Merge branch 'master' into badclient

author: Yash Tibrewal <yashkt@google.com> 2018-01-24 10:58:25 -0800
committer: Yash Tibrewal <yashkt@google.com> 2018-01-24 10:58:25 -0800
commit: ea8027a0b1b5ca2ba2e29f9924d5c164cc75aba1 (patch)
tree: a8409e75cbf9966c0aad4fc5df5d8af33dc59fa6 /src/core/lib
parent: 7cbbee745e84d714f826e54fdbc93499341e7fa3 (diff)
parent: 5e7eed29ed747a24a91c3d202066e64d0478d5db (diff)
140 files changed, 652 insertions, 282 deletions
diff --git a/src/core/lib/backoff/backoff.cc b/src/core/lib/backoff/backoff.cc
index 41f625a636..d561fc7460 100644
--- a/src/core/lib/backoff/backoff.cc
+++ b/src/core/lib/backoff/backoff.cc
@@ -41,18 +41,20 @@ double generate_uniform_random_number_between(uint32_t* rng_state, double a,
   const double range = b - a;
   return a + generate_uniform_random_number(rng_state) * range;
 }
-}  // namespace
 
-BackOff::BackOff(const Options& options) : options_(options) {
-  rng_state_ = static_cast<uint32_t>(gpr_now(GPR_CLOCK_REALTIME).tv_nsec);
-}
+}  // namespace
 
-grpc_millis BackOff::Begin() {
-  current_backoff_ = options_.initial_backoff();
-  return current_backoff_ + grpc_core::ExecCtx::Get()->Now();
+BackOff::BackOff(const Options& options)
+    : options_(options),
+      rng_state_(static_cast<uint32_t>(gpr_now(GPR_CLOCK_REALTIME).tv_nsec)) {
+  Reset();
 }
 
-grpc_millis BackOff::Step() {
+grpc_millis BackOff::NextAttemptTime() {
+  if (initial_) {
+    initial_ = false;
+    return current_backoff_ + grpc_core::ExecCtx::Get()->Now();
+  }
   current_backoff_ =
       (grpc_millis)(std::min(current_backoff_ * options_.multiplier(),
                              (double)options_.max_backoff()));
@@ -63,7 +65,10 @@ grpc_millis BackOff::Step() {
   return next_timeout + grpc_core::ExecCtx::Get()->Now();
 }
 
-void BackOff::Reset() { current_backoff_ = options_.initial_backoff(); }
+void BackOff::Reset() {
+  current_backoff_ = options_.initial_backoff();
+  initial_ = true;
+}
 
 void BackOff::SetRandomSeed(uint32_t seed) { rng_state_ = seed; }
 
diff --git a/src/core/lib/backoff/backoff.h b/src/core/lib/backoff/backoff.h
index 84ef9b82e4..de30e5268b 100644
--- a/src/core/lib/backoff/backoff.h
+++ b/src/core/lib/backoff/backoff.h
@@ -32,14 +32,11 @@ class BackOff {
   /// Initialize backoff machinery - does not need to be destroyed
   explicit BackOff(const Options& options);
 
-  /// Begin retry loop: returns the deadline to be used for the next attempt,
-  /// following the backoff strategy.
-  grpc_millis Begin();
-  /// Step a retry loop: returns the deadline to be used for the next attempt,
-  /// following the backoff strategy.
-  grpc_millis Step();
-  /// Reset the backoff, so the next grpc_backoff_step will be a
-  /// grpc_backoff_begin.
+  /// Returns the time at which the next attempt should start.
+  grpc_millis NextAttemptTime();
+
+  /// Reset the backoff, so the next value returned by NextAttemptTime()
+  /// will be the time of the second attempt (rather than the Nth).
   void Reset();
 
   void SetRandomSeed(unsigned int seed);
@@ -80,9 +77,10 @@ class BackOff {
 
  private:
   const Options options_;
+  uint32_t rng_state_;
+  bool initial_;
   /// current delay before retries
   grpc_millis current_backoff_;
-  uint32_t rng_state_;
 };
 
 }  // namespace grpc_core
diff --git a/src/core/lib/channel/channel_args.cc b/src/core/lib/channel/channel_args.cc
index 578475b248..634286d403 100644
--- a/src/core/lib/channel/channel_args.cc
+++ b/src/core/lib/channel/channel_args.cc
@@ -29,7 +29,7 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/channel/channel_args.h"
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/string.h"
 
 static grpc_arg copy_arg(const grpc_arg* src) {
   grpc_arg dst;
diff --git a/src/core/lib/channel/channel_stack.h b/src/core/lib/channel/channel_stack.h
index 716866be26..b9f9748001 100644
--- a/src/core/lib/channel/channel_stack.h
+++ b/src/core/lib/channel/channel_stack.h
@@ -40,9 +40,9 @@
 #include <grpc/support/time.h>
 
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gpr/arena.h"
 #include "src/core/lib/iomgr/call_combiner.h"
 #include "src/core/lib/iomgr/polling_entity.h"
-#include "src/core/lib/support/arena.h"
 #include "src/core/lib/transport/transport.h"
 
 typedef struct grpc_channel_element grpc_channel_element;
diff --git a/src/core/lib/channel/connected_channel.cc b/src/core/lib/channel/connected_channel.cc
index 9d07cfff4e..fb26bdf586 100644
--- a/src/core/lib/channel/connected_channel.cc
+++ b/src/core/lib/channel/connected_channel.cc
@@ -26,8 +26,8 @@
 #include <grpc/slice_buffer.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/lib/transport/transport.h"
 
 #define MAX_BUFFER_LENGTH 8192
diff --git a/src/core/lib/debug/stats.cc b/src/core/lib/debug/stats.cc
index 0b39b2b1e7..465c76114d 100644
--- a/src/core/lib/debug/stats.cc
+++ b/src/core/lib/debug/stats.cc
@@ -25,7 +25,7 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/useful.h>
 
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/string.h"
 
 grpc_stats_data* grpc_stats_per_cpu_storage = nullptr;
 static size_t g_num_cores;
diff --git a/src/core/lib/debug/trace.cc b/src/core/lib/debug/trace.cc
index a76c1afb4c..d870bbc5e7 100644
--- a/src/core/lib/debug/trace.cc
+++ b/src/core/lib/debug/trace.cc
@@ -23,7 +23,7 @@
 #include <grpc/grpc.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
-#include "src/core/lib/support/env.h"
+#include "src/core/lib/gpr/env.h"
 
 int grpc_tracer_set_enabled(const char* name, int enabled);
 
diff --git a/src/core/lib/gpr/README.md b/src/core/lib/gpr/README.md
new file mode 100644
index 0000000000..21fb0c796d
--- /dev/null
+++ b/src/core/lib/gpr/README.md
@@ -0,0 +1,8 @@
+# GPR - Google Portable Runtime for C
+
+The files in this directory contain basic utility code and platform
+abstractions for C code.  None of this code is gRPC-specific; anything
+here may also be useful for other open source projects written in C.
+
+Note that this is one of the few places in src/core where we allow
+the use of portability macros.
diff --git a/src/core/lib/support/alloc.cc b/src/core/lib/gpr/alloc.cc
index 518bdb99f7..000b7dcb25 100644
--- a/src/core/lib/support/alloc.cc
+++ b/src/core/lib/gpr/alloc.cc
@@ -90,8 +90,8 @@ void* gpr_realloc(void* p, size_t size) {
   return p;
 }
 
-void* gpr_malloc_aligned(size_t size, size_t alignment_log) {
-  size_t alignment = ((size_t)1) << alignment_log;
+void* gpr_malloc_aligned(size_t size, size_t alignment) {
+  GPR_ASSERT(((alignment - 1) & alignment) == 0);  // Must be power of 2.
   size_t extra = alignment - 1 + sizeof(void*);
   void* p = gpr_malloc(size + extra);
   void** ret = (void**)(((uintptr_t)p + extra) & ~(alignment - 1));
diff --git a/src/core/lib/support/arena.cc b/src/core/lib/gpr/arena.cc
index 5b9dd370d8..687592a140 100644
--- a/src/core/lib/support/arena.cc
+++ b/src/core/lib/gpr/arena.cc
@@ -16,12 +16,20 @@
  *
  */
 
-#include "src/core/lib/support/arena.h"
+#include "src/core/lib/gpr/arena.h"
+
+#include <string.h>
+
 #include <grpc/support/alloc.h>
 #include <grpc/support/atm.h>
 #include <grpc/support/log.h>
 #include <grpc/support/useful.h>
 
+// TODO(roth): We currently assume that all callers need alignment of 16
+// bytes, which may be wrong in some cases.  As part of converting the
+// arena API to C++, we should consider replacing gpr_arena_alloc() with a
+// template that takes the type of the value being allocated, which
+// would allow us to use the alignment actually needed by the caller.
 #define ROUND_UP_TO_ALIGNMENT_SIZE(x) \
   (((x) + GPR_MAX_ALIGNMENT - 1u) & ~(GPR_MAX_ALIGNMENT - 1u))
 
@@ -36,9 +44,16 @@ struct gpr_arena {
   zone initial_zone;
 };
 
+static void* zalloc_aligned(size_t size) {
+  void* ptr = gpr_malloc_aligned(size, GPR_MAX_ALIGNMENT);
+  memset(ptr, 0, size);
+  return ptr;
+}
+
 gpr_arena* gpr_arena_create(size_t initial_size) {
   initial_size = ROUND_UP_TO_ALIGNMENT_SIZE(initial_size);
-  gpr_arena* a = (gpr_arena*)gpr_zalloc(sizeof(gpr_arena) + initial_size);
+  gpr_arena* a = (gpr_arena*)zalloc_aligned(
+      ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(gpr_arena)) + initial_size);
   a->initial_zone.size_end = initial_size;
   return a;
 }
@@ -46,10 +61,10 @@ gpr_arena* gpr_arena_create(size_t initial_size) {
 size_t gpr_arena_destroy(gpr_arena* arena) {
   gpr_atm size = gpr_atm_no_barrier_load(&arena->size_so_far);
   zone* z = (zone*)gpr_atm_no_barrier_load(&arena->initial_zone.next_atm);
-  gpr_free(arena);
+  gpr_free_aligned(arena);
   while (z) {
     zone* next_z = (zone*)gpr_atm_no_barrier_load(&z->next_atm);
-    gpr_free(z);
+    gpr_free_aligned(z);
     z = next_z;
   }
   return (size_t)size;
@@ -64,11 +79,12 @@ void* gpr_arena_alloc(gpr_arena* arena, size_t size) {
     zone* next_z = (zone*)gpr_atm_acq_load(&z->next_atm);
     if (next_z == nullptr) {
       size_t next_z_size = (size_t)gpr_atm_no_barrier_load(&arena->size_so_far);
-      next_z = (zone*)gpr_zalloc(sizeof(zone) + next_z_size);
+      next_z = (zone*)zalloc_aligned(ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(zone)) +
+                                     next_z_size);
       next_z->size_begin = z->size_end;
       next_z->size_end = z->size_end + next_z_size;
       if (!gpr_atm_rel_cas(&z->next_atm, (gpr_atm)NULL, (gpr_atm)next_z)) {
-        gpr_free(next_z);
+        gpr_free_aligned(next_z);
         next_z = (zone*)gpr_atm_acq_load(&z->next_atm);
       }
     }
@@ -79,5 +95,8 @@ void* gpr_arena_alloc(gpr_arena* arena, size_t size) {
   }
   GPR_ASSERT(start >= z->size_begin);
   GPR_ASSERT(start + size <= z->size_end);
-  return ((char*)(z + 1)) + start - z->size_begin;
+  char* ptr = (z == &arena->initial_zone)
+                  ? (char*)arena + ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(gpr_arena))
+                  : (char*)z + ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(zone));
+  return ptr + start - z->size_begin;
 }
diff --git a/src/core/lib/support/arena.h b/src/core/lib/gpr/arena.h
index cfe973a036..339771c0e3 100644
--- a/src/core/lib/support/arena.h
+++ b/src/core/lib/gpr/arena.h
@@ -22,8 +22,8 @@
 // Tracks the total memory allocated against it, so that future arenas can
 // pre-allocate the right amount of memory
 
-#ifndef GRPC_CORE_LIB_SUPPORT_ARENA_H
-#define GRPC_CORE_LIB_SUPPORT_ARENA_H
+#ifndef GRPC_CORE_LIB_GPR_ARENA_H
+#define GRPC_CORE_LIB_GPR_ARENA_H
 
 #include <stddef.h>
 
@@ -36,4 +36,4 @@ void* gpr_arena_alloc(gpr_arena* arena, size_t size);
 // Destroy an arena, returning the total number of bytes allocated
 size_t gpr_arena_destroy(gpr_arena* arena);
 
-#endif /* GRPC_CORE_LIB_SUPPORT_ARENA_H */
+#endif /* GRPC_CORE_LIB_GPR_ARENA_H */
diff --git a/src/core/lib/support/atm.cc b/src/core/lib/gpr/atm.cc
index 15bfe52d64..15bfe52d64 100644
--- a/src/core/lib/support/atm.cc
+++ b/src/core/lib/gpr/atm.cc
diff --git a/src/core/lib/support/avl.cc b/src/core/lib/gpr/avl.cc
index 0b67a21f2f..0b67a21f2f 100644
--- a/src/core/lib/support/avl.cc
+++ b/src/core/lib/gpr/avl.cc
diff --git a/src/core/lib/support/cmdline.cc b/src/core/lib/gpr/cmdline.cc
index da9f10a496..4118f9a72a 100644
--- a/src/core/lib/support/cmdline.cc
+++ b/src/core/lib/gpr/cmdline.cc
@@ -25,7 +25,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/string.h"
 
 typedef enum { ARGTYPE_INT, ARGTYPE_BOOL, ARGTYPE_STRING } argtype;
 
diff --git a/src/core/lib/support/cpu_iphone.cc b/src/core/lib/gpr/cpu_iphone.cc
index 2847e03ba5..2847e03ba5 100644
--- a/src/core/lib/support/cpu_iphone.cc
+++ b/src/core/lib/gpr/cpu_iphone.cc
diff --git a/src/core/lib/support/cpu_linux.cc b/src/core/lib/gpr/cpu_linux.cc
index 21b1a71dc9..21b1a71dc9 100644
--- a/src/core/lib/support/cpu_linux.cc
+++ b/src/core/lib/gpr/cpu_linux.cc
diff --git a/src/core/lib/support/cpu_posix.cc b/src/core/lib/gpr/cpu_posix.cc
index bca14a0c12..bca14a0c12 100644
--- a/src/core/lib/support/cpu_posix.cc
+++ b/src/core/lib/gpr/cpu_posix.cc
diff --git a/src/core/lib/support/cpu_windows.cc b/src/core/lib/gpr/cpu_windows.cc
index 8d89453403..8d89453403 100644
--- a/src/core/lib/support/cpu_windows.cc
+++ b/src/core/lib/gpr/cpu_windows.cc
diff --git a/src/core/lib/support/env.h b/src/core/lib/gpr/env.h
index 2452fd330d..7f35104be3 100644
--- a/src/core/lib/support/env.h
+++ b/src/core/lib/gpr/env.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_ENV_H
-#define GRPC_CORE_LIB_SUPPORT_ENV_H
+#ifndef GRPC_CORE_LIB_GPR_ENV_H
+#define GRPC_CORE_LIB_GPR_ENV_H
 
