pressure = grpc_resource_quota_get_memory_pressure(
       grpc_resource_user_quota(grpc_endpoint_get_resource_user(tfc->t->ep)));
-  if (memory_pressure > 0.8) {
-    target *= 1 - GPR_MIN(1, (memory_pressure - 0.8) / 0.1);
+  static const double kLowMemPressure = 0.1;
+  static const double kZeroTarget = 22;
+  static const double kHighMemPressure = 0.8;
+  static const double kMaxMemPressure = 0.9;
+  if (memory_pressure < kLowMemPressure && target < kZeroTarget) {
+    target = (target - kZeroTarget) * memory_pressure / kLowMemPressure +
+             kZeroTarget;
+  } else if (memory_pressure > kHighMemPressure) {
+    target *= 1 - GPR_MIN(1, (memory_pressure - kHighMemPressure) /
+                                 (kMaxMemPressure - kHighMemPressure));
   }
   return target;
 }
 
 grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_action(
-    grpc_chttp2_transport_flowctl* tfc, grpc_chttp2_stream_flowctl* sfc) {
+    grpc_exec_ctx* exec_ctx, grpc_chttp2_transport_flowctl* tfc,
+    grpc_chttp2_stream_flowctl* sfc) {
   grpc_chttp2_flowctl_action action;
   memset(&action, 0, sizeof(action));
-  uint32_t target_announced_window = grpc_chttp2_target_announced_window(tfc);
-  if (tfc->announced_window < target_announced_window / 2) {
-    action.send_transport_update = GRPC_CHTTP2_FLOWCTL_UPDATE_IMMEDIATELY;
-  }
   // TODO(ncteisen): tune this
   if (sfc != NULL && !sfc->s->read_closed) {
     uint32_t sent_init_window =
@@ -441,20 +457,12 @@ grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_action(
       action.send_stream_update = GRPC_CHTTP2_FLOWCTL_QUEUE_UPDATE;
     }
   }
-  TRACEACTION(tfc, action);
-  return action;
-}
-
-grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_bdp_action(
-    grpc_chttp2_transport_flowctl* tfc) {
-  grpc_chttp2_flowctl_action action;
-  memset(&action, 0, sizeof(action));
   if (tfc->enable_bdp_probe) {
-    action.need_ping = grpc_bdp_estimator_need_ping(&tfc->bdp_estimator);
+    action.need_ping =
+        grpc_bdp_estimator_need_ping(exec_ctx, &tfc->bdp_estimator);
 
     // get bdp estimate and update initial_window accordingly.
     int64_t estimate = -1;
-    int32_t bdp = -1;
     if (grpc_bdp_estimator_get_estimate(&tfc->bdp_estimator, &estimate)) {
       double target = 1 + log2((double)estimate);
 
@@ -465,17 +473,18 @@ grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_bdp_action(
 
       // run our target through the pid controller to stabilize change.
       // TODO(ncteisen): experiment with other controllers here.
-      double bdp_guess = get_pid_controller_guess(tfc, target);
+      double bdp_guess = get_pid_controller_guess(exec_ctx, tfc, target);
 
       // Though initial window 'could' drop to 0, we keep the floor at 128
-      bdp = GPR_MAX((int32_t)bdp_guess, 128);
+      tfc->target_initial_window_size =
+          (int32_t)GPR_CLAMP(bdp_guess, 128, INT32_MAX);
 
       grpc_chttp2_flowctl_urgency init_window_update_urgency =
-          delta_is_significant(tfc, bdp,
+          delta_is_significant(tfc, tfc->target_initial_window_size,
                                GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE);
       if (init_window_update_urgency != GRPC_CHTTP2_FLOWCTL_NO_ACTION_NEEDED) {
         action.send_setting_update = init_window_update_urgency;
-        action.initial_window_size = (uint32_t)bdp;
+        action.initial_window_size = (uint32_t)tfc->target_initial_window_size;
       }
     }
 
@@ -484,8 +493,9 @@ grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_bdp_action(
     if (grpc_bdp_estimator_get_bw(&tfc->bdp_estimator, &bw_dbl)) {
       // we target the max of BDP or bandwidth in microseconds.
       int32_t frame_size = (int32_t)GPR_CLAMP(
-          GPR_MAX((int32_t)GPR_CLAMP(bw_dbl, 0, INT_MAX) / 1000, bdp), 16384,
-          16777215);
+          GPR_MAX((int32_t)GPR_CLAMP(bw_dbl, 0, INT_MAX) / 1000,
+                  tfc->target_initial_window_size),
+          16384, 16777215);
       grpc_chttp2_flowctl_urgency frame_size_urgency = delta_is_significant(
           tfc, frame_size, GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE);
       if (frame_size_urgency != GRPC_CHTTP2_FLOWCTL_NO_ACTION_NEEDED) {
@@ -496,7 +506,10 @@ grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_bdp_action(
       }
     }
   }
-
+  uint32_t target_announced_window = grpc_chttp2_target_announced_window(tfc);
+  if (tfc->announced_window < target_announced_window / 2) {
+    action.send_transport_update = GRPC_CHTTP2_FLOWCTL_UPDATE_IMMEDIATELY;
+  }
   TRACEACTION(tfc, action);
   return action;
 }
diff --git a/src/core/ext/transport/chttp2/transport/frame.h b/src/core/ext/transport/chttp2/transport/frame.h
index dba4c004ec..e7debdad79 100644
--- a/src/core/ext/transport/chttp2/transport/frame.h
+++ b/src/core/ext/transport/chttp2/transport/frame.h
@@ -24,6 +24,10 @@
 
 #include "src/core/lib/iomgr/error.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* defined in internal.h */
 typedef struct grpc_chttp2_stream grpc_chttp2_stream;
 typedef struct grpc_chttp2_transport grpc_chttp2_transport;
@@ -43,4 +47,8 @@ typedef struct grpc_chttp2_transport grpc_chttp2_transport;
 #define GRPC_CHTTP2_DATA_FLAG_PADDED 8
 #define GRPC_CHTTP2_FLAG_HAS_PRIORITY 0x20
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_H */
diff --git a/src/core/ext/transport/chttp2/transport/frame_data.c b/src/core/ext/transport/chttp2/transport/frame_data.cc
index 73aaab1802..73aaab1802 100644
--- a/src/core/ext/transport/chttp2/transport/frame_data.c
+++ b/src/core/ext/transport/chttp2/transport/frame_data.cc
diff --git a/src/core/ext/transport/chttp2/transport/frame_data.h b/src/core/ext/transport/chttp2/transport/frame_data.h
index 3f1c787847..2df99ccf98 100644
--- a/src/core/ext/transport/chttp2/transport/frame_data.h
+++ b/src/core/ext/transport/chttp2/transport/frame_data.h
@@ -28,6 +28,10 @@
 #include "src/core/lib/transport/byte_stream.h"
 #include "src/core/lib/transport/transport.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef enum {
   GRPC_CHTTP2_DATA_FH_0,
   GRPC_CHTTP2_DATA_FH_1,
@@ -80,4 +84,8 @@ grpc_error *grpc_deframe_unprocessed_incoming_frames(
     grpc_slice_buffer *slices, grpc_slice *slice_out,
     grpc_byte_stream **stream_out);
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_DATA_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_DATA_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/transport/frame_goaway.c b/src/core/ext/transport/chttp2/transport/frame_goaway.cc
index 78ec08e177..78ec08e177 100644
--- a/src/core/ext/transport/chttp2/transport/frame_goaway.c
+++ b/src/core/ext/transport/chttp2/transport/frame_goaway.cc
diff --git a/src/core/ext/transport/chttp2/transport/frame_goaway.h b/src/core/ext/transport/chttp2/transport/frame_goaway.h
index abc48f30c6..ce6f18b35c 100644
--- a/src/core/ext/transport/chttp2/transport/frame_goaway.h
+++ b/src/core/ext/transport/chttp2/transport/frame_goaway.h
@@ -25,6 +25,10 @@
 #include "src/core/ext/transport/chttp2/transport/frame.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef enum {
   GRPC_CHTTP2_GOAWAY_LSI0,
   GRPC_CHTTP2_GOAWAY_LSI1,
@@ -60,4 +64,8 @@ void grpc_chttp2_goaway_append(uint32_t last_stream_id, uint32_t error_code,
                                grpc_slice debug_data,
                                grpc_slice_buffer *slice_buffer);
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_GOAWAY_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_GOAWAY_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/transport/frame_ping.c b/src/core/ext/transport/chttp2/transport/frame_ping.cc
index d431d6b2df..1cfa883ee1 100644
--- a/src/core/ext/transport/chttp2/transport/frame_ping.c
+++ b/src/core/ext/transport/chttp2/transport/frame_ping.cc
@@ -89,10 +89,10 @@ grpc_error *grpc_chttp2_ping_parser_parse(grpc_exec_ctx *exec_ctx, void *parser,
       grpc_chttp2_ack_ping(exec_ctx, t, p->opaque_8bytes);
     } else {
       if (!t->is_client) {
-        gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-        gpr_timespec next_allowed_ping =
-            gpr_time_add(t->ping_recv_state.last_ping_recv_time,
-                         t->ping_policy.min_recv_ping_interval_without_data);
+        grpc_millis now = grpc_exec_ctx_now(exec_ctx);
+        grpc_millis next_allowed_ping =
+            t->ping_recv_state.last_ping_recv_time +
+            t->ping_policy.min_recv_ping_interval_without_data;
 
