urbackup_backend/external/aws-cpp-sdk/include/aws/common/rw_lock.h
2021-07-07 18:47:38 +02:00

80 lines
2.5 KiB
C
Executable File

#ifndef AWS_COMMON_RW_LOCK_H
#define AWS_COMMON_RW_LOCK_H
/*
* Copyright 2010-2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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.
*/
#include <aws/common/common.h>
#ifdef _WIN32
/* NOTE: Do not use this macro before including Windows.h */
# define AWSSRW_TO_WINDOWS(pCV) (PSRWLOCK) pCV
#else
# include <pthread.h>
#endif
struct aws_rw_lock {
#ifdef _WIN32
void *lock_handle;
#else
pthread_rwlock_t lock_handle;
#endif
};
#ifdef _WIN32
# define AWS_RW_LOCK_INIT \
{ .lock_handle = NULL }
#else
# define AWS_RW_LOCK_INIT \
{ .lock_handle = PTHREAD_RWLOCK_INITIALIZER }
#endif
AWS_EXTERN_C_BEGIN
/**
* Initializes a new platform instance of mutex.
*/
AWS_COMMON_API int aws_rw_lock_init(struct aws_rw_lock *lock);
/**
* Cleans up internal resources.
*/
AWS_COMMON_API void aws_rw_lock_clean_up(struct aws_rw_lock *lock);
/**
* Blocks until it acquires the lock. While on some platforms such as Windows,
* this may behave as a reentrant mutex, you should not treat it like one. On
* platforms it is possible for it to be non-reentrant, it will be.
*/
AWS_COMMON_API int aws_rw_lock_rlock(struct aws_rw_lock *lock);
AWS_COMMON_API int aws_rw_lock_wlock(struct aws_rw_lock *lock);
/**
* Attempts to acquire the lock but returns immediately if it can not.
* While on some platforms such as Windows, this may behave as a reentrant mutex,
* you should not treat it like one. On platforms it is possible for it to be non-reentrant, it will be.
*/
AWS_COMMON_API int aws_rw_lock_try_rlock(struct aws_rw_lock *lock);
AWS_COMMON_API int aws_rw_lock_try_wlock(struct aws_rw_lock *lock);
/**
* Releases the lock.
*/
AWS_COMMON_API int aws_rw_lock_runlock(struct aws_rw_lock *lock);
AWS_COMMON_API int aws_rw_lock_wunlock(struct aws_rw_lock *lock);
AWS_EXTERN_C_END
#endif /* AWS_COMMON_RW_LOCK_H */