| 1 | /***************************************************************************** |
| 2 | * Copyright (C) 2013 x265 project |
| 3 | * |
| 4 | * Authors: Steve Borho <steve@borho.org> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111, USA. |
| 19 | * |
| 20 | * This program is also available under a commercial proprietary license. |
| 21 | * For more information, contact us at license @ x265.com |
| 22 | *****************************************************************************/ |
| 23 | |
| 24 | #include "threading.h" |
| 25 | |
| 26 | #if defined(_WIN32) && (_WIN32_WINNT < 0x0600) // _WIN32_WINNT_VISTA |
| 27 | |
| 28 | namespace x265 { |
| 29 | /* Mimic CONDITION_VARIABLE functions only supported on Vista+ */ |
| 30 | |
| 31 | int WINAPI cond_init(ConditionVariable *cond) |
| 32 | { // InitializeConditionVariable |
| 33 | cond->semaphore = CreateSemaphore(NULL, 0, 0x7fffffff, NULL); |
| 34 | if (!cond->semaphore) |
| 35 | return -1; |
| 36 | cond->waitersDone = CreateEvent(NULL, FALSE, FALSE, NULL); |
| 37 | if (!cond->waitersDone) |
| 38 | return -1; |
| 39 | |
| 40 | InitializeCriticalSection(&cond->waiterCountMutex); |
| 41 | InitializeCriticalSection(&cond->broadcastMutex); |
| 42 | cond->waiterCount = 0; |
| 43 | cond->bIsBroadcast = false; |
| 44 | |
| 45 | return 0; |
| 46 | } |
| 47 | |
| 48 | void WINAPI cond_broadcast(ConditionVariable *cond) |
| 49 | { // WakeAllConditionVariable |
| 50 | EnterCriticalSection(&cond->broadcastMutex); |
| 51 | EnterCriticalSection(&cond->waiterCountMutex); |
| 52 | int haveWaiter = 0; |
| 53 | |
| 54 | if (cond->waiterCount) |
| 55 | { |
| 56 | cond->bIsBroadcast = 1; |
| 57 | haveWaiter = 1; |
| 58 | } |
| 59 | |
| 60 | if (haveWaiter) |
| 61 | { |
| 62 | ReleaseSemaphore(cond->semaphore, cond->waiterCount, NULL); |
| 63 | LeaveCriticalSection(&cond->waiterCountMutex); |
| 64 | WaitForSingleObject(cond->waitersDone, INFINITE); |
| 65 | cond->bIsBroadcast = 0; |
| 66 | } |
| 67 | else |
| 68 | LeaveCriticalSection(&cond->waiterCountMutex); |
| 69 | |
| 70 | LeaveCriticalSection(&cond->broadcastMutex); |
| 71 | } |
| 72 | |
| 73 | void WINAPI cond_signal(ConditionVariable *cond) |
| 74 | { // WakeConditionVariable |
| 75 | EnterCriticalSection(&cond->broadcastMutex); |
| 76 | EnterCriticalSection(&cond->waiterCountMutex); |
| 77 | int haveWaiter = cond->waiterCount; |
| 78 | LeaveCriticalSection(&cond->waiterCountMutex); |
| 79 | |
| 80 | if (haveWaiter) |
| 81 | { |
| 82 | ReleaseSemaphore(cond->semaphore, 1, NULL); |
| 83 | WaitForSingleObject(cond->waitersDone, INFINITE); |
| 84 | } |
| 85 | |
| 86 | LeaveCriticalSection(&cond->broadcastMutex); |
| 87 | } |
| 88 | |
| 89 | BOOL WINAPI cond_wait(ConditionVariable *cond, CRITICAL_SECTION *mutex, DWORD wait) |
| 90 | { // SleepConditionVariableCS |
| 91 | EnterCriticalSection(&cond->broadcastMutex); |
| 92 | EnterCriticalSection(&cond->waiterCountMutex); |
| 93 | cond->waiterCount++; |
| 94 | LeaveCriticalSection(&cond->waiterCountMutex); |
| 95 | LeaveCriticalSection(&cond->broadcastMutex); |
| 96 | |
| 97 | // unlock the external mutex |
| 98 | LeaveCriticalSection(mutex); |
| 99 | BOOL ret = WaitForSingleObject(cond->semaphore, wait); |
| 100 | |
| 101 | EnterCriticalSection(&cond->waiterCountMutex); |
| 102 | cond->waiterCount--; |
| 103 | int last_waiter = !cond->waiterCount || !cond->bIsBroadcast; |
| 104 | LeaveCriticalSection(&cond->waiterCountMutex); |
| 105 | |
| 106 | if (last_waiter) |
| 107 | SetEvent(cond->waitersDone); |
| 108 | |
| 109 | // lock the external mutex |
| 110 | EnterCriticalSection(mutex); |
| 111 | |
| 112 | // returns false on timeout or error |
| 113 | return ret; |
| 114 | } |
| 115 | |
| 116 | /* Native CONDITION_VARIABLE instances are not freed, so this is a special case */ |
| 117 | void cond_destroy(ConditionVariable *cond) |
| 118 | { |
| 119 | CloseHandle(cond->semaphore); |
| 120 | CloseHandle(cond->waitersDone); |
| 121 | DeleteCriticalSection(&cond->broadcastMutex); |
| 122 | DeleteCriticalSection(&cond->waiterCountMutex); |
| 123 | } |
| 124 | } // namespace x265 |
| 125 | |
| 126 | #elif defined(_MSC_VER) |
| 127 | |
| 128 | namespace { int _avoid_linker_warnings = 0; } |
| 129 | |
| 130 | #endif // _WIN32_WINNT <= _WIN32_WINNT_WINXP |