loop.h

Overview

The loop.h file declares the loop APIs in C.

File to include: <ffrt/loop.h>

Library: libffrt.z.so

System capability: SystemCapability.Resourceschedule.Ffrt.Core

Since: 12

Related module: FFRT

Summary

Structs

Name	Description
ffrt_loop_t	Defines the handle to a loop.

Function

Name	Description
FFRT_C_API ffrt_loop_t ffrt_loop_create(ffrt_queue_t queue)	Creates a loop.
FFRT_C_API int ffrt_loop_destroy(ffrt_loop_t loop)	Destroys a loop.
FFRT_C_API int ffrt_loop_run(ffrt_loop_t loop)	Runs a loop.
FFRT_C_API void ffrt_loop_stop(ffrt_loop_t loop)	Stops a loop.
FFRT_C_API int ffrt_loop_epoll_ctl(ffrt_loop_t loop, int op, int fd, uint32_t events, void *data, ffrt_poller_cb cb)	Manages listening events on a loop. You are not advised to call the exit function in cb. Otherwise, undefined behavior may occur.
FFRT_C_API ffrt_timer_t ffrt_loop_timer_start(ffrt_loop_t loop, uint64_t timeout, void* data, ffrt_timer_cb cb, bool repeat)	Starts the timer on a loop. You are not advised to call the exit function in cb. Otherwise, undefined behavior may occur.
FFRT_C_API int ffrt_loop_timer_stop(ffrt_loop_t loop, ffrt_timer_t handle)	Stops the timer on a loop.

Function Description

ffrt_loop_create()

FFRT_C_API ffrt_loop_t ffrt_loop_create(ffrt_queue_t queue)

Description

Creates a loop.

Since: 12

Parameters

Name	Description
ffrt_queue_t queue	Concurrent queue.

Returns

Type	Description
FFRT_C_API ffrt_loop_t	Returns the ffrt_loop_t object if the loop is created; returns a null pointer otherwise.

ffrt_loop_destroy()

FFRT_C_API int ffrt_loop_destroy(ffrt_loop_t loop)

Description

Destroys a loop.

Since: 12

Parameters

Name	Description
ffrt_loop_t loop	Loop object.

Returns

Type	Description
FFRT_C_API int	Returns 0 if the loop is destroyed; returns -1 otherwise.

ffrt_loop_run()

FFRT_C_API int ffrt_loop_run(ffrt_loop_t loop)

Description

Runs a loop.

Since: 12

Parameters

Name	Description
ffrt_loop_t loop	Loop object.

Returns

Type	Description
FFRT_C_API int	Returns 0 if the loop runs successfully; returns -1 otherwise.

ffrt_loop_stop()

FFRT_C_API void ffrt_loop_stop(ffrt_loop_t loop)

Description

Stops a loop.

Since: 12

Parameters

Name	Description
ffrt_loop_t loop	Loop object.

ffrt_loop_epoll_ctl()

FFRT_C_API int ffrt_loop_epoll_ctl(ffrt_loop_t loop, int op, int fd, uint32_t events, void *data, ffrt_poller_cb cb)

Description

Manages listening events on a loop.

You are not advised to call the exit function in cb. Otherwise, undefined behavior may occur.

Since: 12

Parameters

Name	Description
ffrt_loop_t loop	Loop object.
int op	Operation to be performed.
int fd	File descriptor.
uint32_t events	Event.
void *data	Pointer to the input parameter in the callback function invoked upon event changes.
ffrt_poller_cb cb	Callback function invoked upon event changes.

Returns

Type	Description
FFRT_C_API int	Returns 0 if the operation is successful; returns -1 otherwise.

ffrt_loop_timer_start()

FFRT_C_API ffrt_timer_t ffrt_loop_timer_start(ffrt_loop_t loop, uint64_t timeout, void* data, ffrt_timer_cb cb, bool repeat)

Description

Starts the timer on a loop.

You are not advised to call the exit function in cb. Otherwise, undefined behavior may occur.

Since: 12

Parameters

Name	Description
ffrt_loop_t loop	Loop object.
uint64_t timeout	Timeout, in milliseconds.
void* data	Pointer to the input parameter in the callback function invoked upon event changes.
ffrt_timer_cb cb	Callback function invoked upon event changes.
bool repeat	Whether to repeat the timer.

Returns

Type	Description
FFRT_C_API ffrt_timer_t	Returns the timer handle.

ffrt_loop_timer_stop()

FFRT_C_API int ffrt_loop_timer_stop(ffrt_loop_t loop, ffrt_timer_t handle)

Description

Stops the timer on a loop.

Since: 12

Parameters

Name	Description
ffrt_loop_t loop	Loop object.
ffrt_timer_t handle	Timer handle.

Returns

Type	Description
FFRT_C_API int	Returns 0 if the operation is successful; returns -1 otherwise.