Use a shared executor for g3 timers.

PiperOrigin-RevId: 933431037

internal/platform/implementation/g3/BUILD

@@ -59,10 +59,11 @@ cc_library(
         "//internal/platform/implementation:types",
         "//internal/platform/implementation/shared:count_down_latch",
         "//internal/platform/implementation/shared:posix_mutex",
-        "//internal/test",
         "@com_google_absl//absl/base:core_headers",
+        "@com_google_absl//absl/base:nullability",
         "@com_google_absl//absl/container:btree",
         "@com_google_absl//absl/container:flat_hash_map",
+        "@com_google_absl//absl/functional:any_invocable",
         "@com_google_absl//absl/strings",
         "@com_google_absl//absl/strings:str_format",
         "@com_google_absl//absl/synchronization",
@@ -217,6 +218,7 @@ cc_library(
         "//internal/platform/implementation/shared:file",
         "//third_party/gloop/thread",
         "@com_google_absl//absl/base:core_headers",
+        "@com_google_absl//absl/base:no_destructor",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:statusor",
         "@com_google_absl//absl/strings",

internal/platform/implementation/g3/platform.cc

@@ -20,6 +20,7 @@
 #include <string>
 
 #include "absl/base/attributes.h"
+#include "absl/base/no_destructor.h"
 #include "absl/status/status.h"
 #include "absl/status/statusor.h"
 #include "absl/strings/str_cat.h"
@@ -239,7 +240,8 @@ ImplementationPlatform::CreateConditionVariable(Mutex* mutex) {
 }
 
 std::unique_ptr<Timer> ImplementationPlatform::CreateTimer() {
-  return std::make_unique<g3::Timer>();
+  static absl::NoDestructor<g3::ScheduledExecutor> timer_executor;
+  return std::make_unique<g3::Timer>(timer_executor.get());
 }
 
 std::unique_ptr<nearby::api::DeviceInfo>

internal/platform/implementation/g3/timer.h

@@ -19,10 +19,13 @@
 #include <memory>
 #include <utility>
 
+#include "absl/base/nullability.h"
 #include "absl/base/thread_annotations.h"
+#include "absl/functional/any_invocable.h"
 #include "absl/synchronization/mutex.h"
 #include "absl/time/time.h"
-#include "internal/platform/implementation/g3/scheduled_executor.h"
+#include "internal/platform/implementation/cancelable.h"
+#include "internal/platform/implementation/scheduled_executor.h"
 #include "internal/platform/implementation/timer.h"
 
 namespace nearby {
@@ -30,8 +33,11 @@ namespace g3 {
 
 class Timer : public api::Timer {
  public:
-  Timer() = default;
-  ~Timer() override = default;
+  explicit Timer(api::ScheduledExecutor* absl_nonnull executor)
+      : executor_(executor) {};
+  ~Timer() override {
+    Stop();
+  };
 
   bool Create(int delay, int interval,
               absl::AnyInvocable<void()> callback) override {
@@ -52,13 +58,16 @@ class Timer : public api::Timer {
       task_.reset();
       return result;
     }
-    return false;
+    return true;
   }
 
  private:
   bool Schedule(absl::Duration delay) {
     absl::MutexLock lock(mutex_);
-    task_ = executor_.Schedule([this]() { TriggerCallback(); }, delay);
+    if (is_stopped_) {
+      return false;
+    }
+    task_ = executor_->Schedule([this]() { TriggerCallback(); }, delay);
     return true;
   }
 
@@ -77,7 +86,7 @@ class Timer : public api::Timer {
   std::atomic_bool is_stopped_;
   absl::Duration interval_;
   std::shared_ptr<api::Cancelable> task_ ABSL_GUARDED_BY(mutex_);
-  ScheduledExecutor executor_;
+  api::ScheduledExecutor* absl_nonnull const executor_;
 };
 
 }  // namespace g3