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//===--- A platform independent abstraction layer for mutexes ---*- 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
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIBC_SRC_SUPPORT_THREAD_MUTEX_H
#define LLVM_LIBC_SRC_SUPPORT_THREAD_MUTEX_H
#include "src/__support/macros/properties/architectures.h"
// Platform independent code will include this header file which pulls
// the platfrom specific specializations using platform macros.
//
// The platform specific specializations should define a class by name
// Mutex with non-static methods having the following signature:
//
// MutexError lock();
// MutexError trylock();
// MutexError timedlock(...);
// MutexError unlock();
// MutexError reset(); // Used to reset inconsistent robust mutexes.
//
// Apart from the above non-static methods, the specializations should
// also provide few static methods with the following signature:
//
// static MutexError init(mtx_t *);
// static MutexError destroy(mtx_t *);
//
// All of the static and non-static methods should ideally be implemented
// as inline functions so that implementations of public functions can
// call them without a function call overhead.
//
// Another point to keep in mind that is that the libc internally needs a
// few global locks. So, to avoid static initialization order fiasco, we
// want the constructors of the Mutex classes to be constexprs.
#if defined(__unix__)
#include "linux/mutex.h"
#elif defined(LIBC_TARGET_ARCH_IS_GPU)
#include "gpu/mutex.h"
#endif // __unix__
namespace __llvm_libc {
// An RAII class for easy locking and unlocking of mutexes.
class MutexLock {
Mutex *mutex;
public:
explicit MutexLock(Mutex *m) : mutex(m) { mutex->lock(); }
~MutexLock() { mutex->unlock(); }
};
} // namespace __llvm_libc
#endif // LLVM_LIBC_SRC_SUPPORT_THREAD_MUTEX_H
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