From 6bf0a5cb5034a7e684dcc3500e841785237ce2dd Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 19:32:43 +0200 Subject: Adding upstream version 1:115.7.0. Signed-off-by: Daniel Baumann --- xpcom/base/nsMemory.h | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 xpcom/base/nsMemory.h (limited to 'xpcom/base/nsMemory.h') diff --git a/xpcom/base/nsMemory.h b/xpcom/base/nsMemory.h new file mode 100644 index 0000000000..7fda7ae837 --- /dev/null +++ b/xpcom/base/nsMemory.h @@ -0,0 +1,62 @@ +/* -*- 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 nsMemory_h__ +#define nsMemory_h__ + +#include "nsError.h" + +/** + * + * A client that wishes to be notified of low memory situations (for + * example, because the client maintains a large memory cache that + * could be released when memory is tight) should register with the + * observer service (see nsIObserverService) using the topic + * "memory-pressure". There are specific types of notifications + * that can occur. These types will be passed as the |aData| + * parameter of the of the "memory-pressure" notification: + * + * "low-memory" + * This will be passed as the extra data when the pressure + * observer is being asked to flush for low-memory conditions. + * + * "low-memory-ongoing" + * This will be passed when we continue to be in a low-memory + * condition and we want to flush caches and do other cheap + * forms of memory minimization, but heavy handed approaches like + * a GC are unlikely to succeed. + * + * "heap-minimize" + * This will be passed as the extra data when the pressure + * observer is being asked to flush because of a heap minimize + * call. + */ + +// This is implemented in nsMemoryImpl.cpp. + +namespace nsMemory { + +/** + * Attempts to shrink the heap. + * @param immediate - if true, heap minimization will occur + * immediately if the call was made on the main thread. If + * false, the flush will be scheduled to happen when the app is + * idle. + * @throws NS_ERROR_FAILURE if 'immediate' is set and the call + * was not on the application's main thread. + */ +nsresult HeapMinimize(bool aImmediate); + +/** + * This predicate can be used to determine if the platform is a "low-memory" + * platform. Callers may use this to dynamically tune their behaviour + * to favour reduced memory usage at the expense of performance. The value + * returned by this function will not change over the lifetime of the process. + */ +bool IsLowMemoryPlatform(); +} // namespace nsMemory + +#endif // nsMemory_h__ -- cgit v1.2.3