annotate_smart_pointer.cpp revision 19aa39213866b6a26674d1f002a58531db53c5ca
1e32f8626804ace131a11b074784f335af71e2299bart/* 2e32f8626804ace131a11b074784f335af71e2299bart * Test program that illustrates how to annotate a smart pointer 3e32f8626804ace131a11b074784f335af71e2299bart * implementation. In a multithreaded program the following is relevant when 4e32f8626804ace131a11b074784f335af71e2299bart * working with smart pointers: 5e32f8626804ace131a11b074784f335af71e2299bart * - whether or not the objects pointed at are shared over threads. 6e32f8626804ace131a11b074784f335af71e2299bart * - whether or not the methods of the objects pointed at are thread-safe. 7e32f8626804ace131a11b074784f335af71e2299bart * - whether or not the smart pointer objects are shared over threads. 8e32f8626804ace131a11b074784f335af71e2299bart * - whether or not the smart pointer object itself is thread-safe. 9e32f8626804ace131a11b074784f335af71e2299bart * 10e32f8626804ace131a11b074784f335af71e2299bart * Most smart pointer implemenations are not thread-safe 11e32f8626804ace131a11b074784f335af71e2299bart * (e.g. boost::shared_ptr<>, tr1::shared_ptr<> and the smart_ptr<> 12e32f8626804ace131a11b074784f335af71e2299bart * implementation below). This means that it is not safe to modify a shared 13e32f8626804ace131a11b074784f335af71e2299bart * pointer object that is shared over threads without proper synchronization. 14e32f8626804ace131a11b074784f335af71e2299bart * 15e32f8626804ace131a11b074784f335af71e2299bart * Even for non-thread-safe smart pointers it is possible to have different 16e32f8626804ace131a11b074784f335af71e2299bart * threads access the same object via smart pointers without triggering data 17e32f8626804ace131a11b074784f335af71e2299bart * races on the smart pointer objects. 18e32f8626804ace131a11b074784f335af71e2299bart * 19e32f8626804ace131a11b074784f335af71e2299bart * A smart pointer implementation guarantees that the destructor of the object 20e32f8626804ace131a11b074784f335af71e2299bart * pointed at is invoked after the last smart pointer that points to that 21e32f8626804ace131a11b074784f335af71e2299bart * object has been destroyed or reset. Data race detection tools cannot detect 22e32f8626804ace131a11b074784f335af71e2299bart * this ordering without explicit annotation for smart pointers that track 23e32f8626804ace131a11b074784f335af71e2299bart * references without invoking synchronization operations recognized by data 24e32f8626804ace131a11b074784f335af71e2299bart * race detection tools. 25e32f8626804ace131a11b074784f335af71e2299bart */ 26e32f8626804ace131a11b074784f335af71e2299bart 27e32f8626804ace131a11b074784f335af71e2299bart 28e32f8626804ace131a11b074784f335af71e2299bart#include <cassert> // assert() 29e32f8626804ace131a11b074784f335af71e2299bart#include <climits> // PTHREAD_STACK_MIN 305530f5f35830ab84a42a69e01f7762666813b75dbart#include <iostream> // std::cerr 31e32f8626804ace131a11b074784f335af71e2299bart#include <stdlib.h> // atoi() 32c710de6053e28508b4d49065f50bf10e4861b508bart#ifdef _WIN32 33e32f8626804ace131a11b074784f335af71e2299bart#include <process.h> // _beginthreadex() 34e32f8626804ace131a11b074784f335af71e2299bart#include <windows.h> // CRITICAL_SECTION 35c710de6053e28508b4d49065f50bf10e4861b508bart#else 36e32f8626804ace131a11b074784f335af71e2299bart#include <pthread.h> // pthread_mutex_t 37c710de6053e28508b4d49065f50bf10e4861b508bart#endif 385530f5f35830ab84a42a69e01f7762666813b75dbart#include "unified_annotations.h" 395530f5f35830ab84a42a69e01f7762666813b75dbart 405530f5f35830ab84a42a69e01f7762666813b75dbart 4119aa39213866b6a26674d1f002a58531db53c5cabartstatic bool s_enable_annotations; 42e32f8626804ace131a11b074784f335af71e2299bart 43c710de6053e28508b4d49065f50bf10e4861b508bart 44c710de6053e28508b4d49065f50bf10e4861b508bart#ifdef _WIN32 45e32f8626804ace131a11b074784f335af71e2299bart 46c710de6053e28508b4d49065f50bf10e4861b508bartclass AtomicInt32 47c710de6053e28508b4d49065f50bf10e4861b508bart{ 48c710de6053e28508b4d49065f50bf10e4861b508bartpublic: 49c710de6053e28508b4d49065f50bf10e4861b508bart AtomicInt32(const int value = 0) : m_value(value) { } 50c710de6053e28508b4d49065f50bf10e4861b508bart ~AtomicInt32() { } 51c710de6053e28508b4d49065f50bf10e4861b508bart LONG operator++() { return InterlockedIncrement(&m_value); } 52c710de6053e28508b4d49065f50bf10e4861b508bart LONG operator--() { return InterlockedDecrement(&m_value); } 53c710de6053e28508b4d49065f50bf10e4861b508bart 54c710de6053e28508b4d49065f50bf10e4861b508bartprivate: 55c710de6053e28508b4d49065f50bf10e4861b508bart volatile LONG m_value; 56c710de6053e28508b4d49065f50bf10e4861b508bart}; 57c710de6053e28508b4d49065f50bf10e4861b508bart 58c710de6053e28508b4d49065f50bf10e4861b508bartclass Mutex 59c710de6053e28508b4d49065f50bf10e4861b508bart{ 60c710de6053e28508b4d49065f50bf10e4861b508bartpublic: 61c710de6053e28508b4d49065f50bf10e4861b508bart Mutex() : m_mutex() 62c710de6053e28508b4d49065f50bf10e4861b508bart { InitializeCriticalSection(&m_mutex); } 63c710de6053e28508b4d49065f50bf10e4861b508bart ~Mutex() 64c710de6053e28508b4d49065f50bf10e4861b508bart { DeleteCriticalSection(&m_mutex); } 65c710de6053e28508b4d49065f50bf10e4861b508bart void Lock() 66c710de6053e28508b4d49065f50bf10e4861b508bart { EnterCriticalSection(&m_mutex); } 67c710de6053e28508b4d49065f50bf10e4861b508bart void Unlock() 68c710de6053e28508b4d49065f50bf10e4861b508bart { LeaveCriticalSection(&m_mutex); } 69c710de6053e28508b4d49065f50bf10e4861b508bart 70c710de6053e28508b4d49065f50bf10e4861b508bartprivate: 71c710de6053e28508b4d49065f50bf10e4861b508bart CRITICAL_SECTION m_mutex; 72c710de6053e28508b4d49065f50bf10e4861b508bart}; 73c710de6053e28508b4d49065f50bf10e4861b508bart 74c710de6053e28508b4d49065f50bf10e4861b508bartclass Thread 75c710de6053e28508b4d49065f50bf10e4861b508bart{ 76c710de6053e28508b4d49065f50bf10e4861b508bartpublic: 77c710de6053e28508b4d49065f50bf10e4861b508bart Thread() : m_thread(INVALID_HANDLE_VALUE) { } 78c710de6053e28508b4d49065f50bf10e4861b508bart ~Thread() { } 79c710de6053e28508b4d49065f50bf10e4861b508bart void Create(void* (*pf)(void*), void* arg) 80c710de6053e28508b4d49065f50bf10e4861b508bart { 81e32f8626804ace131a11b074784f335af71e2299bart WrapperArgs* wrapper_arg_p = new WrapperArgs(pf, arg); 82e32f8626804ace131a11b074784f335af71e2299bart m_thread = reinterpret_cast<HANDLE>(_beginthreadex(NULL, 0, wrapper, 83e32f8626804ace131a11b074784f335af71e2299bart wrapper_arg_p, 0, NULL)); 84c710de6053e28508b4d49065f50bf10e4861b508bart } 85c710de6053e28508b4d49065f50bf10e4861b508bart void Join() 86c710de6053e28508b4d49065f50bf10e4861b508bart { WaitForSingleObject(m_thread, INFINITE); } 87c710de6053e28508b4d49065f50bf10e4861b508bart 88c710de6053e28508b4d49065f50bf10e4861b508bartprivate: 89e32f8626804ace131a11b074784f335af71e2299bart struct WrapperArgs 90c710de6053e28508b4d49065f50bf10e4861b508bart { 91e32f8626804ace131a11b074784f335af71e2299bart WrapperArgs(void* (*pf)(void*), void* arg) : m_pf(pf), m_arg(arg) { } 92c710de6053e28508b4d49065f50bf10e4861b508bart 93c710de6053e28508b4d49065f50bf10e4861b508bart void* (*m_pf)(void*); 94c710de6053e28508b4d49065f50bf10e4861b508bart void* m_arg; 95c710de6053e28508b4d49065f50bf10e4861b508bart }; 96c710de6053e28508b4d49065f50bf10e4861b508bart static unsigned int __stdcall wrapper(void* arg) 97c710de6053e28508b4d49065f50bf10e4861b508bart { 98e32f8626804ace131a11b074784f335af71e2299bart WrapperArgs* wrapper_arg_p = reinterpret_cast<WrapperArgs*>(arg); 99e32f8626804ace131a11b074784f335af71e2299bart WrapperArgs wa = *wrapper_arg_p; 100c710de6053e28508b4d49065f50bf10e4861b508bart delete wrapper_arg_p; 101c710de6053e28508b4d49065f50bf10e4861b508bart return reinterpret_cast<unsigned>((wa.m_pf)(wa.m_arg)); 102c710de6053e28508b4d49065f50bf10e4861b508bart } 103c710de6053e28508b4d49065f50bf10e4861b508bart HANDLE m_thread; 104c710de6053e28508b4d49065f50bf10e4861b508bart}; 105e32f8626804ace131a11b074784f335af71e2299bart 106c710de6053e28508b4d49065f50bf10e4861b508bart#else // _WIN32 107e32f8626804ace131a11b074784f335af71e2299bart 108c710de6053e28508b4d49065f50bf10e4861b508bartclass AtomicInt32 109c710de6053e28508b4d49065f50bf10e4861b508bart{ 110c710de6053e28508b4d49065f50bf10e4861b508bartpublic: 111c710de6053e28508b4d49065f50bf10e4861b508bart AtomicInt32(const int value = 0) : m_value(value) { } 112c710de6053e28508b4d49065f50bf10e4861b508bart ~AtomicInt32() { } 113c710de6053e28508b4d49065f50bf10e4861b508bart int operator++() { return __sync_add_and_fetch(&m_value, 1); } 114c710de6053e28508b4d49065f50bf10e4861b508bart int operator--() { return __sync_sub_and_fetch(&m_value, 1); } 115c710de6053e28508b4d49065f50bf10e4861b508bartprivate: 116c710de6053e28508b4d49065f50bf10e4861b508bart volatile int m_value; 117c710de6053e28508b4d49065f50bf10e4861b508bart}; 118c710de6053e28508b4d49065f50bf10e4861b508bart 119c710de6053e28508b4d49065f50bf10e4861b508bartclass Mutex 120c710de6053e28508b4d49065f50bf10e4861b508bart{ 121c710de6053e28508b4d49065f50bf10e4861b508bartpublic: 122c710de6053e28508b4d49065f50bf10e4861b508bart Mutex() : m_mutex() 123c710de6053e28508b4d49065f50bf10e4861b508bart { pthread_mutex_init(&m_mutex, NULL); } 124c710de6053e28508b4d49065f50bf10e4861b508bart ~Mutex() 125c710de6053e28508b4d49065f50bf10e4861b508bart { pthread_mutex_destroy(&m_mutex); } 126c710de6053e28508b4d49065f50bf10e4861b508bart void Lock() 127c710de6053e28508b4d49065f50bf10e4861b508bart { pthread_mutex_lock(&m_mutex); } 128c710de6053e28508b4d49065f50bf10e4861b508bart void Unlock() 129c710de6053e28508b4d49065f50bf10e4861b508bart { pthread_mutex_unlock(&m_mutex); } 130c710de6053e28508b4d49065f50bf10e4861b508bart 131c710de6053e28508b4d49065f50bf10e4861b508bartprivate: 132c710de6053e28508b4d49065f50bf10e4861b508bart pthread_mutex_t m_mutex; 133c710de6053e28508b4d49065f50bf10e4861b508bart}; 134c710de6053e28508b4d49065f50bf10e4861b508bart 135c710de6053e28508b4d49065f50bf10e4861b508bartclass Thread 