1 //===- RWMutex.cpp - Reader/Writer Mutual Exclusion Lock --------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the llvm::sys::RWMutex class.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Config/config.h"
15 #include "llvm/Support/RWMutex.h"
18 //===----------------------------------------------------------------------===//
19 //=== WARNING: Implementation here must contain only TRULY operating system
20 //=== independent code.
21 //===----------------------------------------------------------------------===//
23 #if !defined(LLVM_ENABLE_THREADS) || LLVM_ENABLE_THREADS == 0
24 // Define all methods as no-ops if threading is explicitly disabled
27 RWMutexImpl::RWMutexImpl() { }
28 RWMutexImpl::~RWMutexImpl() { }
29 bool RWMutexImpl::reader_acquire() { return true; }
30 bool RWMutexImpl::reader_release() { return true; }
31 bool RWMutexImpl::writer_acquire() { return true; }
32 bool RWMutexImpl::writer_release() { return true; }
36 #if defined(HAVE_PTHREAD_H) && defined(HAVE_PTHREAD_RWLOCK_INIT)
45 // Construct a RWMutex using pthread calls
46 RWMutexImpl::RWMutexImpl()
49 // Declare the pthread_rwlock data structures
50 pthread_rwlock_t* rwlock =
51 static_cast<pthread_rwlock_t*>(malloc(sizeof(pthread_rwlock_t)));
54 // Workaround a bug/mis-feature in Darwin's pthread_rwlock_init.
55 bzero(rwlock, sizeof(pthread_rwlock_t));
58 // Initialize the rwlock
59 int errorcode = pthread_rwlock_init(rwlock, NULL);
61 assert(errorcode == 0);
63 // Assign the data member
68 RWMutexImpl::~RWMutexImpl()
70 pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
72 pthread_rwlock_destroy(rwlock);
77 RWMutexImpl::reader_acquire()
79 pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
82 int errorcode = pthread_rwlock_rdlock(rwlock);
83 return errorcode == 0;
87 RWMutexImpl::reader_release()
89 pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
92 int errorcode = pthread_rwlock_unlock(rwlock);
93 return errorcode == 0;
97 RWMutexImpl::writer_acquire()
99 pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
102 int errorcode = pthread_rwlock_wrlock(rwlock);
103 return errorcode == 0;
107 RWMutexImpl::writer_release()
109 pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
112 int errorcode = pthread_rwlock_unlock(rwlock);
113 return errorcode == 0;
118 #elif defined(LLVM_ON_UNIX)
119 #include "Unix/RWMutex.inc"
120 #elif defined( LLVM_ON_WIN32)
121 #include "Windows/RWMutex.inc"
123 #warning Neither LLVM_ON_UNIX nor LLVM_ON_WIN32 was set in Support/Mutex.cpp