The Tor Browser / file comparison
comparison: xpcom/threads/nsEventQueue.cpp
xpcom/threads/nsEventQueue.cpp
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
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| -1:000000000000 | 0:f6d7c35eb980 |
|---|---|
| 1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ | |
| 2 /* vim:set ts=2 sw=2 sts=2 et cindent: */ | |
| 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 | |
| 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 6 | |
| 7 #include "nsEventQueue.h" | |
| 8 #include "nsAutoPtr.h" | |
| 9 #include "prlog.h" | |
| 10 #include "nsThreadUtils.h" | |
| 11 #include "prthread.h" | |
| 12 #include "mozilla/ChaosMode.h" | |
| 13 | |
| 14 using namespace mozilla; | |
| 15 | |
| 16 #ifdef PR_LOGGING | |
| 17 static PRLogModuleInfo * | |
| 18 GetLog() | |
| 19 { | |
| 20 static PRLogModuleInfo *sLog; | |
| 21 if (!sLog) | |
| 22 sLog = PR_NewLogModule("nsEventQueue"); | |
| 23 return sLog; | |
| 24 } | |
| 25 #endif | |
| 26 #ifdef LOG | |
| 27 #undef LOG | |
| 28 #endif | |
| 29 #define LOG(args) PR_LOG(GetLog(), PR_LOG_DEBUG, args) | |
| 30 | |
| 31 nsEventQueue::nsEventQueue() | |
| 32 : mReentrantMonitor("nsEventQueue.mReentrantMonitor") | |
| 33 , mHead(nullptr) | |
| 34 , mTail(nullptr) | |
| 35 , mOffsetHead(0) | |
| 36 , mOffsetTail(0) | |
| 37 { | |
| 38 } | |
| 39 | |
| 40 nsEventQueue::~nsEventQueue() | |
| 41 { | |
| 42 // It'd be nice to be able to assert that no one else is holding the monitor, | |
| 43 // but NSPR doesn't really expose APIs for it. | |
| 44 NS_ASSERTION(IsEmpty(), "Non-empty event queue being destroyed; events being leaked."); | |
| 45 | |
| 46 if (mHead) | |
| 47 FreePage(mHead); | |
| 48 } | |
| 49 | |
| 50 bool | |
| 51 nsEventQueue::GetEvent(bool mayWait, nsIRunnable **result) | |
| 52 { | |
| 53 { | |
| 54 ReentrantMonitorAutoEnter mon(mReentrantMonitor); | |
| 55 | |
| 56 while (IsEmpty()) { | |
| 57 if (!mayWait) { | |
| 58 if (result) | |
| 59 *result = nullptr; | |
| 60 return false; | |
| 61 } | |
| 62 LOG(("EVENTQ(%p): wait begin\n", this)); | |
| 63 mon.Wait(); | |
| 64 LOG(("EVENTQ(%p): wait end\n", this)); | |
| 65 } | |
| 66 | |
| 67 if (result) { | |
| 68 *result = mHead->mEvents[mOffsetHead++]; | |
| 69 | |
| 70 // Check if mHead points to empty Page | |
| 71 if (mOffsetHead == EVENTS_PER_PAGE) { | |
| 72 Page *dead = mHead; | |
| 73 mHead = mHead->mNext; | |
| 74 FreePage(dead); | |
| 75 mOffsetHead = 0; | |
| 76 } | |
| 77 } | |
| 78 } | |
| 79 | |
| 80 return true; | |
| 81 } | |
| 82 | |
| 83 bool | |
| 84 nsEventQueue::PutEvent(nsIRunnable *runnable) | |
| 85 { | |
| 86 // Avoid calling AddRef+Release while holding our monitor. | |
| 87 nsRefPtr<nsIRunnable> event(runnable); | |
| 88 bool rv = true; | |
| 89 { | |
| 90 if (ChaosMode::isActive()) { | |
| 91 // With probability 0.5, yield so other threads have a chance to | |
| 92 // dispatch events to this queue first. | |
| 93 if (ChaosMode::randomUint32LessThan(2)) { | |
| 94 PR_Sleep(PR_INTERVAL_NO_WAIT); | |
| 95 } | |
| 96 } | |
| 97 | |
| 98 ReentrantMonitorAutoEnter mon(mReentrantMonitor); | |
| 99 | |
| 100 if (!mHead) { | |
| 101 mHead = NewPage(); | |
| 102 if (!mHead) { | |
| 103 rv = false; | |
| 104 } else { | |
| 105 mTail = mHead; | |
| 106 mOffsetHead = 0; | |
| 107 mOffsetTail = 0; | |
| 108 } | |
| 109 } else if (mOffsetTail == EVENTS_PER_PAGE) { | |
| 110 Page *page = NewPage(); | |
| 111 if (!page) { | |
| 112 rv = false; | |
| 113 } else { | |
| 114 mTail->mNext = page; | |
| 115 mTail = page; | |
| 116 mOffsetTail = 0; | |
| 117 } | |
| 118 } | |
| 119 if (rv) { | |
| 120 event.swap(mTail->mEvents[mOffsetTail]); | |
| 121 ++mOffsetTail; | |
| 122 LOG(("EVENTQ(%p): notify\n", this)); | |
| 123 mon.NotifyAll(); | |
| 124 } | |
| 125 } | |
| 126 return rv; | |
| 127 } |
