Merge remote-tracking branch 'upstream/master' into handshake_api

7 files changed, 388 insertions, 102 deletions

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.c
index f071e31cb3..4554c33c8c 100644
--- a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
+++ b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
@@ -98,11 +98,13 @@ static void on_secure_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
                                      grpc_auth_context *auth_context) {
   connector *c = arg;
   gpr_mu_lock(&c->mu);
+  grpc_error *error = GRPC_ERROR_NONE;
   if (c->connecting_endpoint == NULL) {
     memset(c->result, 0, sizeof(*c->result));
     gpr_mu_unlock(&c->mu);
   } else if (status != GRPC_SECURITY_OK) {
-    gpr_log(GPR_ERROR, "Secure handshake failed with error %d.", status);
+    error = grpc_error_set_int(GRPC_ERROR_CREATE("Secure handshake failed"),
+                               GRPC_ERROR_INT_SECURITY_STATUS, status);
     memset(c->result, 0, sizeof(*c->result));
     c->connecting_endpoint = NULL;
     gpr_mu_unlock(&c->mu);
@@ -120,7 +122,7 @@ static void on_secure_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
   }
   grpc_closure *notify = c->notify;
   c->notify = NULL;
-  grpc_exec_ctx_sched(exec_ctx, notify, GRPC_ERROR_NONE, NULL);
+  grpc_exec_ctx_sched(exec_ctx, notify, error, NULL);
 }
 
 static void on_handshake_done(grpc_exec_ctx *exec_ctx, grpc_endpoint *endpoint,
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_plugin.c b/src/core/ext/transport/chttp2/transport/chttp2_plugin.c
index bd87253ed3..7d5279b9da 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_plugin.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_plugin.c
@@ -36,11 +36,14 @@
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/transport/metadata.h"
 
+extern int grpc_http_write_state_trace;
+
 void grpc_chttp2_plugin_init(void) {
   grpc_chttp2_base64_encode_and_huffman_compress =
       grpc_chttp2_base64_encode_and_huffman_compress_impl;
   grpc_register_tracer("http", &grpc_http_trace);
   grpc_register_tracer("flowctl", &grpc_flowctl_trace);
+  grpc_register_tracer("http_write_state", &grpc_http_write_state_trace);
 }
 
 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.c
index 5aae753c07..be8a8f8498 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -48,6 +48,7 @@
 #include "src/core/ext/transport/chttp2/transport/status_conversion.h"
 #include "src/core/ext/transport/chttp2/transport/timeout_encoding.h"
 #include "src/core/lib/http/parser.h"
+#include "src/core/lib/iomgr/workqueue.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/transport/static_metadata.h"
@@ -60,9 +61,9 @@
 #define DEFAULT_MAX_HEADER_LIST_SIZE (16 * 1024)
 
 #define MAX_CLIENT_STREAM_ID 0x7fffffffu
-
 int grpc_http_trace = 0;
 int grpc_flowctl_trace = 0;
+int grpc_http_write_state_trace = 0;
 
 #define TRANSPORT_FROM_WRITING(tw)                                        \
   ((grpc_chttp2_transport *)((char *)(tw)-offsetof(grpc_chttp2_transport, \
@@ -88,10 +89,16 @@ static const grpc_transport_vtable vtable;
 static void writing_action(grpc_exec_ctx *exec_ctx, void *t, grpc_error *error);
 static void reading_action(grpc_exec_ctx *exec_ctx, void *t, grpc_error *error);
 static void parsing_action(grpc_exec_ctx *exec_ctx, void *t, grpc_error *error);
+static void initiate_writing(grpc_exec_ctx *exec_ctx, void *t,
+                             grpc_error *error);
+
+static void start_writing(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t);
+static void end_waiting_for_write(grpc_exec_ctx *exec_ctx,
+                                  grpc_chttp2_transport *t, grpc_error *error);
 
 /** Set a transport level setting, and push it to our peer */
-static void push_setting(grpc_chttp2_transport *t, grpc_chttp2_setting_id id,
-                         uint32_t value);
+static void push_setting(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                         grpc_chttp2_setting_id id, uint32_t value);
 
 /** Start disconnection chain */
 static void drop_connection(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
@@ -137,7 +144,7 @@ static void check_read_ops(grpc_exec_ctx *exec_ctx,
                            grpc_chttp2_transport_global *transport_global);
 
 static void incoming_byte_stream_update_flow_control(
-    grpc_chttp2_transport_global *transport_global,
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
     grpc_chttp2_stream_global *stream_global, size_t max_size_hint,
     size_t have_already);
 static void incoming_byte_stream_destroy_locked(grpc_exec_ctx *exec_ctx,
@@ -201,6 +208,7 @@ static void destruct_transport(grpc_exec_ctx *exec_ctx,
   gpr_free(t);
 }
 
+/*#define REFCOUNTING_DEBUG 1*/
 #ifdef REFCOUNTING_DEBUG
 #define REF_TRANSPORT(t, r) ref_transport(t, r, __FILE__, __LINE__)
 #define UNREF_TRANSPORT(cl, t, r) unref_transport(cl, t, r, __FILE__, __LINE__)
@@ -231,7 +239,7 @@ static void ref_transport(grpc_chttp2_transport *t) { gpr_ref(&t->refs); }
 
 static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                            const grpc_channel_args *channel_args,
-                           grpc_endpoint *ep, uint8_t is_client) {
+                           grpc_endpoint *ep, bool is_client) {
   size_t i;
   int j;
 
@@ -273,6 +281,7 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   grpc_closure_init(&t->writing_action, writing_action, t);
   grpc_closure_init(&t->reading_action, reading_action, t);
   grpc_closure_init(&t->parsing_action, parsing_action, t);
+  grpc_closure_init(&t->initiate_writing, initiate_writing, t);
 
   gpr_slice_buffer_init(&t->parsing.qbuf);
   grpc_chttp2_goaway_parser_init(&t->parsing.goaway_parser);
@@ -286,6 +295,7 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
     gpr_slice_buffer_add(
         &t->global.qbuf,
         gpr_slice_from_copied_string(GRPC_CHTTP2_CLIENT_CONNECT_STRING));
+    grpc_chttp2_initiate_write(exec_ctx, &t->global, false, "initial_write");
   }
   /* 8 is a random stab in the dark as to a good initial size: it's small enough
      that it shouldn't waste memory for infrequently used connections, yet
@@ -311,11 +321,12 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
 
