ipc/chromium/src/base/lock_impl.h@6474c204b198 (annotated)
ipc/chromium/src/base/lock_impl.h
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. |
| michael@0 | 2 | // Use of this source code is governed by a BSD-style license that can be |
| michael@0 | 3 | // found in the LICENSE file. |
| michael@0 | 4 | |
| michael@0 | 5 | #ifndef BASE_LOCK_IMPL_H_ |
| michael@0 | 6 | #define BASE_LOCK_IMPL_H_ |
| michael@0 | 7 | |
| michael@0 | 8 | #include "build/build_config.h" |
| michael@0 | 9 | |
| michael@0 | 10 | #if defined(OS_WIN) |
| michael@0 | 11 | #include <windows.h> |
| michael@0 | 12 | #elif defined(OS_POSIX) |
| michael@0 | 13 | #include <pthread.h> |
| michael@0 | 14 | #endif |
| michael@0 | 15 | |
| michael@0 | 16 | #include "base/basictypes.h" |
| michael@0 | 17 | #include "base/platform_thread.h" |
| michael@0 | 18 | |
| michael@0 | 19 | // This class implements the underlying platform-specific spin-lock mechanism |
| michael@0 | 20 | // used for the Lock class. Most users should not use LockImpl directly, but |
| michael@0 | 21 | // should instead use Lock. |
| michael@0 | 22 | class LockImpl { |
| michael@0 | 23 | public: |
| michael@0 | 24 | #if defined(OS_WIN) |
| michael@0 | 25 | typedef CRITICAL_SECTION OSLockType; |
| michael@0 | 26 | #elif defined(OS_POSIX) |
| michael@0 | 27 | typedef pthread_mutex_t OSLockType; |
| michael@0 | 28 | #endif |
| michael@0 | 29 | |
| michael@0 | 30 | LockImpl(); |
| michael@0 | 31 | ~LockImpl(); |
| michael@0 | 32 | |
| michael@0 | 33 | // If the lock is not held, take it and return true. If the lock is already |
| michael@0 | 34 | // held by something else, immediately return false. |
| michael@0 | 35 | bool Try(); |
| michael@0 | 36 | |
| michael@0 | 37 | // Take the lock, blocking until it is available if necessary. |
| michael@0 | 38 | void Lock(); |
| michael@0 | 39 | |
| michael@0 | 40 | // Release the lock. This must only be called by the lock's holder: after |
| michael@0 | 41 | // a successful call to Try, or a call to Lock. |
| michael@0 | 42 | void Unlock(); |
| michael@0 | 43 | |
| michael@0 | 44 | // Debug-only method that will DCHECK() if the lock is not acquired by the |
| michael@0 | 45 | // current thread. In non-debug builds, no check is performed. |
| michael@0 | 46 | // Because linux and mac condition variables modify the underlyning lock |
| michael@0 | 47 | // through the os_lock() method, runtime assertions can not be done on those |
| michael@0 | 48 | // builds. |
| michael@0 | 49 | #if defined(NDEBUG) || !defined(OS_WIN) |
| michael@0 | 50 | void AssertAcquired() const {} |
| michael@0 | 51 | #else |
| michael@0 | 52 | void AssertAcquired() const; |
| michael@0 | 53 | #endif |
| michael@0 | 54 | |
| michael@0 | 55 | // Return the native underlying lock. Not supported for Windows builds. |
| michael@0 | 56 | // TODO(awalker): refactor lock and condition variables so that this is |
| michael@0 | 57 | // unnecessary. |
| michael@0 | 58 | #if !defined(OS_WIN) |
| michael@0 | 59 | OSLockType* os_lock() { return &os_lock_; } |
| michael@0 | 60 | #endif |
| michael@0 | 61 | |
| michael@0 | 62 | private: |
| michael@0 | 63 | OSLockType os_lock_; |
| michael@0 | 64 | |
| michael@0 | 65 | #if !defined(NDEBUG) && defined(OS_WIN) |
| michael@0 | 66 | // All private data is implicitly protected by lock_. |
| michael@0 | 67 | // Be VERY careful to only access members under that lock. |
| michael@0 | 68 | PlatformThreadId owning_thread_id_; |
| michael@0 | 69 | int32_t recursion_count_shadow_; |
| michael@0 | 70 | bool recursion_used_; // Allow debugging to continued after a DCHECK(). |
| michael@0 | 71 | #endif // NDEBUG |
| michael@0 | 72 | |
| michael@0 | 73 | DISALLOW_COPY_AND_ASSIGN(LockImpl); |
| michael@0 | 74 | }; |
| michael@0 | 75 | |
| michael@0 | 76 | |
| michael@0 | 77 | #endif // BASE_LOCK_IMPL_H_ |