 #include <stdio.h>
 
@@ -38,4 +38,4 @@ void gpr_setenv(const char* name, const char* value);
    level of logging. So DO NOT USE THIS. */
 const char* gpr_getenv_silent(const char* name, char** dst);
 
-#endif /* GRPC_CORE_LIB_SUPPORT_ENV_H */
+#endif /* GRPC_CORE_LIB_GPR_ENV_H */
diff --git a/src/core/lib/support/env_linux.cc b/src/core/lib/gpr/env_linux.cc
index 0af2de9f7e..17902c3d0b 100644
--- a/src/core/lib/support/env_linux.cc
+++ b/src/core/lib/gpr/env_linux.cc
@@ -25,7 +25,7 @@
 
 #ifdef GPR_LINUX_ENV
 
-#include "src/core/lib/support/env.h"
+#include "src/core/lib/gpr/env.h"
 
 #include <dlfcn.h>
 #include <features.h>
@@ -36,7 +36,7 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/useful.h>
 
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/string.h"
 
 const char* gpr_getenv_silent(const char* name, char** dst) {
   const char* insecure_func_used = nullptr;
diff --git a/src/core/lib/support/env_posix.cc b/src/core/lib/gpr/env_posix.cc
index 7bea31ca55..599f85aa72 100644
--- a/src/core/lib/support/env_posix.cc
+++ b/src/core/lib/gpr/env_posix.cc
@@ -20,23 +20,23 @@
 
 #ifdef GPR_POSIX_ENV
 
-#include "src/core/lib/support/env.h"
+#include "src/core/lib/gpr/env.h"
 
 #include <stdlib.h>
 
 #include <grpc/support/log.h>
 
 #include <grpc/support/string_util.h>
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/string.h"
 
 const char* gpr_getenv_silent(const char* name, char** dst) {
   *dst = gpr_getenv(name);
-  return NULL;
+  return nullptr;
 }
 
 char* gpr_getenv(const char* name) {
   char* result = getenv(name);
-  return result == NULL ? result : gpr_strdup(result);
+  return result == nullptr ? result : gpr_strdup(result);
 }
 
 void gpr_setenv(const char* name, const char* value) {
diff --git a/src/core/lib/support/env_windows.cc b/src/core/lib/gpr/env_windows.cc
index cdb1d58ccd..9ca1e02d03 100644
--- a/src/core/lib/support/env_windows.cc
+++ b/src/core/lib/gpr/env_windows.cc
@@ -22,9 +22,9 @@
 
 #include <windows.h>
 
-#include "src/core/lib/support/env.h"
-#include "src/core/lib/support/string.h"
-#include "src/core/lib/support/string_windows.h"
+#include "src/core/lib/gpr/env.h"
+#include "src/core/lib/gpr/string.h"
+#include "src/core/lib/gpr/string_windows.h"
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
diff --git a/src/core/lib/support/fork.cc b/src/core/lib/gpr/fork.cc
index d59ca5584c..92023f4350 100644
--- a/src/core/lib/support/fork.cc
+++ b/src/core/lib/gpr/fork.cc
@@ -16,14 +16,14 @@
  *
  */
 
-#include "src/core/lib/support/fork.h"
+#include "src/core/lib/gpr/fork.h"
 
 #include <string.h>
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/useful.h>
 
-#include "src/core/lib/support/env.h"
+#include "src/core/lib/gpr/env.h"
 
 /*
  * NOTE: FORKING IS NOT GENERALLY SUPPORTED, THIS IS ONLY INTENDED TO WORK
@@ -38,18 +38,32 @@ void grpc_fork_support_init() {
   fork_support_enabled = 1;
 #else
   fork_support_enabled = 0;
+#endif
+  bool env_var_set = false;
   char* env = gpr_getenv("GRPC_ENABLE_FORK_SUPPORT");
-  if (env != NULL) {
+  if (env != nullptr) {
     static const char* truthy[] = {"yes",  "Yes",  "YES", "true",
                                    "True", "TRUE", "1"};
+    static const char* falsey[] = {"no",    "No",    "NO", "false",
+                                   "False", "FALSE", "0"};
     for (size_t i = 0; i < GPR_ARRAY_SIZE(truthy); i++) {
       if (0 == strcmp(env, truthy[i])) {
         fork_support_enabled = 1;
+        env_var_set = true;
+        break;
+      }
+    }
+    if (!env_var_set) {
+      for (size_t i = 0; i < GPR_ARRAY_SIZE(falsey); i++) {
+        if (0 == strcmp(env, falsey[i])) {
+          fork_support_enabled = 0;
+          env_var_set = true;
+          break;
+        }
       }
     }
     gpr_free(env);
   }
-#endif
   if (override_fork_support_enabled != -1) {
     fork_support_enabled = override_fork_support_enabled;
   }
diff --git a/src/core/lib/support/fork.h b/src/core/lib/gpr/fork.h
index 215d4214a6..94c61bb836 100644
--- a/src/core/lib/support/fork.h
+++ b/src/core/lib/gpr/fork.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_FORK_H
-#define GRPC_CORE_LIB_SUPPORT_FORK_H
+#ifndef GRPC_CORE_LIB_GPR_FORK_H
+#define GRPC_CORE_LIB_GPR_FORK_H
 
 /*
  * NOTE: FORKING IS NOT GENERALLY SUPPORTED, THIS IS ONLY INTENDED TO WORK
@@ -32,4 +32,4 @@ int grpc_fork_support_enabled(void);
 // environment variables/compile flags
 void grpc_enable_fork_support(int enable);
 
-#endif /* GRPC_CORE_LIB_SUPPORT_FORK_H */
+#endif /* GRPC_CORE_LIB_GPR_FORK_H */
diff --git a/src/core/lib/support/host_port.cc b/src/core/lib/gpr/host_port.cc
index cb8e3d4479..29178279d3 100644
--- a/src/core/lib/support/host_port.cc
+++ b/src/core/lib/gpr/host_port.cc
@@ -23,7 +23,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/string.h"
 
 int gpr_join_host_port(char** out, const char* host, int port) {
   if (host[0] != '[' && strchr(host, ':') != nullptr) {
diff --git a/src/core/lib/support/log.cc b/src/core/lib/gpr/log.cc
index 2a40745e97..19c0f6c34d 100644
--- a/src/core/lib/support/log.cc
+++ b/src/core/lib/gpr/log.cc
@@ -21,8 +21,8 @@
 #include <grpc/support/log.h>
 #include <grpc/support/port_platform.h>
 
-#include "src/core/lib/support/env.h"
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/env.h"
+#include "src/core/lib/gpr/string.h"
 
 #include <stdio.h>
 #include <string.h>
diff --git a/src/core/lib/support/log_android.cc b/src/core/lib/gpr/log_android.cc
index 0d3ac0fe52..0d3ac0fe52 100644
--- a/src/core/lib/support/log_android.cc
+++ b/src/core/lib/gpr/log_android.cc
diff --git a/src/core/lib/support/log_linux.cc b/src/core/lib/gpr/log_linux.cc
index 6b1f1c71e4..6b1f1c71e4 100644
--- a/src/core/lib/support/log_linux.cc
+++ b/src/core/lib/gpr/log_linux.cc
diff --git a/src/core/lib/support/log_posix.cc b/src/core/lib/gpr/log_posix.cc
index 9fab480a8d..6f93cdefcd 100644
--- a/src/core/lib/support/log_posix.cc
+++ b/src/core/lib/gpr/log_posix.cc
@@ -35,15 +35,15 @@ static intptr_t gettid(void) { return (intptr_t)pthread_self(); }
 void gpr_log(const char* file, int line, gpr_log_severity severity,
              const char* format, ...) {
   char buf[64];
-  char* allocated = NULL;
-  char* message = NULL;
+  char* allocated = nullptr;
+  char* message = nullptr;
   int ret;
   va_list args;
   va_start(args, format);
   ret = vsnprintf(buf, sizeof(buf), format, args);
   va_end(args);
   if (ret < 0) {
-    message = NULL;
+    message = nullptr;
   } else if ((size_t)ret <= sizeof(buf) - 1) {
     message = buf;
   } else {
@@ -66,7 +66,7 @@ void gpr_default_log(gpr_log_func_args* args) {
 
   timer = (time_t)now.tv_sec;
   final_slash = strrchr(args->file, '/');
-  if (final_slash == NULL)
+  if (final_slash == nullptr)
     display_file = args->file;
   else
     display_file = final_slash + 1;
diff --git a/src/core/lib/support/log_windows.cc b/src/core/lib/gpr/log_windows.cc
index 0013bf448f..caaa973f5a 100644
--- a/src/core/lib/support/log_windows.cc
+++ b/src/core/lib/gpr/log_windows.cc
@@ -29,8 +29,8 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
 
-#include "src/core/lib/support/string.h"
-#include "src/core/lib/support/string_windows.h"
+#include "src/core/lib/gpr/string.h"
+#include "src/core/lib/gpr/string_windows.h"
 
 void gpr_log(const char* file, int line, gpr_log_severity severity,
              const char* format, ...) {
diff --git a/src/core/lib/support/mpscq.cc b/src/core/lib/gpr/mpscq.cc
index 47e896d2df..34fc050a11 100644
--- a/src/core/lib/support/mpscq.cc
+++ b/src/core/lib/gpr/mpscq.cc
@@ -16,7 +16,7 @@
  *
  */
 
-#include "src/core/lib/support/mpscq.h"
+#include "src/core/lib/gpr/mpscq.h"
 
 #include <grpc/support/log.h>
 
diff --git a/src/core/lib/support/mpscq.h b/src/core/lib/gpr/mpscq.h
index 648ead1f5b..4409c5c9f5 100644
--- a/src/core/lib/support/mpscq.h
+++ b/src/core/lib/gpr/mpscq.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_MPSCQ_H
-#define GRPC_CORE_LIB_SUPPORT_MPSCQ_H
+#ifndef GRPC_CORE_LIB_GPR_MPSCQ_H
+#define GRPC_CORE_LIB_GPR_MPSCQ_H
 
 #include <grpc/support/atm.h>
 #include <grpc/support/sync.h>
@@ -81,4 +81,4 @@ gpr_mpscq_node* gpr_locked_mpscq_try_pop(gpr_locked_mpscq* q);
 // calling this function
 gpr_mpscq_node* gpr_locked_mpscq_pop(gpr_locked_mpscq* q);
 
-#endif /* GRPC_CORE_LIB_SUPPORT_MPSCQ_H */
+#endif /* GRPC_CORE_LIB_GPR_MPSCQ_H */
diff --git a/src/core/lib/support/murmur_hash.cc b/src/core/lib/gpr/murmur_hash.cc
index 2f0e71a53c..3f5e04d211 100644
--- a/src/core/lib/support/murmur_hash.cc
+++ b/src/core/lib/gpr/murmur_hash.cc
@@ -16,7 +16,7 @@
  *
  */
 
-#include "src/core/lib/support/murmur_hash.h"
+#include "src/core/lib/gpr/murmur_hash.h"
 
 #include <string.h>
 
diff --git a/src/core/lib/support/murmur_hash.h b/src/core/lib/gpr/murmur_hash.h
index 422770f103..8004889a9a 100644
--- a/src/core/lib/support/murmur_hash.h
+++ b/src/core/lib/gpr/murmur_hash.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_MURMUR_HASH_H
-#define GRPC_CORE_LIB_SUPPORT_MURMUR_HASH_H
+#ifndef GRPC_CORE_LIB_GPR_MURMUR_HASH_H
+#define GRPC_CORE_LIB_GPR_MURMUR_HASH_H
 
 #include <grpc/support/port_platform.h>
 
@@ -26,4 +26,4 @@
 /* compute the hash of key (length len) */
 uint32_t gpr_murmur_hash3(const void* key, size_t len, uint32_t seed);
 
-#endif /* GRPC_CORE_LIB_SUPPORT_MURMUR_HASH_H */
+#endif /* GRPC_CORE_LIB_GPR_MURMUR_HASH_H */
diff --git a/src/core/lib/support/spinlock.h b/src/core/lib/gpr/spinlock.h
index 8b439642e9..f03be1d791 100644
--- a/src/core/lib/support/spinlock.h
+++ b/src/core/lib/gpr/spinlock.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_SPINLOCK_H
-#define GRPC_CORE_LIB_SUPPORT_SPINLOCK_H
+#ifndef GRPC_CORE_LIB_GPR_SPINLOCK_H
+#define GRPC_CORE_LIB_GPR_SPINLOCK_H
 
 #include <grpc/support/atm.h>
 
@@ -41,4 +41,4 @@ typedef struct {
   do {                          \
   } while (!gpr_spinlock_trylock((lock)))
 
-#endif /* GRPC_CORE_LIB_SUPPORT_SPINLOCK_H */
+#endif /* GRPC_CORE_LIB_GPR_SPINLOCK_H */
diff --git a/src/core/lib/support/string.cc b/src/core/lib/gpr/string.cc
index e31ad72c68..919d957d1b 100644
--- a/src/core/lib/support/string.cc
+++ b/src/core/lib/gpr/string.cc
@@ -16,7 +16,7 @@
  *
  */
 
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/string.h"
 
 #include <ctype.h>
 #include <limits.h>
diff --git a/src/core/lib/support/string.h b/src/core/lib/gpr/string.h
index dd37f0b0e1..ef3a8c6086 100644
--- a/src/core/lib/support/string.h
+++ b/src/core/lib/gpr/string.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_STRING_H
-#define GRPC_CORE_LIB_SUPPORT_STRING_H
+#ifndef GRPC_CORE_LIB_GPR_STRING_H
+#define GRPC_CORE_LIB_GPR_STRING_H
 
 #include <stdbool.h>
 #include <stddef.h>
@@ -106,4 +106,4 @@ void* gpr_memrchr(const void* s, int c, size_t n);
 /** Return true if lower(s) equals "true", "yes" or "1", otherwise false. */
 bool gpr_is_true(const char* s);
 
