[call-v3] Idle/max-age filters (#35270)

Closes #35270

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/35270 from ctiller:cg-idle 5312003ca6
PiperOrigin-RevId: 589913523

CMakeLists.txt

@@ -1756,6 +1756,7 @@ add_library(grpc
   src/core/ext/filters/census/grpc_context.cc
   src/core/ext/filters/channel_idle/channel_idle_filter.cc
   src/core/ext/filters/channel_idle/idle_filter_state.cc
+  src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc
   src/core/ext/filters/client_channel/backend_metric.cc
   src/core/ext/filters/client_channel/backup_poller.cc
   src/core/ext/filters/client_channel/channel_connectivity.cc
@@ -2820,6 +2821,7 @@ add_library(grpc_unsecure
   src/core/ext/filters/census/grpc_context.cc
   src/core/ext/filters/channel_idle/channel_idle_filter.cc
   src/core/ext/filters/channel_idle/idle_filter_state.cc
+  src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc
   src/core/ext/filters/client_channel/backend_metric.cc
   src/core/ext/filters/client_channel/backup_poller.cc
   src/core/ext/filters/client_channel/channel_connectivity.cc

Makefile

@@ -958,6 +958,7 @@ LIBGRPC_SRC = \
     src/core/ext/filters/census/grpc_context.cc \
     src/core/ext/filters/channel_idle/channel_idle_filter.cc \
     src/core/ext/filters/channel_idle/idle_filter_state.cc \
+    src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc \
     src/core/ext/filters/client_channel/backend_metric.cc \
     src/core/ext/filters/client_channel/backup_poller.cc \
     src/core/ext/filters/client_channel/channel_connectivity.cc \
@@ -1872,6 +1873,7 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/ext/filters/census/grpc_context.cc \
     src/core/ext/filters/channel_idle/channel_idle_filter.cc \
     src/core/ext/filters/channel_idle/idle_filter_state.cc \
+    src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc \
     src/core/ext/filters/client_channel/backend_metric.cc \
     src/core/ext/filters/client_channel/backup_poller.cc \
     src/core/ext/filters/client_channel/channel_connectivity.cc \

Package.swift

@@ -121,6 +121,8 @@ let package = Package(
         "src/core/ext/filters/channel_idle/channel_idle_filter.h",
         "src/core/ext/filters/channel_idle/idle_filter_state.cc",
         "src/core/ext/filters/channel_idle/idle_filter_state.h",
+        "src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc",
+        "src/core/ext/filters/channel_idle/legacy_channel_idle_filter.h",
         "src/core/ext/filters/client_channel/backend_metric.cc",
         "src/core/ext/filters/client_channel/backend_metric.h",
         "src/core/ext/filters/client_channel/backup_poller.cc",

bazel/experiments.bzl

@@ -50,6 +50,7 @@ EXPERIMENT_ENABLES = {
     "tcp_rcv_lowat": "tcp_rcv_lowat",
     "trace_record_callops": "trace_record_callops",
     "unconstrained_max_quota_buffer_size": "unconstrained_max_quota_buffer_size",
+    "v3_channel_idle_filters": "v3_channel_idle_filters",
     "work_serializer_clears_time_cache": "work_serializer_clears_time_cache",
     "work_serializer_dispatch": "work_serializer_dispatch",
     "write_size_policy": "write_size_policy",

build_autogenerated.yaml

@@ -218,6 +218,7 @@ libs:
   - src/core/ext/filters/backend_metrics/backend_metric_provider.h
   - src/core/ext/filters/channel_idle/channel_idle_filter.h
   - src/core/ext/filters/channel_idle/idle_filter_state.h
+  - src/core/ext/filters/channel_idle/legacy_channel_idle_filter.h
   - src/core/ext/filters/client_channel/backend_metric.h
   - src/core/ext/filters/client_channel/backup_poller.h
   - src/core/ext/filters/client_channel/client_channel.h
@@ -1209,6 +1210,7 @@ libs:
   - src/core/ext/filters/census/grpc_context.cc
   - src/core/ext/filters/channel_idle/channel_idle_filter.cc
   - src/core/ext/filters/channel_idle/idle_filter_state.cc
+  - src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc
   - src/core/ext/filters/client_channel/backend_metric.cc
   - src/core/ext/filters/client_channel/backup_poller.cc
   - src/core/ext/filters/client_channel/channel_connectivity.cc
@@ -2154,6 +2156,7 @@ libs:
   - src/core/ext/filters/backend_metrics/backend_metric_provider.h
   - src/core/ext/filters/channel_idle/channel_idle_filter.h
   - src/core/ext/filters/channel_idle/idle_filter_state.h
+  - src/core/ext/filters/channel_idle/legacy_channel_idle_filter.h
   - src/core/ext/filters/client_channel/backend_metric.h
   - src/core/ext/filters/client_channel/backup_poller.h
   - src/core/ext/filters/client_channel/client_channel.h
@@ -2625,6 +2628,7 @@ libs:
   - src/core/ext/filters/census/grpc_context.cc
   - src/core/ext/filters/channel_idle/channel_idle_filter.cc
   - src/core/ext/filters/channel_idle/idle_filter_state.cc
+  - src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc
   - src/core/ext/filters/client_channel/backend_metric.cc
   - src/core/ext/filters/client_channel/backup_poller.cc
   - src/core/ext/filters/client_channel/channel_connectivity.cc

config.m4

@@ -45,6 +45,7 @@ if test "$PHP_GRPC" != "no"; then
     src/core/ext/filters/census/grpc_context.cc \
     src/core/ext/filters/channel_idle/channel_idle_filter.cc \
     src/core/ext/filters/channel_idle/idle_filter_state.cc \
+    src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc \
     src/core/ext/filters/client_channel/backend_metric.cc \
     src/core/ext/filters/client_channel/backup_poller.cc \
     src/core/ext/filters/client_channel/channel_connectivity.cc \