         if (t->keepalive_permit_without_calls == 0 &&
             grpc_chttp2_stream_map_size(&t->stream_map) == 0) {
@@ -100,11 +100,10 @@ grpc_error *grpc_chttp2_ping_parser_parse(grpc_exec_ctx *exec_ctx, void *parser,
              no less than two hours. When there is no outstanding streams, we
              restrict the number of PINGS equivalent to TCP Keep-Alive. */
           next_allowed_ping =
-              gpr_time_add(t->ping_recv_state.last_ping_recv_time,
-                           gpr_time_from_seconds(7200, GPR_TIMESPAN));
+              t->ping_recv_state.last_ping_recv_time + 7200 * GPR_MS_PER_SEC;
         }
 
-        if (gpr_time_cmp(next_allowed_ping, now) > 0) {
+        if (next_allowed_ping > now) {
           grpc_chttp2_add_ping_strike(exec_ctx, t);
         }
 
diff --git a/src/core/ext/transport/chttp2/transport/frame_ping.h b/src/core/ext/transport/chttp2/transport/frame_ping.h
index 5969ace9bd..91f16f050f 100644
--- a/src/core/ext/transport/chttp2/transport/frame_ping.h
+++ b/src/core/ext/transport/chttp2/transport/frame_ping.h
@@ -23,6 +23,10 @@
 #include "src/core/ext/transport/chttp2/transport/frame.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct {
   uint8_t byte;
   uint8_t is_ack;
@@ -41,4 +45,8 @@ grpc_error *grpc_chttp2_ping_parser_parse(grpc_exec_ctx *exec_ctx, void *parser,
 /* Test-only function for disabling ping ack */
 void grpc_set_disable_ping_ack(bool disable_ping_ack);
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_PING_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_PING_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/transport/frame_rst_stream.c b/src/core/ext/transport/chttp2/transport/frame_rst_stream.cc
index 0133b6efa2..0133b6efa2 100644
--- a/src/core/ext/transport/chttp2/transport/frame_rst_stream.c
+++ b/src/core/ext/transport/chttp2/transport/frame_rst_stream.cc
diff --git a/src/core/ext/transport/chttp2/transport/frame_rst_stream.h b/src/core/ext/transport/chttp2/transport/frame_rst_stream.h
index d088221b52..bdca064a91 100644
--- a/src/core/ext/transport/chttp2/transport/frame_rst_stream.h
+++ b/src/core/ext/transport/chttp2/transport/frame_rst_stream.h
@@ -24,6 +24,10 @@
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/transport/transport.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct {
   uint8_t byte;
   uint8_t reason_bytes[4];
@@ -40,4 +44,8 @@ grpc_error *grpc_chttp2_rst_stream_parser_parse(grpc_exec_ctx *exec_ctx,
                                                 grpc_chttp2_stream *s,
                                                 grpc_slice slice, int is_last);
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_RST_STREAM_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_RST_STREAM_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/transport/frame_settings.c b/src/core/ext/transport/chttp2/transport/frame_settings.cc
index 2995bf7310..2995bf7310 100644
--- a/src/core/ext/transport/chttp2/transport/frame_settings.c
+++ b/src/core/ext/transport/chttp2/transport/frame_settings.cc
diff --git a/src/core/ext/transport/chttp2/transport/frame_settings.h b/src/core/ext/transport/chttp2/transport/frame_settings.h
index 47479d675d..f0793f0e73 100644
--- a/src/core/ext/transport/chttp2/transport/frame_settings.h
+++ b/src/core/ext/transport/chttp2/transport/frame_settings.h
@@ -25,6 +25,10 @@
 #include "src/core/ext/transport/chttp2/transport/http2_settings.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef enum {
   GRPC_CHTTP2_SPS_ID0,
   GRPC_CHTTP2_SPS_ID1,
@@ -58,4 +62,8 @@ grpc_error *grpc_chttp2_settings_parser_parse(grpc_exec_ctx *exec_ctx,
                                               grpc_chttp2_stream *s,
                                               grpc_slice slice, int is_last);
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_SETTINGS_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_SETTINGS_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/transport/frame_window_update.c b/src/core/ext/transport/chttp2/transport/frame_window_update.cc
index c9ab8d1b50..c9ab8d1b50 100644
--- a/src/core/ext/transport/chttp2/transport/frame_window_update.c
+++ b/src/core/ext/transport/chttp2/transport/frame_window_update.cc
diff --git a/src/core/ext/transport/chttp2/transport/frame_window_update.h b/src/core/ext/transport/chttp2/transport/frame_window_update.h
index 698da4e351..29cf0cc740 100644
--- a/src/core/ext/transport/chttp2/transport/frame_window_update.h
+++ b/src/core/ext/transport/chttp2/transport/frame_window_update.h
@@ -24,6 +24,10 @@
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/transport/transport.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct {
   uint8_t byte;
   uint8_t is_connection_update;
@@ -39,4 +43,8 @@ grpc_error *grpc_chttp2_window_update_parser_parse(
     grpc_exec_ctx *exec_ctx, void *parser, grpc_chttp2_transport *t,
     grpc_chttp2_stream *s, grpc_slice slice, int is_last);
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_WINDOW_UPDATE_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_FRAME_WINDOW_UPDATE_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/transport/hpack_encoder.c b/src/core/ext/transport/chttp2/transport/hpack_encoder.cc
index a404b664e3..17b8c4ab85 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_encoder.c
+++ b/src/core/ext/transport/chttp2/transport/hpack_encoder.cc
@@ -57,7 +57,7 @@ static const grpc_slice terminal_slice = {
     {{0, 0}}                  /* data.refcounted */
 };
 
