llvm-mirror/lib/Support/Mutex.cpp
Serge Pavlov 7f357d43f7 Use uniform mechanism for OOM errors handling
This is a recommit of r333506, which was reverted in r333518.
The original commit message is below.

In r325551 many calls of malloc/calloc/realloc were replaces with calls of
their safe counterparts defined in the namespace llvm. There functions
generate crash if memory cannot be allocated, such behavior facilitates
handling of out of memory errors on Windows.

If the result of *alloc function were checked for success, the function was
not replaced with the safe variant. In these cases the calling function made
the error handling, like:

    T *NewElts = static_cast<T*>(malloc(NewCapacity*sizeof(T)));
    if (NewElts == nullptr)
      report_bad_alloc_error("Allocation of SmallVector element failed.");

Actually knowledge about the function where OOM occurred is useless. Moreover
having a single entry point for OOM handling is convenient for investigation
of memory problems. This change removes custom OOM errors handling and
replaces them with calls to functions `llvm::safe_*alloc`.

Declarations of `safe_*alloc` are moved to a separate include file, to avoid
cyclic dependency in SmallVector.h

Differential Revision: https://reviews.llvm.org/D47440

llvm-svn: 334344
2018-06-09 05:19:45 +00:00

125 lines
3.2 KiB
C++

//===- 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