config.w32

@@ -10,6 +10,7 @@ if (PHP_GRPC != "no") {
     "src\\core\\ext\\filters\\census\\grpc_context.cc " +
     "src\\core\\ext\\filters\\channel_idle\\channel_idle_filter.cc " +
     "src\\core\\ext\\filters\\channel_idle\\idle_filter_state.cc " +
+    "src\\core\\ext\\filters\\channel_idle\\legacy_channel_idle_filter.cc " +
     "src\\core\\ext\\filters\\client_channel\\backend_metric.cc " +
     "src\\core\\ext\\filters\\client_channel\\backup_poller.cc " +
     "src\\core\\ext\\filters\\client_channel\\channel_connectivity.cc " +

gRPC-C++.podspec

@@ -251,6 +251,7 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/backend_metrics/backend_metric_provider.h',
                       'src/core/ext/filters/channel_idle/channel_idle_filter.h',
                       'src/core/ext/filters/channel_idle/idle_filter_state.h',
+                      'src/core/ext/filters/channel_idle/legacy_channel_idle_filter.h',
                       'src/core/ext/filters/client_channel/backend_metric.h',
                       'src/core/ext/filters/client_channel/backup_poller.h',
                       'src/core/ext/filters/client_channel/client_channel.h',
@@ -1503,6 +1504,7 @@ Pod::Spec.new do |s|
                               'src/core/ext/filters/backend_metrics/backend_metric_provider.h',
                               'src/core/ext/filters/channel_idle/channel_idle_filter.h',
                               'src/core/ext/filters/channel_idle/idle_filter_state.h',
+                              'src/core/ext/filters/channel_idle/legacy_channel_idle_filter.h',
                               'src/core/ext/filters/client_channel/backend_metric.h',
                               'src/core/ext/filters/client_channel/backup_poller.h',
                               'src/core/ext/filters/client_channel/client_channel.h',

gRPC-Core.podspec

@@ -224,6 +224,8 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/channel_idle/channel_idle_filter.h',
                       'src/core/ext/filters/channel_idle/idle_filter_state.cc',
                       'src/core/ext/filters/channel_idle/idle_filter_state.h',
+                      'src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc',
+                      'src/core/ext/filters/channel_idle/legacy_channel_idle_filter.h',
                       'src/core/ext/filters/client_channel/backend_metric.cc',
                       'src/core/ext/filters/client_channel/backend_metric.h',
                       'src/core/ext/filters/client_channel/backup_poller.cc',
@@ -2286,6 +2288,7 @@ Pod::Spec.new do |s|
                               'src/core/ext/filters/backend_metrics/backend_metric_provider.h',
                               'src/core/ext/filters/channel_idle/channel_idle_filter.h',
                               'src/core/ext/filters/channel_idle/idle_filter_state.h',
+                              'src/core/ext/filters/channel_idle/legacy_channel_idle_filter.h',
                               'src/core/ext/filters/client_channel/backend_metric.h',
                               'src/core/ext/filters/client_channel/backup_poller.h',
                               'src/core/ext/filters/client_channel/client_channel.h',

grpc.gemspec

@@ -127,6 +127,8 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/ext/filters/channel_idle/channel_idle_filter.h )
   s.files += %w( src/core/ext/filters/channel_idle/idle_filter_state.cc )
   s.files += %w( src/core/ext/filters/channel_idle/idle_filter_state.h )
+  s.files += %w( src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc )
+  s.files += %w( src/core/ext/filters/channel_idle/legacy_channel_idle_filter.h )
   s.files += %w( src/core/ext/filters/client_channel/backend_metric.cc )
   s.files += %w( src/core/ext/filters/client_channel/backend_metric.h )
   s.files += %w( src/core/ext/filters/client_channel/backup_poller.cc )

grpc.gyp

@@ -278,6 +278,7 @@
         'src/core/ext/filters/census/grpc_context.cc',
         'src/core/ext/filters/channel_idle/channel_idle_filter.cc',
         'src/core/ext/filters/channel_idle/idle_filter_state.cc',
+        'src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc',
         'src/core/ext/filters/client_channel/backend_metric.cc',
         'src/core/ext/filters/client_channel/backup_poller.cc',
         'src/core/ext/filters/client_channel/channel_connectivity.cc',
@@ -1134,6 +1135,7 @@
         'src/core/ext/filters/census/grpc_context.cc',
         'src/core/ext/filters/channel_idle/channel_idle_filter.cc',
         'src/core/ext/filters/channel_idle/idle_filter_state.cc',
+        'src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc',
         'src/core/ext/filters/client_channel/backend_metric.cc',
         'src/core/ext/filters/client_channel/backup_poller.cc',
         'src/core/ext/filters/client_channel/channel_connectivity.cc',

package.xml

@@ -109,6 +109,8 @@
     <file baseinstalldir="/" name="src/core/ext/filters/channel_idle/channel_idle_filter.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/channel_idle/idle_filter_state.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/channel_idle/idle_filter_state.h" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/filters/channel_idle/legacy_channel_idle_filter.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/backend_metric.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/backend_metric.h" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/backup_poller.cc" role="src" />

src/core/BUILD

@@ -3892,9 +3892,11 @@ grpc_cc_library(
     name = "grpc_channel_idle_filter",
     srcs = [
         "ext/filters/channel_idle/channel_idle_filter.cc",
+        "ext/filters/channel_idle/legacy_channel_idle_filter.cc",
     ],
     hdrs = [
         "ext/filters/channel_idle/channel_idle_filter.h",
+        "ext/filters/channel_idle/legacy_channel_idle_filter.h",
     ],
     external_deps = [
         "absl/base:core_headers",

src/core/ext/filters/channel_idle/channel_idle_filter.cc

@@ -56,6 +56,13 @@
 
 namespace grpc_core {
 
+const NoInterceptor ChannelIdleFilter::Call::OnClientInitialMetadata;
+const NoInterceptor ChannelIdleFilter::Call::OnServerInitialMetadata;
+const NoInterceptor ChannelIdleFilter::Call::OnServerTrailingMetadata;
+const NoInterceptor ChannelIdleFilter::Call::OnClientToServerMessage;
+const NoInterceptor ChannelIdleFilter::Call::OnServerToClientMessage;
+const NoInterceptor ChannelIdleFilter::Call::OnFinalize;
+
 namespace {
 