-extern grpc_tracer_flag grpc_http_trace;
+extern "C" grpc_tracer_flag grpc_http_trace;
 
 typedef struct {
   int is_first_frame;
@@ -535,12 +535,12 @@ static void hpack_enc(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
 #define TIMEOUT_KEY "grpc-timeout"
 
 static void deadline_enc(grpc_exec_ctx *exec_ctx,
-                         grpc_chttp2_hpack_compressor *c, gpr_timespec deadline,
+                         grpc_chttp2_hpack_compressor *c, grpc_millis deadline,
                          framer_state *st) {
   char timeout_str[GRPC_HTTP2_TIMEOUT_ENCODE_MIN_BUFSIZE];
   grpc_mdelem mdelem;
-  grpc_http2_encode_timeout(
-      gpr_time_sub(deadline, gpr_now(deadline.clock_type)), timeout_str);
+  grpc_http2_encode_timeout(deadline - grpc_exec_ctx_now(exec_ctx),
+                            timeout_str);
   mdelem = grpc_mdelem_from_slices(exec_ctx, GRPC_MDSTR_GRPC_TIMEOUT,
                                    grpc_slice_from_copied_string(timeout_str));
   hpack_enc(exec_ctx, c, mdelem, st);
@@ -660,8 +660,8 @@ void grpc_chttp2_encode_header(grpc_exec_ctx *exec_ctx,
   for (grpc_linked_mdelem *l = metadata->list.head; l; l = l->next) {
     hpack_enc(exec_ctx, c, l->md, &st);
   }
-  gpr_timespec deadline = metadata->deadline;
-  if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) != 0) {
+  grpc_millis deadline = metadata->deadline;
+  if (deadline != GRPC_MILLIS_INF_FUTURE) {
     deadline_enc(exec_ctx, c, deadline, &st);
   }
 
diff --git a/src/core/ext/transport/chttp2/transport/hpack_encoder.h b/src/core/ext/transport/chttp2/transport/hpack_encoder.h
index 271192f894..dc28b5566a 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_encoder.h
+++ b/src/core/ext/transport/chttp2/transport/hpack_encoder.h
@@ -34,6 +34,10 @@
 /* maximum table size we'll actually use */
 #define GRPC_CHTTP2_HPACKC_MAX_TABLE_SIZE (1024 * 1024)
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct {
   uint32_t filter_elems_sum;
   uint32_t max_table_size;
@@ -91,4 +95,8 @@ void grpc_chttp2_encode_header(grpc_exec_ctx *exec_ctx,
                                const grpc_encode_header_options *options,
                                grpc_slice_buffer *outbuf);
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_ENCODER_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_ENCODER_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/transport/hpack_parser.c b/src/core/ext/transport/chttp2/transport/hpack_parser.cc
index 3d1df19bc3..3d1df19bc3 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_parser.c
+++ b/src/core/ext/transport/chttp2/transport/hpack_parser.cc
diff --git a/src/core/ext/transport/chttp2/transport/hpack_parser.h b/src/core/ext/transport/chttp2/transport/hpack_parser.h
index 8fbc6a602b..6c36ebdf8d 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_parser.h
+++ b/src/core/ext/transport/chttp2/transport/hpack_parser.h
@@ -27,6 +27,10 @@
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/transport/metadata.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct grpc_chttp2_hpack_parser grpc_chttp2_hpack_parser;
 
 typedef grpc_error *(*grpc_chttp2_hpack_parser_state)(
@@ -111,4 +115,8 @@ grpc_error *grpc_chttp2_header_parser_parse(grpc_exec_ctx *exec_ctx,
                                             grpc_chttp2_stream *s,
                                             grpc_slice slice, int is_last);
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_PARSER_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_PARSER_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/transport/hpack_table.c b/src/core/ext/transport/chttp2/transport/hpack_table.cc
index bbd135a318..82c284b36e 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_table.c
+++ b/src/core/ext/transport/chttp2/transport/hpack_table.cc
@@ -28,7 +28,7 @@
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/support/murmur_hash.h"
 
-extern grpc_tracer_flag grpc_http_trace;
+extern "C" grpc_tracer_flag grpc_http_trace;
 
 static struct {
   const char *key;
diff --git a/src/core/ext/transport/chttp2/transport/hpack_table.h b/src/core/ext/transport/chttp2/transport/hpack_table.h
index 2cf8f68506..a3ce2730a8 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_table.h
+++ b/src/core/ext/transport/chttp2/transport/hpack_table.h
@@ -24,6 +24,10 @@
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/transport/metadata.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* HPACK header table */
 
 /* last index in the static table */
@@ -94,4 +98,8 @@ typedef struct {
 grpc_chttp2_hptbl_find_result grpc_chttp2_hptbl_find(
     const grpc_chttp2_hptbl *tbl, grpc_mdelem md);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_TABLE_H */
diff --git a/src/core/ext/transport/chttp2/transport/http2_settings.c b/src/core/ext/transport/chttp2/transport/http2_settings.cc
index 46b7c0c49c..46b7c0c49c 100644
--- a/src/core/ext/transport/chttp2/transport/http2_settings.c
+++ b/src/core/ext/transport/chttp2/transport/http2_settings.cc
diff --git a/src/core/ext/transport/chttp2/transport/http2_settings.h b/src/core/ext/transport/chttp2/transport/http2_settings.h
index 706dfc3139..01e80b8d01 100644
--- a/src/core/ext/transport/chttp2/transport/http2_settings.h
+++ b/src/core/ext/transport/chttp2/transport/http2_settings.h
@@ -35,6 +35,10 @@ typedef enum {
 } grpc_chttp2_setting_id;
 
 #define GRPC_CHTTP2_NUM_SETTINGS 7
+
+#ifdef __cplusplus
+extern "C" {
+#endif
 extern const uint16_t grpc_setting_id_to_wire_id[];
 
 bool grpc_wire_id_to_setting_id(uint32_t wire_id, grpc_chttp2_setting_id *out);
@@ -56,4 +60,8 @@ typedef struct {
 extern const grpc_chttp2_setting_parameters
     grpc_chttp2_settings_parameters[GRPC_CHTTP2_NUM_SETTINGS];
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HTTP2_SETTINGS_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HTTP2_SETTINGS_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/transport/huffsyms.c b/src/core/ext/transport/chttp2/transport/huffsyms.cc
index f28d8cc30a..f28d8cc30a 100644
--- a/src/core/ext/transport/chttp2/transport/huffsyms.c
+++ b/src/core/ext/transport/chttp2/transport/huffsyms.cc
diff --git a/src/core/ext/transport/chttp2/transport/huffsyms.h b/src/core/ext/transport/chttp2/transport/huffsyms.h
index 2e2a5dacae..4002706bc0 100644
--- a/src/core/ext/transport/chttp2/transport/huffsyms.h
+++ b/src/core/ext/transport/chttp2/transport/huffsyms.h
@@ -19,6 +19,10 @@
 #ifndef GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HUFFSYMS_H
 #define GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HUFFSYMS_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* HPACK static huffman table */
 
 #define GRPC_CHTTP2_NUM_HUFFSYMS 257
@@ -30,4 +34,8 @@ typedef struct {
 
 extern const grpc_chttp2_huffsym grpc_chttp2_huffsyms[GRPC_CHTTP2_NUM_HUFFSYMS];
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HUFFSYMS_H */
diff --git a/src/core/ext/transport/chttp2/transport/incoming_metadata.c b/src/core/ext/transport/chttp2/transport/incoming_metadata.cc
index ba680a89db..187ce0ea87 100644
--- a/src/core/ext/transport/chttp2/transport/incoming_metadata.c
+++ b/src/core/ext/transport/chttp2/transport/incoming_metadata.cc
@@ -29,7 +29,7 @@ void grpc_chttp2_incoming_metadata_buffer_init(
     grpc_chttp2_incoming_metadata_buffer *buffer, gpr_arena *arena) {
   buffer->arena = arena;
   grpc_metadata_batch_init(&buffer->batch);
-  buffer->batch.deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
+  buffer->batch.deadline = GRPC_MILLIS_INF_FUTURE;
 }
 
 void grpc_chttp2_incoming_metadata_buffer_destroy(
@@ -62,7 +62,7 @@ grpc_error *grpc_chttp2_incoming_metadata_buffer_replace_or_add(
 }
 
 void grpc_chttp2_incoming_metadata_buffer_set_deadline(
-    grpc_chttp2_incoming_metadata_buffer *buffer, gpr_timespec deadline) {
+    grpc_chttp2_incoming_metadata_buffer *buffer, grpc_millis deadline) {
   buffer->batch.deadline = deadline;
 }
 
diff --git a/src/core/ext/transport/chttp2/transport/incoming_metadata.h b/src/core/ext/transport/chttp2/transport/incoming_metadata.h
index a951d8764c..995e8001b1 100644
--- a/src/core/ext/transport/chttp2/transport/incoming_metadata.h
+++ b/src/core/ext/transport/chttp2/transport/incoming_metadata.h
@@ -21,6 +21,10 @@
 