   /* configure http2 the way we like it */
   if (is_client) {
-    push_setting(t, GRPC_CHTTP2_SETTINGS_ENABLE_PUSH, 0);
-    push_setting(t, GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS, 0);
+    push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_ENABLE_PUSH, 0);
+    push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS, 0);
   }
-  push_setting(t, GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE, DEFAULT_WINDOW);
-  push_setting(t, GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE,
+  push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE,
+               DEFAULT_WINDOW);
+  push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE,
                DEFAULT_MAX_HEADER_LIST_SIZE);
 
   if (channel_args) {
@@ -329,7 +340,7 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
           gpr_log(GPR_ERROR, "%s: must be an integer",
                   GRPC_ARG_MAX_CONCURRENT_STREAMS);
         } else {
-          push_setting(t, GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS,
+          push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS,
                        (uint32_t)channel_args->args[i].value.integer);
         }
       } else if (0 == strcmp(channel_args->args[i].key,
@@ -368,7 +379,7 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
           gpr_log(GPR_ERROR, "%s: must be non-negative",
                   GRPC_ARG_HTTP2_HPACK_TABLE_SIZE_DECODER);
         } else {
-          push_setting(t, GRPC_CHTTP2_SETTINGS_HEADER_TABLE_SIZE,
+          push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_HEADER_TABLE_SIZE,
                        (uint32_t)channel_args->args[i].value.integer);
         }
       } else if (0 == strcmp(channel_args->args[i].key,
@@ -393,7 +404,7 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
           gpr_log(GPR_ERROR, "%s: must be non-negative",
                   GRPC_ARG_MAX_METADATA_SIZE);
         } else {
-          push_setting(t, GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE,
+          push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE,
                        (uint32_t)channel_args->args[i].value.integer);
         }
       }
@@ -444,6 +455,9 @@ static void close_transport_locked(grpc_exec_ctx *exec_ctx,
                                    grpc_chttp2_transport *t,
                                    grpc_error *error) {
   if (!t->closed) {
+    if (grpc_http_write_state_trace) {
+      gpr_log(GPR_DEBUG, "W:%p close transport", t);
+    }
     t->closed = 1;
     connectivity_state_set(exec_ctx, &t->global, GRPC_CHANNEL_SHUTDOWN,
                            GRPC_ERROR_REF(error), "close_transport");
@@ -590,7 +604,8 @@ static void destroy_stream_locked(grpc_exec_ctx *exec_ctx,
   grpc_chttp2_incoming_metadata_buffer_destroy(
       &s->global.received_trailing_metadata);
   gpr_slice_buffer_destroy(&s->writing.flow_controlled_buffer);
-  GRPC_ERROR_UNREF(s->global.removal_error);
+  GRPC_ERROR_UNREF(s->global.read_closed_error);
+  GRPC_ERROR_UNREF(s->global.write_closed_error);
 
   UNREF_TRANSPORT(exec_ctx, t, "stream");
 
@@ -634,6 +649,36 @@ grpc_chttp2_stream_parsing *grpc_chttp2_parsing_accept_stream(
  * LOCK MANAGEMENT
  */
 
+static const char *write_state_name(grpc_chttp2_write_state state) {
+  switch (state) {
+    case GRPC_CHTTP2_WRITING_INACTIVE:
+      return "INACTIVE";
+    case GRPC_CHTTP2_WRITE_REQUESTED_NO_POLLER:
+      return "REQUESTED[p=0]";
+    case GRPC_CHTTP2_WRITE_REQUESTED_WITH_POLLER:
+      return "REQUESTED[p=1]";
+    case GRPC_CHTTP2_WRITE_SCHEDULED:
+      return "SCHEDULED";
+    case GRPC_CHTTP2_WRITING:
+      return "WRITING";
+    case GRPC_CHTTP2_WRITING_STALE_WITH_POLLER:
+      return "WRITING[p=1]";
+    case GRPC_CHTTP2_WRITING_STALE_NO_POLLER:
+      return "WRITING[p=0]";
+  }
+  GPR_UNREACHABLE_CODE(return "UNKNOWN");
+}
+
+static void set_write_state(grpc_chttp2_transport *t,
+                            grpc_chttp2_write_state state, const char *reason) {
+  if (grpc_http_write_state_trace) {
+    gpr_log(GPR_DEBUG, "W:%p %s -> %s because %s", t,
+            write_state_name(t->executor.write_state), write_state_name(state),
+            reason);
+  }
+  t->executor.write_state = state;
+}
+
 static void finish_global_actions(grpc_exec_ctx *exec_ctx,
                                   grpc_chttp2_transport *t) {
   grpc_chttp2_executor_action_header *hdr;
@@ -642,13 +687,6 @@ static void finish_global_actions(grpc_exec_ctx *exec_ctx,
   GPR_TIMER_BEGIN("finish_global_actions", 0);
 
   for (;;) {
-    if (!t->executor.writing_active && !t->closed &&
-        grpc_chttp2_unlocking_check_writes(exec_ctx, &t->global, &t->writing)) {
-      t->executor.writing_active = 1;
-      REF_TRANSPORT(t, "writing");
-      prevent_endpoint_shutdown(t);
-      grpc_exec_ctx_sched(exec_ctx, &t->writing_action, GRPC_ERROR_NONE, NULL);
-    }
     check_read_ops(exec_ctx, &t->global);
 
     gpr_mu_lock(&t->executor.mu);
@@ -669,8 +707,28 @@ static void finish_global_actions(grpc_exec_ctx *exec_ctx,
       continue;
     } else {
       t->executor.global_active = false;
+      switch (t->executor.write_state) {
+        case GRPC_CHTTP2_WRITE_REQUESTED_WITH_POLLER:
+          set_write_state(t, GRPC_CHTTP2_WRITE_SCHEDULED, "unlocking");
+          REF_TRANSPORT(t, "initiate_writing");
+          gpr_mu_unlock(&t->executor.mu);
+          grpc_exec_ctx_sched(
+              exec_ctx, &t->initiate_writing, GRPC_ERROR_NONE,
+              t->ep != NULL ? grpc_endpoint_get_workqueue(t->ep) : NULL);
+          break;
+        case GRPC_CHTTP2_WRITE_REQUESTED_NO_POLLER:
+          start_writing(exec_ctx, t);
+          gpr_mu_unlock(&t->executor.mu);
+          break;
+        case GRPC_CHTTP2_WRITING_INACTIVE:
+        case GRPC_CHTTP2_WRITING:
+        case GRPC_CHTTP2_WRITING_STALE_WITH_POLLER:
+        case GRPC_CHTTP2_WRITING_STALE_NO_POLLER:
+        case GRPC_CHTTP2_WRITE_SCHEDULED:
+          gpr_mu_unlock(&t->executor.mu);
+          break;
+      }
     }
-    gpr_mu_unlock(&t->executor.mu);
     break;
   }
 
