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//===- Mutex.cpp - Mutual Exclusion Lock ------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the llvm::sys::Mutex class.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/Mutex.h"
#include "llvm/Config/config.h"
#include "llvm/Support/ErrorHandling.h"
//===----------------------------------------------------------------------===//
//=== WARNING: Implementation here must contain only TRULY operating system
//=== independent code.
//===----------------------------------------------------------------------===//
#if !defined(LLVM_ENABLE_THREADS) || LLVM_ENABLE_THREADS == 0
// Define all methods as no-ops if threading is explicitly disabled
namespace llvm {
using namespace sys;
MutexImpl::MutexImpl( bool recursive) { }
MutexImpl::~MutexImpl() { }
bool MutexImpl::acquire() { return true; }
bool MutexImpl::release() { return true; }
bool MutexImpl::tryacquire() { return true; }
}
#else
#if defined(HAVE_PTHREAD_H) && defined(HAVE_PTHREAD_MUTEX_LOCK)
#include <cassert>
#include <pthread.h>
#include <stdlib.h>
namespace llvm {
using namespace sys;
// Construct a Mutex using pthread calls
MutexImpl::MutexImpl( bool recursive)
: data_(nullptr)
{
// Declare the pthread_mutex data structures
pthread_mutex_t* mutex =
static_cast<pthread_mutex_t*>(safe_malloc(sizeof(pthread_mutex_t)));
pthread_mutexattr_t attr;
// Initialize the mutex attributes
int errorcode = pthread_mutexattr_init(&attr);
assert(errorcode == 0); (void)errorcode;
// Initialize the mutex as a recursive mutex, if requested, or normal
// otherwise.
int kind = ( recursive ? PTHREAD_MUTEX_RECURSIVE : PTHREAD_MUTEX_NORMAL );
errorcode = pthread_mutexattr_settype(&attr, kind);
assert(errorcode == 0);
// Initialize the mutex
errorcode = pthread_mutex_init(mutex, &attr);
assert(errorcode == 0);
// Destroy the attributes
errorcode = pthread_mutexattr_destroy(&attr);
assert(errorcode == 0);
// Assign the data member
data_ = mutex;
}
// Destruct a Mutex
MutexImpl::~MutexImpl()
{
pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
assert(mutex != nullptr);
pthread_mutex_destroy(mutex);
free(mutex);
}
bool
MutexImpl::acquire()
{
pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
assert(mutex != nullptr);
int errorcode = pthread_mutex_lock(mutex);
return errorcode == 0;
}
bool
MutexImpl::release()
{
pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
assert(mutex != nullptr);
int errorcode = pthread_mutex_unlock(mutex);
return errorcode == 0;
}
bool
MutexImpl::tryacquire()
{
pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
assert(mutex != nullptr);
int errorcode = pthread_mutex_trylock(mutex);
return errorcode == 0;
}
}
#elif defined(LLVM_ON_UNIX)
#include "Unix/Mutex.inc"
#elif defined( _WIN32)
#include "Windows/Mutex.inc"
#else
#warning Neither LLVM_ON_UNIX nor _WIN32 was set in Support/Mutex.cpp
#endif
#endif