memory_pressure_listener.cc 5.6 KB

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  1. // Copyright 2013 The Chromium Authors. All rights reserved.
  2. // Use of this source code is governed by a BSD-style license that can be
  3. // found in the LICENSE file.
  4. #include "base/memory/memory_pressure_listener.h"
  5. #include <atomic>
  6. #include "base/observer_list.h"
  7. #include "base/observer_list_threadsafe.h"
  8. #include "base/threading/sequenced_task_runner_handle.h"
  9. #include "base/trace_event/base_tracing.h"
  10. #include "base/tracing_buildflags.h"
  11. #if BUILDFLAG(ENABLE_BASE_TRACING)
  12. #include "base/trace_event/memory_pressure_level_proto.h" // no-presubmit-check
  13. #endif
  14. namespace base {
  15. namespace {
  16. // This class is thread safe and internally synchronized.
  17. class MemoryPressureObserver {
  18. public:
  19. // There is at most one MemoryPressureObserver and it is never deleted.
  20. ~MemoryPressureObserver() = delete;
  21. void AddObserver(MemoryPressureListener* listener, bool sync) {
  22. // TODO(crbug.com/1063868): DCHECK instead of silently failing when a
  23. // MemoryPressureListener is created in a non-sequenced context. Tests will
  24. // need to be adjusted for that to work.
  25. if (SequencedTaskRunnerHandle::IsSet()) {
  26. async_observers_->AddObserver(listener);
  27. }
  28. if (sync) {
  29. AutoLock lock(sync_observers_lock_);
  30. sync_observers_.AddObserver(listener);
  31. }
  32. }
  33. void RemoveObserver(MemoryPressureListener* listener) {
  34. async_observers_->RemoveObserver(listener);
  35. AutoLock lock(sync_observers_lock_);
  36. sync_observers_.RemoveObserver(listener);
  37. }
  38. void Notify(
  39. MemoryPressureListener::MemoryPressureLevel memory_pressure_level) {
  40. async_observers_->Notify(FROM_HERE, &MemoryPressureListener::Notify,
  41. memory_pressure_level);
  42. AutoLock lock(sync_observers_lock_);
  43. for (auto& observer : sync_observers_)
  44. observer.SyncNotify(memory_pressure_level);
  45. }
  46. private:
  47. const scoped_refptr<ObserverListThreadSafe<MemoryPressureListener>>
  48. async_observers_ =
  49. base::MakeRefCounted<ObserverListThreadSafe<MemoryPressureListener>>(
  50. ObserverListPolicy::EXISTING_ONLY);
  51. ObserverList<MemoryPressureListener>::Unchecked sync_observers_;
  52. Lock sync_observers_lock_;
  53. };
  54. // Gets the shared MemoryPressureObserver singleton instance.
  55. MemoryPressureObserver* GetMemoryPressureObserver() {
  56. static auto* const observer = new MemoryPressureObserver();
  57. return observer;
  58. }
  59. std::atomic<bool> g_notifications_suppressed;
  60. } // namespace
  61. MemoryPressureListener::MemoryPressureListener(
  62. const base::Location& creation_location,
  63. const MemoryPressureListener::MemoryPressureCallback& callback)
  64. : callback_(callback), creation_location_(creation_location) {
  65. GetMemoryPressureObserver()->AddObserver(this, false);
  66. }
  67. MemoryPressureListener::MemoryPressureListener(
  68. const base::Location& creation_location,
  69. const MemoryPressureListener::MemoryPressureCallback& callback,
  70. const MemoryPressureListener::SyncMemoryPressureCallback&
  71. sync_memory_pressure_callback)
  72. : callback_(callback),
  73. sync_memory_pressure_callback_(sync_memory_pressure_callback),
  74. creation_location_(creation_location) {
  75. GetMemoryPressureObserver()->AddObserver(this, true);
  76. }
  77. MemoryPressureListener::~MemoryPressureListener() {
  78. GetMemoryPressureObserver()->RemoveObserver(this);
  79. }
  80. void MemoryPressureListener::Notify(MemoryPressureLevel memory_pressure_level) {
  81. TRACE_EVENT(
  82. "base", "MemoryPressureListener::Notify",
  83. [&](perfetto::EventContext ctx) {
  84. auto* event = ctx.event<perfetto::protos::pbzero::ChromeTrackEvent>();
  85. auto* data = event->set_chrome_memory_pressure_notification();
  86. data->set_level(
  87. trace_event::MemoryPressureLevelToTraceEnum(memory_pressure_level));
  88. data->set_creation_location_iid(
  89. base::trace_event::InternedSourceLocation::Get(&ctx,
  90. creation_location_));
  91. });
  92. callback_.Run(memory_pressure_level);
  93. }
  94. void MemoryPressureListener::SyncNotify(
  95. MemoryPressureLevel memory_pressure_level) {
  96. if (!sync_memory_pressure_callback_.is_null()) {
  97. sync_memory_pressure_callback_.Run(memory_pressure_level);
  98. }
  99. }
  100. // static
  101. void MemoryPressureListener::NotifyMemoryPressure(
  102. MemoryPressureLevel memory_pressure_level) {
  103. DCHECK_NE(memory_pressure_level, MEMORY_PRESSURE_LEVEL_NONE);
  104. TRACE_EVENT_INSTANT(
  105. trace_event::MemoryDumpManager::kTraceCategory,
  106. "MemoryPressureListener::NotifyMemoryPressure",
  107. [&](perfetto::EventContext ctx) {
  108. auto* event = ctx.event<perfetto::protos::pbzero::ChromeTrackEvent>();
  109. auto* data = event->set_chrome_memory_pressure_notification();
  110. data->set_level(
  111. trace_event::MemoryPressureLevelToTraceEnum(memory_pressure_level));
  112. });
  113. if (AreNotificationsSuppressed())
  114. return;
  115. DoNotifyMemoryPressure(memory_pressure_level);
  116. }
  117. // static
  118. bool MemoryPressureListener::AreNotificationsSuppressed() {
  119. return g_notifications_suppressed.load(std::memory_order_acquire);
  120. }
  121. // static
  122. void MemoryPressureListener::SetNotificationsSuppressed(bool suppress) {
  123. g_notifications_suppressed.store(suppress, std::memory_order_release);
  124. }
  125. // static
  126. void MemoryPressureListener::SimulatePressureNotification(
  127. MemoryPressureLevel memory_pressure_level) {
  128. // Notify all listeners even if regular pressure notifications are suppressed.
  129. DoNotifyMemoryPressure(memory_pressure_level);
  130. }
  131. // static
  132. void MemoryPressureListener::DoNotifyMemoryPressure(
  133. MemoryPressureLevel memory_pressure_level) {
  134. DCHECK_NE(memory_pressure_level, MEMORY_PRESSURE_LEVEL_NONE);
  135. GetMemoryPressureObserver()->Notify(memory_pressure_level);
  136. }
  137. } // namespace base