 #include "src/core/lib/transport/transport.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct {
   gpr_arena *arena;
   grpc_metadata_batch batch;
@@ -43,6 +47,10 @@ grpc_error *grpc_chttp2_incoming_metadata_buffer_replace_or_add(
     grpc_exec_ctx *exec_ctx, grpc_chttp2_incoming_metadata_buffer *buffer,
     grpc_mdelem elem) GRPC_MUST_USE_RESULT;
 void grpc_chttp2_incoming_metadata_buffer_set_deadline(
-    grpc_chttp2_incoming_metadata_buffer *buffer, gpr_timespec deadline);
+    grpc_chttp2_incoming_metadata_buffer *buffer, grpc_millis deadline);
+
+#ifdef __cplusplus
+}
+#endif
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_INCOMING_METADATA_H */
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_INCOMING_METADATA_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/transport/internal.h b/src/core/ext/transport/chttp2/transport/internal.h
index 49022155aa..b51854fcf8 100644
--- a/src/core/ext/transport/chttp2/transport/internal.h
+++ b/src/core/ext/transport/chttp2/transport/internal.h
@@ -42,6 +42,10 @@
 #include "src/core/lib/transport/pid_controller.h"
 #include "src/core/lib/transport/transport_impl.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* streams are kept in various linked lists depending on what things need to
    happen to them... this enum labels each list */
 typedef enum {
@@ -62,12 +66,6 @@ typedef enum {
 } grpc_chttp2_write_state;
 
 typedef enum {
-  GRPC_CHTTP2_PING_ON_NEXT_WRITE = 0,
-  GRPC_CHTTP2_PING_BEFORE_TRANSPORT_WINDOW_UPDATE,
-  GRPC_CHTTP2_PING_TYPE_COUNT /* must be last */
-} grpc_chttp2_ping_type;
-
-typedef enum {
   GRPC_CHTTP2_OPTIMIZE_FOR_LATENCY,
   GRPC_CHTTP2_OPTIMIZE_FOR_THROUGHPUT,
 } grpc_chttp2_optimization_target;
@@ -93,7 +91,6 @@ typedef enum {
   GRPC_CHTTP2_INITIATE_WRITE_STREAM_FLOW_CONTROL,
   GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL,
   GRPC_CHTTP2_INITIATE_WRITE_SEND_SETTINGS,
-  GRPC_CHTTP2_INITIATE_WRITE_BDP_ESTIMATOR_PING,
   GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_SETTING,
   GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE,
   GRPC_CHTTP2_INITIATE_WRITE_APPLICATION_PING,
@@ -114,19 +111,19 @@ typedef struct {
 typedef struct {
   int max_pings_without_data;
   int max_ping_strikes;
-  gpr_timespec min_sent_ping_interval_without_data;
-  gpr_timespec min_recv_ping_interval_without_data;
+  grpc_millis min_sent_ping_interval_without_data;
+  grpc_millis min_recv_ping_interval_without_data;
 } grpc_chttp2_repeated_ping_policy;
 
 typedef struct {
-  gpr_timespec last_ping_sent_time;
+  grpc_millis last_ping_sent_time;
   int pings_before_data_required;
   grpc_timer delayed_ping_timer;
   bool is_delayed_ping_timer_set;
 } grpc_chttp2_repeated_ping_state;
 
 typedef struct {
-  gpr_timespec last_ping_recv_time;
+  grpc_millis last_ping_recv_time;
   int ping_strikes;
 } grpc_chttp2_server_ping_recv_state;
 
@@ -265,6 +262,8 @@ typedef struct {
    * to send WINDOW_UPDATE frames. */
   int64_t announced_window;
 
+  int32_t target_initial_window_size;
+
   /** should we probe bdp? */
   bool enable_bdp_probe;
 
@@ -272,8 +271,9 @@ typedef struct {
   grpc_bdp_estimator bdp_estimator;
 
   /* pid controller */
+  bool pid_controller_initialized;
   grpc_pid_controller pid_controller;
-  gpr_timespec last_pid_update;
+  grpc_millis last_pid_update;
 
   // pointer back to transport for tracing
   const grpc_chttp2_transport *t;
@@ -370,7 +370,7 @@ struct grpc_chttp2_transport {
   uint32_t last_new_stream_id;
 
   /** ping queues for various ping insertion points */
-  grpc_chttp2_ping_queue ping_queues[GRPC_CHTTP2_PING_TYPE_COUNT];
+  grpc_chttp2_ping_queue ping_queue;
   grpc_chttp2_repeated_ping_policy ping_policy;
   grpc_chttp2_repeated_ping_state ping_state;
   uint64_t ping_ctr; /* unique id for pings */
@@ -455,9 +455,9 @@ struct grpc_chttp2_transport {
   /** watchdog to kill the transport when waiting for the keepalive ping */
   grpc_timer keepalive_watchdog_timer;
   /** time duration in between pings */
-  gpr_timespec keepalive_time;
+  grpc_millis keepalive_time;
   /** grace period for a ping to complete before watchdog kicks in */
-  gpr_timespec keepalive_timeout;
+  grpc_millis keepalive_timeout;
   /** if keepalive pings are allowed when there's no outstanding streams */
   bool keepalive_permit_without_calls;
   /** keep-alive state machine state */
@@ -566,7 +566,7 @@ struct grpc_chttp2_stream {
   grpc_error *byte_stream_error; /* protected by t combiner */
   bool received_last_frame;      /* protected by t combiner */
 
-  gpr_timespec deadline;
+  grpc_millis deadline;
 
   /** saw some stream level error */
   grpc_error *forced_close_error;
@@ -707,7 +707,7 @@ grpc_error *grpc_chttp2_flowctl_recv_data(grpc_chttp2_transport_flowctl *tfc,
 // returns an announce if we should send a transport update to our peer,
 // else returns zero
 uint32_t grpc_chttp2_flowctl_maybe_send_transport_update(
-    grpc_chttp2_transport_flowctl *tfc);
+    grpc_chttp2_transport_flowctl *tfc, bool writing_anyway);
 
 // returns an announce if we should send a stream update to our peer, else
 // returns zero
@@ -754,10 +754,8 @@ typedef struct {
 // Reads the flow control data and returns and actionable struct that will tell
 // chttp2 exactly what it needs to do
 grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_action(
-    grpc_chttp2_transport_flowctl *tfc, grpc_chttp2_stream_flowctl *sfc);
-
-grpc_chttp2_flowctl_action grpc_chttp2_flowctl_get_bdp_action(
-    grpc_chttp2_transport_flowctl *tfc);
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_flowctl *tfc,
+    grpc_chttp2_stream_flowctl *sfc);
 
