From 5f8de423f190bbb79a62f804151bc24824fa32d8 Mon Sep 17 00:00:00 2001 From: "Matt A. Tobin" Date: Fri, 2 Feb 2018 04:16:08 -0500 Subject: Add m-esr52 at 52.6.0 --- xpcom/threads/nsMemoryPressure.h | 77 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 xpcom/threads/nsMemoryPressure.h (limited to 'xpcom/threads/nsMemoryPressure.h') diff --git a/xpcom/threads/nsMemoryPressure.h b/xpcom/threads/nsMemoryPressure.h new file mode 100644 index 000000000..a05728c61 --- /dev/null +++ b/xpcom/threads/nsMemoryPressure.h @@ -0,0 +1,77 @@ +/* -*- 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/. */ + +#ifndef nsMemoryPressure_h__ +#define nsMemoryPressure_h__ + +#include "nscore.h" + +enum MemoryPressureState +{ + /* + * No memory pressure. + */ + MemPressure_None = 0, + + /* + * New memory pressure deteced. + * + * On a new memory pressure, we stop everything to start cleaning + * aggresively the memory used, in order to free as much memory as + * possible. + */ + MemPressure_New, + + /* + * Repeated memory pressure. + * + * A repeated memory pressure implies to clean softly recent allocations. + * It is supposed to happen after a new memory pressure which already + * cleaned aggressivley. So there is no need to damage the reactivity of + * Gecko by stopping the world again. + * + * In case of conflict with an new memory pressue, the new memory pressure + * takes precedence over an ongoing memory pressure. The reason being + * that if no events are processed between 2 notifications (new followed + * by ongoing, or ongoing followed by a new) we want to be as aggresive as + * possible on the clean-up of the memory. After all, we are trying to + * keep Gecko alive as long as possible. + */ + MemPressure_Ongoing +}; + +/** + * Return and erase the latest state of the memory pressure event set by any of + * the corresponding dispatch function. + */ +MemoryPressureState +NS_GetPendingMemoryPressure(); + +/** + * This function causes the main thread to fire a memory pressure event + * before processing the next event, but if there are no events pending in + * the main thread's event queue, the memory pressure event would not be + * dispatched until one is enqueued. It is infallible and does not allocate + * any memory. + * + * You may call this function from any thread. + */ +void +NS_DispatchEventualMemoryPressure(MemoryPressureState aState); + +/** + * This function causes the main thread to fire a memory pressure event + * before processing the next event. We wake up the main thread by adding a + * dummy event to its event loop, so, unlike with + * NS_DispatchEventualMemoryPressure, this memory-pressure event is always + * fired relatively quickly, even if the event loop is otherwise empty. + * + * You may call this function from any thread. + */ +nsresult +NS_DispatchMemoryPressure(MemoryPressureState aState); + +#endif // nsMemoryPressure_h__ -- cgit v1.2.3