forked from OSchip/llvm-project
115 lines
2.9 KiB
C++
115 lines
2.9 KiB
C++
//===----------------------------- Registers.hpp --------------------------===//
|
|
//
|
|
// 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
|
|
//
|
|
//
|
|
// Abstract interface to shared reader/writer log, hiding platform and
|
|
// configuration differences.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef __RWMUTEX_HPP__
|
|
#define __RWMUTEX_HPP__
|
|
|
|
#if defined(_WIN32)
|
|
#include <windows.h>
|
|
#elif !defined(_LIBUNWIND_HAS_NO_THREADS)
|
|
#include <pthread.h>
|
|
#if defined(__ELF__) && defined(_LIBUNWIND_LINK_PTHREAD_LIB)
|
|
#pragma comment(lib, "pthread")
|
|
#endif
|
|
#endif
|
|
|
|
namespace libunwind {
|
|
|
|
#if defined(_LIBUNWIND_HAS_NO_THREADS)
|
|
|
|
class _LIBUNWIND_HIDDEN RWMutex {
|
|
public:
|
|
bool lock_shared() { return true; }
|
|
bool unlock_shared() { return true; }
|
|
bool lock() { return true; }
|
|
bool unlock() { return true; }
|
|
};
|
|
|
|
#elif defined(_WIN32)
|
|
|
|
class _LIBUNWIND_HIDDEN RWMutex {
|
|
public:
|
|
bool lock_shared() {
|
|
AcquireSRWLockShared(&_lock);
|
|
return true;
|
|
}
|
|
bool unlock_shared() {
|
|
ReleaseSRWLockShared(&_lock);
|
|
return true;
|
|
}
|
|
bool lock() {
|
|
AcquireSRWLockExclusive(&_lock);
|
|
return true;
|
|
}
|
|
bool unlock() {
|
|
ReleaseSRWLockExclusive(&_lock);
|
|
return true;
|
|
}
|
|
|
|
private:
|
|
SRWLOCK _lock = SRWLOCK_INIT;
|
|
};
|
|
|
|
#elif !defined(LIBUNWIND_USE_WEAK_PTHREAD)
|
|
|
|
class _LIBUNWIND_HIDDEN RWMutex {
|
|
public:
|
|
bool lock_shared() { return pthread_rwlock_rdlock(&_lock) == 0; }
|
|
bool unlock_shared() { return pthread_rwlock_unlock(&_lock) == 0; }
|
|
bool lock() { return pthread_rwlock_wrlock(&_lock) == 0; }
|
|
bool unlock() { return pthread_rwlock_unlock(&_lock) == 0; }
|
|
|
|
private:
|
|
pthread_rwlock_t _lock = PTHREAD_RWLOCK_INITIALIZER;
|
|
};
|
|
|
|
#else
|
|
|
|
extern "C" int __attribute__((weak))
|
|
pthread_create(pthread_t *thread, const pthread_attr_t *attr,
|
|
void *(*start_routine)(void *), void *arg);
|
|
extern "C" int __attribute__((weak))
|
|
pthread_rwlock_rdlock(pthread_rwlock_t *lock);
|
|
extern "C" int __attribute__((weak))
|
|
pthread_rwlock_wrlock(pthread_rwlock_t *lock);
|
|
extern "C" int __attribute__((weak))
|
|
pthread_rwlock_unlock(pthread_rwlock_t *lock);
|
|
|
|
// Calls to the locking functions are gated on pthread_create, and not the
|
|
// functions themselves, because the data structure should only be locked if
|
|
// another thread has been created. This is what similar libraries do.
|
|
|
|
class _LIBUNWIND_HIDDEN RWMutex {
|
|
public:
|
|
bool lock_shared() {
|
|
return !pthread_create || (pthread_rwlock_rdlock(&_lock) == 0);
|
|
}
|
|
bool unlock_shared() {
|
|
return !pthread_create || (pthread_rwlock_unlock(&_lock) == 0);
|
|
}
|
|
bool lock() {
|
|
return !pthread_create || (pthread_rwlock_wrlock(&_lock) == 0);
|
|
}
|
|
bool unlock() {
|
|
return !pthread_create || (pthread_rwlock_unlock(&_lock) == 0);
|
|
}
|
|
|
|
private:
|
|
pthread_rwlock_t _lock = PTHREAD_RWLOCK_INITIALIZER;
|
|
};
|
|
|
|
#endif
|
|
|
|
} // namespace libunwind
|
|
|
|
#endif // __RWMUTEX_HPP__
|