 // TODO(roth): This can go back to being a constant when the experiment
@@ -221,17 +228,6 @@ void MaxAgeFilter::PostInit() {
   }
 }
 
-// Construct a promise for one call.
-ArenaPromise<ServerMetadataHandle> ChannelIdleFilter::MakeCallPromise(
-    CallArgs call_args, NextPromiseFactory next_promise_factory) {
-  using Decrementer = std::unique_ptr<ChannelIdleFilter, CallCountDecreaser>;
-  IncreaseCallCount();
-  return ArenaPromise<ServerMetadataHandle>(
-      [decrementer = Decrementer(this),
-       next = next_promise_factory(std::move(call_args))]() mutable
-      -> Poll<ServerMetadataHandle> { return next(); });
-}
-
 bool ChannelIdleFilter::StartTransportOp(grpc_transport_op* op) {
   // Catch the disconnect_with_error transport op.
   if (!op->disconnect_with_error.ok()) Shutdown();
@@ -298,6 +294,7 @@ const grpc_channel_filter MaxAgeFilter::kFilter =
     MakePromiseBasedFilter<MaxAgeFilter, FilterEndpoint::kServer>("max_age");
 
 void RegisterChannelIdleFilters(CoreConfiguration::Builder* builder) {
+  if (!IsV3ChannelIdleFiltersEnabled()) return;
   builder->channel_init()
       ->RegisterFilter(GRPC_CLIENT_CHANNEL, &ClientIdleFilter::kFilter)
       .ExcludeFromMinimalStack()

src/core/ext/filters/channel_idle/channel_idle_filter.h

@@ -40,7 +40,7 @@
 
 namespace grpc_core {
 
-class ChannelIdleFilter : public ChannelFilter {
+class ChannelIdleFilter : public ImplementChannelFilter<ChannelIdleFilter> {
  public:
   ~ChannelIdleFilter() override = default;
 
@@ -49,9 +49,23 @@ class ChannelIdleFilter : public ChannelFilter {
   ChannelIdleFilter(ChannelIdleFilter&&) = default;
   ChannelIdleFilter& operator=(ChannelIdleFilter&&) = default;
 
-  // Construct a promise for one call.
+  class Call {
-  ArenaPromise<ServerMetadataHandle> MakeCallPromise(
+   public:
-      CallArgs call_args, NextPromiseFactory next_promise_factory) override;
+    explicit Call(ChannelIdleFilter* filter) : filter_(filter) {
+      filter_->IncreaseCallCount();
+    }
+    ~Call() { filter_->DecreaseCallCount(); }
+
+    static const NoInterceptor OnClientInitialMetadata;
+    static const NoInterceptor OnServerInitialMetadata;
+    static const NoInterceptor OnServerTrailingMetadata;
+    static const NoInterceptor OnClientToServerMessage;
+    static const NoInterceptor OnServerToClientMessage;
+    static const NoInterceptor OnFinalize;
+
+   private:
+    ChannelIdleFilter* filter_;
+  };
 
   bool StartTransportOp(grpc_transport_op* op) override;
 
@@ -75,12 +89,6 @@ class ChannelIdleFilter : public ChannelFilter {
  private:
   void StartIdleTimer();
 
-  struct CallCountDecreaser {
-    void operator()(ChannelIdleFilter* filter) const {
-      filter->DecreaseCallCount();
-    }
-  };
-
   // The channel stack to which we take refs for pending callbacks.
   grpc_channel_stack* channel_stack_;
   Duration client_idle_timeout_;

