Wrapper for std::set<> that overrides the allocator.

BUILD

@@ -521,6 +521,7 @@ grpc_cc_library(
         "src/core/lib/gprpp/map.h",
         "src/core/lib/gprpp/memory.h",
         "src/core/lib/gprpp/mpscq.h",
+        "src/core/lib/gprpp/set.h",
         "src/core/lib/gprpp/string_view.h",
         "src/core/lib/gprpp/sync.h",
         "src/core/lib/gprpp/thd.h",

BUILD.gn

@@ -149,6 +149,7 @@ config("grpc_config") {
         "src/core/lib/gprpp/memory.h",
         "src/core/lib/gprpp/mpscq.cc",
         "src/core/lib/gprpp/mpscq.h",
+        "src/core/lib/gprpp/set.h",
         "src/core/lib/gprpp/sync.h",
         "src/core/lib/gprpp/thd.h",
         "src/core/lib/gprpp/thd_posix.cc",
@@ -1253,6 +1254,7 @@ config("grpc_config") {
         "src/core/lib/gprpp/orphanable.h",
         "src/core/lib/gprpp/ref_counted.h",
         "src/core/lib/gprpp/ref_counted_ptr.h",
+        "src/core/lib/gprpp/set.h",
         "src/core/lib/gprpp/string_view.h",
         "src/core/lib/gprpp/sync.h",
         "src/core/lib/gprpp/thd.h",

build.yaml

@@ -291,6 +291,7 @@ filegroups:
   - src/core/lib/gprpp/map.h
   - src/core/lib/gprpp/memory.h
   - src/core/lib/gprpp/mpscq.h
+  - src/core/lib/gprpp/set.h
   - src/core/lib/gprpp/sync.h
   - src/core/lib/gprpp/thd.h
   - src/core/lib/profiling/timers.h

gRPC-C++.podspec

@@ -311,6 +311,7 @@ Pod::Spec.new do |s|
                               'src/core/lib/gprpp/map.h',
                               'src/core/lib/gprpp/memory.h',
                               'src/core/lib/gprpp/mpscq.h',
+                              'src/core/lib/gprpp/set.h',
                               'src/core/lib/gprpp/sync.h',
                               'src/core/lib/gprpp/thd.h',
                               'src/core/lib/profiling/timers.h',

gRPC-Core.podspec

@@ -214,6 +214,7 @@ Pod::Spec.new do |s|
                       'src/core/lib/gprpp/map.h',
                       'src/core/lib/gprpp/memory.h',
                       'src/core/lib/gprpp/mpscq.h',
+                      'src/core/lib/gprpp/set.h',
                       'src/core/lib/gprpp/sync.h',
                       'src/core/lib/gprpp/thd.h',
                       'src/core/lib/profiling/timers.h',
@@ -988,6 +989,7 @@ Pod::Spec.new do |s|
                               'src/core/lib/gprpp/map.h',
                               'src/core/lib/gprpp/memory.h',
                               'src/core/lib/gprpp/mpscq.h',
+                              'src/core/lib/gprpp/set.h',
                               'src/core/lib/gprpp/sync.h',
                               'src/core/lib/gprpp/thd.h',
                               'src/core/lib/profiling/timers.h',

grpc.gemspec

@@ -108,6 +108,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/gprpp/map.h )
   s.files += %w( src/core/lib/gprpp/memory.h )
   s.files += %w( src/core/lib/gprpp/mpscq.h )
+  s.files += %w( src/core/lib/gprpp/set.h )
   s.files += %w( src/core/lib/gprpp/sync.h )
   s.files += %w( src/core/lib/gprpp/thd.h )
   s.files += %w( src/core/lib/profiling/timers.h )

package.xml

@@ -113,6 +113,7 @@
     <file baseinstalldir="/" name="src/core/lib/gprpp/map.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/memory.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/mpscq.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/gprpp/set.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/sync.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/thd.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/profiling/timers.h" role="src" />

src/core/ext/filters/client_channel/client_channel.cc

@@ -26,9 +26,6 @@
 #include <stdio.h>
 #include <string.h>
 
-#include <map>
-#include <set>
-
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
@@ -56,6 +53,7 @@
 #include "src/core/lib/gprpp/inlined_vector.h"
 #include "src/core/lib/gprpp/manual_constructor.h"
 #include "src/core/lib/gprpp/map.h"
+#include "src/core/lib/gprpp/set.h"
 #include "src/core/lib/gprpp/sync.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/iomgr.h"
@@ -297,7 +295,7 @@ class ChannelData {
   // The set of SubchannelWrappers that currently exist.
   // No need to hold a ref, since the map is updated in the control-plane
   // combiner when the SubchannelWrappers are created and destroyed.
-  std::set<SubchannelWrapper*> subchannel_wrappers_;
+  Set<SubchannelWrapper*> subchannel_wrappers_;
   // Pending ConnectedSubchannel updates for each SubchannelWrapper.
   // Updates are queued here in the control plane combiner and then applied
   // in the data plane mutex when the picker is updated.

src/core/lib/gprpp/memory.h

@@ -103,6 +103,11 @@ class Allocator {
   };
   typedef std::true_type is_always_equal;
 
+  Allocator() = default;
+
+  template <class U>
+  Allocator(const Allocator<U>&) {}
+
   pointer address(reference x) const { return &x; }
   const_pointer address(const_reference x) const { return &x; }
   pointer allocate(std::size_t n,

src/core/lib/gprpp/set.h

@@ -0,0 +1,33 @@
+//
+// 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_SET_H
+#define GRPC_CORE_LIB_GPRPP_SET_H
+
+#include <grpc/support/port_platform.h>
+
+#include <set>
+
+#include "src/core/lib/gprpp/memory.h"
+
+namespace grpc_core {
+
+template <typename T, typename Compare = std::less<T>>
+using Set = std::set<T, Compare, Allocator<T>>;
+
+}  // namespace grpc_core
+
+#endif /* GRPC_CORE_LIB_GPRPP_SET_H */

tools/doxygen/Doxyfile.c++.internal

@@ -1119,6 +1119,7 @@ src/core/lib/gprpp/optional.h \
 src/core/lib/gprpp/orphanable.h \
 src/core/lib/gprpp/ref_counted.h \
 src/core/lib/gprpp/ref_counted_ptr.h \
+src/core/lib/gprpp/set.h \
 src/core/lib/gprpp/string_view.h \
 src/core/lib/gprpp/sync.h \
 src/core/lib/gprpp/thd.h \

tools/doxygen/Doxyfile.core.internal

@@ -1255,6 +1255,7 @@ src/core/lib/gprpp/optional.h \
 src/core/lib/gprpp/orphanable.h \
 src/core/lib/gprpp/ref_counted.h \
 src/core/lib/gprpp/ref_counted_ptr.h \
+src/core/lib/gprpp/set.h \
 src/core/lib/gprpp/string_view.h \
 src/core/lib/gprpp/sync.h \
 src/core/lib/gprpp/thd.h \