@@ -741,16 +799,118 @@ void grpc_chttp2_run_with_global_lock(grpc_exec_ctx *exec_ctx,
  * OUTPUT PROCESSING
  */
 
-void grpc_chttp2_become_writable(grpc_chttp2_transport_global *transport_global,
-                                 grpc_chttp2_stream_global *stream_global) {
+void grpc_chttp2_initiate_write(grpc_exec_ctx *exec_ctx,
+                                grpc_chttp2_transport_global *transport_global,
+                                bool covered_by_poller, const char *reason) {
+  /* Perform state checks, and transition to a scheduled state if appropriate.
+     Each time we finish the global lock execution, we check if we need to
+     write. If we do:
+      - (if there is a poller surrounding the write) schedule
+        initiate_writing, which locks and calls initiate_writing_locked to...
+      - call start_writing, which verifies (under the global lock) that there
+        are things that need to be written by calling
+        grpc_chttp2_unlocking_check_writes, and if so schedules writing_action
+        against the current exec_ctx, to be executed OUTSIDE of the global lock
+      - eventually writing_action results in grpc_chttp2_terminate_writing being
+        called, which re-takes the global lock, updates state, checks if we need
+        to do *another* write immediately, and if so loops back to
+        start_writing.
+
+      Current problems:
+       - too much lock entry/exiting
+       - the writing thread can become stuck indefinitely (punt through the
+         workqueue periodically to fix) */
+
+  grpc_chttp2_transport *t = TRANSPORT_FROM_GLOBAL(transport_global);
+  switch (t->executor.write_state) {
+    case GRPC_CHTTP2_WRITING_INACTIVE:
+      set_write_state(t, covered_by_poller
+                             ? GRPC_CHTTP2_WRITE_REQUESTED_WITH_POLLER
+                             : GRPC_CHTTP2_WRITE_REQUESTED_NO_POLLER,
+                      reason);
+      break;
+    case GRPC_CHTTP2_WRITE_REQUESTED_WITH_POLLER:
+      /* nothing to do: write already requested */
+      break;
+    case GRPC_CHTTP2_WRITE_REQUESTED_NO_POLLER:
+      if (covered_by_poller) {
+        /* upgrade to note poller is available to cover the write */
+        set_write_state(t, GRPC_CHTTP2_WRITE_REQUESTED_WITH_POLLER, reason);
+      }
+      break;
+    case GRPC_CHTTP2_WRITE_SCHEDULED:
+      /* nothing to do: write already scheduled */
+      break;
+    case GRPC_CHTTP2_WRITING:
+      set_write_state(t,
+                      covered_by_poller ? GRPC_CHTTP2_WRITING_STALE_WITH_POLLER
+                                        : GRPC_CHTTP2_WRITING_STALE_NO_POLLER,
+                      reason);
+      break;
+    case GRPC_CHTTP2_WRITING_STALE_WITH_POLLER:
+      /* nothing to do: write already requested */
+      break;
+    case GRPC_CHTTP2_WRITING_STALE_NO_POLLER:
+      if (covered_by_poller) {
+        /* upgrade to note poller is available to cover the write */
+        set_write_state(t, GRPC_CHTTP2_WRITING_STALE_WITH_POLLER, reason);
+      }
+      break;
+  }
+}
+
+static void start_writing(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t) {
+  GPR_ASSERT(t->executor.write_state == GRPC_CHTTP2_WRITE_SCHEDULED ||
+             t->executor.write_state == GRPC_CHTTP2_WRITE_REQUESTED_NO_POLLER);
+  if (!t->closed &&
+      grpc_chttp2_unlocking_check_writes(exec_ctx, &t->global, &t->writing)) {
+    set_write_state(t, GRPC_CHTTP2_WRITING, "start_writing");
+    REF_TRANSPORT(t, "writing");
+    prevent_endpoint_shutdown(t);
+    grpc_exec_ctx_sched(exec_ctx, &t->writing_action, GRPC_ERROR_NONE, NULL);
+  } else {
+    if (t->closed) {
+      set_write_state(t, GRPC_CHTTP2_WRITING_INACTIVE,
+                      "start_writing:transport_closed");
+    } else {
+      set_write_state(t, GRPC_CHTTP2_WRITING_INACTIVE,
+                      "start_writing:nothing_to_write");
+    }
+    end_waiting_for_write(exec_ctx, t, GRPC_ERROR_CREATE("Nothing to write"));
+    if (t->ep && !t->endpoint_reading) {
+      destroy_endpoint(exec_ctx, t);
+    }
+  }
+}
+
+static void initiate_writing_locked(grpc_exec_ctx *exec_ctx,
+                                    grpc_chttp2_transport *t,
+                                    grpc_chttp2_stream *s_unused,
+                                    void *arg_ignored) {
+  start_writing(exec_ctx, t);
+  UNREF_TRANSPORT(exec_ctx, t, "initiate_writing");
+}
+
+static void initiate_writing(grpc_exec_ctx *exec_ctx, void *arg,
+                             grpc_error *error) {
+  grpc_chttp2_run_with_global_lock(exec_ctx, arg, NULL, initiate_writing_locked,
+                                   NULL, 0);
+}
+
+void grpc_chttp2_become_writable(grpc_exec_ctx *exec_ctx,
+                                 grpc_chttp2_transport_global *transport_global,
+                                 grpc_chttp2_stream_global *stream_global,
+                                 bool covered_by_poller, const char *reason) {
   if (!TRANSPORT_FROM_GLOBAL(transport_global)->closed &&
       grpc_chttp2_list_add_writable_stream(transport_global, stream_global)) {
     GRPC_CHTTP2_STREAM_REF(stream_global, "chttp2_writing");
+    grpc_chttp2_initiate_write(exec_ctx, transport_global, covered_by_poller,
+                               reason);
   }
 }
 