src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc

@@ -0,0 +1,326 @@
+// Copyright 2022 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.
+
+// TODO(ctiller): Add a unit test suite for these filters once it's practical to
+// mock transport operations.
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/ext/filters/channel_idle/legacy_channel_idle_filter.h"
+
+#include <functional>
+#include <utility>
+
+#include "absl/base/thread_annotations.h"
+#include "absl/meta/type_traits.h"
+#include "absl/random/random.h"
+#include "absl/types/optional.h"
+
+#include <grpc/impl/channel_arg_names.h>
+#include <grpc/support/log.h>
+
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/channel/promise_based_filter.h"
+#include "src/core/lib/config/core_configuration.h"
+#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/experiments/experiments.h"
+#include "src/core/lib/gprpp/debug_location.h"
+#include "src/core/lib/gprpp/no_destruct.h"
+#include "src/core/lib/gprpp/orphanable.h"
+#include "src/core/lib/gprpp/per_cpu.h"
+#include "src/core/lib/gprpp/status_helper.h"
+#include "src/core/lib/gprpp/sync.h"
+#include "src/core/lib/iomgr/closure.h"
+#include "src/core/lib/iomgr/error.h"
+#include "src/core/lib/iomgr/exec_ctx.h"
+#include "src/core/lib/promise/exec_ctx_wakeup_scheduler.h"
+#include "src/core/lib/promise/loop.h"
+#include "src/core/lib/promise/poll.h"
+#include "src/core/lib/promise/promise.h"
+#include "src/core/lib/promise/sleep.h"
+#include "src/core/lib/promise/try_seq.h"
+#include "src/core/lib/surface/channel_stack_type.h"
+#include "src/core/lib/transport/http2_errors.h"
+#include "src/core/lib/transport/metadata_batch.h"
+
+namespace grpc_core {
+
+namespace {
+
+// TODO(roth): This can go back to being a constant when the experiment
+// is removed.
+Duration DefaultIdleTimeout() {
+  if (IsClientIdlenessEnabled()) return Duration::Minutes(30);
+  return Duration::Infinity();
+}
+
+// If these settings change, make sure that we are not sending a GOAWAY for
+// inproc transport, since a GOAWAY to inproc ends up destroying the transport.
+const auto kDefaultMaxConnectionAge = Duration::Infinity();
+const auto kDefaultMaxConnectionAgeGrace = Duration::Infinity();
+const auto kDefaultMaxConnectionIdle = Duration::Infinity();
+const auto kMaxConnectionAgeJitter = 0.1;
+
+TraceFlag grpc_trace_client_idle_filter(false, "client_idle_filter");
+}  // namespace
+
+#define GRPC_IDLE_FILTER_LOG(format, ...)                               \
+  do {                                                                  \
+    if (GRPC_TRACE_FLAG_ENABLED(grpc_trace_client_idle_filter)) {       \
+      gpr_log(GPR_INFO, "(client idle filter) " format, ##__VA_ARGS__); \
+    }                                                                   \
+  } while (0)
+
+namespace {
+
+Duration GetClientIdleTimeout(const ChannelArgs& args) {
+  return args.GetDurationFromIntMillis(GRPC_ARG_CLIENT_IDLE_TIMEOUT_MS)
+      .value_or(DefaultIdleTimeout());
+}
+
+}  // namespace
+
+struct LegacyMaxAgeFilter::Config {
+  Duration max_connection_age;
+  Duration max_connection_idle;
+  Duration max_connection_age_grace;
+
+  bool enable() const {
+    return max_connection_age != Duration::Infinity() ||
+           max_connection_idle != Duration::Infinity();
+  }
+
+  // A random jitter of +/-10% will be added to MAX_CONNECTION_AGE and
+  // MAX_CONNECTION_IDLE to spread out reconnection storms.
+  static Config FromChannelArgs(const ChannelArgs& args) {
+    const Duration args_max_age =
+        args.GetDurationFromIntMillis(GRPC_ARG_MAX_CONNECTION_AGE_MS)
+            .value_or(kDefaultMaxConnectionAge);
+    const Duration args_max_idle =
+        args.GetDurationFromIntMillis(GRPC_ARG_MAX_CONNECTION_IDLE_MS)
+            .value_or(kDefaultMaxConnectionIdle);
+    const Duration args_max_age_grace =
+        args.GetDurationFromIntMillis(GRPC_ARG_MAX_CONNECTION_AGE_GRACE_MS)
+            .value_or(kDefaultMaxConnectionAgeGrace);
+    // generate a random number between 1 - kMaxConnectionAgeJitter and
+    // 1 + kMaxConnectionAgeJitter
+    struct BitGen {
+      Mutex mu;
+      absl::BitGen bit_gen ABSL_GUARDED_BY(mu);
+      double MakeUniformDouble(double min, double max) {
+        MutexLock lock(&mu);
+        return absl::Uniform(bit_gen, min, max);
+      }
+    };
+    static NoDestruct<PerCpu<BitGen>> bit_gen(PerCpuOptions().SetMaxShards(8));
+    const double multiplier = bit_gen->this_cpu().MakeUniformDouble(
+        1.0 - kMaxConnectionAgeJitter, 1.0 + kMaxConnectionAgeJitter);
+    // GRPC_MILLIS_INF_FUTURE - 0.5 converts the value to float, so that result
+    // will not be cast to int implicitly before the comparison.
+    return Config{args_max_age * multiplier, args_max_idle * multiplier,
+                  args_max_age_grace};
+  }
+};
+
+absl::StatusOr<LegacyClientIdleFilter> LegacyClientIdleFilter::Create(
+    const ChannelArgs& args, ChannelFilter::Args filter_args) {
+  LegacyClientIdleFilter filter(filter_args.channel_stack(),
+                                GetClientIdleTimeout(args));
+  return absl::StatusOr<LegacyClientIdleFilter>(std::move(filter));
+}
+
+absl::StatusOr<LegacyMaxAgeFilter> LegacyMaxAgeFilter::Create(
+    const ChannelArgs& args, ChannelFilter::Args filter_args) {
+  LegacyMaxAgeFilter filter(filter_args.channel_stack(),
+                            Config::FromChannelArgs(args));
+  return absl::StatusOr<LegacyMaxAgeFilter>(std::move(filter));
+}
+
+void LegacyMaxAgeFilter::Shutdown() {
+  max_age_activity_.Reset();
+  LegacyChannelIdleFilter::Shutdown();
+}
+
+void LegacyMaxAgeFilter::PostInit() {
+  struct StartupClosure {
+    RefCountedPtr<grpc_channel_stack> channel_stack;
+    LegacyMaxAgeFilter* filter;
+    grpc_closure closure;
+  };
+  auto run_startup = [](void* p, grpc_error_handle) {
+    auto* startup = static_cast<StartupClosure*>(p);
+    // Trigger idle timer
+    startup->filter->IncreaseCallCount();
+    startup->filter->DecreaseCallCount();
+    grpc_transport_op* op = grpc_make_transport_op(nullptr);
+    op->start_connectivity_watch.reset(
+        new ConnectivityWatcher(startup->filter));
+    op->start_connectivity_watch_state = GRPC_CHANNEL_IDLE;
+    grpc_channel_next_op(
+        grpc_channel_stack_element(startup->channel_stack.get(), 0), op);
