shared_mutex.h

Overview

The shared_mutex.h file declares read-write lock APIs in C.

File to include: <ffrt/shared_mutex.h>

Library: libffrt.z.so

System capability: SystemCapability.Resourceschedule.Ffrt.Core

Since: 18

Related module: FFRT

Summary

Function

Name	Description
FFRT_C_API int ffrt_rwlock_init(ffrt_rwlock_t* rwlock, const ffrt_rwlockattr_t* attr)	Initializes a read-write lock.
FFRT_C_API int ffrt_rwlock_wrlock(ffrt_rwlock_t* rwlock)	Obtains a write lock.
FFRT_C_API int ffrt_rwlock_trywrlock(ffrt_rwlock_t* rwlock)	Attempts to obtain a write lock.
FFRT_C_API int ffrt_rwlock_rdlock(ffrt_rwlock_t* rwlock)	Obtains a read lock.
FFRT_C_API int ffrt_rwlock_tryrdlock(ffrt_rwlock_t* rwlock)	Attempts to obtain a read lock.
FFRT_C_API int ffrt_rwlock_unlock(ffrt_rwlock_t* rwlock)	Releases the read-write lock.
FFRT_C_API int ffrt_rwlock_destroy(ffrt_rwlock_t* rwlock)	Destroys the read-write lock.

Function Description

ffrt_rwlock_init()

FFRT_C_API int ffrt_rwlock_init(ffrt_rwlock_t* rwlock, const ffrt_rwlockattr_t* attr)

Description

Initializes a read-write lock.

Since: 18

Parameters

Name	Description
ffrt_rwlock_t* rwlock	Pointer to the read-write lock.
const ffrt_rwlockattr_t* attr	Pointer to the rwlock property. Only the default value (null) is supported.

Returns

Type	Description
FFRT_C_API int	If rwlock is not empty and attr is empty, the initialization is successful, and ffrt_success is returned. Otherwise, the rwlock fails to be initialized, and ffrt_error_inval is returned.

ffrt_rwlock_wrlock()

FFRT_C_API int ffrt_rwlock_wrlock(ffrt_rwlock_t* rwlock)

Description

Obtains a write lock.

Since: 18

Parameters

Name	Description
ffrt_rwlock_t* rwlock	Pointer to the read-write lock.

Returns

Type	Description
FFRT_C_API int	Returns ffrt_success if the write lock is successfully obtained; returns ffrt_error_inval or blocks the task otherwise.

ffrt_rwlock_trywrlock()

FFRT_C_API int ffrt_rwlock_trywrlock(ffrt_rwlock_t* rwlock)

Description

Attempts to obtain a write lock.

Since: 18

Parameters

Name	Description
ffrt_rwlock_t* rwlock	Pointer to the read-write lock.

Returns

Type	Description
FFRT_C_API int	Returns ffrt_success if the write lock is successfully obtained; returns ffrt_error_inval or ffrt_error_busy otherwise.

ffrt_rwlock_rdlock()

FFRT_C_API int ffrt_rwlock_rdlock(ffrt_rwlock_t* rwlock)

Description

Obtains a read lock.

Since: 18

Parameters

Name	Description
ffrt_rwlock_t* rwlock	Pointer to the read-write lock.

Returns

Type	Description
FFRT_C_API int	Returns ffrt_success if the read lock is successfully obtained; returns ffrt_error_inval or blocks the task otherwise.

ffrt_rwlock_tryrdlock()

FFRT_C_API int ffrt_rwlock_tryrdlock(ffrt_rwlock_t* rwlock)

Description

Attempts to obtain a read lock.

Since: 18

Parameters

Name	Description
ffrt_rwlock_t* rwlock	Pointer to the read-write lock.

Returns

Type	Description
FFRT_C_API int	Returns ffrt_success if the read lock is successfully obtained; returns ffrt_error_inval or ffrt_error_busy otherwise.

ffrt_rwlock_unlock()

FFRT_C_API int ffrt_rwlock_unlock(ffrt_rwlock_t* rwlock)

Description

Releases the read-write lock.

Since: 18

Parameters

Name	Description
ffrt_rwlock_t* rwlock	Pointer to the read-write lock.

Returns

Type	Description
FFRT_C_API int	Returns ffrt_success if the read-write lock is successfully released; returns ffrt_error_inval otherwise.

ffrt_rwlock_destroy()

FFRT_C_API int ffrt_rwlock_destroy(ffrt_rwlock_t* rwlock)

Description

Destroys the read-write lock.

Since: 18

Parameters

Name	Description
ffrt_rwlock_t* rwlock	Pointer to the read-write lock.

Returns

Type	Description
FFRT_C_API int	Returns ffrt_success if the read-write lock is destroyed successfully; returns ffrt_error_inval otherwise.