-static void push_setting(grpc_chttp2_transport *t, grpc_chttp2_setting_id id,
-                         uint32_t value) {
+static void push_setting(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                         grpc_chttp2_setting_id id, uint32_t value) {
   const grpc_chttp2_setting_parameters *sp =
       &grpc_chttp2_settings_parameters[id];
   uint32_t use_value = GPR_CLAMP(value, sp->min_value, sp->max_value);
@@ -761,9 +921,22 @@ static void push_setting(grpc_chttp2_transport *t, grpc_chttp2_setting_id id,
   if (use_value != t->global.settings[GRPC_LOCAL_SETTINGS][id]) {
     t->global.settings[GRPC_LOCAL_SETTINGS][id] = use_value;
     t->global.dirtied_local_settings = 1;
+    grpc_chttp2_initiate_write(exec_ctx, &t->global, false, "push_setting");
   }
 }
 
+static void end_waiting_for_write(grpc_exec_ctx *exec_ctx,
+                                  grpc_chttp2_transport *t, grpc_error *error) {
+  grpc_chttp2_stream_global *stream_global;
+  while (grpc_chttp2_list_pop_closed_waiting_for_writing(&t->global,
+                                                         &stream_global)) {
+    fail_pending_writes(exec_ctx, &t->global, stream_global,
+                        GRPC_ERROR_REF(error));
+    GRPC_CHTTP2_STREAM_UNREF(exec_ctx, stream_global, "finish_writes");
+  }
+  GRPC_ERROR_UNREF(error);
+}
+
 static void terminate_writing_with_lock(grpc_exec_ctx *exec_ctx,
                                         grpc_chttp2_transport *t,
                                         grpc_chttp2_stream *s_ignored,
@@ -778,24 +951,32 @@ static void terminate_writing_with_lock(grpc_exec_ctx *exec_ctx,
 
   grpc_chttp2_cleanup_writing(exec_ctx, &t->global, &t->writing);
 
-  grpc_chttp2_stream_global *stream_global;
-  while (grpc_chttp2_list_pop_closed_waiting_for_writing(&t->global,
-                                                         &stream_global)) {
-    fail_pending_writes(exec_ctx, &t->global, stream_global,
-                        GRPC_ERROR_REF(error));
-    GRPC_CHTTP2_STREAM_UNREF(exec_ctx, stream_global, "finish_writes");
+  end_waiting_for_write(exec_ctx, t, error);
+
+  switch (t->executor.write_state) {
+    case GRPC_CHTTP2_WRITING_INACTIVE:
+    case GRPC_CHTTP2_WRITE_REQUESTED_WITH_POLLER:
+    case GRPC_CHTTP2_WRITE_REQUESTED_NO_POLLER:
+    case GRPC_CHTTP2_WRITE_SCHEDULED:
+      GPR_UNREACHABLE_CODE(break);
+    case GRPC_CHTTP2_WRITING:
+      set_write_state(t, GRPC_CHTTP2_WRITING_INACTIVE, "terminate_writing");
+      break;
+    case GRPC_CHTTP2_WRITING_STALE_WITH_POLLER:
+      set_write_state(t, GRPC_CHTTP2_WRITE_REQUESTED_WITH_POLLER,
+                      "terminate_writing");
+      break;
+    case GRPC_CHTTP2_WRITING_STALE_NO_POLLER:
+      set_write_state(t, GRPC_CHTTP2_WRITE_REQUESTED_NO_POLLER,
+                      "terminate_writing");
+      break;
   }
 
-  /* leave the writing flag up on shutdown to prevent further writes in
-     unlock()
-     from starting */
-  t->executor.writing_active = 0;
   if (t->ep && !t->endpoint_reading) {
     destroy_endpoint(exec_ctx, t);
   }
 
   UNREF_TRANSPORT(exec_ctx, t, "writing");
-  GRPC_ERROR_UNREF(error);
 }
 
 void grpc_chttp2_terminate_writing(grpc_exec_ctx *exec_ctx,
@@ -878,7 +1059,8 @@ static void maybe_start_some_streams(
         stream_global->id, STREAM_FROM_GLOBAL(stream_global));
     stream_global->in_stream_map = true;
     transport_global->concurrent_stream_count++;
-    grpc_chttp2_become_writable(transport_global, stream_global);
+    grpc_chttp2_become_writable(exec_ctx, transport_global, stream_global, true,
+                                "new_stream");
   }
   /* cancel out streams that will never be started */
   while (transport_global->next_stream_id >= MAX_CLIENT_STREAM_ID &&
@@ -1018,9 +1200,11 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx,
           maybe_start_some_streams(exec_ctx, transport_global);
         } else {
           GPR_ASSERT(stream_global->id != 0);
-          grpc_chttp2_become_writable(transport_global, stream_global);
+          grpc_chttp2_become_writable(exec_ctx, transport_global, stream_global,
+                                      true, "op.send_initial_metadata");
         }
       } else {
+        stream_global->send_trailing_metadata = NULL;
         grpc_chttp2_complete_closure_step(
             exec_ctx, transport_global, stream_global,
             &stream_global->send_initial_metadata_finished,
@@ -1042,7 +1226,8 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx,
     } else {
       stream_global->send_message = op->send_message;
       if (stream_global->id != 0) {
-        grpc_chttp2_become_writable(transport_global, stream_global);
+        grpc_chttp2_become_writable(exec_ctx, transport_global, stream_global,
+                                    true, "op.send_message");
       }
     }
   }
@@ -1075,6 +1260,7 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx,
         grpc_chttp2_list_add_check_read_ops(transport_global, stream_global);
       }
       if (stream_global->write_closed) {
+        stream_global->send_trailing_metadata = NULL;
         grpc_chttp2_complete_closure_step(
             exec_ctx, transport_global, stream_global,
             &stream_global->send_trailing_metadata_finished,
@@ -1085,7 +1271,8 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx,
       } else if (stream_global->id != 0) {
         /* TODO(ctiller): check if there's flow control for any outstanding
            bytes before going writable */
-        grpc_chttp2_become_writable(transport_global, stream_global);
+        grpc_chttp2_become_writable(exec_ctx, transport_global, stream_global,
+                                    true, "op.send_trailing_metadata");
       }
     }
   }
@@ -1106,8 +1293,8 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx,
         (stream_global->incoming_frames.head == NULL ||
          stream_global->incoming_frames.head->is_tail)) {
       incoming_byte_stream_update_flow_control(
-          transport_global, stream_global, transport_global->stream_lookahead,
-          0);
+          exec_ctx, transport_global, stream_global,
+          transport_global->stream_lookahead, 0);
     }
     grpc_chttp2_list_add_check_read_ops(transport_global, stream_global);
   }
@@ -1135,7 +1322,8 @@ static void perform_stream_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
                                    sizeof(*op));
 }
 