+    delete startup;
+  };
+  auto* startup =
+      new StartupClosure{this->channel_stack()->Ref(), this, grpc_closure{}};
+  GRPC_CLOSURE_INIT(&startup->closure, run_startup, startup, nullptr);
+  ExecCtx::Run(DEBUG_LOCATION, &startup->closure, absl::OkStatus());
+
+  auto channel_stack = this->channel_stack()->Ref();
+
+  // Start the max age timer
+  if (max_connection_age_ != Duration::Infinity()) {
+    max_age_activity_.Set(MakeActivity(
+        TrySeq(
+            // First sleep until the max connection age
+            Sleep(Timestamp::Now() + max_connection_age_),
+            // Then send a goaway.
+            [this] {
+              GRPC_CHANNEL_STACK_REF(this->channel_stack(),
+                                     "max_age send_goaway");
+              // Jump out of the activity to send the goaway.
+              auto fn = [](void* arg, grpc_error_handle) {
+                auto* channel_stack = static_cast<grpc_channel_stack*>(arg);
+                grpc_transport_op* op = grpc_make_transport_op(nullptr);
+                op->goaway_error = grpc_error_set_int(
+                    GRPC_ERROR_CREATE("max_age"),
+                    StatusIntProperty::kHttp2Error, GRPC_HTTP2_NO_ERROR);
+                grpc_channel_element* elem =
+                    grpc_channel_stack_element(channel_stack, 0);
+                elem->filter->start_transport_op(elem, op);
+                GRPC_CHANNEL_STACK_UNREF(channel_stack, "max_age send_goaway");
+              };
+              ExecCtx::Run(
+                  DEBUG_LOCATION,
+                  GRPC_CLOSURE_CREATE(fn, this->channel_stack(), nullptr),
+                  absl::OkStatus());
+              return Immediate(absl::OkStatus());
+            },
+            // Sleep for the grace period
+            [this] {
+              return Sleep(Timestamp::Now() + max_connection_age_grace_);
+            }),
+        ExecCtxWakeupScheduler(),
+        [channel_stack, this](absl::Status status) {
+          // OnDone -- close the connection if the promise completed
+          // successfully.
+          // (if it did not, it was cancelled)
+          if (status.ok()) CloseChannel();
+        },
+        channel_stack->EventEngine()));
+  }
+}
+
+// Construct a promise for one call.
+ArenaPromise<ServerMetadataHandle> LegacyChannelIdleFilter::MakeCallPromise(
+    CallArgs call_args, NextPromiseFactory next_promise_factory) {
+  using Decrementer =
+      std::unique_ptr<LegacyChannelIdleFilter, CallCountDecreaser>;
+  IncreaseCallCount();
+  return ArenaPromise<ServerMetadataHandle>(
+      [decrementer = Decrementer(this),
+       next = next_promise_factory(std::move(call_args))]() mutable
+      -> Poll<ServerMetadataHandle> { return next(); });
+}
+
+bool LegacyChannelIdleFilter::StartTransportOp(grpc_transport_op* op) {
+  // Catch the disconnect_with_error transport op.
+  if (!op->disconnect_with_error.ok()) Shutdown();
+  // Pass the op to the next filter.
+  return false;
+}
+
+void LegacyChannelIdleFilter::Shutdown() {
+  // IncreaseCallCount() introduces a phony call and prevent the timer from
+  // being reset by other threads.
+  IncreaseCallCount();
+  activity_.Reset();
+}
+
+void LegacyChannelIdleFilter::IncreaseCallCount() {
+  idle_filter_state_->IncreaseCallCount();
+}
+
+void LegacyChannelIdleFilter::DecreaseCallCount() {
+  if (idle_filter_state_->DecreaseCallCount()) {
+    // If there are no more calls in progress, start the idle timer.
+    StartIdleTimer();
+  }
+}
+
+void LegacyChannelIdleFilter::StartIdleTimer() {
+  GRPC_IDLE_FILTER_LOG("timer has started");
+  auto idle_filter_state = idle_filter_state_;
+  // Hold a ref to the channel stack for the timer callback.
+  auto channel_stack = channel_stack_->Ref();
+  auto timeout = client_idle_timeout_;
+  auto promise = Loop([timeout, idle_filter_state]() {
+    return TrySeq(Sleep(Timestamp::Now() + timeout),
+                  [idle_filter_state]() -> Poll<LoopCtl<absl::Status>> {
+                    if (idle_filter_state->CheckTimer()) {
+                      return Continue{};
+                    } else {
+                      return absl::OkStatus();
+                    }
+                  });
+  });
+  activity_.Set(MakeActivity(
+      std::move(promise), ExecCtxWakeupScheduler{},
+      [channel_stack, this](absl::Status status) {
+        if (status.ok()) CloseChannel();
+      },
+      channel_stack->EventEngine()));
+}
+
+void LegacyChannelIdleFilter::CloseChannel() {
+  auto* op = grpc_make_transport_op(nullptr);
+  op->disconnect_with_error = grpc_error_set_int(
+      GRPC_ERROR_CREATE("enter idle"),
+      StatusIntProperty::ChannelConnectivityState, GRPC_CHANNEL_IDLE);
+  // Pass the transport op down to the channel stack.
+  auto* elem = grpc_channel_stack_element(channel_stack_, 0);
+  elem->filter->start_transport_op(elem, op);
+}
+
+const grpc_channel_filter LegacyClientIdleFilter::kFilter =
+    MakePromiseBasedFilter<LegacyClientIdleFilter, FilterEndpoint::kClient>(
+        "client_idle");
+const grpc_channel_filter LegacyMaxAgeFilter::kFilter =
+    MakePromiseBasedFilter<LegacyMaxAgeFilter, FilterEndpoint::kServer>(
+        "max_age");
+
+void RegisterLegacyChannelIdleFilters(CoreConfiguration::Builder* builder) {
+  if (IsV3ChannelIdleFiltersEnabled()) return;
+  builder->channel_init()
+      ->RegisterFilter(GRPC_CLIENT_CHANNEL, &LegacyClientIdleFilter::kFilter)
+      .ExcludeFromMinimalStack()
+      .If([](const ChannelArgs& channel_args) {
+        return GetClientIdleTimeout(channel_args) != Duration::Infinity();
+      });
+  builder->channel_init()
+      ->RegisterFilter(GRPC_SERVER_CHANNEL, &LegacyMaxAgeFilter::kFilter)
+      .ExcludeFromMinimalStack()
+      .If([](const ChannelArgs& channel_args) {
+        return LegacyMaxAgeFilter::Config::FromChannelArgs(channel_args)
+            .enable();
+      });
+}
+
+LegacyMaxAgeFilter::LegacyMaxAgeFilter(grpc_channel_stack* channel_stack,
+                                       const Config& max_age_config)
+    : LegacyChannelIdleFilter(channel_stack,
+                              max_age_config.max_connection_idle),
+      max_connection_age_(max_age_config.max_connection_age),
+      max_connection_age_grace_(max_age_config.max_connection_age_grace) {}
+
+}  // namespace grpc_core

