1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 /* ThreadSync implementation */ 18 19 #include "sles_allinclusive.h" 20 21 IThreadSync_EnterCriticalSection(SLThreadSyncItf self)22 static SLresult IThreadSync_EnterCriticalSection(SLThreadSyncItf self) 23 { 24 SL_ENTER_INTERFACE 25 26 IThreadSync *thiz = (IThreadSync *) self; 27 interface_lock_exclusive(thiz); 28 for (;;) { 29 if (thiz->mInCriticalSection) { 30 if (!pthread_equal(thiz->mOwner, pthread_self())) { 31 ++thiz->mWaiting; 32 interface_cond_wait(thiz); 33 continue; 34 } 35 // nested locks are not allowed 36 result = SL_RESULT_PRECONDITIONS_VIOLATED; 37 break; 38 } 39 thiz->mInCriticalSection = SL_BOOLEAN_TRUE; 40 thiz->mOwner = pthread_self(); 41 result = SL_RESULT_SUCCESS; 42 break; 43 } 44 interface_unlock_exclusive(thiz); 45 46 SL_LEAVE_INTERFACE 47 } 48 49 IThreadSync_ExitCriticalSection(SLThreadSyncItf self)50 static SLresult IThreadSync_ExitCriticalSection(SLThreadSyncItf self) 51 { 52 SL_ENTER_INTERFACE 53 54 IThreadSync *thiz = (IThreadSync *) self; 55 interface_lock_exclusive(thiz); 56 if (!thiz->mInCriticalSection || !pthread_equal(thiz->mOwner, pthread_self())) { 57 result = SL_RESULT_PRECONDITIONS_VIOLATED; 58 } else { 59 thiz->mInCriticalSection = SL_BOOLEAN_FALSE; 60 memset(&thiz->mOwner, 0, sizeof(pthread_t)); 61 if (thiz->mWaiting) { 62 --thiz->mWaiting; 63 interface_cond_signal(thiz); 64 } 65 result = SL_RESULT_SUCCESS; 66 } 67 interface_unlock_exclusive(thiz); 68 69 SL_LEAVE_INTERFACE 70 } 71 72 73 static const struct SLThreadSyncItf_ IThreadSync_Itf = { 74 IThreadSync_EnterCriticalSection, 75 IThreadSync_ExitCriticalSection 76 }; 77 IThreadSync_init(void * self)78 void IThreadSync_init(void *self) 79 { 80 IThreadSync *thiz = (IThreadSync *) self; 81 thiz->mItf = &IThreadSync_Itf; 82 thiz->mInCriticalSection = SL_BOOLEAN_FALSE; 83 thiz->mWaiting = 0; 84 memset(&thiz->mOwner, 0, sizeof(pthread_t)); 85 } 86 IThreadSync_deinit(void * self)87 void IThreadSync_deinit(void *self) 88 { 89 IThreadSync *thiz = (IThreadSync *) self; 90 if (thiz->mInCriticalSection) { 91 SL_LOGW("ThreadSync::EnterCriticalSection was active at Engine::Destroy"); 92 } 93 } 94