The Tor Browser / file comparison
comparison: dom/ipc/ProcessPriorityManager.h
dom/ipc/ProcessPriorityManager.h
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- TOR_BUG_9701
- changeset 15
- b8a032363ba2
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| -1:000000000000 | 0:3c484926e16d |
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| 1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ | |
| 2 /* vim: set sw=2 ts=8 et ft=cpp : */ | |
| 3 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 4 * License, v. 2.0. If a copy of the MPL was not distributed with this file, | |
| 5 * You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 6 | |
| 7 #ifndef mozilla_ProcessPriorityManager_h_ | |
| 8 #define mozilla_ProcessPriorityManager_h_ | |
| 9 | |
| 10 #include "mozilla/HalTypes.h" | |
| 11 | |
| 12 namespace mozilla { | |
| 13 namespace dom { | |
| 14 class ContentParent; | |
| 15 } | |
| 16 | |
| 17 /** | |
| 18 * This class sets the priority of subprocesses in response to explicit | |
| 19 * requests and events in the system. | |
| 20 * | |
| 21 * A process's priority changes e.g. when it goes into the background via | |
| 22 * mozbrowser's setVisible(false). Process priority affects CPU scheduling and | |
| 23 * also which processes get killed when we run out of memory. | |
| 24 * | |
| 25 * After you call Initialize(), the only thing you probably have to do is call | |
| 26 * SetProcessPriority on processes immediately after creating them in order to | |
| 27 * set their initial priority. The ProcessPriorityManager takes care of the | |
| 28 * rest. | |
| 29 */ | |
| 30 class ProcessPriorityManager MOZ_FINAL | |
| 31 { | |
| 32 public: | |
| 33 /** | |
| 34 * Initialize the ProcessPriorityManager machinery, causing the | |
| 35 * ProcessPriorityManager to actively manage the priorities of all | |
| 36 * subprocesses. You should call this before creating any subprocesses. | |
| 37 * | |
| 38 * You should also call this function even if you're in a child process, | |
| 39 * since it will initialize ProcessPriorityManagerChild. | |
| 40 */ | |
| 41 static void Init(); | |
| 42 | |
| 43 /** | |
| 44 * Set the process priority of a given ContentParent's process. | |
| 45 * | |
| 46 * Note that because this method takes a ContentParent*, you can only set the | |
| 47 * priority of your subprocesses. In fact, because we don't support nested | |
| 48 * content processes (bug 761935), you can only call this method from the | |
| 49 * main process. | |
| 50 * | |
| 51 * It probably only makes sense to call this function immediately after a | |
| 52 * process is created. At this point, the process priority manager doesn't | |
| 53 * have enough context about the processs to know what its priority should | |
| 54 * be. | |
| 55 * | |
| 56 * Eventually whatever priority you set here can and probably will be | |
| 57 * overwritten by the process priority manager. | |
| 58 */ | |
| 59 static void SetProcessPriority(dom::ContentParent* aContentParent, | |
| 60 hal::ProcessPriority aPriority); | |
| 61 | |
| 62 /** | |
| 63 * Returns true iff this process's priority is FOREGROUND*. | |
| 64 * | |
| 65 * Note that because process priorities are set in the main process, it's | |
| 66 * possible for this method to return a stale value. So be careful about | |
| 67 * what you use this for. | |
| 68 */ | |
| 69 static bool CurrentProcessIsForeground(); | |
| 70 | |
| 71 /** | |
| 72 * Returns true if one or more processes with FOREGROUND_HIGH priority are | |
| 73 * present, false otherwise. | |
| 74 */ | |
| 75 static bool AnyProcessHasHighPriority(); | |
| 76 | |
| 77 /** | |
| 78 * Used to remove a ContentParent from background LRU pool when | |
| 79 * it is destroyed or its priority changed from BACKGROUND to others. | |
| 80 */ | |
| 81 static void RemoveFromBackgroundLRUPool(dom::ContentParent* aContentParent); | |
| 82 | |
| 83 /** | |
| 84 * Used to add a ContentParent into background LRU pool when | |
| 85 * its priority changed to BACKGROUND from others. | |
| 86 */ | |
| 87 static void AddIntoBackgroundLRUPool(dom::ContentParent* aContentParent); | |
| 88 | |
| 89 private: | |
| 90 ProcessPriorityManager(); | |
| 91 DISALLOW_EVIL_CONSTRUCTORS(ProcessPriorityManager); | |
| 92 }; | |
| 93 | |
| 94 } // namespace mozilla | |
| 95 | |
| 96 #endif |