src/core/ext/filters/channel_idle/legacy_channel_idle_filter.h

@@ -0,0 +1,143 @@
+// Copyright 2022 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_SRC_CORE_EXT_FILTERS_CHANNEL_IDLE_LEGACY_CHANNEL_IDLE_FILTER_H
+#define GRPC_SRC_CORE_EXT_FILTERS_CHANNEL_IDLE_LEGACY_CHANNEL_IDLE_FILTER_H
+
+#include <grpc/support/port_platform.h>
+
+#include <memory>
+
+#include "absl/status/status.h"
+#include "absl/status/statusor.h"
+
+#include <grpc/impl/connectivity_state.h>
+
+#include "src/core/ext/filters/channel_idle/idle_filter_state.h"
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/channel/channel_fwd.h"
+#include "src/core/lib/channel/channel_stack.h"
+#include "src/core/lib/channel/promise_based_filter.h"
+#include "src/core/lib/gprpp/orphanable.h"
+#include "src/core/lib/gprpp/ref_counted_ptr.h"
+#include "src/core/lib/gprpp/single_set_ptr.h"
+#include "src/core/lib/gprpp/time.h"
+#include "src/core/lib/promise/activity.h"
+#include "src/core/lib/promise/arena_promise.h"
+#include "src/core/lib/transport/connectivity_state.h"
+#include "src/core/lib/transport/transport.h"
+
+namespace grpc_core {
+
+class LegacyChannelIdleFilter : public ChannelFilter {
+ public:
+  ~LegacyChannelIdleFilter() override = default;
+
+  LegacyChannelIdleFilter(const LegacyChannelIdleFilter&) = delete;
+  LegacyChannelIdleFilter& operator=(const LegacyChannelIdleFilter&) = delete;
+  LegacyChannelIdleFilter(LegacyChannelIdleFilter&&) = default;
+  LegacyChannelIdleFilter& operator=(LegacyChannelIdleFilter&&) = default;
+
+  // Construct a promise for one call.
+  ArenaPromise<ServerMetadataHandle> MakeCallPromise(
+      CallArgs call_args, NextPromiseFactory next_promise_factory) override;
+
+  bool StartTransportOp(grpc_transport_op* op) override;
+
+ protected:
+  using SingleSetActivityPtr =
+      SingleSetPtr<Activity, typename ActivityPtr::deleter_type>;
+
+  LegacyChannelIdleFilter(grpc_channel_stack* channel_stack,
+                          Duration client_idle_timeout)
+      : channel_stack_(channel_stack),
+        client_idle_timeout_(client_idle_timeout) {}
+
+  grpc_channel_stack* channel_stack() { return channel_stack_; };
+
+  virtual void Shutdown();
+  void CloseChannel();
+
+  void IncreaseCallCount();
+  void DecreaseCallCount();
+
+ private:
+  void StartIdleTimer();
+
+  struct CallCountDecreaser {
+    void operator()(LegacyChannelIdleFilter* filter) const {
+      filter->DecreaseCallCount();
+    }
+  };
+
+  // The channel stack to which we take refs for pending callbacks.
+  grpc_channel_stack* channel_stack_;
+  Duration client_idle_timeout_;
+  std::shared_ptr<IdleFilterState> idle_filter_state_{
+      std::make_shared<IdleFilterState>(false)};
+
+  SingleSetActivityPtr activity_;
+};
+
+class LegacyClientIdleFilter final : public LegacyChannelIdleFilter {
+ public:
+  static const grpc_channel_filter kFilter;
+
+  static absl::StatusOr<LegacyClientIdleFilter> Create(
+      const ChannelArgs& args, ChannelFilter::Args filter_args);
+
+ private:
+  using LegacyChannelIdleFilter::LegacyChannelIdleFilter;
+};
+
+class LegacyMaxAgeFilter final : public LegacyChannelIdleFilter {
+ public:
+  static const grpc_channel_filter kFilter;
+  struct Config;
+
+  static absl::StatusOr<LegacyMaxAgeFilter> Create(
+      const ChannelArgs& args, ChannelFilter::Args filter_args);
+
+  void PostInit() override;
+
+ private:
+  class ConnectivityWatcher : public AsyncConnectivityStateWatcherInterface {
+   public:
+    explicit ConnectivityWatcher(LegacyMaxAgeFilter* filter)
+        : channel_stack_(filter->channel_stack()->Ref()), filter_(filter) {}
+    ~ConnectivityWatcher() override = default;
+
+    void OnConnectivityStateChange(grpc_connectivity_state new_state,
+                                   const absl::Status&) override {
+      if (new_state == GRPC_CHANNEL_SHUTDOWN) filter_->Shutdown();
+    }
+
+   private:
+    RefCountedPtr<grpc_channel_stack> channel_stack_;
+    LegacyMaxAgeFilter* filter_;
+  };
+
+  LegacyMaxAgeFilter(grpc_channel_stack* channel_stack,
+                     const Config& max_age_config);
+
+  void Shutdown() override;
+
+  SingleSetActivityPtr max_age_activity_;
+  Duration max_connection_age_;
+  Duration max_connection_age_grace_;
+};
+
+}  // namespace grpc_core
+
+#endif  // GRPC_SRC_CORE_EXT_FILTERS_CHANNEL_IDLE_LEGACY_CHANNEL_IDLE_FILTER_H