136c710de6053e28508b4d49065f50bf10e4861b508bart{ 137c710de6053e28508b4d49065f50bf10e4861b508bartpublic: 138c710de6053e28508b4d49065f50bf10e4861b508bart Thread() : m_tid() { } 139c710de6053e28508b4d49065f50bf10e4861b508bart ~Thread() { } 140c710de6053e28508b4d49065f50bf10e4861b508bart void Create(void* (*pf)(void*), void* arg) 141e32f8626804ace131a11b074784f335af71e2299bart { 142e32f8626804ace131a11b074784f335af71e2299bart pthread_attr_t attr; 143e32f8626804ace131a11b074784f335af71e2299bart pthread_attr_init(&attr); 144e32f8626804ace131a11b074784f335af71e2299bart pthread_attr_setstacksize(&attr, PTHREAD_STACK_MIN + 4096); 145e32f8626804ace131a11b074784f335af71e2299bart pthread_create(&m_tid, &attr, pf, arg); 146e32f8626804ace131a11b074784f335af71e2299bart pthread_attr_destroy(&attr); 147e32f8626804ace131a11b074784f335af71e2299bart } 148c710de6053e28508b4d49065f50bf10e4861b508bart void Join() 149c710de6053e28508b4d49065f50bf10e4861b508bart { pthread_join(m_tid, NULL); } 150c710de6053e28508b4d49065f50bf10e4861b508bartprivate: 151c710de6053e28508b4d49065f50bf10e4861b508bart pthread_t m_tid; 152c710de6053e28508b4d49065f50bf10e4861b508bart}; 153e32f8626804ace131a11b074784f335af71e2299bart 154e32f8626804ace131a11b074784f335af71e2299bart#endif // !defined(_WIN32) 155c710de6053e28508b4d49065f50bf10e4861b508bart 15621e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 15721e49d778a698f3e28ba2ad6b3b0430a26f9255ebarttemplate<class T> 15821e49d778a698f3e28ba2ad6b3b0430a26f9255ebartclass smart_ptr 15921e49d778a698f3e28ba2ad6b3b0430a26f9255ebart{ 16021e49d778a698f3e28ba2ad6b3b0430a26f9255ebartpublic: 161c710de6053e28508b4d49065f50bf10e4861b508bart typedef AtomicInt32 counter_t; 16221e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 16321e49d778a698f3e28ba2ad6b3b0430a26f9255ebart template <typename Q> friend class smart_ptr; 16421e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 16521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart explicit smart_ptr() 16621e49d778a698f3e28ba2ad6b3b0430a26f9255ebart : m_ptr(NULL), m_count_ptr(NULL) 16721e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { } 16821e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 16921e49d778a698f3e28ba2ad6b3b0430a26f9255ebart explicit smart_ptr(T* const pT) 17021e49d778a698f3e28ba2ad6b3b0430a26f9255ebart : m_ptr(NULL), m_count_ptr(NULL) 17121e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 17221e49d778a698f3e28ba2ad6b3b0430a26f9255ebart set(pT, pT ? new counter_t(0) : NULL); 17321e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 17421e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 17521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart template <typename Q> 17621e49d778a698f3e28ba2ad6b3b0430a26f9255ebart explicit smart_ptr(Q* const q) 17721e49d778a698f3e28ba2ad6b3b0430a26f9255ebart : m_ptr(NULL), m_count_ptr(NULL) 17821e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 17921e49d778a698f3e28ba2ad6b3b0430a26f9255ebart set(q, q ? new counter_t(0) : NULL); 18021e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 18121e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 18221e49d778a698f3e28ba2ad6b3b0430a26f9255ebart ~smart_ptr() 18321e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 18421e49d778a698f3e28ba2ad6b3b0430a26f9255ebart