 // Takes in a flow control action and performs all the needed operations.
 void grpc_chttp2_act_on_flowctl_action(grpc_exec_ctx *exec_ctx,
@@ -908,4 +906,8 @@ void grpc_chttp2_fail_pending_writes(grpc_exec_ctx *exec_ctx,
 void grpc_chttp2_config_default_keepalive_args(grpc_channel_args *args,
                                                bool is_client);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_INTERNAL_H */
diff --git a/src/core/ext/transport/chttp2/transport/parsing.c b/src/core/ext/transport/chttp2/transport/parsing.cc
index 3db1ad4123..78886b497a 100644
--- a/src/core/ext/transport/chttp2/transport/parsing.c
+++ b/src/core/ext/transport/chttp2/transport/parsing.cc
@@ -359,8 +359,9 @@ static grpc_error *init_data_frame_parser(grpc_exec_ctx *exec_ctx,
                                       s == NULL ? NULL : &s->flow_control,
                                       t->incoming_frame_size);
   grpc_chttp2_act_on_flowctl_action(
-      exec_ctx, grpc_chttp2_flowctl_get_action(
-                    &t->flow_control, s == NULL ? NULL : &s->flow_control),
+      exec_ctx,
+      grpc_chttp2_flowctl_get_action(exec_ctx, &t->flow_control,
+                                     s == NULL ? NULL : &s->flow_control),
       t, s);
   if (err != GRPC_ERROR_NONE) {
     goto error_handler;
@@ -385,7 +386,7 @@ error_handler:
     t->parser_data = &s->data_parser;
     t->ping_state.pings_before_data_required =
         t->ping_policy.max_pings_without_data;
-    t->ping_state.last_ping_sent_time = gpr_inf_past(GPR_CLOCK_MONOTONIC);
+    t->ping_state.last_ping_sent_time = GRPC_MILLIS_INF_PAST;
     return GRPC_ERROR_NONE;
   } else if (grpc_error_get_int(err, GRPC_ERROR_INT_STREAM_ID, NULL)) {
     /* handle stream errors by closing the stream */
@@ -430,26 +431,27 @@ static void on_initial_header(grpc_exec_ctx *exec_ctx, void *tp,
   }
 
   if (grpc_slice_eq(GRPC_MDKEY(md), GRPC_MDSTR_GRPC_TIMEOUT)) {
-    gpr_timespec *cached_timeout =
-        (gpr_timespec *)grpc_mdelem_get_user_data(md, free_timeout);
-    gpr_timespec timeout;
+    grpc_millis *cached_timeout =
+        static_cast<grpc_millis *>(grpc_mdelem_get_user_data(md, free_timeout));
+    grpc_millis timeout;
     if (cached_timeout == NULL) {
       /* not already parsed: parse it now, and store the result away */
-      cached_timeout = (gpr_timespec *)gpr_malloc(sizeof(gpr_timespec));
+      cached_timeout = (grpc_millis *)gpr_malloc(sizeof(grpc_millis));
       if (!grpc_http2_decode_timeout(GRPC_MDVALUE(md), cached_timeout)) {
         char *val = grpc_slice_to_c_string(GRPC_MDVALUE(md));
         gpr_log(GPR_ERROR, "Ignoring bad timeout value '%s'", val);
         gpr_free(val);
-        *cached_timeout = gpr_inf_future(GPR_TIMESPAN);
+        *cached_timeout = GRPC_MILLIS_INF_FUTURE;
       }
       timeout = *cached_timeout;
       grpc_mdelem_set_user_data(md, free_timeout, cached_timeout);
     } else {
       timeout = *cached_timeout;
     }
-    grpc_chttp2_incoming_metadata_buffer_set_deadline(
-        &s->metadata_buffer[0],
-        gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), timeout));
+    if (timeout != GRPC_MILLIS_INF_FUTURE) {
+      grpc_chttp2_incoming_metadata_buffer_set_deadline(
+          &s->metadata_buffer[0], grpc_exec_ctx_now(exec_ctx) + timeout);
+    }
     GRPC_MDELEM_UNREF(exec_ctx, md);
   } else {
     const size_t new_size = s->metadata_buffer[0].size + GRPC_MDELEM_LENGTH(md);
@@ -564,7 +566,7 @@ static grpc_error *init_header_frame_parser(grpc_exec_ctx *exec_ctx,
 
   t->ping_state.pings_before_data_required =
       t->ping_policy.max_pings_without_data;
-  t->ping_state.last_ping_sent_time = gpr_inf_past(GPR_CLOCK_MONOTONIC);
+  t->ping_state.last_ping_sent_time = GRPC_MILLIS_INF_PAST;
 
   /* could be a new grpc_chttp2_stream or an existing grpc_chttp2_stream */
   s = grpc_chttp2_parsing_lookup_stream(t, t->incoming_stream_id);
diff --git a/src/core/ext/transport/chttp2/transport/stream_lists.c b/src/core/ext/transport/chttp2/transport/stream_lists.cc
index 47cd22d177..9f731a397f 100644
--- a/src/core/ext/transport/chttp2/transport/stream_lists.c
+++ b/src/core/ext/transport/chttp2/transport/stream_lists.cc
@@ -16,11 +16,12 @@
  *
  */
 
+#include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 #include "src/core/ext/transport/chttp2/transport/internal.h"
 
 #include <grpc/support/log.h>
 
-static char *stream_list_id_string(grpc_chttp2_stream_list_id id) {
+static const char *stream_list_id_string(grpc_chttp2_stream_list_id id) {
   switch (id) {
     case GRPC_CHTTP2_LIST_WRITABLE:
       return "writable";
diff --git a/src/core/ext/transport/chttp2/transport/stream_map.c b/src/core/ext/transport/chttp2/transport/stream_map.cc
index d6079a9a33..d6079a9a33 100644
--- a/src/core/ext/transport/chttp2/transport/stream_map.c
+++ b/src/core/ext/transport/chttp2/transport/stream_map.cc
diff --git a/src/core/ext/transport/chttp2/transport/stream_map.h b/src/core/ext/transport/chttp2/transport/stream_map.h
index 30c50ba32e..364d37c33a 100644
--- a/src/core/ext/transport/chttp2/transport/stream_map.h
+++ b/src/core/ext/transport/chttp2/transport/stream_map.h
@@ -23,6 +23,10 @@
 
 #include <stddef.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Data structure to map a uint32_t to a data object (represented by a void*)
 
    Represented as a sorted array of keys, and a corresponding array of values.
@@ -65,4 +69,8 @@ void grpc_chttp2_stream_map_for_each(grpc_chttp2_stream_map *map,
                                                void *value),
                                      void *user_data);
 
-#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_STREAM_MAP_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_STREAM_MAP_H */
\ No newline at end of file
diff --git a/src/core/ext/transport/chttp2/transport/varint.c b/src/core/ext/transport/chttp2/transport/varint.cc
index 0d94ddcbc3..0d94ddcbc3 100644
--- a/src/core/ext/transport/chttp2/transport/varint.c
+++ b/src/core/ext/transport/chttp2/transport/varint.cc
diff --git a/src/core/ext/transport/chttp2/transport/varint.h b/src/core/ext/transport/chttp2/transport/varint.h
index 5a2b670f06..d3a9d902c4 100644
--- a/src/core/ext/transport/chttp2/transport/varint.h
+++ b/src/core/ext/transport/chttp2/transport/varint.h
@@ -21,6 +21,10 @@
 
 #include <grpc/support/port_platform.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Helpers for hpack varint encoding */
 
 /* length of a value that needs varint tail encoding (it's bigger than can be
@@ -57,4 +61,8 @@ void grpc_chttp2_hpack_write_varint_tail(uint32_t tail_value, uint8_t* target,
     }                                                                         \
   } while (0)
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_VARINT_H */
diff --git a/src/core/ext/transport/chttp2/transport/writing.c b/src/core/ext/transport/chttp2/transport/writing.cc
index be1af16019..4134890f3f 100644
--- a/src/core/ext/transport/chttp2/transport/writing.c
+++ b/src/core/ext/transport/chttp2/transport/writing.cc
@@ -42,18 +42,9 @@ static void finish_write_cb(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   t->write_cb_pool = cb;
 }
 