src/core/lib/experiments/experiments.cc

@@ -147,6 +147,9 @@ const char* const description_unconstrained_max_quota_buffer_size =
     "Discard the cap on the max free pool size for one memory allocator";
 const char* const additional_constraints_unconstrained_max_quota_buffer_size =
     "{}";
+const char* const description_v3_channel_idle_filters =
+    "Use the v3 filter API version of the idle filters.";
+const char* const additional_constraints_v3_channel_idle_filters = "{}";
 const char* const description_work_serializer_clears_time_cache =
     "Have the work serializer clear the time cache when it dispatches work.";
 const char* const additional_constraints_work_serializer_clears_time_cache =
@@ -259,6 +262,8 @@ const ExperimentMetadata g_experiment_metadata[] = {
      description_unconstrained_max_quota_buffer_size,
      additional_constraints_unconstrained_max_quota_buffer_size, nullptr, 0,
      false, true},
+    {"v3_channel_idle_filters", description_v3_channel_idle_filters,
+     additional_constraints_v3_channel_idle_filters, nullptr, 0, false, true},
     {"work_serializer_clears_time_cache",
      description_work_serializer_clears_time_cache,
      additional_constraints_work_serializer_clears_time_cache, nullptr, 0, true,
@@ -401,6 +406,9 @@ const char* const description_unconstrained_max_quota_buffer_size =
     "Discard the cap on the max free pool size for one memory allocator";
 const char* const additional_constraints_unconstrained_max_quota_buffer_size =
     "{}";
+const char* const description_v3_channel_idle_filters =
+    "Use the v3 filter API version of the idle filters.";
+const char* const additional_constraints_v3_channel_idle_filters = "{}";
 const char* const description_work_serializer_clears_time_cache =
     "Have the work serializer clear the time cache when it dispatches work.";
 const char* const additional_constraints_work_serializer_clears_time_cache =
@@ -513,6 +521,8 @@ const ExperimentMetadata g_experiment_metadata[] = {
      description_unconstrained_max_quota_buffer_size,
      additional_constraints_unconstrained_max_quota_buffer_size, nullptr, 0,
      false, true},
+    {"v3_channel_idle_filters", description_v3_channel_idle_filters,
+     additional_constraints_v3_channel_idle_filters, nullptr, 0, false, true},
     {"work_serializer_clears_time_cache",
      description_work_serializer_clears_time_cache,
      additional_constraints_work_serializer_clears_time_cache, nullptr, 0, true,
@@ -655,6 +665,9 @@ const char* const description_unconstrained_max_quota_buffer_size =
     "Discard the cap on the max free pool size for one memory allocator";
 const char* const additional_constraints_unconstrained_max_quota_buffer_size =
     "{}";
+const char* const description_v3_channel_idle_filters =
+    "Use the v3 filter API version of the idle filters.";
+const char* const additional_constraints_v3_channel_idle_filters = "{}";
 const char* const description_work_serializer_clears_time_cache =
     "Have the work serializer clear the time cache when it dispatches work.";
 const char* const additional_constraints_work_serializer_clears_time_cache =
@@ -767,6 +780,8 @@ const ExperimentMetadata g_experiment_metadata[] = {
      description_unconstrained_max_quota_buffer_size,
      additional_constraints_unconstrained_max_quota_buffer_size, nullptr, 0,
      false, true},
+    {"v3_channel_idle_filters", description_v3_channel_idle_filters,
+     additional_constraints_v3_channel_idle_filters, nullptr, 0, false, true},
     {"work_serializer_clears_time_cache",
      description_work_serializer_clears_time_cache,
      additional_constraints_work_serializer_clears_time_cache, nullptr, 0, true,

