1 /* 2 * Copyright (C) 2009 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #ifndef ThreadIdentifierDataPthreads_h 32 #define ThreadIdentifierDataPthreads_h 33 34 #include "wtf/Noncopyable.h" 35 #include "wtf/Threading.h" 36 #include <pthread.h> 37 38 namespace WTF { 39 40 // Holds ThreadIdentifier in the thread-specific storage and employs pthreads-specific 2-pass destruction to reliably remove 41 // ThreadIdentifier from threadMap. It assumes regular ThreadSpecific types don't use multiple-pass destruction. 42 class ThreadIdentifierData { 43 WTF_MAKE_NONCOPYABLE(ThreadIdentifierData); 44 public: 45 ~ThreadIdentifierData(); 46 47 // One time initialization for this class as a whole. 48 // This method must be called before initialize() and it is not thread-safe. 49 static void initializeOnce(); 50 51 // Creates and puts an instance of ThreadIdentifierData into thread-specific storage. 52 static void initialize(ThreadIdentifier identifier); 53 54 // Returns 0 if thread-specific storage was not initialized. 55 static ThreadIdentifier identifier(); 56 57 private: 58 ThreadIdentifierData(ThreadIdentifier identifier) 59 : m_identifier(identifier) 60 , m_isDestroyedOnce(false) 61 { 62 } 63 64 // This thread-specific destructor is called 2 times when thread terminates: 65 // - first, when all the other thread-specific destructors are called, it simply remembers it was 'destroyed once' 66 // and re-sets itself into the thread-specific slot to make Pthreads to call it again later. 67 // - second, after all thread-specific destructors were invoked, it gets called again - this time, we remove the 68 // ThreadIdentifier from the threadMap, completing the cleanup. 69 static void destruct(void* data); 70 71 ThreadIdentifier m_identifier; 72 bool m_isDestroyedOnce; 73 static pthread_key_t m_key; 74 }; 75 76 } // namespace WTF 77 78 #endif // ThreadIdentifierDataPthreads_h 79 80 81