-#endif /* GRPC_CORE_LIB_SUPPORT_STRING_H */
+#endif /* GRPC_CORE_LIB_GPR_STRING_H */
diff --git a/src/core/lib/support/string_posix.cc b/src/core/lib/gpr/string_posix.cc
index 8b818e39b9..8b818e39b9 100644
--- a/src/core/lib/support/string_posix.cc
+++ b/src/core/lib/gpr/string_posix.cc
diff --git a/src/core/lib/support/string_util_windows.cc b/src/core/lib/gpr/string_util_windows.cc
index e2b386be55..8c8c99cd21 100644
--- a/src/core/lib/support/string_util_windows.cc
+++ b/src/core/lib/gpr/string_util_windows.cc
@@ -36,8 +36,8 @@
 #include <grpc/support/log_windows.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/lib/support/string.h"
-#include "src/core/lib/support/string_windows.h"
+#include "src/core/lib/gpr/string.h"
+#include "src/core/lib/gpr/string_windows.h"
 
 #if defined UNICODE || defined _UNICODE
 LPTSTR
diff --git a/src/core/lib/support/string_windows.cc b/src/core/lib/gpr/string_windows.cc
index ceb78f0054..25bfd412e4 100644
--- a/src/core/lib/support/string_windows.cc
+++ b/src/core/lib/gpr/string_windows.cc
@@ -29,7 +29,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/string.h"
 
 int gpr_asprintf(char** strp, const char* format, ...) {
   va_list args;
diff --git a/src/core/lib/support/string_windows.h b/src/core/lib/gpr/string_windows.h
index 7c7f31e7aa..e370f802cf 100644
--- a/src/core/lib/support/string_windows.h
+++ b/src/core/lib/gpr/string_windows.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_STRING_WINDOWS_H
-#define GRPC_CORE_LIB_SUPPORT_STRING_WINDOWS_H
+#ifndef GRPC_CORE_LIB_GPR_STRING_WINDOWS_H
+#define GRPC_CORE_LIB_GPR_STRING_WINDOWS_H
 
 #include <grpc/support/port_platform.h>
 
@@ -29,4 +29,4 @@ LPSTR gpr_tchar_to_char(LPCTSTR input);
 
 #endif /* GPR_WINDOWS */
 
-#endif /* GRPC_CORE_LIB_SUPPORT_STRING_WINDOWS_H */
+#endif /* GRPC_CORE_LIB_GPR_STRING_WINDOWS_H */
diff --git a/src/core/lib/support/subprocess_posix.cc b/src/core/lib/gpr/subprocess_posix.cc
index dc046b6499..dc046b6499 100644
--- a/src/core/lib/support/subprocess_posix.cc
+++ b/src/core/lib/gpr/subprocess_posix.cc
diff --git a/src/core/lib/support/subprocess_windows.cc b/src/core/lib/gpr/subprocess_windows.cc
index dcdafb5a63..1947d475e3 100644
--- a/src/core/lib/support/subprocess_windows.cc
+++ b/src/core/lib/gpr/subprocess_windows.cc
@@ -27,8 +27,8 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/subprocess.h>
-#include "src/core/lib/support/string.h"
-#include "src/core/lib/support/string_windows.h"
+#include "src/core/lib/gpr/string.h"
+#include "src/core/lib/gpr/string_windows.h"
 
 struct gpr_subprocess {
   PROCESS_INFORMATION pi;
diff --git a/src/core/lib/support/sync.cc b/src/core/lib/gpr/sync.cc
index 347ffcd00e..347ffcd00e 100644
--- a/src/core/lib/support/sync.cc
+++ b/src/core/lib/gpr/sync.cc
diff --git a/src/core/lib/support/sync_posix.cc b/src/core/lib/gpr/sync_posix.cc
index c3f6b10463..c3f6b10463 100644
--- a/src/core/lib/support/sync_posix.cc
+++ b/src/core/lib/gpr/sync_posix.cc
diff --git a/src/core/lib/support/sync_windows.cc b/src/core/lib/gpr/sync_windows.cc
index 7cd41633d5..7cd41633d5 100644
--- a/src/core/lib/support/sync_windows.cc
+++ b/src/core/lib/gpr/sync_windows.cc
diff --git a/src/core/lib/support/thd.cc b/src/core/lib/gpr/thd.cc
index ca62615d65..ca62615d65 100644
--- a/src/core/lib/support/thd.cc
+++ b/src/core/lib/gpr/thd.cc
diff --git a/src/core/lib/support/thd_internal.h b/src/core/lib/gpr/thd_internal.h
index 38bffc847d..692c00c8e1 100644
--- a/src/core/lib/support/thd_internal.h
+++ b/src/core/lib/gpr/thd_internal.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_THD_INTERNAL_H
-#define GRPC_CORE_LIB_SUPPORT_THD_INTERNAL_H
+#ifndef GRPC_CORE_LIB_GPR_THD_INTERNAL_H
+#define GRPC_CORE_LIB_GPR_THD_INTERNAL_H
 
 #include <grpc/support/time.h>
 
@@ -27,4 +27,4 @@ void gpr_thd_init();
 /* Wait for all outstanding threads to finish, up to deadline */
 int gpr_await_threads(gpr_timespec deadline);
 
-#endif /* GRPC_CORE_LIB_SUPPORT_THD_INTERNAL_H */
+#endif /* GRPC_CORE_LIB_GPR_THD_INTERNAL_H */
diff --git a/src/core/lib/support/thd_posix.cc b/src/core/lib/gpr/thd_posix.cc
index f0ed48dbfc..cfff0df6de 100644
--- a/src/core/lib/support/thd_posix.cc
+++ b/src/core/lib/gpr/thd_posix.cc
@@ -31,7 +31,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "src/core/lib/support/fork.h"
+#include "src/core/lib/gpr/fork.h"
 
 static gpr_mu g_mu;
 static gpr_cv g_cv;
diff --git a/src/core/lib/support/thd_windows.cc b/src/core/lib/gpr/thd_windows.cc
index f920770f32..f920770f32 100644
--- a/src/core/lib/support/thd_windows.cc
+++ b/src/core/lib/gpr/thd_windows.cc
diff --git a/src/core/lib/support/time.cc b/src/core/lib/gpr/time.cc
index 6903674d75..6903674d75 100644
--- a/src/core/lib/support/time.cc
+++ b/src/core/lib/gpr/time.cc
diff --git a/src/core/lib/support/time_posix.cc b/src/core/lib/gpr/time_posix.cc
index 47a849480f..9c7e86b080 100644
--- a/src/core/lib/support/time_posix.cc
+++ b/src/core/lib/gpr/time_posix.cc
@@ -17,7 +17,7 @@
  */
 
 #include <grpc/support/port_platform.h>
-#include "src/core/lib/support/time_precise.h"
+#include "src/core/lib/gpr/time_precise.h"
 
 #ifdef GPR_POSIX_TIME
 
@@ -107,7 +107,7 @@ static gpr_timespec now_impl(gpr_clock_type clock) {
   now.clock_type = clock;
   switch (clock) {
     case GPR_CLOCK_REALTIME:
-      gettimeofday(&now_tv, NULL);
+      gettimeofday(&now_tv, nullptr);
       now.tv_sec = now_tv.tv_sec;
       now.tv_nsec = now_tv.tv_usec * 1000;
       break;
diff --git a/src/core/lib/support/time_precise.cc b/src/core/lib/gpr/time_precise.cc
index b7372df1b8..3c7aaabc40 100644
--- a/src/core/lib/support/time_precise.cc
+++ b/src/core/lib/gpr/time_precise.cc
@@ -20,7 +20,7 @@
 #include <grpc/support/time.h>
 #include <stdio.h>
 
-#include "src/core/lib/support/time_precise.h"
+#include "src/core/lib/gpr/time_precise.h"
 
 #ifdef GRPC_TIMERS_RDTSC
 #if defined(__i386__)
diff --git a/src/core/lib/support/time_precise.h b/src/core/lib/gpr/time_precise.h
index 35cd154dbd..acc4ee3d1b 100644
--- a/src/core/lib/support/time_precise.h
+++ b/src/core/lib/gpr/time_precise.h
@@ -16,12 +16,12 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_TIME_PRECISE_H
-#define GRPC_CORE_LIB_SUPPORT_TIME_PRECISE_H
+#ifndef GRPC_CORE_LIB_GPR_TIME_PRECISE_H
+#define GRPC_CORE_LIB_GPR_TIME_PRECISE_H
 
 #include <grpc/support/time.h>
 
 void gpr_precise_clock_init(void);
 void gpr_precise_clock_now(gpr_timespec* clk);
 
-#endif /* GRPC_CORE_LIB_SUPPORT_TIME_PRECISE_H */
+#endif /* GRPC_CORE_LIB_GPR_TIME_PRECISE_H */
diff --git a/src/core/lib/support/time_windows.cc b/src/core/lib/gpr/time_windows.cc
index fb17e5c079..247cc16468 100644
--- a/src/core/lib/support/time_windows.cc
+++ b/src/core/lib/gpr/time_windows.cc
@@ -28,7 +28,7 @@
 #include <process.h>
 #include <sys/timeb.h>
 
-#include "src/core/lib/support/time_precise.h"
+#include "src/core/lib/gpr/time_precise.h"
 
 static LARGE_INTEGER g_start_time;
 static double g_time_scale;
diff --git a/src/core/lib/support/tls_pthread.cc b/src/core/lib/gpr/tls_pthread.cc
index ebeef2a8c2..ebeef2a8c2 100644
--- a/src/core/lib/support/tls_pthread.cc
+++ b/src/core/lib/gpr/tls_pthread.cc
diff --git a/src/core/lib/support/tmpfile.h b/src/core/lib/gpr/tmpfile.h
index c5ceda8675..f47ec7aa63 100644
--- a/src/core/lib/support/tmpfile.h
+++ b/src/core/lib/gpr/tmpfile.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_TMPFILE_H
-#define GRPC_CORE_LIB_SUPPORT_TMPFILE_H
+#ifndef GRPC_CORE_LIB_GPR_TMPFILE_H
+#define GRPC_CORE_LIB_GPR_TMPFILE_H
 
 #include <stdio.h>
 
@@ -27,4 +27,4 @@
    unless an error occurs in which case it will be set to NULL. */
 FILE* gpr_tmpfile(const char* prefix, char** tmp_filename);
 
-#endif /* GRPC_CORE_LIB_SUPPORT_TMPFILE_H */
+#endif /* GRPC_CORE_LIB_GPR_TMPFILE_H */
diff --git a/src/core/lib/support/tmpfile_msys.cc b/src/core/lib/gpr/tmpfile_msys.cc
index 430e866629..76cd886f3a 100644
--- a/src/core/lib/support/tmpfile_msys.cc
+++ b/src/core/lib/gpr/tmpfile_msys.cc
@@ -29,8 +29,8 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/lib/support/string_windows.h"
-#include "src/core/lib/support/tmpfile.h"
+#include "src/core/lib/gpr/string_windows.h"
+#include "src/core/lib/gpr/tmpfile.h"
 
 FILE* gpr_tmpfile(const char* prefix, char** tmp_filename_out) {
   FILE* result = NULL;
diff --git a/src/core/lib/support/tmpfile_posix.cc b/src/core/lib/gpr/tmpfile_posix.cc
index 79c5c68874..ffdad335d6 100644
--- a/src/core/lib/support/tmpfile_posix.cc
+++ b/src/core/lib/gpr/tmpfile_posix.cc
@@ -20,7 +20,7 @@
 
 #ifdef GPR_POSIX_TMPFILE
 
-#include "src/core/lib/support/tmpfile.h"
+#include "src/core/lib/gpr/tmpfile.h"
 
 #include <errno.h>
 #include <stdlib.h>
@@ -31,7 +31,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/string.h"
 
 FILE* gpr_tmpfile(const char* prefix, char** tmp_filename) {
   FILE* result = nullptr;
diff --git a/src/core/lib/support/tmpfile_windows.cc b/src/core/lib/gpr/tmpfile_windows.cc
index 2b10bcde43..d486808418 100644
--- a/src/core/lib/support/tmpfile_windows.cc
+++ b/src/core/lib/gpr/tmpfile_windows.cc
@@ -29,8 +29,8 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/lib/support/string_windows.h"
-#include "src/core/lib/support/tmpfile.h"
+#include "src/core/lib/gpr/string_windows.h"
+#include "src/core/lib/gpr/tmpfile.h"
 
 FILE* gpr_tmpfile(const char* prefix, char** tmp_filename_out) {
   FILE* result = NULL;
diff --git a/src/core/lib/support/wrap_memcpy.cc b/src/core/lib/gpr/wrap_memcpy.cc
index 9b8608e056..9b8608e056 100644
--- a/src/core/lib/support/wrap_memcpy.cc
+++ b/src/core/lib/gpr/wrap_memcpy.cc
diff --git a/src/core/lib/gprpp/README.md b/src/core/lib/gprpp/README.md
new file mode 100644
index 0000000000..eab018bb31
--- /dev/null
+++ b/src/core/lib/gprpp/README.md
@@ -0,0 +1,16 @@
+# GPR++ - Google Portable Runtime for C++
+
+The files in this directory contain various utility code for C++ code.
+None of this code is gRPC-specific; anything here may also be useful
+for other open source projects written in C++.
+
+Note that this is one of the few places in src/core where we allow
+the use of portability macros.
+
+Note that this is the only place in src/core where we allow
+use of the C++ standard library (i.e., anything in the `std::`
+namespace).  And for now, we require that any use of the
+standard library is build-time-only -- i.e., we do not allow
+run-time dependencies on libstdc++.  For more details, see
+[gRFC L6](/grpc/proposal/blob/master/L6-allow-c%2B%2B-in-grpc-core.md) and
+[Moving gRPC core to C++](/grpc/grpc/blob/master/doc/core/moving-to-c%2B%2B.md).
diff --git a/src/core/lib/support/abstract.h b/src/core/lib/gprpp/abstract.h
index 5498769a7d..cc96edc49b 100644
--- a/src/core/lib/support/abstract.h
+++ b/src/core/lib/gprpp/abstract.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_ABSTRACT_H
-#define GRPC_CORE_LIB_SUPPORT_ABSTRACT_H
+#ifndef GRPC_CORE_LIB_GPRPP_ABSTRACT_H
+#define GRPC_CORE_LIB_GPRPP_ABSTRACT_H
 
 // This is needed to support abstract base classes in the c core. Since gRPC
 // doesn't have a c++ runtime, it will hit a linker error on delete unless
@@ -26,4 +26,9 @@
 #define GRPC_ABSTRACT_BASE_CLASS \
   static void operator delete(void* p) { abort(); }
 