-static void collapse_pings_from_into(grpc_chttp2_transport *t,
-                                     grpc_chttp2_ping_type ping_type,
-                                     grpc_chttp2_ping_queue *pq) {
-  for (size_t i = 0; i < GRPC_CHTTP2_PCL_COUNT; i++) {
-    grpc_closure_list_move(&t->ping_queues[ping_type].lists[i], &pq->lists[i]);
-  }
-}
-
 static void maybe_initiate_ping(grpc_exec_ctx *exec_ctx,
-                                grpc_chttp2_transport *t,
-                                grpc_chttp2_ping_type ping_type) {
-  grpc_chttp2_ping_queue *pq = &t->ping_queues[ping_type];
+                                grpc_chttp2_transport *t) {
+  grpc_chttp2_ping_queue *pq = &t->ping_queue;
   if (grpc_closure_list_empty(pq->lists[GRPC_CHTTP2_PCL_NEXT])) {
     /* no ping needed: wait */
     return;
@@ -62,7 +53,8 @@ static void maybe_initiate_ping(grpc_exec_ctx *exec_ctx,
     /* ping already in-flight: wait */
     if (GRPC_TRACER_ON(grpc_http_trace) ||
         GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
-      gpr_log(GPR_DEBUG, "Ping delayed [%p]: already pinging", t->peer_string);
+      gpr_log(GPR_DEBUG, "%s: Ping delayed [%p]: already pinging",
+              t->is_client ? "CLIENT" : "SERVER", t->peer_string);
     }
     return;
   }
@@ -71,51 +63,38 @@ static void maybe_initiate_ping(grpc_exec_ctx *exec_ctx,
     /* need to receive something of substance before sending a ping again */
     if (GRPC_TRACER_ON(grpc_http_trace) ||
         GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
-      gpr_log(GPR_DEBUG, "Ping delayed [%p]: too many recent pings: %d/%d",
-              t->peer_string, t->ping_state.pings_before_data_required,
+      gpr_log(GPR_DEBUG, "%s: Ping delayed [%p]: too many recent pings: %d/%d",
+              t->is_client ? "CLIENT" : "SERVER", t->peer_string,
+              t->ping_state.pings_before_data_required,
               t->ping_policy.max_pings_without_data);
     }
     return;
   }
-  gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
-  gpr_timespec next_allowed_ping =
-      gpr_time_add(t->ping_state.last_ping_sent_time,
-                   t->ping_policy.min_sent_ping_interval_without_data);
+  grpc_millis now = grpc_exec_ctx_now(exec_ctx);
+  grpc_millis next_allowed_ping =
+      t->ping_state.last_ping_sent_time +
+      t->ping_policy.min_sent_ping_interval_without_data;
   if (t->keepalive_permit_without_calls == 0 &&
       grpc_chttp2_stream_map_size(&t->stream_map) == 0) {
-    next_allowed_ping = gpr_time_add(t->ping_recv_state.last_ping_recv_time,
-                                     gpr_time_from_seconds(7200, GPR_TIMESPAN));
+    next_allowed_ping =
+        t->ping_recv_state.last_ping_recv_time + 7200 * GPR_MS_PER_SEC;
   }
-  /* gpr_log(GPR_DEBUG, "next_allowed_ping:%d.%09d now:%d.%09d",
-          (int)next_allowed_ping.tv_sec, (int)next_allowed_ping.tv_nsec,
-          (int)now.tv_sec, (int)now.tv_nsec); */
-  if (gpr_time_cmp(next_allowed_ping, now) > 0) {
+  if (next_allowed_ping > now) {
     /* not enough elapsed time between successive pings */
     if (GRPC_TRACER_ON(grpc_http_trace) ||
         GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
       gpr_log(GPR_DEBUG,
-              "Ping delayed [%p]: not enough time elapsed since last ping",
-              t->peer_string);
+              "%s: Ping delayed [%p]: not enough time elapsed since last ping",
+              t->is_client ? "CLIENT" : "SERVER", t->peer_string);
     }
     if (!t->ping_state.is_delayed_ping_timer_set) {
       t->ping_state.is_delayed_ping_timer_set = true;
       grpc_timer_init(exec_ctx, &t->ping_state.delayed_ping_timer,
-                      next_allowed_ping, &t->retry_initiate_ping_locked,
-                      gpr_now(GPR_CLOCK_MONOTONIC));
+                      next_allowed_ping, &t->retry_initiate_ping_locked);
     }
     return;
   }
-  /* coalesce equivalent pings into this one */
-  switch (ping_type) {
-    case GRPC_CHTTP2_PING_BEFORE_TRANSPORT_WINDOW_UPDATE:
-      collapse_pings_from_into(t, GRPC_CHTTP2_PING_ON_NEXT_WRITE, pq);
-      break;
-    case GRPC_CHTTP2_PING_ON_NEXT_WRITE:
-      break;
-    case GRPC_CHTTP2_PING_TYPE_COUNT:
-      GPR_UNREACHABLE_CODE(break);
-  }
-  pq->inflight_id = t->ping_ctr * GRPC_CHTTP2_PING_TYPE_COUNT + ping_type;
+  pq->inflight_id = t->ping_ctr;
   t->ping_ctr++;
   GRPC_CLOSURE_LIST_SCHED(exec_ctx, &pq->lists[GRPC_CHTTP2_PCL_INITIATE]);
   grpc_closure_list_move(&pq->lists[GRPC_CHTTP2_PCL_NEXT],
@@ -126,7 +105,8 @@ static void maybe_initiate_ping(grpc_exec_ctx *exec_ctx,
   t->ping_state.last_ping_sent_time = now;
   if (GRPC_TRACER_ON(grpc_http_trace) ||
       GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
-    gpr_log(GPR_DEBUG, "Ping sent [%p]: %d/%d", t->peer_string,
+    gpr_log(GPR_DEBUG, "%s: Ping sent [%p]: %d/%d",
+            t->is_client ? "CLIENT" : "SERVER", t->peer_string,
             t->ping_state.pings_before_data_required,
             t->ping_policy.max_pings_without_data);
   }
@@ -156,6 +136,25 @@ static bool update_list(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   return sched_any;
 }
 
+static void report_stall(grpc_chttp2_transport *t, grpc_chttp2_stream *s,
+                         const char *staller) {
+  gpr_log(
+      GPR_DEBUG,
+      "%s:%p stream %d stalled by %s [fc:pending=%" PRIdPTR ":flowed=%" PRId64
+      ":peer_initwin=%d:t_win=%" PRId64 ":s_win=%d:s_delta=%" PRId64 "]",
+      t->peer_string, t, s->id, staller, s->flow_controlled_buffer.length,
+      s->flow_controlled_bytes_flowed,
+      t->settings[GRPC_ACKED_SETTINGS]
+                 [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE],
+      t->flow_control.remote_window,
+      (uint32_t)GPR_MAX(
+          0,
+          s->flow_control.remote_window_delta +
+              (int64_t)t->settings[GRPC_PEER_SETTINGS]
+                                  [GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE]),
+      s->flow_control.remote_window_delta);
+}
+
 static bool stream_ref_if_not_destroyed(gpr_refcount *r) {
   gpr_atm count;
   do {
@@ -202,6 +201,12 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
     GRPC_STATS_INC_HTTP2_SETTINGS_WRITES(exec_ctx);
   }
 
