/*
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* Copyright (C) 2010 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/* ThreadSync implementation */
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#include "sles_allinclusive.h"
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static SLresult IThreadSync_EnterCriticalSection(SLThreadSyncItf self)
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{
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SL_ENTER_INTERFACE
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IThreadSync *thiz = (IThreadSync *) self;
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interface_lock_exclusive(thiz);
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for (;;) {
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if (thiz->mInCriticalSection) {
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if (!pthread_equal(thiz->mOwner, pthread_self())) {
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++thiz->mWaiting;
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interface_cond_wait(thiz);
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continue;
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}
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// nested locks are not allowed
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result = SL_RESULT_PRECONDITIONS_VIOLATED;
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break;
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}
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thiz->mInCriticalSection = SL_BOOLEAN_TRUE;
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thiz->mOwner = pthread_self();
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result = SL_RESULT_SUCCESS;
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break;
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}
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interface_unlock_exclusive(thiz);
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SL_LEAVE_INTERFACE
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}
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static SLresult IThreadSync_ExitCriticalSection(SLThreadSyncItf self)
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{
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SL_ENTER_INTERFACE
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IThreadSync *thiz = (IThreadSync *) self;
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interface_lock_exclusive(thiz);
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if (!thiz->mInCriticalSection || !pthread_equal(thiz->mOwner, pthread_self())) {
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result = SL_RESULT_PRECONDITIONS_VIOLATED;
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} else {
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thiz->mInCriticalSection = SL_BOOLEAN_FALSE;
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memset(&thiz->mOwner, 0, sizeof(pthread_t));
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if (thiz->mWaiting) {
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--thiz->mWaiting;
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interface_cond_signal(thiz);
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}
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result = SL_RESULT_SUCCESS;
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}
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interface_unlock_exclusive(thiz);
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SL_LEAVE_INTERFACE
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}
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static const struct SLThreadSyncItf_ IThreadSync_Itf = {
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IThreadSync_EnterCriticalSection,
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IThreadSync_ExitCriticalSection
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};
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void IThreadSync_init(void *self)
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{
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IThreadSync *thiz = (IThreadSync *) self;
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thiz->mItf = &IThreadSync_Itf;
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thiz->mInCriticalSection = SL_BOOLEAN_FALSE;
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thiz->mWaiting = 0;
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memset(&thiz->mOwner, 0, sizeof(pthread_t));
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}
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void IThreadSync_deinit(void *self)
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{
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IThreadSync *thiz = (IThreadSync *) self;
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if (thiz->mInCriticalSection) {
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SL_LOGW("ThreadSync::EnterCriticalSection was active at Engine::Destroy");
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}
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}
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