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/base/nsIMemory.idl | 78 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 xpcom/base/nsIMemory.idl (limited to 'xpcom/base/nsIMemory.idl') diff --git a/xpcom/base/nsIMemory.idl b/xpcom/base/nsIMemory.idl new file mode 100644 index 000000000..0c1a050b7 --- /dev/null +++ b/xpcom/base/nsIMemory.idl @@ -0,0 +1,78 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* 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 "nsISupports.idl" + +/** + * + * nsIMemory: interface to allocate and deallocate memory. Also provides + * for notifications in low-memory situations. + * + * The frozen exported symbols moz_xmalloc, moz_xrealloc, and free + * provide a more efficient way to access XPCOM memory allocation. Using + * those symbols is preferred to using the methods on this interface. + * + * 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 notications + * 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. + * + * "-no-forward" + * This is appended to the above two parameters when the resulting + * notification should not be forwarded to the child processes. + * + * "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. + * + * "alloc-failure" + * This will be passed as the extra data when the pressure + * observer has been asked to flush because a malloc() or + * realloc() has failed. + * + * "lowering-priority" + * This will be passed as the extra data when the priority of a child + * process is lowered. The pressure observers could take the chance to + * clear caches that could be easily regenerated. This type of + * notification only appears in child processes. + */ + +[scriptable, uuid(1e004834-6d8f-425a-bc9c-a2812ed43bb7)] +interface nsIMemory : nsISupports +{ + /** + * 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 an the call + * was not on the application's main thread. + */ + void heapMinimize(in boolean immediate); + + /** + * 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. + */ + boolean isLowMemoryPlatform(); +}; + -- cgit v1.2.3