-#endif /* GRPC_CORE_LIB_SUPPORT_ABSTRACT_H */
+// gRPC currently can't depend on libstdc++, so we can't use "= 0" for
+// pure virtual methods.  Instead, we use this macro.
+#define GRPC_ABSTRACT \
+  { GPR_ASSERT(false); }
+
+#endif /* GRPC_CORE_LIB_GPRPP_ABSTRACT_H */
diff --git a/src/core/lib/support/atomic.h b/src/core/lib/gprpp/atomic.h
index 73c59ae3cd..8b08fc4e9c 100644
--- a/src/core/lib/support/atomic.h
+++ b/src/core/lib/gprpp/atomic.h
@@ -16,15 +16,15 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_ATOMIC_H
-#define GRPC_CORE_LIB_SUPPORT_ATOMIC_H
+#ifndef GRPC_CORE_LIB_GPRPP_ATOMIC_H
+#define GRPC_CORE_LIB_GPRPP_ATOMIC_H
 
 #include <grpc/support/port_platform.h>
 
 #ifdef GPR_HAS_CXX11_ATOMIC
-#include "src/core/lib/support/atomic_with_std.h"
+#include "src/core/lib/gprpp/atomic_with_std.h"
 #else
-#include "src/core/lib/support/atomic_with_atm.h"
+#include "src/core/lib/gprpp/atomic_with_atm.h"
 #endif
 
-#endif /* GRPC_CORE_LIB_SUPPORT_ATOMIC_H */
+#endif /* GRPC_CORE_LIB_GPRPP_ATOMIC_H */
diff --git a/src/core/lib/support/atomic_with_atm.h b/src/core/lib/gprpp/atomic_with_atm.h
index fe00e9b5bc..6abf0bc38d 100644
--- a/src/core/lib/support/atomic_with_atm.h
+++ b/src/core/lib/gprpp/atomic_with_atm.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_ATOMIC_WITH_ATM_H
-#define GRPC_CORE_LIB_SUPPORT_ATOMIC_WITH_ATM_H
+#ifndef GRPC_CORE_LIB_GPRPP_ATOMIC_WITH_ATM_H
+#define GRPC_CORE_LIB_GPRPP_ATOMIC_WITH_ATM_H
 
 #include <grpc/support/atm.h>
 
@@ -52,4 +52,4 @@ class atomic<bool> {
 
 }  // namespace grpc_core
 
-#endif /* GRPC_CORE_LIB_SUPPORT_ATOMIC_WITH_ATM_H */
+#endif /* GRPC_CORE_LIB_GPRPP_ATOMIC_WITH_ATM_H */
diff --git a/src/core/lib/support/atomic_with_std.h b/src/core/lib/gprpp/atomic_with_std.h
index c7a92f7012..83322b81c1 100644
--- a/src/core/lib/support/atomic_with_std.h
+++ b/src/core/lib/gprpp/atomic_with_std.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_ATOMIC_WITH_STD_H
-#define GRPC_CORE_LIB_SUPPORT_ATOMIC_WITH_STD_H
+#ifndef GRPC_CORE_LIB_GPRPP_ATOMIC_WITH_STD_H
+#define GRPC_CORE_LIB_GPRPP_ATOMIC_WITH_STD_H
 
 #include <atomic>
 
@@ -30,4 +30,4 @@ typedef std::memory_order memory_order;
 
 }  // namespace grpc_core
 
-#endif /* GRPC_CORE_LIB_SUPPORT_ATOMIC_WITH_STD_H */
+#endif /* GRPC_CORE_LIB_GPRPP_ATOMIC_WITH_STD_H */
diff --git a/src/core/lib/support/debug_location.h b/src/core/lib/gprpp/debug_location.h
index 9b3f9220fc..287761beaf 100644
--- a/src/core/lib/support/debug_location.h
+++ b/src/core/lib/gprpp/debug_location.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_DEBUG_LOCATION_H
-#define GRPC_CORE_LIB_SUPPORT_DEBUG_LOCATION_H
+#ifndef GRPC_CORE_LIB_GPRPP_DEBUG_LOCATION_H
+#define GRPC_CORE_LIB_GPRPP_DEBUG_LOCATION_H
 
 namespace grpc_core {
 
@@ -49,4 +49,4 @@ class DebugLocation {
 
 }  // namespace grpc_core
 
-#endif /* GRPC_CORE_LIB_SUPPORT_DEBUG_LOCATION_H */
+#endif /* GRPC_CORE_LIB_GPRPP_DEBUG_LOCATION_H */
diff --git a/src/core/lib/gprpp/inlined_vector.h b/src/core/lib/gprpp/inlined_vector.h
new file mode 100644
index 0000000000..b78f85b893
--- /dev/null
+++ b/src/core/lib/gprpp/inlined_vector.h
@@ -0,0 +1,112 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_GPRPP_INLINED_VECTOR_H
+#define GRPC_CORE_LIB_GPRPP_INLINED_VECTOR_H
+
+#include <cassert>
+
+#include "src/core/lib/gprpp/memory.h"
+
+namespace grpc_core {
+
+// NOTE: We eventually want to use absl::InlinedVector here.  However,
+// there are currently build problems that prevent us from using absl.
+// In the interim, we define a custom implementation as a place-holder,
+// with the intent to eventually replace this with the absl
+// implementation.
+//
+// This place-holder implementation does not implement the full set of
+// functionality from the absl version; it has just the methods that we
+// currently happen to need in gRPC.  If additional functionality is
+// needed before this gets replaced with the absl version, it can be
+// added, with the following proviso:
+//
+// ANY METHOD ADDED HERE MUST COMPLY WITH THE INTERFACE IN THE absl
+// IMPLEMENTATION!
+//
+// TODO(ctiller, nnoble, roth): Replace this with absl::InlinedVector
+// once we integrate absl into the gRPC build system in a usable way.
+template <typename T, size_t N>
+class InlinedVector {
+ public:
+  InlinedVector() {}
+  ~InlinedVector() {
+    for (size_t i = 0; i < size_ && i < N; ++i) {
+      T& value = *reinterpret_cast<T*>(inline_ + i);
+      value.~T();
+    }
+    if (size_ > N) {  // Avoid subtracting two signed values.
+      for (size_t i = 0; i < size_ - N; ++i) {
+        dynamic_[i].~T();
+      }
+    }
+    gpr_free(dynamic_);
+  }
+
+  // For now, we do not support copying.
+  InlinedVector(const InlinedVector&) = delete;
+  InlinedVector& operator=(const InlinedVector&) = delete;
+
+  T& operator[](size_t offset) {
+    assert(offset < size_);
+    if (offset < N) {
+      return *reinterpret_cast<T*>(inline_ + offset);
+    } else {
+      return dynamic_[offset - N];
+    }
+  }
+
+  template <typename... Args>
+  void emplace_back(Args&&... args) {
+    if (size_ < N) {
+      new (&inline_[size_]) T(std::forward<Args>(args)...);
+    } else {
+      if (size_ - N == dynamic_capacity_) {
+        size_t new_capacity =
+            dynamic_capacity_ == 0 ? 2 : dynamic_capacity_ * 2;
+        T* new_dynamic = static_cast<T*>(gpr_malloc(sizeof(T) * new_capacity));
+        for (size_t i = 0; i < dynamic_capacity_; ++i) {
+          new (&new_dynamic[i]) T(std::move(dynamic_[i]));
+          dynamic_[i].~T();
+        }
+        gpr_free(dynamic_);
+        dynamic_ = new_dynamic;
+        dynamic_capacity_ = new_capacity;
+      }
+      new (&dynamic_[size_ - N]) T(std::forward<Args>(args)...);
+    }
+    ++size_;
+  }
+
+  void push_back(const T& value) { emplace_back(value); }
+
+  void push_back(T&& value) { emplace_back(std::move(value)); }
+
+  size_t size() const { return size_; }
+
+ private:
+  typename std::aligned_storage<sizeof(T)>::type inline_[N];
+  T* dynamic_ = nullptr;
+  size_t size_ = 0;
+  size_t dynamic_capacity_ = 0;
+};
+
+}  // namespace grpc_core
+
+#endif /* GRPC_CORE_LIB_GPRPP_INLINED_VECTOR_H */
diff --git a/src/core/lib/support/manual_constructor.h b/src/core/lib/gprpp/manual_constructor.h
index fda7653dbc..cee38abc1b 100644
--- a/src/core/lib/support/manual_constructor.h
+++ b/src/core/lib/gprpp/manual_constructor.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_MANUAL_CONSTRUCTOR_H
-#define GRPC_CORE_LIB_SUPPORT_MANUAL_CONSTRUCTOR_H
+#ifndef GRPC_CORE_LIB_GPRPP_MANUAL_CONSTRUCTOR_H
+#define GRPC_CORE_LIB_GPRPP_MANUAL_CONSTRUCTOR_H
 
 // manually construct a region of memory with some type
 
diff --git a/src/core/lib/support/memory.h b/src/core/lib/gprpp/memory.h
index 695418e3e1..17f42f5983 100644
--- a/src/core/lib/support/memory.h
+++ b/src/core/lib/gprpp/memory.h
@@ -16,8 +16,8 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_MEMORY_H
-#define GRPC_CORE_LIB_SUPPORT_MEMORY_H
+#ifndef GRPC_CORE_LIB_GPRPP_MEMORY_H
+#define GRPC_CORE_LIB_GPRPP_MEMORY_H
 
 #include <grpc/support/alloc.h>
 
@@ -97,4 +97,4 @@ class Allocator {
 
 }  // namespace grpc_core
 
-#endif /* GRPC_CORE_LIB_SUPPORT_MEMORY_H */
+#endif /* GRPC_CORE_LIB_GPRPP_MEMORY_H */
diff --git a/src/core/lib/gprpp/orphanable.h b/src/core/lib/gprpp/orphanable.h
new file mode 100644
index 0000000000..50199730c9
--- /dev/null
+++ b/src/core/lib/gprpp/orphanable.h
@@ -0,0 +1,171 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_GPRPP_ORPHANABLE_H
+#define GRPC_CORE_LIB_GPRPP_ORPHANABLE_H
+
+#include <grpc/support/log.h>
+#include <grpc/support/sync.h>
+
+#include <memory>
+
+#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gprpp/abstract.h"
+#include "src/core/lib/gprpp/debug_location.h"
+#include "src/core/lib/gprpp/memory.h"
+
+namespace grpc_core {
+
+// A base class for orphanable objects, which have one external owner
+// but are not necessarily destroyed immediately when the external owner
+// gives up ownership.  Instead, the owner calls the object's Orphan()
+// method, and the object then takes responsibility for its own cleanup
+// and destruction.
+class Orphanable {
+ public:
+  // Gives up ownership of the object.  The implementation must arrange
+  // to eventually destroy the object without further interaction from the
+  // caller.
+  virtual void Orphan() GRPC_ABSTRACT;
+
+  // Not copyable or movable.
+  Orphanable(const Orphanable&) = delete;
+  Orphanable& operator=(const Orphanable&) = delete;
+
+  GRPC_ABSTRACT_BASE_CLASS
+
+ protected:
+  Orphanable() {}
+  virtual ~Orphanable() {}
+};
+
+template <typename T>
+class OrphanableDelete {
+ public:
+  void operator()(T* p) { p->Orphan(); }
+};
+
+template <typename T, typename Deleter = OrphanableDelete<T>>
+using OrphanablePtr = std::unique_ptr<T, Deleter>;
+
+template <typename T, typename... Args>
+inline OrphanablePtr<T> MakeOrphanable(Args&&... args) {
+  return OrphanablePtr<T>(New<T>(std::forward<Args>(args)...));
+}
+
+// A type of Orphanable with internal ref-counting.
+class InternallyRefCounted : public Orphanable {
+ public:
+  // Not copyable nor movable.
+  InternallyRefCounted(const InternallyRefCounted&) = delete;
+  InternallyRefCounted& operator=(const InternallyRefCounted&) = delete;
+
+  GRPC_ABSTRACT_BASE_CLASS
+
+ protected:
+  InternallyRefCounted() { gpr_ref_init(&refs_, 1); }
+  virtual ~InternallyRefCounted() {}
+
+  void Ref() { gpr_ref(&refs_); }
+
+  void Unref() {
+    if (gpr_unref(&refs_)) {
+      Delete(this);
+    }
+  }
+
+  // Allow Delete() to access destructor.
+  template <typename T>
+  friend void Delete(T*);
+
+ private:
+  gpr_refcount refs_;
+};
+
+// An alternative version of the InternallyRefCounted base class that
+// supports tracing.  This is intended to be used in cases where the
+// object will be handled both by idiomatic C++ code using smart
+// pointers and legacy code that is manually calling Ref() and Unref().
+// Once all of our code is converted to idiomatic C++, we may be able to
+// eliminate this class.
+class InternallyRefCountedWithTracing : public Orphanable {
+ public:
+  // Not copyable nor movable.
+  InternallyRefCountedWithTracing(const InternallyRefCountedWithTracing&) =
+      delete;
+  InternallyRefCountedWithTracing& operator=(
+      const InternallyRefCountedWithTracing&) = delete;
+
+  GRPC_ABSTRACT_BASE_CLASS
+
+ protected:
+  // Allow Delete() to access destructor.
+  template <typename T>
+  friend void Delete(T*);
+
+  InternallyRefCountedWithTracing()
+      : InternallyRefCountedWithTracing(static_cast<TraceFlag*>(nullptr)) {}
+
+  explicit InternallyRefCountedWithTracing(TraceFlag* trace_flag)
+      : trace_flag_(trace_flag) {
+    gpr_ref_init(&refs_, 1);
+  }
+
+#ifdef NDEBUG
+  explicit InternallyRefCountedWithTracing(DebugOnlyTraceFlag* trace_flag)
+      : InternallyRefCountedWithTracing() {}
+#endif
+
+  virtual ~InternallyRefCountedWithTracing() {}
+
+  void Ref() { gpr_ref(&refs_); }
+
+  void Ref(const DebugLocation& location, const char* reason) {
+    if (location.Log() && trace_flag_ != nullptr && trace_flag_->enabled()) {
+      gpr_atm old_refs = gpr_atm_no_barrier_load(&refs_.count);
+      gpr_log(GPR_DEBUG, "%s:%p %s:%d ref %" PRIdPTR " -> %" PRIdPTR " %s",
+              trace_flag_->name(), this, location.file(), location.line(),
+              old_refs, old_refs + 1, reason);
+    }
+    Ref();
+  }
+
+  void Unref() {
+    if (gpr_unref(&refs_)) {
+      Delete(this);
+    }
+  }
+
+  void Unref(const DebugLocation& location, const char* reason) {
+    if (location.Log() && trace_flag_ != nullptr && trace_flag_->enabled()) {
+      gpr_atm old_refs = gpr_atm_no_barrier_load(&refs_.count);
+      gpr_log(GPR_DEBUG, "%s:%p %s:%d unref %" PRIdPTR " -> %" PRIdPTR " %s",
+              trace_flag_->name(), this, location.file(), location.line(),
+              old_refs, old_refs - 1, reason);
+    }
+    Unref();
+  }
+
+ private:
+  TraceFlag* trace_flag_ = nullptr;
+  gpr_refcount refs_;
+};
+
+}  // namespace grpc_core
+
+#endif /* GRPC_CORE_LIB_GPRPP_ORPHANABLE_H */
diff --git a/src/core/lib/support/ref_counted.h b/src/core/lib/gprpp/ref_counted.h
index 4c662f9119..c68118a71a 100644
--- a/src/core/lib/support/ref_counted.h
+++ b/src/core/lib/gprpp/ref_counted.h
@@ -16,15 +16,16 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_REF_COUNTED_H
-#define GRPC_CORE_LIB_SUPPORT_REF_COUNTED_H
+#ifndef GRPC_CORE_LIB_GPRPP_REF_COUNTED_H
+#define GRPC_CORE_LIB_GPRPP_REF_COUNTED_H
 
