126 lines
3.4 KiB
C++
126 lines
3.4 KiB
C++
/*
|
|
* Copyright (C) 2007 The Android Open Source Project
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#ifndef _LIBS_UTILS_RWLOCK_H
|
|
#define _LIBS_UTILS_RWLOCK_H
|
|
|
|
#include <stdint.h>
|
|
#include <sys/types.h>
|
|
|
|
#if defined(HAVE_PTHREADS)
|
|
# include <pthread.h>
|
|
#endif
|
|
|
|
#include <utils/Errors.h>
|
|
#include <utils/ThreadDefs.h>
|
|
|
|
// ---------------------------------------------------------------------------
|
|
namespace android {
|
|
// ---------------------------------------------------------------------------
|
|
|
|
#if defined(HAVE_PTHREADS)
|
|
|
|
/*
|
|
* Simple mutex class. The implementation is system-dependent.
|
|
*
|
|
* The mutex must be unlocked by the thread that locked it. They are not
|
|
* recursive, i.e. the same thread can't lock it multiple times.
|
|
*/
|
|
class RWLock {
|
|
public:
|
|
enum {
|
|
PRIVATE = 0,
|
|
SHARED = 1
|
|
};
|
|
|
|
RWLock();
|
|
RWLock(const char* name);
|
|
RWLock(int type, const char* name = NULL);
|
|
~RWLock();
|
|
|
|
status_t readLock();
|
|
status_t tryReadLock();
|
|
status_t writeLock();
|
|
status_t tryWriteLock();
|
|
void unlock();
|
|
|
|
class AutoRLock {
|
|
public:
|
|
inline AutoRLock(RWLock& rwlock) : mLock(rwlock) { mLock.readLock(); }
|
|
inline ~AutoRLock() { mLock.unlock(); }
|
|
private:
|
|
RWLock& mLock;
|
|
};
|
|
|
|
class AutoWLock {
|
|
public:
|
|
inline AutoWLock(RWLock& rwlock) : mLock(rwlock) { mLock.writeLock(); }
|
|
inline ~AutoWLock() { mLock.unlock(); }
|
|
private:
|
|
RWLock& mLock;
|
|
};
|
|
|
|
private:
|
|
// A RWLock cannot be copied
|
|
RWLock(const RWLock&);
|
|
RWLock& operator = (const RWLock&);
|
|
|
|
pthread_rwlock_t mRWLock;
|
|
};
|
|
|
|
inline RWLock::RWLock() {
|
|
pthread_rwlock_init(&mRWLock, NULL);
|
|
}
|
|
inline RWLock::RWLock(__attribute__((unused)) const char* name) {
|
|
pthread_rwlock_init(&mRWLock, NULL);
|
|
}
|
|
inline RWLock::RWLock(int type, __attribute__((unused)) const char* name) {
|
|
if (type == SHARED) {
|
|
pthread_rwlockattr_t attr;
|
|
pthread_rwlockattr_init(&attr);
|
|
pthread_rwlockattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
|
|
pthread_rwlock_init(&mRWLock, &attr);
|
|
pthread_rwlockattr_destroy(&attr);
|
|
} else {
|
|
pthread_rwlock_init(&mRWLock, NULL);
|
|
}
|
|
}
|
|
inline RWLock::~RWLock() {
|
|
pthread_rwlock_destroy(&mRWLock);
|
|
}
|
|
inline status_t RWLock::readLock() {
|
|
return -pthread_rwlock_rdlock(&mRWLock);
|
|
}
|
|
inline status_t RWLock::tryReadLock() {
|
|
return -pthread_rwlock_tryrdlock(&mRWLock);
|
|
}
|
|
inline status_t RWLock::writeLock() {
|
|
return -pthread_rwlock_wrlock(&mRWLock);
|
|
}
|
|
inline status_t RWLock::tryWriteLock() {
|
|
return -pthread_rwlock_trywrlock(&mRWLock);
|
|
}
|
|
inline void RWLock::unlock() {
|
|
pthread_rwlock_unlock(&mRWLock);
|
|
}
|
|
|
|
#endif // HAVE_PTHREADS
|
|
|
|
// ---------------------------------------------------------------------------
|
|
}; // namespace android
|
|
// ---------------------------------------------------------------------------
|
|
|
|
#endif // _LIBS_UTILS_RWLOCK_H
|