set(NULL, NULL); 18521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 18621e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 18721e49d778a698f3e28ba2ad6b3b0430a26f9255ebart smart_ptr(const smart_ptr<T>& sp) 18821e49d778a698f3e28ba2ad6b3b0430a26f9255ebart : m_ptr(NULL), m_count_ptr(NULL) 18921e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 19021e49d778a698f3e28ba2ad6b3b0430a26f9255ebart set(sp.m_ptr, sp.m_count_ptr); 19121e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 19221e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 19321e49d778a698f3e28ba2ad6b3b0430a26f9255ebart template <typename Q> 19421e49d778a698f3e28ba2ad6b3b0430a26f9255ebart smart_ptr(const smart_ptr<Q>& sp) 19521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart : m_ptr(NULL), m_count_ptr(NULL) 19621e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 19721e49d778a698f3e28ba2ad6b3b0430a26f9255ebart set(sp.m_ptr, sp.m_count_ptr); 19821e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 19921e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 20021e49d778a698f3e28ba2ad6b3b0430a26f9255ebart smart_ptr& operator=(const smart_ptr<T>& sp) 20121e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 20221e49d778a698f3e28ba2ad6b3b0430a26f9255ebart set(sp.m_ptr, sp.m_count_ptr); 20321e49d778a698f3e28ba2ad6b3b0430a26f9255ebart return *this; 20421e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 20521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 20621e49d778a698f3e28ba2ad6b3b0430a26f9255ebart smart_ptr& operator=(T* const p) 20721e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 20821e49d778a698f3e28ba2ad6b3b0430a26f9255ebart set(p, p ? new counter_t(0) : NULL); 20921e49d778a698f3e28ba2ad6b3b0430a26f9255ebart return *this; 21021e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 21121e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 21221e49d778a698f3e28ba2ad6b3b0430a26f9255ebart template <typename Q> 21321e49d778a698f3e28ba2ad6b3b0430a26f9255ebart smart_ptr& operator=(Q* const q) 21421e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 21521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart set(q, q ? new counter_t(0) : NULL); 21621e49d778a698f3e28ba2ad6b3b0430a26f9255ebart return *this; 21721e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 21821e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 21921e49d778a698f3e28ba2ad6b3b0430a26f9255ebart T* operator->() const 22021e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 22121e49d778a698f3e28ba2ad6b3b0430a26f9255ebart assert(m_ptr); 22221e49d778a698f3e28ba2ad6b3b0430a26f9255ebart return m_ptr; 22321e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 22421e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 22521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart T& operator*() const 22621e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 22721e49d778a698f3e28ba2ad6b3b0430a26f9255ebart assert(m_ptr); 22821e49d778a698f3e28ba2ad6b3b0430a26f9255ebart return *m_ptr; 22921e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 23021e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 23121e49d778a698f3e28ba2ad6b3b0430a26f9255ebartprivate: 232c710de6053e28508b4d49065f50bf10e4861b508bart void set(T* const pT, counter_t* const count_ptr) 