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
 
 #include "src/core/lib/debug/trace.h"
-#include "src/core/lib/support/debug_location.h"
-#include "src/core/lib/support/memory.h"
+#include "src/core/lib/gprpp/abstract.h"
+#include "src/core/lib/gprpp/debug_location.h"
+#include "src/core/lib/gprpp/memory.h"
 
 namespace grpc_core {
 
@@ -45,6 +46,8 @@ class RefCounted {
   RefCounted(const RefCounted&) = delete;
   RefCounted& operator=(const RefCounted&) = delete;
 
+  GRPC_ABSTRACT_BASE_CLASS
+
  protected:
   // Allow Delete() to access destructor.
   template <typename T>
@@ -98,18 +101,26 @@ class RefCountedWithTracing {
   RefCountedWithTracing(const RefCountedWithTracing&) = delete;
   RefCountedWithTracing& operator=(const RefCountedWithTracing&) = delete;
 
+  GRPC_ABSTRACT_BASE_CLASS
+
  protected:
   // Allow Delete() to access destructor.
   template <typename T>
   friend void Delete(T*);
 
-  RefCountedWithTracing() : RefCountedWithTracing(nullptr) {}
+  RefCountedWithTracing()
+      : RefCountedWithTracing(static_cast<TraceFlag*>(nullptr)) {}
 
   explicit RefCountedWithTracing(TraceFlag* trace_flag)
       : trace_flag_(trace_flag) {
     gpr_ref_init(&refs_, 1);
   }
 
+#ifdef NDEBUG
+  explicit RefCountedWithTracing(DebugOnlyTraceFlag* trace_flag)
+      : RefCountedWithTracing() {}
+#endif
+
   virtual ~RefCountedWithTracing() {}
 
  private:
@@ -119,4 +130,4 @@ class RefCountedWithTracing {
 
 }  // namespace grpc_core
 
-#endif /* GRPC_CORE_LIB_SUPPORT_REF_COUNTED_H */
+#endif /* GRPC_CORE_LIB_GPRPP_REF_COUNTED_H */
diff --git a/src/core/lib/support/ref_counted_ptr.h b/src/core/lib/gprpp/ref_counted_ptr.h
index dc2385e369..dda0f00d79 100644
--- a/src/core/lib/support/ref_counted_ptr.h
+++ b/src/core/lib/gprpp/ref_counted_ptr.h
@@ -16,12 +16,12 @@
  *
  */
 
-#ifndef GRPC_CORE_LIB_SUPPORT_REF_COUNTED_PTR_H
-#define GRPC_CORE_LIB_SUPPORT_REF_COUNTED_PTR_H
+#ifndef GRPC_CORE_LIB_GPRPP_REF_COUNTED_PTR_H
+#define GRPC_CORE_LIB_GPRPP_REF_COUNTED_PTR_H
 
 #include <utility>
 
-#include "src/core/lib/support/memory.h"
+#include "src/core/lib/gprpp/memory.h"
 
 namespace grpc_core {
 
@@ -76,6 +76,15 @@ class RefCountedPtr {
   T& operator*() const { return *value_; }
   T* operator->() const { return value_; }
 
+  bool operator==(const RefCountedPtr& other) const {
+    return value_ == other.value_;
+  }
+  bool operator==(const T* other) const { return value_ == other; }
+  bool operator!=(const RefCountedPtr& other) const {
+    return value_ != other.value_;
+  }
+  bool operator!=(const T* other) const { return value_ != other; }
+
  private:
   T* value_ = nullptr;
 };
@@ -87,4 +96,4 @@ inline RefCountedPtr<T> MakeRefCounted(Args&&... args) {
 
 }  // namespace grpc_core
 
-#endif /* GRPC_CORE_LIB_SUPPORT_REF_COUNTED_PTR_H */
+#endif /* GRPC_CORE_LIB_GPRPP_REF_COUNTED_PTR_H */
diff --git a/src/core/lib/http/format_request.cc b/src/core/lib/http/format_request.cc
index f3f3cbda7b..473fa71790 100644
--- a/src/core/lib/http/format_request.cc
+++ b/src/core/lib/http/format_request.cc
@@ -26,7 +26,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/useful.h>
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/string.h"
 
 static void fill_common_header(const grpc_httpcli_request* request,
                                gpr_strvec* buf, bool connection_close) {
diff --git a/src/core/lib/http/httpcli.cc b/src/core/lib/http/httpcli.cc
index ed874c4265..c43c92b57d 100644
--- a/src/core/lib/http/httpcli.cc
+++ b/src/core/lib/http/httpcli.cc
@@ -26,6 +26,7 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/http/format_request.h"
 #include "src/core/lib/http/parser.h"
 #include "src/core/lib/iomgr/endpoint.h"
@@ -34,7 +35,6 @@
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/iomgr/tcp_client.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/support/string.h"
 
 typedef struct {
   grpc_slice request_text;
diff --git a/src/core/lib/http/httpcli_security_connector.cc b/src/core/lib/http/httpcli_security_connector.cc
index bfb536a921..8664418144 100644
--- a/src/core/lib/http/httpcli_security_connector.cc
+++ b/src/core/lib/http/httpcli_security_connector.cc
@@ -26,9 +26,9 @@
 
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/handshaker_registry.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/security/transport/security_handshaker.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/tsi/ssl_transport_security.h"
 #include "src/core/tsi/transport_security_adapter.h"
 
diff --git a/src/core/lib/iomgr/call_combiner.h b/src/core/lib/iomgr/call_combiner.h
index 9f7e6ce1c9..4814dbf8d2 100644
--- a/src/core/lib/iomgr/call_combiner.h
+++ b/src/core/lib/iomgr/call_combiner.h
@@ -23,9 +23,9 @@
 
 #include <grpc/support/atm.h>
 
+#include "src/core/lib/gpr/mpscq.h"
 #include "src/core/lib/iomgr/closure.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
-#include "src/core/lib/support/mpscq.h"
 
 // A simple, lock-free mechanism for serializing activity related to a
 // single call.  This is similar to a combiner but is more lightweight.
diff --git a/src/core/lib/iomgr/closure.h b/src/core/lib/iomgr/closure.h
index 88af76006a..249fca6cd6 100644
--- a/src/core/lib/iomgr/closure.h
+++ b/src/core/lib/iomgr/closure.h
@@ -22,13 +22,12 @@
 #include <grpc/support/port_platform.h>
 
 #include <assert.h>
-#include <grpc/impl/codegen/exec_ctx_fwd.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <stdbool.h>
+#include "src/core/lib/gpr/mpscq.h"
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/mpscq.h"
 
 struct grpc_closure;
 typedef struct grpc_closure grpc_closure;
diff --git a/src/core/lib/iomgr/combiner.h b/src/core/lib/iomgr/combiner.h
index 46b9ac58be..c62d21a051 100644
--- a/src/core/lib/iomgr/combiner.h
+++ b/src/core/lib/iomgr/combiner.h
@@ -23,8 +23,8 @@
 
 #include <grpc/support/atm.h>
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gpr/mpscq.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
-#include "src/core/lib/support/mpscq.h"
 
 // Provides serialized access to some resource.
 // Each action queued on a combiner is executed serially in a borrowed thread.
diff --git a/src/core/lib/iomgr/endpoint_pair_posix.cc b/src/core/lib/iomgr/endpoint_pair_posix.cc
index 0b4aefd1b7..3ad6b47756 100644
--- a/src/core/lib/iomgr/endpoint_pair_posix.cc
+++ b/src/core/lib/iomgr/endpoint_pair_posix.cc
@@ -33,8 +33,8 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/tcp_posix.h"
-#include "src/core/lib/support/string.h"
 
 static void create_sockets(int sv[2]) {
   int flags;
diff --git a/src/core/lib/iomgr/ev_epoll1_linux.cc b/src/core/lib/iomgr/ev_epoll1_linux.cc
index 1ab7e516de..42d7cdd348 100644
--- a/src/core/lib/iomgr/ev_epoll1_linux.cc
+++ b/src/core/lib/iomgr/ev_epoll1_linux.cc
@@ -20,12 +20,14 @@
 
 #include <grpc/support/log.h>
 
-/* This polling engine is only relevant on linux kernels supporting epoll() */
+/* This polling engine is only relevant on linux kernels supporting epoll
+   epoll_create() or epoll_create1() */
 #ifdef GRPC_LINUX_EPOLL
 #include "src/core/lib/iomgr/ev_epoll1_linux.h"
 
 #include <assert.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <limits.h>
 #include <poll.h>
 #include <pthread.h>
@@ -41,14 +43,14 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/debug/stats.h"
+#include "src/core/lib/gpr/string.h"
+#include "src/core/lib/gprpp/manual_constructor.h"
 #include "src/core/lib/iomgr/block_annotate.h"
 #include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/lockfree_event.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/manual_constructor.h"
-#include "src/core/lib/support/string.h"
 
 static grpc_wakeup_fd global_wakeup_fd;
 
@@ -84,11 +86,28 @@ typedef struct epoll_set {
 /* The global singleton epoll set */
 static epoll_set g_epoll_set;
 
+static int epoll_create_and_cloexec() {
+#ifdef GRPC_LINUX_EPOLL_CREATE1
+  int fd = epoll_create1(EPOLL_CLOEXEC);
+  if (fd < 0) {
+    gpr_log(GPR_ERROR, "epoll_create1 unavailable");
+  }
+#else
+  int fd = epoll_create(MAX_EPOLL_EVENTS);
+  if (fd < 0) {
+    gpr_log(GPR_ERROR, "epoll_create unavailable");
+  } else if (fcntl(fd, F_SETFD, FD_CLOEXEC) != 0) {
+    gpr_log(GPR_ERROR, "fcntl following epoll_create failed");
+    return -1;
+  }
+#endif
+  return fd;
+}
+
 /* Must be called *only* once */
 static bool epoll_set_init() {
-  g_epoll_set.epfd = epoll_create1(EPOLL_CLOEXEC);
+  g_epoll_set.epfd = epoll_create_and_cloexec();
   if (g_epoll_set.epfd < 0) {
-    gpr_log(GPR_ERROR, "epoll unavailable");
     return false;
   }
 
diff --git a/src/core/lib/iomgr/ev_epollex_linux.cc b/src/core/lib/iomgr/ev_epollex_linux.cc
index 5f5f45a7a5..416e8384b4 100644
--- a/src/core/lib/iomgr/ev_epollex_linux.cc
+++ b/src/core/lib/iomgr/ev_epollex_linux.cc
@@ -21,7 +21,7 @@
 #include <grpc/support/log.h>
 
 /* This polling engine is only relevant on linux kernels supporting epoll() */
-#ifdef GRPC_LINUX_EPOLL
+#ifdef GRPC_LINUX_EPOLL_CREATE1
 
 #include "src/core/lib/iomgr/ev_epollex_linux.h"
 
@@ -41,6 +41,8 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/debug/stats.h"
+#include "src/core/lib/gpr/spinlock.h"
+#include "src/core/lib/gprpp/manual_constructor.h"
 #include "src/core/lib/iomgr/block_annotate.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/is_epollexclusive_available.h"
@@ -49,8 +51,6 @@
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/manual_constructor.h"
-#include "src/core/lib/support/spinlock.h"
 
 // debug aid: create workers on the heap (allows asan to spot
 // use-after-destruction)
@@ -1442,15 +1442,15 @@ const grpc_event_engine_vtable* grpc_init_epollex_linux(
   return &vtable;
 }
 
-#else /* defined(GRPC_LINUX_EPOLL) */
+#else /* defined(GRPC_LINUX_EPOLL_CREATE1) */
 #if defined(GRPC_POSIX_SOCKET)
 #include "src/core/lib/iomgr/ev_epollex_linux.h"
-/* If GRPC_LINUX_EPOLL is not defined, it means epoll is not available. Return
- * NULL */
+/* If GRPC_LINUX_EPOLL_CREATE1 is not defined, it means
+   epoll_create1 is not available. Return NULL */
 const grpc_event_engine_vtable* grpc_init_epollex_linux(
     bool explicitly_requested) {
   return nullptr;
 }
 #endif /* defined(GRPC_POSIX_SOCKET) */
 
-#endif /* !defined(GRPC_LINUX_EPOLL) */
+#endif /* !defined(GRPC_LINUX_EPOLL_CREATE1) */
diff --git a/src/core/lib/iomgr/ev_epollsig_linux.cc b/src/core/lib/iomgr/ev_epollsig_linux.cc
index 8072a6cbed..1518348992 100644
--- a/src/core/lib/iomgr/ev_epollsig_linux.cc
+++ b/src/core/lib/iomgr/ev_epollsig_linux.cc
@@ -22,7 +22,7 @@
 #include <grpc/support/log.h>
 
 /* This polling engine is only relevant on linux kernels supporting epoll() */
-#ifdef GRPC_LINUX_EPOLL
+#ifdef GRPC_LINUX_EPOLL_CREATE1
 
 #include "src/core/lib/iomgr/ev_epollsig_linux.h"
 
@@ -43,6 +43,7 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/debug/stats.h"
+#include "src/core/lib/gprpp/manual_constructor.h"
 #include "src/core/lib/iomgr/block_annotate.h"
 #include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
@@ -50,7 +51,6 @@
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/manual_constructor.h"
 
 #define GRPC_POLLSET_KICK_BROADCAST ((grpc_pollset_worker*)1)
 
@@ -1725,11 +1725,11 @@ const grpc_event_engine_vtable* grpc_init_epollsig_linux(
   return &vtable;
 }
 
