xpcom/glue/CondVar.h@97036ab72558
xpcom/glue/CondVar.h
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
2 * vim: sw=4 ts=4 et :
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/. */
7 #ifndef mozilla_CondVar_h
8 #define mozilla_CondVar_h
10 #include "prcvar.h"
12 #include "mozilla/BlockingResourceBase.h"
13 #include "mozilla/Mutex.h"
15 #ifdef MOZILLA_INTERNAL_API
16 #include "GeckoProfiler.h"
17 #endif //MOZILLA_INTERNAL_API
19 namespace mozilla {
22 /**
23 * CondVar
24 * Vanilla condition variable. Please don't use this unless you have a
25 * compelling reason --- Monitor provides a simpler API.
26 */
27 class NS_COM_GLUE CondVar : BlockingResourceBase
28 {
29 public:
30 /**
31 * CondVar
32 *
33 * The CALLER owns |lock|.
34 *
35 * @param aLock A Mutex to associate with this condition variable.
36 * @param aName A name which can reference this monitor
37 * @returns If failure, nullptr.
38 * If success, a valid Monitor* which must be destroyed
39 * by Monitor::DestroyMonitor()
40 **/
41 CondVar(Mutex& aLock, const char* aName) :
42 BlockingResourceBase(aName, eCondVar),
43 mLock(&aLock)
44 {
45 MOZ_COUNT_CTOR(CondVar);
46 // |lock| must necessarily already be known to the deadlock detector
47 mCvar = PR_NewCondVar(mLock->mLock);
48 if (!mCvar)
49 NS_RUNTIMEABORT("Can't allocate mozilla::CondVar");
50 }
52 /**
53 * ~CondVar
54 * Clean up after this CondVar, but NOT its associated Mutex.
55 **/
56 ~CondVar()
57 {
58 NS_ASSERTION(mCvar && mLock,
59 "improperly constructed CondVar or double free");
60 PR_DestroyCondVar(mCvar);
61 mCvar = 0;
62 mLock = 0;
63 MOZ_COUNT_DTOR(CondVar);
64 }
66 #ifndef DEBUG
67 /**
68 * Wait
69 * @see prcvar.h
70 **/
71 nsresult Wait(PRIntervalTime interval = PR_INTERVAL_NO_TIMEOUT)
72 {
74 #ifdef MOZILLA_INTERNAL_API
75 GeckoProfilerSleepRAII profiler_sleep;
76 #endif //MOZILLA_INTERNAL_API
77 // NSPR checks for lock ownership
78 return PR_WaitCondVar(mCvar, interval) == PR_SUCCESS
79 ? NS_OK : NS_ERROR_FAILURE;
80 }
81 #else
82 nsresult Wait(PRIntervalTime interval = PR_INTERVAL_NO_TIMEOUT);
83 #endif // ifndef DEBUG
85 /**
86 * Notify
87 * @see prcvar.h
88 **/
89 nsresult Notify()
90 {
91 // NSPR checks for lock ownership
92 return PR_NotifyCondVar(mCvar) == PR_SUCCESS
93 ? NS_OK : NS_ERROR_FAILURE;
94 }
96 /**
97 * NotifyAll
98 * @see prcvar.h
99 **/
100 nsresult NotifyAll()
101 {
102 // NSPR checks for lock ownership
103 return PR_NotifyAllCondVar(mCvar) == PR_SUCCESS
104 ? NS_OK : NS_ERROR_FAILURE;
105 }
107 #ifdef DEBUG
108 /**
109 * AssertCurrentThreadOwnsMutex
110 * @see Mutex::AssertCurrentThreadOwns
111 **/
112 void AssertCurrentThreadOwnsMutex()
113 {
114 mLock->AssertCurrentThreadOwns();
115 }
117 /**
118 * AssertNotCurrentThreadOwnsMutex
119 * @see Mutex::AssertNotCurrentThreadOwns
120 **/
121 void AssertNotCurrentThreadOwnsMutex()
122 {
123 mLock->AssertNotCurrentThreadOwns();
124 }
126 #else
127 void AssertCurrentThreadOwnsMutex()
128 {
129 }
130 void AssertNotCurrentThreadOwnsMutex()
131 {
132 }
134 #endif // ifdef DEBUG
136 private:
137 CondVar();
138 CondVar(CondVar&);
139 CondVar& operator=(CondVar&);
141 Mutex* mLock;
142 PRCondVar* mCvar;
143 };
146 } // namespace mozilla
149 #endif // ifndef mozilla_CondVar_h
