/* -*- 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 "nsThreadUtils.h" using namespace mozilla; static Atomic<int32_t, Relaxed> sMemoryPressurePending; static_assert(MemPressure_None == 0, "Bad static initialization with the default constructor."); MemoryPressureState NS_GetPendingMemoryPressure() { int32_t value = sMemoryPressurePending.exchange(MemPressure_None); return MemoryPressureState(value); } void NS_DispatchEventualMemoryPressure(MemoryPressureState aState) { /* * A new memory pressure event erases an ongoing memory pressure, but an * existing "new" memory pressure event takes precedence over a new "ongoing" * memory pressure event. */ switch (aState) { case MemPressure_None: sMemoryPressurePending = MemPressure_None; break; case MemPressure_New: sMemoryPressurePending = MemPressure_New; break; case MemPressure_Ongoing: sMemoryPressurePending.compareExchange(MemPressure_None, MemPressure_Ongoing); break; } } nsresult NS_DispatchMemoryPressure(MemoryPressureState aState) { NS_DispatchEventualMemoryPressure(aState); nsCOMPtr<nsIRunnable> event = new Runnable; return NS_DispatchToMainThread(event); }