+  for (size_t i = 0; i < t->ping_ack_count; i++) {
+    grpc_slice_buffer_add(&t->outbuf,
+                          grpc_chttp2_ping_create(1, t->ping_acks[i]));
+  }
+  t->ping_ack_count = 0;
+
   /* simple writes are queued to qbuf, and flushed here */
   grpc_slice_buffer_move_into(&t->qbuf, &t->outbuf);
   GPR_ASSERT(t->qbuf.count == 0);
@@ -257,21 +262,20 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
           s->send_trailing_metadata == NULL ||
           !is_default_initial_metadata(s->send_initial_metadata)) {
         grpc_encode_header_options hopt = {
-            .stream_id = s->id,
-            .is_eof = false,
-            .use_true_binary_metadata =
-                t->settings
-                    [GRPC_PEER_SETTINGS]
-                    [GRPC_CHTTP2_SETTINGS_GRPC_ALLOW_TRUE_BINARY_METADATA] != 0,
-            .max_frame_size = t->settings[GRPC_PEER_SETTINGS]
-                                         [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE],
-            .stats = &s->stats.outgoing};
+            s->id,  // stream_id
+            false,  // is_eof
+            t->settings[GRPC_PEER_SETTINGS]
+                       [GRPC_CHTTP2_SETTINGS_GRPC_ALLOW_TRUE_BINARY_METADATA] !=
+                0,  // use_true_binary_metadata
+            t->settings[GRPC_PEER_SETTINGS]
+                       [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE],  // max_frame_size
+            &s->stats.outgoing                                 // stats
+        };
         grpc_chttp2_encode_header(exec_ctx, &t->hpack_compressor, NULL, 0,
                                   s->send_initial_metadata, &hopt, &t->outbuf);
         now_writing = true;
         if (!t->is_client) {
-          t->ping_recv_state.last_ping_recv_time =
-              gpr_inf_past(GPR_CLOCK_MONOTONIC);
+          t->ping_recv_state.last_ping_recv_time = GRPC_MILLIS_INF_PAST;
           t->ping_recv_state.ping_strikes = 0;
         }
         initial_metadata_writes++;
@@ -300,6 +304,7 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
           exec_ctx, t, s, &s->send_initial_metadata_finished, GRPC_ERROR_NONE,
           "send_initial_metadata_finished");
     }
+
     /* send any window updates */
     uint32_t stream_announce = grpc_chttp2_flowctl_maybe_send_stream_update(
         &t->flow_control, &s->flow_control);
@@ -308,8 +313,7 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
           &t->outbuf, grpc_chttp2_window_update_create(s->id, stream_announce,
                                                        &s->stats.outgoing));
       if (!t->is_client) {
-        t->ping_recv_state.last_ping_recv_time =
-            gpr_inf_past(GPR_CLOCK_MONOTONIC);
+        t->ping_recv_state.last_ping_recv_time = GRPC_MILLIS_INF_PAST;
         t->ping_recv_state.ping_strikes = 0;
       }
       flow_control_writes++;
@@ -386,8 +390,7 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
             }
           }
           if (!t->is_client) {
-            t->ping_recv_state.last_ping_recv_time =
-                gpr_inf_past(GPR_CLOCK_MONOTONIC);
+            t->ping_recv_state.last_ping_recv_time = 0;
             t->ping_recv_state.ping_strikes = 0;
           }
           if (is_last_frame) {
@@ -414,9 +417,11 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
           }
           message_writes++;
         } else if (t->flow_control.remote_window == 0) {
+          report_stall(t, s, "transport");
           grpc_chttp2_list_add_stalled_by_transport(t, s);
           now_writing = true;
         } else if (stream_remote_window == 0) {
+          report_stall(t, s, "stream");
           grpc_chttp2_list_add_stalled_by_stream(t, s);
           now_writing = true;
         }
@@ -431,17 +436,16 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
                                   &s->stats.outgoing, &t->outbuf);
         } else {
           grpc_encode_header_options hopt = {
-              .stream_id = s->id,
-              .is_eof = true,
-              .use_true_binary_metadata =
-                  t->settings
+              s->id, true,
+
+              t->settings
                       [GRPC_PEER_SETTINGS]
                       [GRPC_CHTTP2_SETTINGS_GRPC_ALLOW_TRUE_BINARY_METADATA] !=
                   0,
-              .max_frame_size =
-                  t->settings[GRPC_PEER_SETTINGS]
-                             [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE],
-              .stats = &s->stats.outgoing};
+
+              t->settings[GRPC_PEER_SETTINGS]
+                         [GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE],
+              &s->stats.outgoing};
           grpc_chttp2_encode_header(exec_ctx, &t->hpack_compressor,
                                     extra_headers_for_trailing_metadata,
                                     num_extra_headers_for_trailing_metadata,
@@ -451,6 +455,10 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
         }
         s->send_trailing_metadata = NULL;
         s->sent_trailing_metadata = true;
+        if (!t->is_client) {
+          t->ping_recv_state.last_ping_recv_time = GRPC_MILLIS_INF_PAST;
+          t->ping_recv_state.ping_strikes = 0;
+        }
         if (!t->is_client && !s->read_closed) {
           grpc_slice_buffer_add(
               &t->outbuf, grpc_chttp2_rst_stream_create(
@@ -484,30 +492,21 @@ grpc_chttp2_begin_write_result grpc_chttp2_begin_write(
     }
   }
 
-  uint32_t transport_announce =
-      grpc_chttp2_flowctl_maybe_send_transport_update(&t->flow_control);
+  maybe_initiate_ping(exec_ctx, t);
+
+  uint32_t transport_announce = grpc_chttp2_flowctl_maybe_send_transport_update(
+      &t->flow_control, t->outbuf.count > 0);
   if (transport_announce) {
-    maybe_initiate_ping(exec_ctx, t,
-                        GRPC_CHTTP2_PING_BEFORE_TRANSPORT_WINDOW_UPDATE);
     grpc_transport_one_way_stats throwaway_stats;
     grpc_slice_buffer_add(
         &t->outbuf, grpc_chttp2_window_update_create(0, transport_announce,
                                                      &throwaway_stats));
     if (!t->is_client) {
-      t->ping_recv_state.last_ping_recv_time =
-          gpr_inf_past(GPR_CLOCK_MONOTONIC);
+      t->ping_recv_state.last_ping_recv_time = GRPC_MILLIS_INF_PAST;
       t->ping_recv_state.ping_strikes = 0;
     }
   }
 
-  for (size_t i = 0; i < t->ping_ack_count; i++) {
-    grpc_slice_buffer_add(&t->outbuf,
-                          grpc_chttp2_ping_create(1, t->ping_acks[i]));
-  }
-  t->ping_ack_count = 0;
-
-  maybe_initiate_ping(exec_ctx, t, GRPC_CHTTP2_PING_ON_NEXT_WRITE);
-
   GPR_TIMER_END("grpc_chttp2_begin_write", 0);
 
   result.writing = t->outbuf.count > 0;
diff --git a/src/core/ext/transport/cronet/client/secure/cronet_channel_create.c b/src/core/ext/transport/cronet/client/secure/cronet_channel_create.cc
index 83365192e3..b280487ca3 100644
--- a/src/core/ext/transport/cronet/client/secure/cronet_channel_create.c
+++ b/src/core/ext/transport/cronet/client/secure/cronet_channel_create.cc
@@ -21,6 +21,8 @@
 #include <stdio.h>
 #include <string.h>
 
