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 24namespace llvm { 25using namespace sys; 26MutexImpl::MutexImpl( bool recursive) { } 27MutexImpl::~MutexImpl() { } 28bool MutexImpl::acquire() { return true; } 29bool MutexImpl::release() { return true; } 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 40namespace llvm { 41using namespace sys; 42 43// Construct a Mutex using pthread calls 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 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 89bool 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 99bool 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 109bool 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