1 //===- Mutex.cpp - Mutual Exclusion Lock ------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file implements the llvm::sys::Mutex class. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/Config/config.h" 15 #include "llvm/Support/Mutex.h" 16 17 //===----------------------------------------------------------------------===// 18 //=== WARNING: Implementation here must contain only TRULY operating system 19 //=== independent code. 20 //===----------------------------------------------------------------------===// 21 22 #if !defined(LLVM_ENABLE_THREADS) || LLVM_ENABLE_THREADS == 0 23 // Define all methods as no-ops if threading is explicitly disabled 24 namespace llvm { 25 using namespace sys; MutexImpl(bool recursive)26MutexImpl::MutexImpl( bool recursive) { } ~MutexImpl()27MutexImpl::~MutexImpl() { } acquire()28bool MutexImpl::acquire() { return true; } release()29bool MutexImpl::release() { return true; } tryacquire()30bool MutexImpl::tryacquire() { return true; } 31 } 32 #else 33 34 #if defined(HAVE_PTHREAD_H) && defined(HAVE_PTHREAD_MUTEX_LOCK) 35 36 #include <cassert> 37 #include <pthread.h> 38 #include <stdlib.h> 39 40 namespace llvm { 41 using namespace sys; 42 43 // Construct a Mutex using pthread calls MutexImpl(bool recursive)44MutexImpl::MutexImpl( bool recursive) 45 : data_(0) 46 { 47 // Declare the pthread_mutex data structures 48 pthread_mutex_t* mutex = 49 static_cast<pthread_mutex_t*>(malloc(sizeof(pthread_mutex_t))); 50 pthread_mutexattr_t attr; 51 52 // Initialize the mutex attributes 53 int errorcode = pthread_mutexattr_init(&attr); 54 assert(errorcode == 0); (void)errorcode; 55 56 // Initialize the mutex as a recursive mutex, if requested, or normal 57 // otherwise. 58 int kind = ( recursive ? PTHREAD_MUTEX_RECURSIVE : PTHREAD_MUTEX_NORMAL ); 59 errorcode = pthread_mutexattr_settype(&attr, kind); 60 assert(errorcode == 0); 61 62 #if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) && \ 63 !defined(__DragonFly__) && !defined(__Bitrig__) 64 // Make it a process local mutex 65 errorcode = pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_PRIVATE); 66 assert(errorcode == 0); 67 #endif 68 69 // Initialize the mutex 70 errorcode = pthread_mutex_init(mutex, &attr); 71 assert(errorcode == 0); 72 73 // Destroy the attributes 74 errorcode = pthread_mutexattr_destroy(&attr); 75 assert(errorcode == 0); 76 77 // Assign the data member 78 data_ = mutex; 79 } 80 81 // Destruct a Mutex ~MutexImpl()82MutexImpl::~MutexImpl() 83 { 84 pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_); 85 assert(mutex != 0); 86 pthread_mutex_destroy(mutex); 87 free(mutex); 88 } 89 90 bool acquire()91MutexImpl::acquire() 92 { 93 pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_); 94 assert(mutex != 0); 95 96 int errorcode = pthread_mutex_lock(mutex); 97 return errorcode == 0; 98 } 99 100 bool release()101MutexImpl::release() 102 { 103 pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_); 104 assert(mutex != 0); 105 106 int errorcode = pthread_mutex_unlock(mutex); 107 return errorcode == 0; 108 } 109 110 bool tryacquire()111MutexImpl::tryacquire() 112 { 113 pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_); 114 assert(mutex != 0); 115 116 int errorcode = pthread_mutex_trylock(mutex); 117 return errorcode == 0; 118 } 119 120 } 121 122 #elif defined(LLVM_ON_UNIX) 123 #include "Unix/Mutex.inc" 124 #elif defined( LLVM_ON_WIN32) 125 #include "Windows/Mutex.inc" 126 #else 127 #warning Neither LLVM_ON_UNIX nor LLVM_ON_WIN32 was set in Support/Mutex.cpp 128 #endif 129 #endif 130