Line data    Source code

       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/Support/Mutex.h"
      15             : #include "llvm/Config/config.h"
      16             : #include "llvm/Support/ErrorHandling.h"
      17             : 
      18             : //===----------------------------------------------------------------------===//
      19             : //=== WARNING: Implementation here must contain only TRULY operating system
      20             : //===          independent code.
      21             : //===----------------------------------------------------------------------===//
      22             : 
      23             : #if !defined(LLVM_ENABLE_THREADS) || LLVM_ENABLE_THREADS == 0
      24             : // Define all methods as no-ops if threading is explicitly disabled
      25             : namespace llvm {
      26             : using namespace sys;
      27             : MutexImpl::MutexImpl( bool recursive) { }
      28             : MutexImpl::~MutexImpl() { }
      29             : bool MutexImpl::acquire() { return true; }
      30             : bool MutexImpl::release() { return true; }
      31             : bool MutexImpl::tryacquire() { return true; }
      32             : }
      33             : #else
      34             : 
      35             : #if defined(HAVE_PTHREAD_H) && defined(HAVE_PTHREAD_MUTEX_LOCK)
      36             : 
      37             : #include <cassert>
      38             : #include <pthread.h>
      39             : #include <stdlib.h>
      40             : 
      41             : namespace llvm {
      42             : using namespace sys;
      43             : 
      44             : // Construct a Mutex using pthread calls
      45      645233 : MutexImpl::MutexImpl( bool recursive)
      46      645233 :   : data_(nullptr)
      47             : {
      48             :   // Declare the pthread_mutex data structures
      49             :   pthread_mutex_t* mutex =
      50      645233 :     static_cast<pthread_mutex_t*>(safe_malloc(sizeof(pthread_mutex_t)));
      51             : 
      52             :   pthread_mutexattr_t attr;
      53             : 
      54             :   // Initialize the mutex attributes
      55      645233 :   int errorcode = pthread_mutexattr_init(&attr);
      56             :   assert(errorcode == 0); (void)errorcode;
      57             : 
      58             :   // Initialize the mutex as a recursive mutex, if requested, or normal
      59             :   // otherwise.
      60      645233 :   int kind = ( recursive  ? PTHREAD_MUTEX_RECURSIVE : PTHREAD_MUTEX_NORMAL );
      61      645233 :   errorcode = pthread_mutexattr_settype(&attr, kind);
      62             :   assert(errorcode == 0);
      63             : 
      64             :   // Initialize the mutex
      65      645233 :   errorcode = pthread_mutex_init(mutex, &attr);
      66             :   assert(errorcode == 0);
      67             : 
      68             :   // Destroy the attributes
      69      645233 :   errorcode = pthread_mutexattr_destroy(&attr);
      70             :   assert(errorcode == 0);
      71             : 
      72             :   // Assign the data member
      73      645233 :   data_ = mutex;
      74      645233 : }
      75             : 
      76             : // Destruct a Mutex
      77      905742 : MutexImpl::~MutexImpl()
      78             : {
      79      452871 :   pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
      80             :   assert(mutex != nullptr);
      81      452871 :   pthread_mutex_destroy(mutex);
      82      452871 :   free(mutex);
      83      452871 : }
      84             : 
      85             : bool
      86     2181186 : MutexImpl::acquire()
      87             : {
      88     2181186 :   pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
      89             :   assert(mutex != nullptr);
      90             : 
      91     2181186 :   int errorcode = pthread_mutex_lock(mutex);
      92     2181186 :   return errorcode == 0;
      93             : }
      94             : 
      95             : bool
      96     2181186 : MutexImpl::release()
      97             : {
      98     2181186 :   pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
      99             :   assert(mutex != nullptr);
     100             : 
     101     2181186 :   int errorcode = pthread_mutex_unlock(mutex);
     102     2181186 :   return errorcode == 0;
     103             : }
     104             : 
     105             : bool
     106           6 : MutexImpl::tryacquire()
     107             : {
     108           6 :   pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
     109             :   assert(mutex != nullptr);
     110             : 
     111           6 :   int errorcode = pthread_mutex_trylock(mutex);
     112           6 :   return errorcode == 0;
     113             : }
     114             : 
     115             : }
     116             : 
     117             : #elif defined(LLVM_ON_UNIX)
     118             : #include "Unix/Mutex.inc"
     119             : #elif defined( _WIN32)
     120             : #include "Windows/Mutex.inc"
     121             : #else
     122             : #warning Neither LLVM_ON_UNIX nor _WIN32 was set in Support/Mutex.cpp
     123             : #endif
     124             : #endif