-#else /* defined(GRPC_LINUX_EPOLL) */
+#else /* defined(GRPC_LINUX_EPOLL_CREATE1) */
 #if defined(GRPC_POSIX_SOCKET)
 #include "src/core/lib/iomgr/ev_epollsig_linux.h"
-/* If GRPC_LINUX_EPOLL is not defined, it means epoll is not available. Return
- * NULL */
+/* If GRPC_LINUX_EPOLL_CREATE1 is not defined, it means
+   epoll_create1 is not available. Return NULL */
 const grpc_event_engine_vtable* grpc_init_epollsig_linux(
     bool explicit_request) {
   return nullptr;
@@ -1737,4 +1737,4 @@ const grpc_event_engine_vtable* grpc_init_epollsig_linux(
 #endif /* defined(GRPC_POSIX_SOCKET) */
 
 void grpc_use_signal(int signum) {}
-#endif /* !defined(GRPC_LINUX_EPOLL) */
+#endif /* !defined(GRPC_LINUX_EPOLL_CREATE1) */
diff --git a/src/core/lib/iomgr/ev_epollsig_linux.h b/src/core/lib/iomgr/ev_epollsig_linux.h
index 5b8aba9d9f..48178d3713 100644
--- a/src/core/lib/iomgr/ev_epollsig_linux.h
+++ b/src/core/lib/iomgr/ev_epollsig_linux.h
@@ -24,10 +24,10 @@
 
 const grpc_event_engine_vtable* grpc_init_epollsig_linux(bool explicit_request);
 
-#ifdef GRPC_LINUX_EPOLL
+#ifdef GRPC_LINUX_EPOLL_CREATE1
 void* grpc_fd_get_polling_island(grpc_fd* fd);
 void* grpc_pollset_get_polling_island(grpc_pollset* ps);
 bool grpc_are_polling_islands_equal(void* p, void* q);
-#endif /* defined(GRPC_LINUX_EPOLL) */
+#endif /* defined(GRPC_LINUX_EPOLL_CREATE1) */
 
 #endif /* GRPC_CORE_LIB_IOMGR_EV_EPOLLSIG_LINUX_H */
diff --git a/src/core/lib/iomgr/ev_poll_posix.cc b/src/core/lib/iomgr/ev_poll_posix.cc
index 08edff5159..3b79728055 100644
--- a/src/core/lib/iomgr/ev_poll_posix.cc
+++ b/src/core/lib/iomgr/ev_poll_posix.cc
@@ -38,12 +38,12 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/debug/stats.h"
+#include "src/core/lib/gpr/murmur_hash.h"
 #include "src/core/lib/iomgr/block_annotate.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/wakeup_fd_cv.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/murmur_hash.h"
 
 #define GRPC_POLLSET_KICK_BROADCAST ((grpc_pollset_worker*)1)
 
diff --git a/src/core/lib/iomgr/ev_posix.cc b/src/core/lib/iomgr/ev_posix.cc
index b516f93058..3a5714132d 100644
--- a/src/core/lib/iomgr/ev_posix.cc
+++ b/src/core/lib/iomgr/ev_posix.cc
@@ -30,11 +30,11 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gpr/env.h"
 #include "src/core/lib/iomgr/ev_epoll1_linux.h"
 #include "src/core/lib/iomgr/ev_epollex_linux.h"
 #include "src/core/lib/iomgr/ev_epollsig_linux.h"
 #include "src/core/lib/iomgr/ev_poll_posix.h"
-#include "src/core/lib/support/env.h"
 
 grpc_core::TraceFlag grpc_polling_trace(false,
                                         "polling"); /* Disabled by default */
diff --git a/src/core/lib/iomgr/exec_ctx.h b/src/core/lib/iomgr/exec_ctx.h
index 8f8d518def..2e71482fb7 100644
--- a/src/core/lib/iomgr/exec_ctx.h
+++ b/src/core/lib/iomgr/exec_ctx.h
@@ -111,7 +111,7 @@ class ExecCtx {
 
   /** Checks if there is work to be done */
   bool HasWork() {
-    return combiner_data_.active_combiner != NULL ||
+    return combiner_data_.active_combiner != nullptr ||
            !grpc_closure_list_empty(closure_list_);
   }
 
@@ -158,10 +158,6 @@ on outside context */
     now_is_valid_ = true;
   }
 
-  /** Finish any pending work for a grpc_exec_ctx. Must be called before
-   *  the instance is destroyed, or work may be lost. */
-  void Finish();
-
   /** Global initialization for ExecCtx. Called by iomgr */
   static void GlobalInit(void);
 
diff --git a/src/core/lib/iomgr/executor.cc b/src/core/lib/iomgr/executor.cc
index 67a0412dc3..835dc9d0f7 100644
--- a/src/core/lib/iomgr/executor.cc
+++ b/src/core/lib/iomgr/executor.cc
@@ -29,8 +29,8 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/debug/stats.h"
+#include "src/core/lib/gpr/spinlock.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
-#include "src/core/lib/support/spinlock.h"
 
 #define MAX_DEPTH 2
 
diff --git a/src/core/lib/iomgr/fork_posix.cc b/src/core/lib/iomgr/fork_posix.cc
index cc131408af..9bfa79219a 100644
--- a/src/core/lib/iomgr/fork_posix.cc
+++ b/src/core/lib/iomgr/fork_posix.cc
@@ -27,13 +27,13 @@
 #include <grpc/support/thd.h>
 #include <grpc/support/useful.h>
 
+#include "src/core/lib/gpr/env.h"
+#include "src/core/lib/gpr/fork.h"
+#include "src/core/lib/gpr/thd_internal.h"
 #include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/iomgr/timer_manager.h"
 #include "src/core/lib/iomgr/wakeup_fd_posix.h"
-#include "src/core/lib/support/env.h"
-#include "src/core/lib/support/fork.h"
-#include "src/core/lib/support/thd_internal.h"
 #include "src/core/lib/surface/init.h"
 
 /*
diff --git a/src/core/lib/iomgr/gethostname_sysconf.cc b/src/core/lib/iomgr/gethostname_sysconf.cc
index e099fbd388..3d74e03338 100644
--- a/src/core/lib/iomgr/gethostname_sysconf.cc
+++ b/src/core/lib/iomgr/gethostname_sysconf.cc
@@ -30,7 +30,7 @@ char* grpc_gethostname() {
   char* hostname = (char*)gpr_malloc(host_name_max);
   if (gethostname(hostname, host_name_max) != 0) {
     gpr_free(hostname);
-    return NULL;
+    return nullptr;
   }
   return hostname;
 }
diff --git a/src/core/lib/iomgr/iomgr.cc b/src/core/lib/iomgr/iomgr.cc
index 70807c479d..4cd0a4f1de 100644
--- a/src/core/lib/iomgr/iomgr.cc
+++ b/src/core/lib/iomgr/iomgr.cc
@@ -31,14 +31,14 @@
 #include <grpc/support/thd.h>
 #include <grpc/support/useful.h>
 
+#include "src/core/lib/gpr/env.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/network_status_tracker.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/iomgr/timer_manager.h"
-#include "src/core/lib/support/env.h"
-#include "src/core/lib/support/string.h"
 
 static gpr_mu g_mu;
 static gpr_cv g_rcv;
diff --git a/src/core/lib/iomgr/iomgr.h b/src/core/lib/iomgr/iomgr.h
index 3f238c660a..c7cde7ea59 100644
--- a/src/core/lib/iomgr/iomgr.h
+++ b/src/core/lib/iomgr/iomgr.h
@@ -19,7 +19,6 @@
 #ifndef GRPC_CORE_LIB_IOMGR_IOMGR_H
 #define GRPC_CORE_LIB_IOMGR_IOMGR_H
 
-#include <grpc/impl/codegen/exec_ctx_fwd.h>
 #include "src/core/lib/iomgr/port.h"
 
 /** Initializes the iomgr. */
diff --git a/src/core/lib/iomgr/is_epollexclusive_available.cc b/src/core/lib/iomgr/is_epollexclusive_available.cc
index e5803532e7..08f9cf2b69 100644
--- a/src/core/lib/iomgr/is_epollexclusive_available.cc
+++ b/src/core/lib/iomgr/is_epollexclusive_available.cc
@@ -20,7 +20,7 @@
 
 #include "src/core/lib/iomgr/is_epollexclusive_available.h"
 
-#ifdef GRPC_LINUX_EPOLL
+#ifdef GRPC_LINUX_EPOLL_CREATE1
 
 #include <grpc/support/log.h>
 
diff --git a/src/core/lib/iomgr/load_file.cc b/src/core/lib/iomgr/load_file.cc
index 4a05de1410..b6586fbc73 100644
--- a/src/core/lib/iomgr/load_file.cc
+++ b/src/core/lib/iomgr/load_file.cc
@@ -25,8 +25,8 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/block_annotate.h"
-#include "src/core/lib/support/string.h"
 
 grpc_error* grpc_load_file(const char* filename, int add_null_terminator,
                            grpc_slice* output) {
diff --git a/src/core/lib/iomgr/port.h b/src/core/lib/iomgr/port.h
index 9fae8c0052..25090898ed 100644
--- a/src/core/lib/iomgr/port.h
+++ b/src/core/lib/iomgr/port.h
@@ -37,6 +37,7 @@
 #define GRPC_POSIX_SOCKETUTILS 1
 #define GRPC_POSIX_WAKEUP_FD 1
 #define GRPC_TIMER_USE_GENERIC 1
+#define GRPC_LINUX_EPOLL 1
 #elif defined(GPR_WINDOWS)
 #define GRPC_TIMER_USE_GENERIC 1
 #define GRPC_WINSOCK_SOCKET 1
@@ -67,8 +68,11 @@
 #define GRPC_POSIX_WAKEUP_FD 1
 #define GRPC_TIMER_USE_GENERIC 1
 #ifdef __GLIBC_PREREQ
-#if __GLIBC_PREREQ(2, 9)
+#if __GLIBC_PREREQ(2, 4)
 #define GRPC_LINUX_EPOLL 1
+#endif
+#if __GLIBC_PREREQ(2, 9)
+#define GRPC_LINUX_EPOLL_CREATE1 1
 #define GRPC_LINUX_EVENTFD 1
 #endif
 #if __GLIBC_PREREQ(2, 10)
@@ -77,6 +81,7 @@
 #endif
 #ifndef __GLIBC__
 #define GRPC_LINUX_EPOLL 1
+#define GRPC_LINUX_EPOLL_CREATE1 1
 #define GRPC_LINUX_EVENTFD 1
 #define GRPC_MSG_IOVLEN_TYPE int
 #endif
diff --git a/src/core/lib/iomgr/resolve_address_posix.cc b/src/core/lib/iomgr/resolve_address_posix.cc
index cc3d4fd7cf..176caee490 100644
--- a/src/core/lib/iomgr/resolve_address_posix.cc
+++ b/src/core/lib/iomgr/resolve_address_posix.cc
@@ -33,11 +33,11 @@
 #include <grpc/support/thd.h>
 #include <grpc/support/time.h>
 #include <grpc/support/useful.h>
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/block_annotate.h"
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/unix_sockets_posix.h"
-#include "src/core/lib/support/string.h"
 
 static grpc_error* blocking_resolve_address_impl(
     const char* name, const char* default_port,
diff --git a/src/core/lib/iomgr/resolve_address_windows.cc b/src/core/lib/iomgr/resolve_address_windows.cc
index ccb1dae689..e44ab396b3 100644
--- a/src/core/lib/iomgr/resolve_address_windows.cc
+++ b/src/core/lib/iomgr/resolve_address_windows.cc
@@ -34,11 +34,11 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/thd.h>
 #include <grpc/support/time.h>
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/block_annotate.h"
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
-#include "src/core/lib/support/string.h"
 
 typedef struct {
   char* name;
diff --git a/src/core/lib/iomgr/sockaddr_utils.cc b/src/core/lib/iomgr/sockaddr_utils.cc
index 0c0a2fe5b2..71e3e38624 100644
--- a/src/core/lib/iomgr/sockaddr_utils.cc
+++ b/src/core/lib/iomgr/sockaddr_utils.cc
@@ -28,10 +28,10 @@
 #include <grpc/support/port_platform.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/sockaddr.h"
 #include "src/core/lib/iomgr/socket_utils.h"
 #include "src/core/lib/iomgr/unix_sockets_posix.h"
-#include "src/core/lib/support/string.h"
 
 static const uint8_t kV4MappedPrefix[] = {0, 0, 0, 0, 0,    0,
                                           0, 0, 0, 0, 0xff, 0xff};
diff --git a/src/core/lib/iomgr/socket_mutator.h b/src/core/lib/iomgr/socket_mutator.h
index 0a97cf657f..f8fd21d15a 100644
--- a/src/core/lib/iomgr/socket_mutator.h
+++ b/src/core/lib/iomgr/socket_mutator.h
@@ -26,7 +26,7 @@
 
 /** The virtual table of grpc_socket_mutator */
 typedef struct {
-  /** Mutates the socket opitons of \a fd */
+  /** Mutates the socket options of \a fd */
   bool (*mutate_fd)(int fd, grpc_socket_mutator* mutator);
   /** Compare socket mutator \a a and \a b */
   int (*compare)(grpc_socket_mutator* a, grpc_socket_mutator* b);
diff --git a/src/core/lib/iomgr/socket_utils_common_posix.cc b/src/core/lib/iomgr/socket_utils_common_posix.cc
index 2d4b8f0add..5068a8081d 100644
--- a/src/core/lib/iomgr/socket_utils_common_posix.cc
+++ b/src/core/lib/iomgr/socket_utils_common_posix.cc
@@ -40,8 +40,8 @@
 #include <grpc/support/log.h>
 #include <grpc/support/port_platform.h>
 #include <grpc/support/sync.h>
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
-#include "src/core/lib/support/string.h"
 
 /* set a socket to non blocking mode */
 grpc_error* grpc_set_socket_nonblocking(int fd, int non_blocking) {
diff --git a/src/core/lib/iomgr/tcp_client_posix.cc b/src/core/lib/iomgr/tcp_client_posix.cc
index 8cd5f8d618..3dff624065 100644
--- a/src/core/lib/iomgr/tcp_client_posix.cc
+++ b/src/core/lib/iomgr/tcp_client_posix.cc
@@ -33,6 +33,7 @@
 #include <grpc/support/time.h>
 
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/iomgr_posix.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
@@ -41,7 +42,6 @@
 #include "src/core/lib/iomgr/tcp_posix.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/iomgr/unix_sockets_posix.h"
-#include "src/core/lib/support/string.h"
 
 extern grpc_core::TraceFlag grpc_tcp_trace;
 
diff --git a/src/core/lib/iomgr/tcp_posix.cc b/src/core/lib/iomgr/tcp_posix.cc
index d47a077251..0ec5926227 100644
--- a/src/core/lib/iomgr/tcp_posix.cc
+++ b/src/core/lib/iomgr/tcp_posix.cc
@@ -42,12 +42,12 @@
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/debug/stats.h"
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
-#include "src/core/lib/support/string.h"
 