-static void send_ping_locked(grpc_chttp2_transport *t, grpc_closure *on_recv) {
+static void send_ping_locked(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
+                             grpc_closure *on_recv) {
   grpc_chttp2_outstanding_ping *p = gpr_malloc(sizeof(*p));
   p->next = &t->global.pings;
   p->prev = p->next->prev;
@@ -1150,6 +1338,7 @@ static void send_ping_locked(grpc_chttp2_transport *t, grpc_closure *on_recv) {
   p->id[7] = (uint8_t)(t->global.ping_counter & 0xff);
   p->on_recv = on_recv;
   gpr_slice_buffer_add(&t->global.qbuf, grpc_chttp2_ping_create(0, p->id));
+  grpc_chttp2_initiate_write(exec_ctx, &t->global, true, "send_ping");
 }
 
 static void ack_ping_locked(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
@@ -1209,6 +1398,7 @@ static void perform_transport_op_locked(grpc_exec_ctx *exec_ctx,
     close_transport = grpc_chttp2_has_streams(t)
                           ? GRPC_ERROR_NONE
                           : GRPC_ERROR_CREATE("GOAWAY sent");
+    grpc_chttp2_initiate_write(exec_ctx, &t->global, false, "goaway_sent");
   }
 
   if (op->set_accept_stream) {
@@ -1226,7 +1416,7 @@ static void perform_transport_op_locked(grpc_exec_ctx *exec_ctx,
   }
 
   if (op->send_ping) {
-    send_ping_locked(t, op->send_ping);
+    send_ping_locked(exec_ctx, t, op->send_ping);
   }
 
   if (close_transport != GRPC_ERROR_NONE) {
@@ -1414,6 +1604,8 @@ static void cancel_from_api(grpc_exec_ctx *exec_ctx,
           &transport_global->qbuf,
           grpc_chttp2_rst_stream_create(stream_global->id, (uint32_t)http_error,
                                         &stream_global->stats.outgoing));
+      grpc_chttp2_initiate_write(exec_ctx, transport_global, false,
+                                 "rst_stream");
     }
 
     const char *msg =
@@ -1473,10 +1665,39 @@ void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx,
   }
 }
 
+static void add_error(grpc_error *error, grpc_error **refs, size_t *nrefs) {
+  if (error == GRPC_ERROR_NONE) return;
+  for (size_t i = 0; i < *nrefs; i++) {
+    if (error == refs[i]) {
+      return;
+    }
+  }
+  refs[*nrefs] = error;
+  ++*nrefs;
+}
+
+static grpc_error *removal_error(grpc_error *extra_error,
+                                 grpc_chttp2_stream_global *stream_global) {
+  grpc_error *refs[3];
+  size_t nrefs = 0;
+  add_error(stream_global->read_closed_error, refs, &nrefs);
+  add_error(stream_global->write_closed_error, refs, &nrefs);
+  add_error(extra_error, refs, &nrefs);
+  grpc_error *error = GRPC_ERROR_NONE;
+  if (nrefs > 0) {
+    error = GRPC_ERROR_CREATE_REFERENCING("Failed due to stream removal", refs,
+                                          nrefs);
+  }
+  GRPC_ERROR_UNREF(extra_error);
+  return error;
+}
+
 static void fail_pending_writes(grpc_exec_ctx *exec_ctx,
                                 grpc_chttp2_transport_global *transport_global,
                                 grpc_chttp2_stream_global *stream_global,
                                 grpc_error *error) {
+  error = removal_error(error, stream_global);
+  stream_global->send_message = NULL;
   grpc_chttp2_complete_closure_step(
       exec_ctx, transport_global, stream_global,
       &stream_global->send_initial_metadata_finished, GRPC_ERROR_REF(error));
@@ -1499,14 +1720,17 @@ void grpc_chttp2_mark_stream_closed(
   }
   grpc_chttp2_list_add_check_read_ops(transport_global, stream_global);
   if (close_reads && !stream_global->read_closed) {
+    stream_global->read_closed_error = GRPC_ERROR_REF(error);
     stream_global->read_closed = true;
     stream_global->published_initial_metadata = true;
     stream_global->published_trailing_metadata = true;
     decrement_active_streams_locked(exec_ctx, transport_global, stream_global);
   }
   if (close_writes && !stream_global->write_closed) {
+    stream_global->write_closed_error = GRPC_ERROR_REF(error);
     stream_global->write_closed = true;
-    if (TRANSPORT_FROM_GLOBAL(transport_global)->executor.writing_active) {
+    if (TRANSPORT_FROM_GLOBAL(transport_global)->executor.write_state !=
+        GRPC_CHTTP2_WRITING_INACTIVE) {
       GRPC_CHTTP2_STREAM_REF(stream_global, "finish_writes");
       grpc_chttp2_list_add_closed_waiting_for_writing(transport_global,
                                                       stream_global);
@@ -1516,7 +1740,6 @@ void grpc_chttp2_mark_stream_closed(
     }
   }
   if (stream_global->read_closed && stream_global->write_closed) {
-    stream_global->removal_error = GRPC_ERROR_REF(error);
     if (stream_global->id != 0 &&
         TRANSPORT_FROM_GLOBAL(transport_global)->executor.parsing_active) {
       grpc_chttp2_list_add_closed_waiting_for_parsing(transport_global,
@@ -1524,7 +1747,8 @@ void grpc_chttp2_mark_stream_closed(
     } else {
       if (stream_global->id != 0) {
         remove_stream(exec_ctx, TRANSPORT_FROM_GLOBAL(transport_global),
-                      stream_global->id, GRPC_ERROR_REF(error));
+                      stream_global->id,
+                      removal_error(GRPC_ERROR_REF(error), stream_global));
       }
       GRPC_CHTTP2_STREAM_UNREF(exec_ctx, stream_global, "chttp2");
     }
@@ -1649,6 +1873,8 @@ static void close_from_api(grpc_exec_ctx *exec_ctx,
 
   grpc_chttp2_mark_stream_closed(exec_ctx, transport_global, stream_global, 1,
                                  1, error);
+  grpc_chttp2_initiate_write(exec_ctx, transport_global, false,
+                             "close_from_api");
 }
 
 typedef struct {
@@ -1678,8 +1904,14 @@ static void drop_connection(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
 }
 
