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__) && !defined(__DragonFly__) 63 // Make it a process local mutex 64 errorcode = pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_PRIVATE); 65 assert(errorcode == 0); 66 #endif 67 68 // Initialize the mutex 69 errorcode = pthread_mutex_init(mutex, &attr); 70 assert(errorcode == 0); 71 72 // Destroy the attributes 73 errorcode = pthread_mutexattr_destroy(&attr); 74 assert(errorcode == 0); 75 76 // Assign the data member 77 data_ = mutex; 78 } 79 80 // Destruct a Mutex ~MutexImpl()81MutexImpl::~MutexImpl() 82 { 83 pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_); 84 assert(mutex != 0); 85 pthread_mutex_destroy(mutex); 86 free(mutex); 87 } 88 89 bool acquire()90MutexImpl::acquire() 91 { 92 pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_); 93 assert(mutex != 0); 94 95 int errorcode = pthread_mutex_lock(mutex); 96 return errorcode == 0; 97 } 98 99 bool release()100MutexImpl::release() 101 { 102 pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_); 103 assert(mutex != 0); 104 105 int errorcode = pthread_mutex_unlock(mutex); 106 return errorcode == 0; 107 } 108 109 bool tryacquire()110MutexImpl::tryacquire() 111 { 112 pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_); 113 assert(mutex != 0); 114 115 int errorcode = pthread_mutex_trylock(mutex); 116 return errorcode == 0; 117 } 118 119 } 120 121 #elif defined(LLVM_ON_UNIX) 122 #include "Unix/Mutex.inc" 123 #elif defined( LLVM_ON_WIN32) 124 #include "Windows/Mutex.inc" 125 #else 126 #warning Neither LLVM_ON_UNIX nor LLVM_ON_WIN32 was set in Support/Mutex.cpp 127 #endif 128 #endif 129