23321e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 23421e49d778a698f3e28ba2ad6b3b0430a26f9255ebart if (m_ptr != pT) 23521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 236e32f8626804ace131a11b074784f335af71e2299bart if (m_count_ptr) 23721e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 2385530f5f35830ab84a42a69e01f7762666813b75dbart if (s_enable_annotations) 23962049c4c03731f028bb5a29c7cb77bfe68cea193bart U_ANNOTATE_HAPPENS_BEFORE(m_count_ptr); 240e32f8626804ace131a11b074784f335af71e2299bart if (--(*m_count_ptr) == 0) 241e32f8626804ace131a11b074784f335af71e2299bart { 2425530f5f35830ab84a42a69e01f7762666813b75dbart if (s_enable_annotations) 24362049c4c03731f028bb5a29c7cb77bfe68cea193bart U_ANNOTATE_HAPPENS_AFTER(m_count_ptr); 244e32f8626804ace131a11b074784f335af71e2299bart delete m_ptr; 245e32f8626804ace131a11b074784f335af71e2299bart m_ptr = NULL; 246e32f8626804ace131a11b074784f335af71e2299bart delete m_count_ptr; 247e32f8626804ace131a11b074784f335af71e2299bart m_count_ptr = NULL; 248e32f8626804ace131a11b074784f335af71e2299bart } 24921e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 25021e49d778a698f3e28ba2ad6b3b0430a26f9255ebart m_ptr = pT; 25121e49d778a698f3e28ba2ad6b3b0430a26f9255ebart m_count_ptr = count_ptr; 25221e49d778a698f3e28ba2ad6b3b0430a26f9255ebart if (count_ptr) 253c710de6053e28508b4d49065f50bf10e4861b508bart ++(*m_count_ptr); 25421e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 25521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 25621e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 257c710de6053e28508b4d49065f50bf10e4861b508bart T* m_ptr; 258c710de6053e28508b4d49065f50bf10e4861b508bart counter_t* m_count_ptr; 25921e49d778a698f3e28ba2ad6b3b0430a26f9255ebart}; 26021e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 26121e49d778a698f3e28ba2ad6b3b0430a26f9255ebartclass counter 26221e49d778a698f3e28ba2ad6b3b0430a26f9255ebart{ 26321e49d778a698f3e28ba2ad6b3b0430a26f9255ebartpublic: 26421e49d778a698f3e28ba2ad6b3b0430a26f9255ebart counter() 26521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart : m_mutex(), m_count() 266e32f8626804ace131a11b074784f335af71e2299bart { } 267e32f8626804ace131a11b074784f335af71e2299bart ~counter() 26821e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 269e32f8626804ace131a11b074784f335af71e2299bart // Data race detection tools that do not recognize the 270e32f8626804ace131a11b074784f335af71e2299bart // ANNOTATE_HAPPENS_BEFORE() / ANNOTATE_HAPPENS_AFTER() annotations in the 271e32f8626804ace131a11b074784f335af71e2299bart // smart_ptr<> implementation will report that the assignment below 272e32f8626804ace131a11b074784f335af71e2299bart // triggers a data race. 273e32f8626804ace131a11b074784f335af71e2299bart m_count = -1; 27421e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 27521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart int get() const 27621e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 27721e49d778a698f3e28ba2ad6b3b0430a26f9255ebart int result; 278c710de6053e28508b4d49065f50bf10e4861b508bart m_mutex.Lock(); 27921e49d778a698f3e28ba2ad6b3b0430a26f9255ebart result = m_count; 280c710de6053e28508b4d49065f50bf10e4861b508bart m_mutex.Unlock(); 28121e49d778a698f3e28ba2ad6b3b0430a26f9255ebart return result; 