 /** update window from a settings change */
+typedef struct {
+  grpc_chttp2_transport *t;
+  grpc_exec_ctx *exec_ctx;
+} update_global_window_args;
+
 static void update_global_window(void *args, uint32_t id, void *stream) {
-  grpc_chttp2_transport *t = args;
+  update_global_window_args *a = args;
+  grpc_chttp2_transport *t = a->t;
   grpc_chttp2_stream *s = stream;
   grpc_chttp2_transport_global *transport_global = &t->global;
   grpc_chttp2_stream_global *stream_global = &s->global;
@@ -1693,7 +1925,8 @@ static void update_global_window(void *args, uint32_t id, void *stream) {
   is_zero = stream_global->outgoing_window <= 0;
 
   if (was_zero && !is_zero) {
-    grpc_chttp2_become_writable(transport_global, stream_global);
+    grpc_chttp2_become_writable(a->exec_ctx, transport_global, stream_global,
+                                true, "update_global_window");
   }
 }
 
@@ -1802,14 +2035,19 @@ static void post_parse_locked(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   grpc_chttp2_transport_global *transport_global = &t->global;
   grpc_chttp2_transport_parsing *transport_parsing = &t->parsing;
   /* copy parsing qbuf to global qbuf */
-  gpr_slice_buffer_move_into(&t->parsing.qbuf, &t->global.qbuf);
+  if (t->parsing.qbuf.count > 0) {
+    gpr_slice_buffer_move_into(&t->parsing.qbuf, &t->global.qbuf);
+    grpc_chttp2_initiate_write(exec_ctx, transport_global, false,
+                               "parsing_qbuf");
+  }
   /* merge stream lists */
   grpc_chttp2_stream_map_move_into(&t->new_stream_map, &t->parsing_stream_map);
   transport_global->concurrent_stream_count =
       (uint32_t)grpc_chttp2_stream_map_size(&t->parsing_stream_map);
   if (transport_parsing->initial_window_update != 0) {
+    update_global_window_args args = {t, exec_ctx};
     grpc_chttp2_stream_map_for_each(&t->parsing_stream_map,
-                                    update_global_window, t);
+                                    update_global_window, &args);
     transport_parsing->initial_window_update = 0;
   }
   /* handle higher level things */
@@ -1832,7 +2070,7 @@ static void post_parse_locked(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
     GPR_ASSERT(stream_global->write_closed);
     GPR_ASSERT(stream_global->read_closed);
     remove_stream(exec_ctx, t, stream_global->id,
-                  GRPC_ERROR_REF(stream_global->removal_error));
+                  removal_error(GRPC_ERROR_NONE, stream_global));
     GRPC_CHTTP2_STREAM_UNREF(exec_ctx, stream_global, "chttp2");
   }
 
@@ -1855,11 +2093,12 @@ static void post_reading_action_locked(grpc_exec_ctx *exec_ctx,
     }
     drop_connection(exec_ctx, t, GRPC_ERROR_REF(error));
     t->endpoint_reading = 0;
-    if (!t->executor.writing_active && t->ep) {
-      grpc_endpoint_destroy(exec_ctx, t->ep);
-      t->ep = NULL;
-      /* safe as we still have a ref for read */
-      UNREF_TRANSPORT(exec_ctx, t, "disconnect");
+    if (grpc_http_write_state_trace) {
+      gpr_log(GPR_DEBUG, "R:%p -> 0 ws=%s", t,
+              write_state_name(t->executor.write_state));
+    }
+    if (t->executor.write_state == GRPC_CHTTP2_WRITING_INACTIVE && t->ep) {
+      destroy_endpoint(exec_ctx, t);
     }
   } else if (!t->closed) {
     keep_reading = true;
@@ -1943,7 +2182,7 @@ static void incoming_byte_stream_unref(grpc_exec_ctx *exec_ctx,
 }
 
 static void incoming_byte_stream_update_flow_control(
-    grpc_chttp2_transport_global *transport_global,
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_global *transport_global,
     grpc_chttp2_stream_global *stream_global, size_t max_size_hint,
     size_t have_already) {
   uint32_t max_recv_bytes;
@@ -1978,7 +2217,8 @@ static void incoming_byte_stream_update_flow_control(
                                    add_max_recv_bytes);
     grpc_chttp2_list_add_unannounced_incoming_window_available(transport_global,
                                                                stream_global);
-    grpc_chttp2_become_writable(transport_global, stream_global);
+    grpc_chttp2_become_writable(exec_ctx, transport_global, stream_global,
+                                false, "read_incoming_stream");
   }
 }
 
@@ -2000,8 +2240,9 @@ static void incoming_byte_stream_next_locked(grpc_exec_ctx *exec_ctx,
   grpc_chttp2_stream_global *stream_global = &bs->stream->global;
 
   if (bs->is_tail) {
-    incoming_byte_stream_update_flow_control(
-        transport_global, stream_global, arg->max_size_hint, bs->slices.length);
+    incoming_byte_stream_update_flow_control(exec_ctx, transport_global,
+                                             stream_global, arg->max_size_hint,
+                                             bs->slices.length);
   }
   if (bs->slices.count > 0) {
     *arg->slice = gpr_slice_buffer_take_first(&bs->slices);
@@ -2185,7 +2426,7 @@ static char *format_flowctl_context_var(const char *context, const char *var,
   if (context == NULL) {
     *scope = NULL;
     gpr_asprintf(&buf, "%s(%" PRId64 ")", var, val);
-    result = gpr_leftpad(buf, ' ', 40);
+    result = gpr_leftpad(buf, ' ', 60);
     gpr_free(buf);
     return result;
   }
@@ -2198,7 +2439,7 @@ static char *format_flowctl_context_var(const char *context, const char *var,
     gpr_free(tmp);
   }
   gpr_asprintf(&buf, "%s.%s(%" PRId64 ")", underscore_pos + 1, var, val);
-  result = gpr_leftpad(buf, ' ', 40);
+  result = gpr_leftpad(buf, ' ', 60);
   gpr_free(buf);
   return result;
 }
@@ -2231,7 +2472,7 @@ void grpc_chttp2_flowctl_trace(const char *file, int line, const char *phase,
 
