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