1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
| //===- RWMutex.cpp - Reader/Writer Mutual Exclusion Lock --------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the llvm::sys::RWMutex class.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/Allocator.h"
#include "llvm/Support/RWMutex.h"
#include "llvm/Config/config.h"
#if defined(LLVM_USE_RW_MUTEX_IMPL)
using namespace llvm;
using namespace sys;
#if !defined(LLVM_ENABLE_THREADS) || LLVM_ENABLE_THREADS == 0
// Define all methods as no-ops if threading is explicitly disabled
RWMutexImpl::RWMutexImpl() = default;
RWMutexImpl::~RWMutexImpl() = default;
bool RWMutexImpl::lock_shared() { return true; }
bool RWMutexImpl::unlock_shared() { return true; }
bool RWMutexImpl::lock() { return true; }
bool RWMutexImpl::unlock() { return true; }
#else
#if defined(HAVE_PTHREAD_H) && defined(HAVE_PTHREAD_RWLOCK_INIT)
#include <cassert>
#include <cstdlib>
#include <pthread.h>
// Construct a RWMutex using pthread calls
RWMutexImpl::RWMutexImpl()
{
// Declare the pthread_rwlock data structures
pthread_rwlock_t* rwlock =
static_cast<pthread_rwlock_t*>(safe_malloc(sizeof(pthread_rwlock_t)));
#ifdef __APPLE__
// Workaround a bug/mis-feature in Darwin's pthread_rwlock_init.
bzero(rwlock, sizeof(pthread_rwlock_t));
#endif
// Initialize the rwlock
int errorcode = pthread_rwlock_init(rwlock, nullptr);
(void)errorcode;
assert(errorcode == 0);
// Assign the data member
data_ = rwlock;
}
// Destruct a RWMutex
RWMutexImpl::~RWMutexImpl()
{
pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
assert(rwlock != nullptr);
pthread_rwlock_destroy(rwlock);
free(rwlock);
}
bool
RWMutexImpl::lock_shared()
{
pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
assert(rwlock != nullptr);
int errorcode = pthread_rwlock_rdlock(rwlock);
return errorcode == 0;
}
bool
RWMutexImpl::unlock_shared()
{
pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
assert(rwlock != nullptr);
int errorcode = pthread_rwlock_unlock(rwlock);
return errorcode == 0;
}
bool
RWMutexImpl::lock()
{
pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
assert(rwlock != nullptr);
int errorcode = pthread_rwlock_wrlock(rwlock);
return errorcode == 0;
}
bool
RWMutexImpl::unlock()
{
pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
assert(rwlock != nullptr);
int errorcode = pthread_rwlock_unlock(rwlock);
return errorcode == 0;
}
#else
RWMutexImpl::RWMutexImpl() : data_(new MutexImpl(false)) { }
RWMutexImpl::~RWMutexImpl() {
delete static_cast<MutexImpl *>(data_);
}
bool RWMutexImpl::lock_shared() {
return static_cast<MutexImpl *>(data_)->acquire();
}
bool RWMutexImpl::unlock_shared() {
return static_cast<MutexImpl *>(data_)->release();
}
bool RWMutexImpl::lock() {
return static_cast<MutexImpl *>(data_)->acquire();
}
bool RWMutexImpl::unlock() {
return static_cast<MutexImpl *>(data_)->release();
}
#endif
#endif
#endif
|