   tmp_phase = gpr_leftpad(phase, ' ', 8);
   tmp_scope1 = gpr_leftpad(scope1, ' ', 11);
-  gpr_asprintf(&prefix, "FLOW %s: %s %s ", phase, clisvr, scope1);
+  gpr_asprintf(&prefix, "FLOW %s: %s %s ", tmp_phase, clisvr, scope1);
   gpr_free(tmp_phase);
   gpr_free(tmp_scope1);
 
diff --git a/src/core/ext/transport/chttp2/transport/internal.h b/src/core/ext/transport/chttp2/transport/internal.h
index 8d79e93ceb..e1dcf5262a 100644
--- a/src/core/ext/transport/chttp2/transport/internal.h
+++ b/src/core/ext/transport/chttp2/transport/internal.h
@@ -305,6 +305,22 @@ typedef struct grpc_chttp2_executor_action_header {
   void *arg;
 } grpc_chttp2_executor_action_header;
 
+typedef enum {
+  /** no writing activity */
+  GRPC_CHTTP2_WRITING_INACTIVE,
+  /** write has been requested, but not scheduled yet */
+  GRPC_CHTTP2_WRITE_REQUESTED_WITH_POLLER,
+  GRPC_CHTTP2_WRITE_REQUESTED_NO_POLLER,
+  /** write has been requested and scheduled against the workqueue */
+  GRPC_CHTTP2_WRITE_SCHEDULED,
+  /** write has been initiated after being reaped from the workqueue */
+  GRPC_CHTTP2_WRITING,
+  /** write has been initiated, AND another write needs to be started once it's
+      done */
+  GRPC_CHTTP2_WRITING_STALE_WITH_POLLER,
+  GRPC_CHTTP2_WRITING_STALE_NO_POLLER,
+} grpc_chttp2_write_state;
+
 struct grpc_chttp2_transport {
   grpc_transport base; /* must be first */
   gpr_refcount refs;
@@ -319,10 +335,10 @@ struct grpc_chttp2_transport {
 
     /** is a thread currently in the global lock */
     bool global_active;
-    /** is a thread currently writing */
-    bool writing_active;
     /** is a thread currently parsing */
     bool parsing_active;
+    /** write execution state of the transport */
+    grpc_chttp2_write_state write_state;
 
     grpc_chttp2_executor_action_header *pending_actions_head;
     grpc_chttp2_executor_action_header *pending_actions_tail;
@@ -342,7 +358,8 @@ struct grpc_chttp2_transport {
   /** global state for reading/writing */
   grpc_chttp2_transport_global global;
   /** state only accessible by the chain of execution that
-      set writing_active=1 */
+      set writing_state >= GRPC_WRITING, and only by the writing closure
+      chain. */
   grpc_chttp2_transport_writing writing;
   /** state only accessible by the chain of execution that
       set parsing_active=1 */
@@ -363,6 +380,8 @@ struct grpc_chttp2_transport {
   grpc_closure reading_action;
   /** closure to actually do parsing */
   grpc_closure parsing_action;
+  /** closure to initiate writing */
+  grpc_closure initiate_writing;
 
   /** incoming read bytes */
   gpr_slice_buffer read_buffer;
@@ -436,8 +455,10 @@ typedef struct {
   bool seen_error;
   bool exceeded_metadata_size;
 
-  /** the error that resulted in this stream being removed */
-  grpc_error *removal_error;
+  /** the error that resulted in this stream being read-closed */
+  grpc_error *read_closed_error;
+  /** the error that resulted in this stream being write-closed */
+  grpc_error *write_closed_error;
 
   bool published_initial_metadata;
   bool published_trailing_metadata;
@@ -514,15 +535,20 @@ struct grpc_chttp2_stream {
 };
 
 /** Transport writing call flow:
-    chttp2_transport.c calls grpc_chttp2_unlocking_check_writes to see if writes
-   are required;
-    if they are, chttp2_transport.c calls grpc_chttp2_perform_writes to do the
-   writes.
-    Once writes have been completed (meaning another write could potentially be
-   started),
-    grpc_chttp2_terminate_writing is called. This will call
-   grpc_chttp2_cleanup_writing, at which
-    point the write phase is complete. */
+    grpc_chttp2_initiate_write() is called anywhere that we know bytes need to
+    go out on the wire.
+    If no other write has been started, a task is enqueued onto our workqueue.
+    When that task executes, it obtains the global lock, and gathers the data
+    to write.
+    The global lock is dropped and we do the syscall to write.
+    After writing, a follow-up check is made to see if another round of writing
+    should be performed.
+
+    The actual call chain is documented in the implementation of this function.
+    */
+void grpc_chttp2_initiate_write(grpc_exec_ctx *exec_ctx,
+                                grpc_chttp2_transport_global *transport_global,
+                                bool covered_by_poller, const char *reason);
 
 /** Someone is unlocking the transport mutex: check to see if writes
     are required, and schedule them if so */
@@ -610,9 +636,8 @@ int grpc_chttp2_list_pop_check_read_ops(
 void grpc_chttp2_list_add_writing_stalled_by_transport(
     grpc_chttp2_transport_writing *transport_writing,
     grpc_chttp2_stream_writing *stream_writing);
-void grpc_chttp2_list_flush_writing_stalled_by_transport(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_writing *transport_writing,
-    bool is_window_available);
+bool grpc_chttp2_list_flush_writing_stalled_by_transport(
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_writing *transport_writing);
 
 void grpc_chttp2_list_add_stalled_by_transport(
     grpc_chttp2_transport_writing *transport_writing,
@@ -822,7 +847,9 @@ void grpc_chttp2_ack_ping(grpc_exec_ctx *exec_ctx,
 
 /** add a ref to the stream and add it to the writable list;
     ref will be dropped in writing.c */
-void grpc_chttp2_become_writable(grpc_chttp2_transport_global *transport_global,
-                                 grpc_chttp2_stream_global *stream_global);
+void grpc_chttp2_become_writable(grpc_exec_ctx *exec_ctx,
+                                 grpc_chttp2_transport_global *transport_global,
+                                 grpc_chttp2_stream_global *stream_global,
+                                 bool covered_by_poller, const char *reason);
 
