| /*------------------------------------------------------------------------- |
| * drawElements Thread Library |
| * --------------------------- |
| * |
| * Copyright 2014 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| *//*! |
| * \file |
| * \brief Thread-safe singleton. |
| *//*--------------------------------------------------------------------*/ |
| |
| #include "deSingleton.h" |
| #include "deAtomic.h" |
| #include "deThread.h" |
| |
| DE_STATIC_ASSERT(sizeof(deSingletonState) == sizeof(deUint32)); |
| |
| void deInitSingleton (volatile deSingletonState* singletonState, deSingletonConstructorFunc constructor, void* arg) |
| { |
| if (*singletonState != DE_SINGLETON_STATE_INITIALIZED) |
| { |
| deSingletonState curState = (deSingletonState)deAtomicCompareExchange32((volatile deUint32*)singletonState, (deUint32)DE_SINGLETON_STATE_NOT_INITIALIZED, (deUint32)DE_SINGLETON_STATE_INITIALIZING); |
| |
| if (curState == DE_SINGLETON_STATE_NOT_INITIALIZED) |
| { |
| constructor(arg); |
| |
| deMemoryReadWriteFence(); |
| |
| *singletonState = DE_SINGLETON_STATE_INITIALIZED; |
| |
| deMemoryReadWriteFence(); |
| } |
| else if (curState == DE_SINGLETON_STATE_INITIALIZING) |
| { |
| for (;;) |
| { |
| deMemoryReadWriteFence(); |
| |
| if (*singletonState == DE_SINGLETON_STATE_INITIALIZED) |
| break; |
| else |
| deYield(); |
| } |
| } |
| |
| DE_ASSERT(*singletonState == DE_SINGLETON_STATE_INITIALIZED); |
| } |
| } |