 #ifdef GRPC_HAVE_MSG_NOSIGNAL
 #define SENDMSG_FLAGS MSG_NOSIGNAL
diff --git a/src/core/lib/iomgr/tcp_server_posix.cc b/src/core/lib/iomgr/tcp_server_posix.cc
index 99e1c6cd06..2fa00a81d2 100644
--- a/src/core/lib/iomgr/tcp_server_posix.cc
+++ b/src/core/lib/iomgr/tcp_server_posix.cc
@@ -45,6 +45,7 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/sockaddr.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
@@ -52,7 +53,6 @@
 #include "src/core/lib/iomgr/tcp_posix.h"
 #include "src/core/lib/iomgr/tcp_server_utils_posix.h"
 #include "src/core/lib/iomgr/unix_sockets_posix.h"
-#include "src/core/lib/support/string.h"
 
 static gpr_once check_init = GPR_ONCE_INIT;
 static bool has_so_reuseport = false;
diff --git a/src/core/lib/iomgr/tcp_uv.cc b/src/core/lib/iomgr/tcp_uv.cc
index baa49d5cc5..b384623a5e 100644
--- a/src/core/lib/iomgr/tcp_uv.cc
+++ b/src/core/lib/iomgr/tcp_uv.cc
@@ -29,6 +29,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/iomgr/iomgr_uv.h"
 #include "src/core/lib/iomgr/network_status_tracker.h"
@@ -36,7 +37,6 @@
 #include "src/core/lib/iomgr/tcp_uv.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
-#include "src/core/lib/support/string.h"
 
 grpc_core::TraceFlag grpc_tcp_trace(false, "tcp");
 
diff --git a/src/core/lib/iomgr/timer_generic.cc b/src/core/lib/iomgr/timer_generic.cc
index 103144eb3b..177bdec8df 100644
--- a/src/core/lib/iomgr/timer_generic.cc
+++ b/src/core/lib/iomgr/timer_generic.cc
@@ -32,9 +32,9 @@
 #include <grpc/support/tls.h>
 #include <grpc/support/useful.h>
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gpr/spinlock.h"
 #include "src/core/lib/iomgr/time_averaged_stats.h"
 #include "src/core/lib/iomgr/timer_heap.h"
-#include "src/core/lib/support/spinlock.h"
 
 #define INVALID_HEAP_INDEX 0xffffffffu
 
diff --git a/src/core/lib/iomgr/udp_server.cc b/src/core/lib/iomgr/udp_server.cc
index 4a97f3353d..27d32c59ae 100644
--- a/src/core/lib/iomgr/udp_server.cc
+++ b/src/core/lib/iomgr/udp_server.cc
@@ -21,6 +21,10 @@
 #define _GNU_SOURCE
 #endif
 
+#ifndef SO_RXQ_OVFL
+#define SO_RXQ_OVFL 40
+#endif
+
 #include "src/core/lib/iomgr/port.h"
 
 #ifdef GRPC_POSIX_SOCKET
@@ -45,6 +49,7 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/executor.h"
@@ -54,7 +59,6 @@
 #include "src/core/lib/iomgr/socket_factory_posix.h"
 #include "src/core/lib/iomgr/socket_utils_posix.h"
 #include "src/core/lib/iomgr/unix_sockets_posix.h"
-#include "src/core/lib/support/string.h"
 
 /* one listening port */
 typedef struct grpc_udp_listener grpc_udp_listener;
@@ -280,11 +284,10 @@ static int bind_socket(grpc_socket_factory* socket_factory, int sockfd,
 
 /* Prepare a recently-created socket for listening. */
 static int prepare_socket(grpc_socket_factory* socket_factory, int fd,
-                          const grpc_resolved_address* addr) {
+                          const grpc_resolved_address* addr, int rcv_buf_size,
+                          int snd_buf_size) {
   grpc_resolved_address sockname_temp;
   struct sockaddr* addr_ptr = (struct sockaddr*)addr->addr;
-  /* Set send/receive socket buffers to 1 MB */
-  int buffer_size_bytes = 1024 * 1024;
 
   if (fd < 0) {
     goto error;
@@ -325,18 +328,25 @@ static int prepare_socket(grpc_socket_factory* socket_factory, int fd,
     goto error;
   }
 
-  if (grpc_set_socket_sndbuf(fd, buffer_size_bytes) != GRPC_ERROR_NONE) {
+  if (grpc_set_socket_sndbuf(fd, snd_buf_size) != GRPC_ERROR_NONE) {
     gpr_log(GPR_ERROR, "Failed to set send buffer size to %d bytes",
-            buffer_size_bytes);
+            snd_buf_size);
     goto error;
   }
 
-  if (grpc_set_socket_rcvbuf(fd, buffer_size_bytes) != GRPC_ERROR_NONE) {
+  if (grpc_set_socket_rcvbuf(fd, rcv_buf_size) != GRPC_ERROR_NONE) {
     gpr_log(GPR_ERROR, "Failed to set receive buffer size to %d bytes",
-            buffer_size_bytes);
+            rcv_buf_size);
     goto error;
   }
 
+  {
+    int get_overflow = 1;
+    if (0 != setsockopt(fd, SOL_SOCKET, SO_RXQ_OVFL, &get_overflow,
+                        sizeof(get_overflow))) {
+      gpr_log(GPR_INFO, "Failed to set socket overflow support");
+    }
+  }
   return grpc_sockaddr_get_port(&sockname_temp);
 
 error:
@@ -451,6 +461,7 @@ static void on_write(void* arg, grpc_error* error) {
 
 static int add_socket_to_server(grpc_udp_server* s, int fd,
                                 const grpc_resolved_address* addr,
+                                int rcv_buf_size, int snd_buf_size,
                                 grpc_udp_server_start_cb start_cb,
                                 grpc_udp_server_read_cb read_cb,
                                 grpc_udp_server_write_cb write_cb,
@@ -460,7 +471,8 @@ static int add_socket_to_server(grpc_udp_server* s, int fd,
   char* addr_str;
   char* name;
 
-  port = prepare_socket(s->socket_factory, fd, addr);
+  port =
+      prepare_socket(s->socket_factory, fd, addr, rcv_buf_size, snd_buf_size);
   if (port >= 0) {
     grpc_sockaddr_to_string(&addr_str, addr, 1);
     gpr_asprintf(&name, "udp-server-listener:%s", addr_str);
@@ -495,6 +507,7 @@ static int add_socket_to_server(grpc_udp_server* s, int fd,
 
 int grpc_udp_server_add_port(grpc_udp_server* s,
                              const grpc_resolved_address* addr,
+                             int rcv_buf_size, int snd_buf_size,
                              grpc_udp_server_start_cb start_cb,
                              grpc_udp_server_read_cb read_cb,
                              grpc_udp_server_write_cb write_cb,
@@ -545,8 +558,9 @@ int grpc_udp_server_add_port(grpc_udp_server* s,
     // TODO(rjshade): Test and propagate the returned grpc_error*:
     GRPC_ERROR_UNREF(grpc_create_dualstack_socket_using_factory(
         s->socket_factory, addr, SOCK_DGRAM, IPPROTO_UDP, &dsmode, &fd));
-    allocated_port1 = add_socket_to_server(s, fd, addr, start_cb, read_cb,
-                                           write_cb, orphan_cb);
+    allocated_port1 =
+        add_socket_to_server(s, fd, addr, rcv_buf_size, snd_buf_size, start_cb,
+                             read_cb, write_cb, orphan_cb);
     if (fd >= 0 && dsmode == GRPC_DSMODE_DUALSTACK) {
       goto done;
     }
@@ -569,7 +583,8 @@ int grpc_udp_server_add_port(grpc_udp_server* s,
     addr = &addr4_copy;
   }
   allocated_port2 =
-      add_socket_to_server(s, fd, addr, start_cb, read_cb, write_cb, orphan_cb);
+      add_socket_to_server(s, fd, addr, rcv_buf_size, snd_buf_size, start_cb,
+                           read_cb, write_cb, orphan_cb);
 
 done:
   gpr_free(allocated_addr);
diff --git a/src/core/lib/iomgr/udp_server.h b/src/core/lib/iomgr/udp_server.h
index a469ab9be5..c1aa49f15d 100644
--- a/src/core/lib/iomgr/udp_server.h
+++ b/src/core/lib/iomgr/udp_server.h
@@ -68,6 +68,7 @@ int grpc_udp_server_get_fd(grpc_udp_server* s, unsigned port_index);
                   all of the multiple socket port matching logic in one place */
 int grpc_udp_server_add_port(grpc_udp_server* s,
                              const grpc_resolved_address* addr,
+                             int rcv_buf_size, int snd_buf_size,
                              grpc_udp_server_start_cb start_cb,
                              grpc_udp_server_read_cb read_cb,
                              grpc_udp_server_write_cb write_cb,
diff --git a/src/core/lib/iomgr/wakeup_fd_nospecial.cc b/src/core/lib/iomgr/wakeup_fd_nospecial.cc
index 4c20b8c1b7..c2b525a254 100644
--- a/src/core/lib/iomgr/wakeup_fd_nospecial.cc
+++ b/src/core/lib/iomgr/wakeup_fd_nospecial.cc
@@ -31,6 +31,6 @@
 static int check_availability_invalid(void) { return 0; }
 
 const grpc_wakeup_fd_vtable grpc_specialized_wakeup_fd_vtable = {
-    NULL, NULL, NULL, NULL, check_availability_invalid};
+    nullptr, nullptr, nullptr, nullptr, check_availability_invalid};
 
 #endif /* GRPC_POSIX_NO_SPECIAL_WAKEUP_FD */
diff --git a/src/core/lib/profiling/basic_timers.cc b/src/core/lib/profiling/basic_timers.cc
index 87dd4ab120..d1c9fd7dec 100644
--- a/src/core/lib/profiling/basic_timers.cc
+++ b/src/core/lib/profiling/basic_timers.cc
@@ -30,7 +30,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "src/core/lib/support/env.h"
+#include "src/core/lib/gpr/env.h"
 
 typedef enum { BEGIN = '{', END = '}', MARK = '.' } marker_type;
 
diff --git a/src/core/lib/security/context/security_context.cc b/src/core/lib/security/context/security_context.cc
index 0371027994..63ec42cf86 100644
--- a/src/core/lib/security/context/security_context.cc
+++ b/src/core/lib/security/context/security_context.cc
@@ -19,8 +19,8 @@
 #include <string.h>
 
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/security/context/security_context.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/call.h"
 
diff --git a/src/core/lib/security/credentials/credentials.cc b/src/core/lib/security/credentials/credentials.cc
index 48b459e1be..009a5ce4ec 100644
--- a/src/core/lib/security/credentials/credentials.cc
+++ b/src/core/lib/security/credentials/credentials.cc
@@ -22,11 +22,11 @@
 #include <string.h>
 
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/http/httpcli.h"
 #include "src/core/lib/http/parser.h"
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/json/json.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/api_trace.h"
 
 #include <grpc/support/alloc.h>
diff --git a/src/core/lib/security/credentials/fake/fake_credentials.cc b/src/core/lib/security/credentials/fake/fake_credentials.cc
index 99b1214951..9065325cdd 100644
--- a/src/core/lib/security/credentials/fake/fake_credentials.cc
+++ b/src/core/lib/security/credentials/fake/fake_credentials.cc
@@ -25,8 +25,8 @@
 #include <grpc/support/string_util.h>
 
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/executor.h"
-#include "src/core/lib/support/string.h"
 
 /* -- Fake transport security credentials. -- */
 
diff --git a/src/core/lib/security/credentials/google_default/credentials_generic.cc b/src/core/lib/security/credentials/google_default/credentials_generic.cc
index af103f5dc5..15ae9d6428 100644
--- a/src/core/lib/security/credentials/google_default/credentials_generic.cc
+++ b/src/core/lib/security/credentials/google_default/credentials_generic.cc
@@ -22,8 +22,8 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/lib/support/env.h"
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/env.h"
+#include "src/core/lib/gpr/string.h"
 
 char* grpc_get_well_known_google_credentials_file_path_impl(void) {
   char* result = nullptr;
diff --git a/src/core/lib/security/credentials/google_default/google_default_credentials.cc b/src/core/lib/security/credentials/google_default/google_default_credentials.cc
index 03d52850d9..dc19202033 100644
--- a/src/core/lib/security/credentials/google_default/google_default_credentials.cc
+++ b/src/core/lib/security/credentials/google_default/google_default_credentials.cc
@@ -24,6 +24,8 @@
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
 
+#include "src/core/lib/gpr/env.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/http/httpcli.h"
 #include "src/core/lib/http/parser.h"
 #include "src/core/lib/iomgr/load_file.h"
@@ -33,8 +35,6 @@
 #include "src/core/lib/security/credentials/oauth2/oauth2_credentials.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
-#include "src/core/lib/support/env.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/api_trace.h"
 
 /* -- Constants. -- */
diff --git a/src/core/lib/security/credentials/jwt/json_token.cc b/src/core/lib/security/credentials/jwt/json_token.cc
index a152ddcaaf..078f04ed11 100644
--- a/src/core/lib/security/credentials/jwt/json_token.cc
+++ b/src/core/lib/security/credentials/jwt/json_token.cc
@@ -26,9 +26,9 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
 
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/security/util/json_util.h"
 #include "src/core/lib/slice/b64.h"
-#include "src/core/lib/support/string.h"
 
 extern "C" {
 #include <openssl/bio.h>
diff --git a/src/core/lib/security/credentials/jwt/jwt_verifier.cc b/src/core/lib/security/credentials/jwt/jwt_verifier.cc
index 39339f07d7..860506df39 100644
--- a/src/core/lib/security/credentials/jwt/jwt_verifier.cc
+++ b/src/core/lib/security/credentials/jwt/jwt_verifier.cc
@@ -31,11 +31,11 @@ extern "C" {
 #include <openssl/pem.h>
 }
 
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/http/httpcli.h"
 #include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/slice/b64.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/tsi/ssl_types.h"
 
 /* --- Utils. --- */
diff --git a/src/core/lib/security/transport/client_auth_filter.cc b/src/core/lib/security/transport/client_auth_filter.cc
index 6a3641f112..045cb3e239 100644
--- a/src/core/lib/security/transport/client_auth_filter.cc
+++ b/src/core/lib/security/transport/client_auth_filter.cc
@@ -25,13 +25,13 @@
 #include <grpc/support/string_util.h>
 