src/core/lib/experiments/experiments.h

@@ -107,6 +107,7 @@ inline bool IsTcpFrameSizeTuningEnabled() { return false; }
 inline bool IsTcpRcvLowatEnabled() { return false; }
 inline bool IsTraceRecordCallopsEnabled() { return false; }
 inline bool IsUnconstrainedMaxQuotaBufferSizeEnabled() { return false; }
+inline bool IsV3ChannelIdleFiltersEnabled() { return false; }
 #define GRPC_EXPERIMENT_IS_INCLUDED_WORK_SERIALIZER_CLEARS_TIME_CACHE
 inline bool IsWorkSerializerClearsTimeCacheEnabled() { return true; }
 inline bool IsWorkSerializerDispatchEnabled() { return false; }
@@ -169,6 +170,7 @@ inline bool IsTcpFrameSizeTuningEnabled() { return false; }
 inline bool IsTcpRcvLowatEnabled() { return false; }
 inline bool IsTraceRecordCallopsEnabled() { return false; }
 inline bool IsUnconstrainedMaxQuotaBufferSizeEnabled() { return false; }
+inline bool IsV3ChannelIdleFiltersEnabled() { return false; }
 #define GRPC_EXPERIMENT_IS_INCLUDED_WORK_SERIALIZER_CLEARS_TIME_CACHE
 inline bool IsWorkSerializerClearsTimeCacheEnabled() { return true; }
 inline bool IsWorkSerializerDispatchEnabled() { return false; }
@@ -231,6 +233,7 @@ inline bool IsTcpFrameSizeTuningEnabled() { return false; }
 inline bool IsTcpRcvLowatEnabled() { return false; }
 inline bool IsTraceRecordCallopsEnabled() { return false; }
 inline bool IsUnconstrainedMaxQuotaBufferSizeEnabled() { return false; }
+inline bool IsV3ChannelIdleFiltersEnabled() { return false; }
 #define GRPC_EXPERIMENT_IS_INCLUDED_WORK_SERIALIZER_CLEARS_TIME_CACHE
 inline bool IsWorkSerializerClearsTimeCacheEnabled() { return true; }
 inline bool IsWorkSerializerDispatchEnabled() { return false; }
@@ -277,6 +280,7 @@ enum ExperimentIds {
   kExperimentIdTcpRcvLowat,
   kExperimentIdTraceRecordCallops,
   kExperimentIdUnconstrainedMaxQuotaBufferSize,
+  kExperimentIdV3ChannelIdleFilters,
   kExperimentIdWorkSerializerClearsTimeCache,
   kExperimentIdWorkSerializerDispatch,
   kExperimentIdWriteSizePolicy,
@@ -416,6 +420,10 @@ inline bool IsTraceRecordCallopsEnabled() {
 inline bool IsUnconstrainedMaxQuotaBufferSizeEnabled() {
   return IsExperimentEnabled(kExperimentIdUnconstrainedMaxQuotaBufferSize);
 }
+#define GRPC_EXPERIMENT_IS_INCLUDED_V3_CHANNEL_IDLE_FILTERS
+inline bool IsV3ChannelIdleFiltersEnabled() {
+  return IsExperimentEnabled(kExperimentIdV3ChannelIdleFilters);
+}
 #define GRPC_EXPERIMENT_IS_INCLUDED_WORK_SERIALIZER_CLEARS_TIME_CACHE
 inline bool IsWorkSerializerClearsTimeCacheEnabled() {
   return IsExperimentEnabled(kExperimentIdWorkSerializerClearsTimeCache);

src/core/lib/experiments/experiments.yaml

@@ -252,6 +252,12 @@
   expiry: 2024/02/01
   owner: ctiller@google.com
   test_tags: [resource_quota_test]
+- name: v3_channel_idle_filters
+  description:
+    Use the v3 filter API version of the idle filters.
+  expiry: 2024/04/04
+  owner: ctiller@google.com
+  test_tags: []
 - name: work_serializer_clears_time_cache
   description:
     Have the work serializer clear the time cache when it dispatches work.

src/core/plugin_registry/grpc_plugin_registry.cc

@@ -40,6 +40,8 @@ extern void SecurityRegisterHandshakerFactories(
     CoreConfiguration::Builder* builder);
 extern void RegisterClientAuthorityFilter(CoreConfiguration::Builder* builder);
 extern void RegisterChannelIdleFilters(CoreConfiguration::Builder* builder);
+extern void RegisterLegacyChannelIdleFilters(
+    CoreConfiguration::Builder* builder);
 extern void RegisterDeadlineFilter(CoreConfiguration::Builder* builder);
 extern void RegisterGrpcLbPolicy(CoreConfiguration::Builder* builder);
 extern void RegisterHttpFilters(CoreConfiguration::Builder* builder);
@@ -89,6 +91,7 @@ void BuildCoreConfiguration(CoreConfiguration::Builder* builder) {
   SecurityRegisterHandshakerFactories(builder);
   RegisterClientAuthorityFilter(builder);
   RegisterChannelIdleFilters(builder);
+  RegisterLegacyChannelIdleFilters(builder);
   RegisterConnectedChannel(builder);
   RegisterGrpcLbPolicy(builder);
   RegisterHttpFilters(builder);

src/python/grpcio/grpc_core_dependencies.py

@@ -19,6 +19,7 @@ CORE_SOURCE_FILES = [
     'src/core/ext/filters/census/grpc_context.cc',
     'src/core/ext/filters/channel_idle/channel_idle_filter.cc',
     'src/core/ext/filters/channel_idle/idle_filter_state.cc',
+    'src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc',
     'src/core/ext/filters/client_channel/backend_metric.cc',
     'src/core/ext/filters/client_channel/backup_poller.cc',
     'src/core/ext/filters/client_channel/channel_connectivity.cc',

tools/doxygen/Doxyfile.c++.internal

@@ -1087,6 +1087,8 @@ src/core/ext/filters/channel_idle/channel_idle_filter.cc \
 src/core/ext/filters/channel_idle/channel_idle_filter.h \
 src/core/ext/filters/channel_idle/idle_filter_state.cc \
 src/core/ext/filters/channel_idle/idle_filter_state.h \
+src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc \
+src/core/ext/filters/channel_idle/legacy_channel_idle_filter.h \
 src/core/ext/filters/client_channel/backend_metric.cc \
 src/core/ext/filters/client_channel/backend_metric.h \
 src/core/ext/filters/client_channel/backup_poller.cc \

tools/doxygen/Doxyfile.core.internal

@@ -891,6 +891,8 @@ src/core/ext/filters/channel_idle/channel_idle_filter.cc \
 src/core/ext/filters/channel_idle/channel_idle_filter.h \
 src/core/ext/filters/channel_idle/idle_filter_state.cc \
 src/core/ext/filters/channel_idle/idle_filter_state.h \
+src/core/ext/filters/channel_idle/legacy_channel_idle_filter.cc \
+src/core/ext/filters/channel_idle/legacy_channel_idle_filter.h \
 src/core/ext/filters/client_channel/README.md \
 src/core/ext/filters/client_channel/backend_metric.cc \
 src/core/ext/filters/client_channel/backend_metric.h \