1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2 * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
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_storage_SQLiteMutex_h_
8 #define mozilla_storage_SQLiteMutex_h_
10 #include "mozilla/BlockingResourceBase.h"
17 * Wrapper class for sqlite3_mutexes. To be used whenever we want to use a
20 * @warning Never EVER wrap the same sqlite3_mutex with a different SQLiteMutex.
21 * If you do this, you void the deadlock detector's warranty!
23 class SQLiteMutex
: private BlockingResourceBase
{
26 * Constructs a wrapper for a sqlite3_mutex that has deadlock detecting.
29 * A name which can be used to reference this mutex.
31 explicit SQLiteMutex(const char *aName
)
32 : BlockingResourceBase(aName
, eMutex
), mMutex(nullptr) {}
35 * Sets the mutex that we are wrapping. We generally do not have access to
36 * our mutex at class construction, so we have to set it once we get access to
40 * The sqlite3_mutex that we are going to wrap.
42 void initWithMutex(sqlite3_mutex
*aMutex
) {
43 NS_ASSERTION(aMutex
, "You must pass in a valid mutex!");
44 NS_ASSERTION(!mMutex
, "A mutex has already been set for this!");
49 * After a connection has been successfully closed, its mutex is a dangling
50 * pointer, and as such it should be destroyed.
52 void destroy() { mMutex
= NULL
; }
54 #if !defined(DEBUG) || defined(MOZ_SYSTEM_SQLITE)
58 void lock() { ::sqlite3_mutex_enter(mMutex
); }
63 void unlock() { ::sqlite3_mutex_leave(mMutex
); }
66 * Asserts that the current thread owns the mutex.
68 void assertCurrentThreadOwns() {}
71 * Asserts that the current thread does not own the mutex.
73 void assertNotCurrentThreadOwns() {}
77 MOZ_ASSERT(mMutex
, "No mutex associated with this wrapper!");
79 // While SQLite Mutexes may be recursive, in our own code we do not want to
80 // treat them as such.
83 ::sqlite3_mutex_enter(mMutex
);
84 Acquire(); // Call is protected by us holding the mutex.
88 MOZ_ASSERT(mMutex
, "No mutex associated with this wrapper!");
90 // While SQLite Mutexes may be recursive, in our own code we do not want to
91 // treat them as such.
92 Release(); // Call is protected by us holding the mutex.
93 ::sqlite3_mutex_leave(mMutex
);
96 void assertCurrentThreadOwns() {
97 MOZ_ASSERT(mMutex
, "No mutex associated with this wrapper!");
98 MOZ_ASSERT(sqlite3_mutex_held(mMutex
),
99 "Mutex is not held, but we expect it to be!");
102 void assertNotCurrentThreadOwns() {
103 MOZ_ASSERT(mMutex
, "No mutex associated with this wrapper!");
104 MOZ_ASSERT(sqlite3_mutex_notheld(mMutex
),
105 "Mutex is held, but we expect it to not be!");
107 #endif // ifndef DEBUG
110 sqlite3_mutex
*mMutex
;
114 * Automatically acquires the mutex when it enters scope, and releases it when
117 class MOZ_STACK_CLASS SQLiteMutexAutoLock
{
119 explicit SQLiteMutexAutoLock(SQLiteMutex
&aMutex
) : mMutex(aMutex
) {
123 ~SQLiteMutexAutoLock() { mMutex
.unlock(); }
130 * Automatically releases the mutex when it enters scope, and acquires it when
133 class MOZ_STACK_CLASS SQLiteMutexAutoUnlock
{
135 explicit SQLiteMutexAutoUnlock(SQLiteMutex
&aMutex
) : mMutex(aMutex
) {
139 ~SQLiteMutexAutoUnlock() { mMutex
.lock(); }
145 } // namespace storage
146 } // namespace mozilla
148 #endif // mozilla_storage_SQLiteMutex_h_