 #include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/security/context/security_context.h"
 #include "src/core/lib/security/credentials/credentials.h"
 #include "src/core/lib/security/transport/security_connector.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/transport/static_metadata.h"
 
@@ -114,7 +114,7 @@ static void on_credentials_metadata(void* arg, grpc_error* input_error) {
     grpc_call_next_op(elem, batch);
   } else {
     error = grpc_error_set_int(error, GRPC_ERROR_INT_GRPC_STATUS,
-                               GRPC_STATUS_UNAUTHENTICATED);
+                               GRPC_STATUS_UNAVAILABLE);
     grpc_transport_stream_op_batch_finish_with_failure(batch, error,
                                                        calld->call_combiner);
   }
diff --git a/src/core/lib/security/transport/secure_endpoint.cc b/src/core/lib/security/transport/secure_endpoint.cc
index e5c089de9c..bd8a6cd76a 100644
--- a/src/core/lib/security/transport/secure_endpoint.cc
+++ b/src/core/lib/security/transport/secure_endpoint.cc
@@ -28,12 +28,12 @@
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/security/transport/secure_endpoint.h"
 #include "src/core/lib/security/transport/tsi_error.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/tsi/transport_security_grpc.h"
 
 #define STAGING_BUFFER_SIZE 8192
diff --git a/src/core/lib/security/transport/security_connector.cc b/src/core/lib/security/transport/security_connector.cc
index fd139714da..1d962f94b2 100644
--- a/src/core/lib/security/transport/security_connector.cc
+++ b/src/core/lib/security/transport/security_connector.cc
@@ -30,6 +30,8 @@
 #include "src/core/ext/transport/chttp2/alpn/alpn.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/handshaker.h"
+#include "src/core/lib/gpr/env.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/load_file.h"
 #include "src/core/lib/security/context/security_context.h"
 #include "src/core/lib/security/credentials/credentials.h"
@@ -38,8 +40,6 @@
 #include "src/core/lib/security/transport/lb_targets_info.h"
 #include "src/core/lib/security/transport/secure_endpoint.h"
 #include "src/core/lib/security/transport/security_handshaker.h"
-#include "src/core/lib/support/env.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/tsi/fake_transport_security.h"
 #include "src/core/tsi/ssl_transport_security.h"
 #include "src/core/tsi/transport_security_adapter.h"
diff --git a/src/core/lib/slice/slice_intern.cc b/src/core/lib/slice/slice_intern.cc
index c578c6d9de..fe1770b92c 100644
--- a/src/core/lib/slice/slice_intern.cc
+++ b/src/core/lib/slice/slice_intern.cc
@@ -24,10 +24,10 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
+#include "src/core/lib/gpr/murmur_hash.h"
 #include "src/core/lib/iomgr/iomgr_internal.h" /* for iomgr_abort_on_leaks() */
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
-#include "src/core/lib/support/murmur_hash.h"
 #include "src/core/lib/transport/static_metadata.h"
 
 #define LOG2_SHARD_COUNT 5
diff --git a/src/core/lib/slice/slice_string_helpers.cc b/src/core/lib/slice/slice_string_helpers.cc
index 5385be9866..be0db09252 100644
--- a/src/core/lib/slice/slice_string_helpers.cc
+++ b/src/core/lib/slice/slice_string_helpers.cc
@@ -22,8 +22,8 @@
 
 #include <grpc/support/log.h>
 
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/support/string.h"
 
 char* grpc_dump_slice(grpc_slice s, uint32_t flags) {
   return gpr_dump((const char*)GRPC_SLICE_START_PTR(s), GRPC_SLICE_LENGTH(s),
diff --git a/src/core/lib/slice/slice_string_helpers.h b/src/core/lib/slice/slice_string_helpers.h
index 7f51b11b9c..109084be1f 100644
--- a/src/core/lib/slice/slice_string_helpers.h
+++ b/src/core/lib/slice/slice_string_helpers.h
@@ -26,7 +26,7 @@
 #include <grpc/slice_buffer.h>
 #include <grpc/support/port_platform.h>
 
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/string.h"
 
 /* Calls gpr_dump on a slice. */
 char* grpc_dump_slice(grpc_slice slice, uint32_t flags);
diff --git a/src/core/lib/support/vector.h b/src/core/lib/support/vector.h
deleted file mode 100644
index 4a7db80676..0000000000
--- a/src/core/lib/support/vector.h
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- *
- * Copyright 2017 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-#ifndef GRPC_CORE_LIB_SUPPORT_VECTOR_H
-#define GRPC_CORE_LIB_SUPPORT_VECTOR_H
-
-#include "absl/container/inlined_vector.h"
-#include "src/core/lib/support/memory.h"
-
-namespace grpc_core {
-
-template <typename T, size_t N>
-using InlinedVector = absl::InlinedVector<T, N, Allocator<T>>;
-
-}  // namespace grpc_core
-
-#endif
diff --git a/src/core/lib/surface/call.cc b/src/core/lib/surface/call.cc
index d677576c14..8a579cabe7 100644
--- a/src/core/lib/surface/call.cc
+++ b/src/core/lib/surface/call.cc
@@ -33,12 +33,12 @@
 #include "src/core/lib/channel/channel_stack.h"
 #include "src/core/lib/compression/algorithm_metadata.h"
 #include "src/core/lib/debug/stats.h"
+#include "src/core/lib/gpr/arena.h"
+#include "src/core/lib/gpr/string.h"
 #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/slice/slice_string_helpers.h"
-#include "src/core/lib/support/arena.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/surface/call_test_only.h"
diff --git a/src/core/lib/surface/call_log_batch.cc b/src/core/lib/surface/call_log_batch.cc
index 535a3d3282..d56ea2a932 100644
--- a/src/core/lib/surface/call_log_batch.cc
+++ b/src/core/lib/surface/call_log_batch.cc
@@ -22,8 +22,8 @@
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
-#include "src/core/lib/support/string.h"
 
 static void add_metadata(gpr_strvec* b, const grpc_metadata* md, size_t count) {
   size_t i;
diff --git a/src/core/lib/surface/channel.cc b/src/core/lib/surface/channel.cc
index cf5e8c2150..62db82a1d9 100644
--- a/src/core/lib/surface/channel.cc
+++ b/src/core/lib/surface/channel.cc
@@ -29,9 +29,9 @@
 
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/debug/stats.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/iomgr.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/surface/channel_init.h"
diff --git a/src/core/lib/surface/completion_queue.cc b/src/core/lib/surface/completion_queue.cc
index aa5808da4c..e731e2139f 100644
--- a/src/core/lib/surface/completion_queue.cc
+++ b/src/core/lib/surface/completion_queue.cc
@@ -31,11 +31,11 @@
 #include <grpc/support/tls.h>
 
 #include "src/core/lib/debug/stats.h"
+#include "src/core/lib/gpr/spinlock.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/pollset.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/spinlock.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/surface/event_string.h"
diff --git a/src/core/lib/surface/event_string.cc b/src/core/lib/surface/event_string.cc
index 5168edc9b5..7f40bb2405 100644
--- a/src/core/lib/surface/event_string.cc
+++ b/src/core/lib/surface/event_string.cc
@@ -22,7 +22,7 @@
 
 #include <grpc/byte_buffer.h>
 #include <grpc/support/string_util.h>
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/string.h"
 
 static void addhdr(gpr_strvec* buf, grpc_event* ev) {
   char* tmp;
diff --git a/src/core/lib/surface/init.cc b/src/core/lib/surface/init.cc
index 0f40965f16..70329b09f4 100644
--- a/src/core/lib/surface/init.cc
+++ b/src/core/lib/surface/init.cc
@@ -31,6 +31,8 @@
 #include "src/core/lib/channel/handshaker_registry.h"
 #include "src/core/lib/debug/stats.h"
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gpr/fork.h"
+#include "src/core/lib/gpr/thd_internal.h"
 #include "src/core/lib/http/parser.h"
 #include "src/core/lib/iomgr/call_combiner.h"
 #include "src/core/lib/iomgr/combiner.h"
@@ -40,8 +42,6 @@
 #include "src/core/lib/iomgr/timer_manager.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/support/fork.h"
-#include "src/core/lib/support/thd_internal.h"
 #include "src/core/lib/surface/alarm_internal.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/call.h"
diff --git a/src/core/lib/surface/lame_client.cc b/src/core/lib/surface/lame_client.cc
index 08611ff730..a1f1cf1107 100644
--- a/src/core/lib/surface/lame_client.cc
+++ b/src/core/lib/surface/lame_client.cc
@@ -23,10 +23,10 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
-#include "src/core/lib/support/atomic.h"
+#include "src/core/lib/gprpp/atomic.h"
 
 #include "src/core/lib/channel/channel_stack.h"
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/surface/channel.h"
diff --git a/src/core/lib/surface/server.cc b/src/core/lib/surface/server.cc
index ee98cf2693..c8c1db337f 100644
--- a/src/core/lib/surface/server.cc
+++ b/src/core/lib/surface/server.cc
@@ -30,12 +30,12 @@
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/connected_channel.h"
 #include "src/core/lib/debug/stats.h"
+#include "src/core/lib/gpr/mpscq.h"
+#include "src/core/lib/gpr/spinlock.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/iomgr/iomgr.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/support/mpscq.h"
-#include "src/core/lib/support/spinlock.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/surface/channel.h"
diff --git a/src/core/lib/surface/version.cc b/src/core/lib/surface/version.cc
index 7d36c6c9e1..19498a6df7 100644
--- a/src/core/lib/surface/version.cc
+++ b/src/core/lib/surface/version.cc
@@ -23,4 +23,4 @@
 
 const char* grpc_version_string(void) { return "5.0.0-dev"; }
 
-const char* grpc_g_stands_for(void) { return "glossy"; }
+const char* grpc_g_stands_for(void) { return "glamorous"; }
diff --git a/src/core/lib/transport/error_utils.cc b/src/core/lib/transport/error_utils.cc
index ffaf327081..891576f4ba 100644
--- a/src/core/lib/transport/error_utils.cc
+++ b/src/core/lib/transport/error_utils.cc
@@ -70,7 +70,7 @@ void grpc_error_get_status(grpc_error* error, grpc_millis deadline,
   }
   if (code != nullptr) *code = status;
 
-  if (error_string != NULL && status != GRPC_STATUS_OK) {
+  if (error_string != nullptr && status != GRPC_STATUS_OK) {
     *error_string = gpr_strdup(grpc_error_string(error));
   }
 
diff --git a/src/core/lib/transport/metadata.cc b/src/core/lib/transport/metadata.cc
index 5f0673e014..652222bd0b 100644
--- a/src/core/lib/transport/metadata.cc
+++ b/src/core/lib/transport/metadata.cc
@@ -31,12 +31,12 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
 
+#include "src/core/lib/gpr/murmur_hash.h"
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
-#include "src/core/lib/support/murmur_hash.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/lib/transport/static_metadata.h"
 
 /* There are two kinds of mdelem and mdstr instances.
diff --git a/src/core/lib/transport/service_config.cc b/src/core/lib/transport/service_config.cc
index cbafc33840..5c9930a273 100644
--- a/src/core/lib/transport/service_config.cc
+++ b/src/core/lib/transport/service_config.cc
@@ -23,11 +23,11 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/json/json.h"
 #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/string.h"
 
 // The main purpose of the code here is to parse the service config in
 // JSON form, which will look like this:
diff --git a/src/core/lib/transport/timeout_encoding.cc b/src/core/lib/transport/timeout_encoding.cc
index 86db6c8344..47f964af45 100644
--- a/src/core/lib/transport/timeout_encoding.cc
+++ b/src/core/lib/transport/timeout_encoding.cc
@@ -22,7 +22,7 @@
 #include <string.h>
 
 #include <grpc/support/port_platform.h>
-#include "src/core/lib/support/string.h"
+#include "src/core/lib/gpr/string.h"
 
 static int64_t round_up(int64_t x, int64_t divisor) {
   return (x / divisor + (x % divisor != 0)) * divisor;
diff --git a/src/core/lib/transport/timeout_encoding.h b/src/core/lib/transport/timeout_encoding.h
index 8611f49b00..4e9268262e 100644
--- a/src/core/lib/transport/timeout_encoding.h
+++ b/src/core/lib/transport/timeout_encoding.h
@@ -22,8 +22,8 @@
 #include <grpc/slice.h>
 #include <grpc/support/time.h>
 
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
-#include "src/core/lib/support/string.h"
 
 #define GRPC_HTTP2_TIMEOUT_ENCODE_MIN_BUFSIZE (GPR_LTOA_MIN_BUFSIZE + 1)
 
diff --git a/src/core/lib/transport/transport.cc b/src/core/lib/transport/transport.cc
index 08aee04ac9..ea0380e591 100644
--- a/src/core/lib/transport/transport.cc
+++ b/src/core/lib/transport/transport.cc
@@ -25,10 +25,10 @@
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
 
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/lib/transport/transport_impl.h"
 
 grpc_core::DebugOnlyTraceFlag grpc_trace_stream_refcount(false,
diff --git a/src/core/lib/transport/transport.h b/src/core/lib/transport/transport.h
index 80a7ff98be..b392c696cd 100644
--- a/src/core/lib/transport/transport.h
+++ b/src/core/lib/transport/transport.h
@@ -22,12 +22,12 @@
 #include <stddef.h>
 
 #include "src/core/lib/channel/context.h"
+#include "src/core/lib/gpr/arena.h"
 #include "src/core/lib/iomgr/call_combiner.h"
 #include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/iomgr/pollset.h"
 #include "src/core/lib/iomgr/pollset_set.h"
-#include "src/core/lib/support/arena.h"
 #include "src/core/lib/transport/byte_stream.h"
 #include "src/core/lib/transport/metadata_batch.h"
 
diff --git a/src/core/lib/transport/transport_op_string.cc b/src/core/lib/transport/transport_op_string.cc
index c0f82fea0d..58a21e9b60 100644
--- a/src/core/lib/transport/transport_op_string.cc
+++ b/src/core/lib/transport/transport_op_string.cc
@@ -28,8 +28,8 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/useful.h>
+#include "src/core/lib/gpr/string.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
-#include "src/core/lib/support/string.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
 /* These routines are here to facilitate debugging - they produce string
author	Yash Tibrewal <yashkt@google.com>	2018-01-24 10:58:25 -0800
committer	Yash Tibrewal <yashkt@google.com>	2018-01-24 10:58:25 -0800
commit	ea8027a0b1b5ca2ba2e29f9924d5c164cc75aba1 (patch)
tree	a8409e75cbf9966c0aad4fc5df5d8af33dc59fa6 /src/core/lib
parent	7cbbee745e84d714f826e54fdbc93499341e7fa3 (diff)
parent	5e7eed29ed747a24a91c3d202066e64d0478d5db (diff)