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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
| commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
| tree | f435a8308119effd964b339f76abb83a57c29483 /xpcom/threads/nsMemoryPressure.cpp | |
| parent | Initial commit. (diff) | |
| download | firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz firefox-26a029d407be480d791972afb5975cf62c9360a6.zip | |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'xpcom/threads/nsMemoryPressure.cpp')
| -rw-r--r-- | xpcom/threads/nsMemoryPressure.cpp | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/xpcom/threads/nsMemoryPressure.cpp b/xpcom/threads/nsMemoryPressure.cpp new file mode 100644 index 0000000000..dbd3a92f79 --- /dev/null +++ b/xpcom/threads/nsMemoryPressure.cpp @@ -0,0 +1,104 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "nsMemoryPressure.h" +#include "mozilla/Assertions.h" +#include "mozilla/Atomics.h" +#include "mozilla/Services.h" + +#include "nsThreadUtils.h" +#include "nsIObserverService.h" + +using namespace mozilla; + +const char* const kTopicMemoryPressure = "memory-pressure"; +const char* const kTopicMemoryPressureStop = "memory-pressure-stop"; +const char16_t* const kSubTopicLowMemoryNew = u"low-memory"; +const char16_t* const kSubTopicLowMemoryOngoing = u"low-memory-ongoing"; + +// This is accessed from any thread through NS_NotifyOfEventualMemoryPressure +static Atomic<MemoryPressureState, Relaxed> sMemoryPressurePending( + MemoryPressureState::NoPressure); + +void NS_NotifyOfEventualMemoryPressure(MemoryPressureState aState) { + MOZ_ASSERT(aState != MemoryPressureState::None); + + /* + * A new memory pressure event erases an ongoing (or stop of) memory pressure, + * but an existing "new" memory pressure event takes precedence over a new + * "ongoing" or "stop" memory pressure event. + */ + switch (aState) { + case MemoryPressureState::None: + case MemoryPressureState::LowMemory: + sMemoryPressurePending = aState; + break; + case MemoryPressureState::NoPressure: + sMemoryPressurePending.compareExchange(MemoryPressureState::None, aState); + break; + } +} + +nsresult NS_NotifyOfMemoryPressure(MemoryPressureState aState) { + NS_NotifyOfEventualMemoryPressure(aState); + nsCOMPtr<nsIRunnable> event = + new Runnable("NS_DispatchEventualMemoryPressure"); + return NS_DispatchToMainThread(event); +} + +void NS_DispatchMemoryPressure() { + MOZ_ASSERT(NS_IsMainThread()); + static MemoryPressureState sMemoryPressureStatus = + MemoryPressureState::NoPressure; + + MemoryPressureState mpPending = + sMemoryPressurePending.exchange(MemoryPressureState::None); + if (mpPending == MemoryPressureState::None) { + return; + } + + nsCOMPtr<nsIObserverService> os = services::GetObserverService(); + if (!os) { + NS_WARNING("Can't get observer service!"); + return; + } + + switch (mpPending) { + case MemoryPressureState::None: + MOZ_ASSERT_UNREACHABLE("Already handled this case above."); + break; + case MemoryPressureState::LowMemory: + switch (sMemoryPressureStatus) { + case MemoryPressureState::None: + MOZ_ASSERT_UNREACHABLE("The internal status should never be None."); + break; + case MemoryPressureState::NoPressure: + sMemoryPressureStatus = MemoryPressureState::LowMemory; + os->NotifyObservers(nullptr, kTopicMemoryPressure, + kSubTopicLowMemoryNew); + break; + case MemoryPressureState::LowMemory: + os->NotifyObservers(nullptr, kTopicMemoryPressure, + kSubTopicLowMemoryOngoing); + break; + } + break; + case MemoryPressureState::NoPressure: + switch (sMemoryPressureStatus) { + case MemoryPressureState::None: + MOZ_ASSERT_UNREACHABLE("The internal status should never be None."); + break; + case MemoryPressureState::NoPressure: + // Already no pressure. Do nothing. + break; + case MemoryPressureState::LowMemory: + sMemoryPressureStatus = MemoryPressureState::NoPressure; + os->NotifyObservers(nullptr, kTopicMemoryPressureStop, nullptr); + break; + } + break; + } +} |