 #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.c
index 84eb5752f1..e1fc0ddee2 100644
--- a/src/core/ext/transport/chttp2/transport/parsing.c
+++ b/src/core/ext/transport/chttp2/transport/parsing.c
@@ -154,10 +154,8 @@ void grpc_chttp2_publish_reads(
                                   transport_parsing, outgoing_window);
   is_zero = transport_global->outgoing_window <= 0;
   if (was_zero && !is_zero) {
-    while (grpc_chttp2_list_pop_stalled_by_transport(transport_global,
-                                                     &stream_global)) {
-      grpc_chttp2_become_writable(transport_global, stream_global);
-    }
+    grpc_chttp2_initiate_write(exec_ctx, transport_global, false,
+                               "new_global_flow_control");
   }
 
   if (transport_parsing->incoming_window <
@@ -168,6 +166,8 @@ void grpc_chttp2_publish_reads(
                                       announce_incoming_window, announce_bytes);
     GRPC_CHTTP2_FLOW_CREDIT_TRANSPORT("parsed", transport_parsing,
                                       incoming_window, announce_bytes);
+    grpc_chttp2_initiate_write(exec_ctx, transport_global, false,
+                               "global incoming window");
   }
 
   /* for each stream that saw an update, fixup global state */
@@ -190,7 +190,8 @@ void grpc_chttp2_publish_reads(
                                  outgoing_window);
     is_zero = stream_global->outgoing_window <= 0;
     if (was_zero && !is_zero) {
-      grpc_chttp2_become_writable(transport_global, stream_global);
+      grpc_chttp2_become_writable(exec_ctx, transport_global, stream_global,
+                                  false, "stream.read_flow_control");
     }
 
     stream_global->max_recv_bytes -= (uint32_t)GPR_MIN(
diff --git a/src/core/ext/transport/chttp2/transport/stream_lists.c b/src/core/ext/transport/chttp2/transport/stream_lists.c
index 8f3ab00e6d..2eb5f5f632 100644
--- a/src/core/ext/transport/chttp2/transport/stream_lists.c
+++ b/src/core/ext/transport/chttp2/transport/stream_lists.c
@@ -329,6 +329,7 @@ void grpc_chttp2_list_add_writing_stalled_by_transport(
     grpc_chttp2_transport_writing *transport_writing,
     grpc_chttp2_stream_writing *stream_writing) {
   grpc_chttp2_stream *stream = STREAM_FROM_WRITING(stream_writing);
+  gpr_log(GPR_DEBUG, "writing stalled %d", stream->global.id);
   if (!stream->included[GRPC_CHTTP2_LIST_WRITING_STALLED_BY_TRANSPORT]) {
     GRPC_CHTTP2_STREAM_REF(&stream->global, "chttp2_writing_stalled");
   }
@@ -336,27 +337,28 @@ void grpc_chttp2_list_add_writing_stalled_by_transport(
                   GRPC_CHTTP2_LIST_WRITING_STALLED_BY_TRANSPORT);
 }
 
-void grpc_chttp2_list_flush_writing_stalled_by_transport(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_writing *transport_writing,
-    bool is_window_available) {
+bool grpc_chttp2_list_flush_writing_stalled_by_transport(
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_writing *transport_writing) {
   grpc_chttp2_stream *stream;
+  bool out = false;
   grpc_chttp2_transport *transport = TRANSPORT_FROM_WRITING(transport_writing);
   while (stream_list_pop(transport, &stream,
                          GRPC_CHTTP2_LIST_WRITING_STALLED_BY_TRANSPORT)) {
-    if (is_window_available) {
-      grpc_chttp2_become_writable(&transport->global, &stream->global);
-    } else {
-      grpc_chttp2_list_add_stalled_by_transport(transport_writing,
-                                                &stream->writing);
-    }
+    gpr_log(GPR_DEBUG, "move %d from writing stalled to just stalled",
+            stream->global.id);
+    grpc_chttp2_list_add_stalled_by_transport(transport_writing,
+                                              &stream->writing);
     GRPC_CHTTP2_STREAM_UNREF(exec_ctx, &stream->global,
                              "chttp2_writing_stalled");
+    out = true;
   }
+  return out;
 }
 
 void grpc_chttp2_list_add_stalled_by_transport(
     grpc_chttp2_transport_writing *transport_writing,
     grpc_chttp2_stream_writing *stream_writing) {
+  gpr_log(GPR_DEBUG, "stalled %d", stream_writing->id);
   stream_list_add(TRANSPORT_FROM_WRITING(transport_writing),
                   STREAM_FROM_WRITING(stream_writing),
                   GRPC_CHTTP2_LIST_STALLED_BY_TRANSPORT);
diff --git a/src/core/ext/transport/chttp2/transport/writing.c b/src/core/ext/transport/chttp2/transport/writing.c
index b19f5f068d..e0d87725e9 100644
--- a/src/core/ext/transport/chttp2/transport/writing.c
+++ b/src/core/ext/transport/chttp2/transport/writing.c
@@ -75,9 +75,13 @@ int grpc_chttp2_unlocking_check_writes(
 
   GRPC_CHTTP2_FLOW_MOVE_TRANSPORT("write", transport_writing, outgoing_window,
                                   transport_global, outgoing_window);
-  bool is_window_available = transport_writing->outgoing_window > 0;
-  grpc_chttp2_list_flush_writing_stalled_by_transport(
-      exec_ctx, transport_writing, is_window_available);
+  if (transport_writing->outgoing_window > 0) {
+    while (grpc_chttp2_list_pop_stalled_by_transport(transport_global,
+                                                     &stream_global)) {
+      grpc_chttp2_become_writable(exec_ctx, transport_global, stream_global,
+                                  false, "transport.read_flow_control");
+    }
+  }
 
   /* for each grpc_chttp2_stream that's become writable, frame it's data
      (according to available window sizes) and add to the output buffer */
@@ -331,6 +335,12 @@ void grpc_chttp2_cleanup_writing(
   grpc_chttp2_stream_writing *stream_writing;
   grpc_chttp2_stream_global *stream_global;
 
+  if (grpc_chttp2_list_flush_writing_stalled_by_transport(exec_ctx,
+                                                          transport_writing)) {
+    grpc_chttp2_initiate_write(exec_ctx, transport_global, false,
+                               "resume_stalled_stream");
+  }
+
   while (grpc_chttp2_list_pop_written_stream(
       transport_global, transport_writing, &stream_global, &stream_writing)) {
     if (stream_writing->sent_initial_metadata) {