+#include <grpc/grpc_cronet.h>
+
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
diff --git a/src/core/ext/transport/cronet/transport/cronet_api_dummy.c b/src/core/ext/transport/cronet/transport/cronet_api_dummy.cc
index 4f248ad919..4f248ad919 100644
--- a/src/core/ext/transport/cronet/transport/cronet_api_dummy.c
+++ b/src/core/ext/transport/cronet/transport/cronet_api_dummy.cc
diff --git a/src/core/ext/transport/cronet/transport/cronet_transport.c b/src/core/ext/transport/cronet/transport/cronet_transport.cc
index 587a3b83b5..ff1367fb28 100644
--- a/src/core/ext/transport/cronet/transport/cronet_transport.c
+++ b/src/core/ext/transport/cronet/transport/cronet_transport.cc
@@ -27,6 +27,7 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/ext/transport/chttp2/transport/incoming_metadata.h"
+#include "src/core/ext/transport/cronet/transport/cronet_transport.h"
 #include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/slice/slice_internal.h"
@@ -288,7 +289,7 @@ static void maybe_flush_read(stream_obj *s) {
       CRONET_LOG(GPR_DEBUG, "%p: Flush read", s);
       s->state.flush_read = true;
       null_and_maybe_free_read_buffer(s);
-      s->state.rs.read_buffer = gpr_malloc(GRPC_FLUSH_READ_SIZE);
+      s->state.rs.read_buffer = (char *)gpr_malloc(GRPC_FLUSH_READ_SIZE);
       if (!s->state.pending_read_from_cronet) {
         CRONET_LOG(GPR_DEBUG, "bidirectional_stream_read(%p)", s->cbs);
         bidirectional_stream_read(s->cbs, s->state.rs.read_buffer,
@@ -313,7 +314,8 @@ static void add_to_storage(struct stream_obj *s,
   struct op_storage *storage = &s->storage;
   /* add new op at the beginning of the linked list. The memory is freed
   in remove_from_storage */
-  struct op_and_state *new_op = gpr_malloc(sizeof(struct op_and_state));
+  struct op_and_state *new_op =
+      (struct op_and_state *)gpr_malloc(sizeof(struct op_and_state));
   memcpy(&new_op->op, op, sizeof(grpc_transport_stream_op_batch));
   memset(&new_op->state, 0, sizeof(new_op->state));
   new_op->s = s;
@@ -685,7 +687,7 @@ static void create_grpc_frame(grpc_exec_ctx *exec_ctx,
   size_t length = GRPC_SLICE_LENGTH(slice);
   *p_write_buffer_size = length + GRPC_HEADER_SIZE_IN_BYTES;
   /* This is freed in the on_write_completed callback */
-  char *write_buffer = gpr_malloc(length + GRPC_HEADER_SIZE_IN_BYTES);
+  char *write_buffer = (char *)gpr_malloc(length + GRPC_HEADER_SIZE_IN_BYTES);
   *pp_write_buffer = write_buffer;
   uint8_t *p = (uint8_t *)write_buffer;
   /* Append 5 byte header */
@@ -1182,7 +1184,7 @@ static enum e_op_result execute_stream_op(grpc_exec_ctx *exec_ctx,
                    stream_state->rs.length_field);
         if (stream_state->rs.length_field > 0) {
           stream_state->rs.read_buffer =
-              gpr_malloc((size_t)stream_state->rs.length_field);
+              (char *)gpr_malloc((size_t)stream_state->rs.length_field);
           GPR_ASSERT(stream_state->rs.read_buffer);
           stream_state->rs.remaining_bytes = stream_state->rs.length_field;
           stream_state->rs.received_bytes = 0;
@@ -1452,13 +1454,14 @@ static const grpc_transport_vtable grpc_cronet_vtable = {
 grpc_transport *grpc_create_cronet_transport(void *engine, const char *target,
                                              const grpc_channel_args *args,
                                              void *reserved) {
-  grpc_cronet_transport *ct = gpr_malloc(sizeof(grpc_cronet_transport));
+  grpc_cronet_transport *ct =
+      (grpc_cronet_transport *)gpr_malloc(sizeof(grpc_cronet_transport));
   if (!ct) {
     goto error;
   }
   ct->base.vtable = &grpc_cronet_vtable;
-  ct->engine = engine;
-  ct->host = gpr_malloc(strlen(target) + 1);
+  ct->engine = (stream_engine *)engine;
+  ct->host = (char *)gpr_malloc(strlen(target) + 1);
   if (!ct->host) {
     goto error;
   }
diff --git a/src/core/ext/transport/cronet/transport/cronet_transport.h b/src/core/ext/transport/cronet/transport/cronet_transport.h
index 3bd4249b79..43ff391f79 100644
--- a/src/core/ext/transport/cronet/transport/cronet_transport.h
+++ b/src/core/ext/transport/cronet/transport/cronet_transport.h
@@ -21,8 +21,16 @@
 
 #include "src/core/lib/transport/transport.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 grpc_transport *grpc_create_cronet_transport(void *engine, const char *target,
                                              const grpc_channel_args *args,
                                              void *reserved);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* GRPC_CORE_EXT_TRANSPORT_CRONET_TRANSPORT_CRONET_TRANSPORT_H */
diff --git a/src/core/ext/transport/inproc/inproc_plugin.c b/src/core/ext/transport/inproc/inproc_plugin.cc
index 6a796a0b19..5d8a1c74ab 100644
--- a/src/core/ext/transport/inproc/inproc_plugin.c
+++ b/src/core/ext/transport/inproc/inproc_plugin.cc
@@ -21,9 +21,11 @@
 
 grpc_tracer_flag grpc_inproc_trace = GRPC_TRACER_INITIALIZER(false, "inproc");
 
-void grpc_inproc_plugin_init(void) {
+extern "C" void grpc_inproc_plugin_init(void) {
   grpc_register_tracer(&grpc_inproc_trace);
   grpc_inproc_transport_init();
 }
 
-void grpc_inproc_plugin_shutdown(void) { grpc_inproc_transport_shutdown(); }
+extern "C" void grpc_inproc_plugin_shutdown(void) {
+  grpc_inproc_transport_shutdown();
+}
diff --git a/src/core/ext/transport/inproc/inproc_transport.c b/src/core/ext/transport/inproc/inproc_transport.cc
index 31739d07dd..1001d74c22 100644
--- a/src/core/ext/transport/inproc/inproc_transport.c
+++ b/src/core/ext/transport/inproc/inproc_transport.cc
@@ -150,7 +150,7 @@ typedef struct inproc_stream {
   grpc_metadata_batch write_buffer_initial_md;
   bool write_buffer_initial_md_filled;
   uint32_t write_buffer_initial_md_flags;
-  gpr_timespec write_buffer_deadline;
+  grpc_millis write_buffer_deadline;
   slice_buffer_list write_buffer_message;
   grpc_metadata_batch write_buffer_trailing_md;
   bool write_buffer_trailing_md_filled;
@@ -180,7 +180,7 @@ typedef struct inproc_stream {
   grpc_error *cancel_self_error;
   grpc_error *cancel_other_error;
 
-  gpr_timespec deadline;
+  grpc_millis deadline;
 
   bool listed;
   struct inproc_stream *stream_list_prev;
@@ -377,8 +377,8 @@ static int init_stream(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
   s->cancel_self_error = GRPC_ERROR_NONE;
   s->cancel_other_error = GRPC_ERROR_NONE;
   s->write_buffer_cancel_error = GRPC_ERROR_NONE;
-  s->deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
-  s->write_buffer_deadline = gpr_inf_future(GPR_CLOCK_MONOTONIC);
+  s->deadline = GRPC_MILLIS_INF_FUTURE;
+  s->write_buffer_deadline = GRPC_MILLIS_INF_FUTURE;
 
   s->stream_list_prev = NULL;
   gpr_mu_lock(&t->mu->mu);
@@ -421,7 +421,7 @@ static int init_stream(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
                        cs->write_buffer_initial_md_flags,
                        &s->to_read_initial_md, &s->to_read_initial_md_flags,
                        &s->to_read_initial_md_filled);
-      s->deadline = gpr_time_min(s->deadline, cs->write_buffer_deadline);
+      s->deadline = GPR_MIN(s->deadline, cs->write_buffer_deadline);
       grpc_metadata_batch_clear(exec_ctx, &cs->write_buffer_initial_md);
       cs->write_buffer_initial_md_filled = false;
     }
@@ -956,10 +956,10 @@ static void perform_stream_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
               dest, destflags, destfilled);
         }
         if (s->t->is_client) {
-          gpr_timespec *dl =
+          grpc_millis *dl =
               (other == NULL) ? &s->write_buffer_deadline : &other->deadline;
-          *dl = gpr_time_min(*dl, op->payload->send_initial_metadata
-                                      .send_initial_metadata->deadline);
+          *dl = GPR_MIN(*dl, op->payload->send_initial_metadata
+                                 .send_initial_metadata->deadline);
           s->initial_md_sent = true;
         }
       }