28221e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 28321e49d778a698f3e28ba2ad6b3b0430a26f9255ebart int post_increment() 28421e49d778a698f3e28ba2ad6b3b0430a26f9255ebart { 28521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart int result; 286c710de6053e28508b4d49065f50bf10e4861b508bart m_mutex.Lock(); 28721e49d778a698f3e28ba2ad6b3b0430a26f9255ebart result = m_count++; 288c710de6053e28508b4d49065f50bf10e4861b508bart m_mutex.Unlock(); 28921e49d778a698f3e28ba2ad6b3b0430a26f9255ebart return result; 29021e49d778a698f3e28ba2ad6b3b0430a26f9255ebart } 29121e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 29221e49d778a698f3e28ba2ad6b3b0430a26f9255ebartprivate: 293c710de6053e28508b4d49065f50bf10e4861b508bart mutable Mutex m_mutex; 294c710de6053e28508b4d49065f50bf10e4861b508bart int m_count; 29521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart}; 29621e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 29721e49d778a698f3e28ba2ad6b3b0430a26f9255ebartstatic void* thread_func(void* arg) 29821e49d778a698f3e28ba2ad6b3b0430a26f9255ebart{ 299e32f8626804ace131a11b074784f335af71e2299bart smart_ptr<counter>* pp = reinterpret_cast<smart_ptr<counter>*>(arg); 300e32f8626804ace131a11b074784f335af71e2299bart (*pp)->post_increment(); 301e32f8626804ace131a11b074784f335af71e2299bart *pp = NULL; 302e32f8626804ace131a11b074784f335af71e2299bart delete pp; 30321e49d778a698f3e28ba2ad6b3b0430a26f9255ebart return NULL; 30421e49d778a698f3e28ba2ad6b3b0430a26f9255ebart} 30521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart 30621e49d778a698f3e28ba2ad6b3b0430a26f9255ebartint main(int argc, char** argv) 30721e49d778a698f3e28ba2ad6b3b0430a26f9255ebart{ 308e32f8626804ace131a11b074784f335af71e2299bart const int nthreads = std::max(argc > 1 ? atoi(argv[1]) : 1, 1); 3095530f5f35830ab84a42a69e01f7762666813b75dbart const int iterations = std::max(argc > 2 ? atoi(argv[2]) : 1, 1); 3105530f5f35830ab84a42a69e01f7762666813b75dbart s_enable_annotations = argc > 3 ? !!atoi(argv[3]) : true; 3115530f5f35830ab84a42a69e01f7762666813b75dbart 3125530f5f35830ab84a42a69e01f7762666813b75dbart for (int j = 0; j < iterations; ++j) 3135530f5f35830ab84a42a69e01f7762666813b75dbart { 3145530f5f35830ab84a42a69e01f7762666813b75dbart Thread T[nthreads]; 3155530f5f35830ab84a42a69e01f7762666813b75dbart 3165530f5f35830ab84a42a69e01f7762666813b75dbart smart_ptr<counter> p(new counter); 3175530f5f35830ab84a42a69e01f7762666813b75dbart p->post_increment(); 3185530f5f35830ab84a42a69e01f7762666813b75dbart for (int i = 0; i < nthreads; ++i) 3195530f5f35830ab84a42a69e01f7762666813b75dbart T[i].Create(thread_func, new smart_ptr<counter>(p)); 3205530f5f35830ab84a42a69e01f7762666813b75dbart p = NULL; 3215530f5f35830ab84a42a69e01f7762666813b75dbart for (int i = 0; i < nthreads; ++i) 3225530f5f35830ab84a42a69e01f7762666813b75dbart T[i].Join(); 3235530f5f35830ab84a42a69e01f7762666813b75dbart } 3245530f5f35830ab84a42a69e01f7762666813b75dbart std::cerr << "Done.\n"; 32521e49d778a698f3e28ba2ad6b3b0430a26f9255ebart return 0; 32621e49d778a698f3e28ba2ad6b3b0430a26f9255ebart} 327e32f8626804ace131a11b074784f335af71e2299bart 328e32f8626804ace131a11b074784f335af71e2299bart// Local variables: 329e32f8626804ace131a11b074784f335af71e2299bart// c-basic-offset: 2 330e32f8626804ace131a11b074784f335af71e2299bart// End: 331