native_fence.h

Overview

This file declares the functions for obtaining and using NativeFence.

Header file: <native_fence/native_fence.h>

Library: libnative_fence.so

Since: 20

System capability: SystemCapability.Graphic.Graphic2D.NativeWindow

Related module: NativeFence

Name	Description
bool OH_NativeFence_IsValid(int fenceFd)	Checks whether fenceFd is valid.
bool OH_NativeFence_Wait(int fenceFd, uint32_t timeout)	Blocks the input fenceFd. The maximum blocking time is determined by the timeout parameter. The input fenceFd needs to be closed by yourself.
bool OH_NativeFence_WaitForever(int fenceFd)	Permanently blocks the input fenceFd. The input fenceFd needs to be closed by yourself.
void OH_NativeFence_Close(int fenceFd)	Closes fenceFd.

bool OH_NativeFence_IsValid(int fenceFd)

Description

Checks whether fenceFd is valid.

Since: 20

Parameters

Name	Description
int fenceFd	File descriptor for periodic sync.

Returns

Type	Description
bool	Returns true if fenceFd is valid; false otherwise.

bool OH_NativeFence_Wait(int fenceFd, uint32_t timeout)

Description

Blocks the input fenceFd. The maximum blocking time is determined by the timeout parameter. The input fenceFd needs to be closed by yourself.

Since: 20

Parameters

Name	Description
int fenceFd	File descriptor for periodic sync.
uint32_t timeout	Wait time. The unit is millisecond. The value -1 indicates that the API waits permanently, and the value 0 indicates that the API returns a response immediately.

Returns

Type	Description
bool	Returns true if the corresponding fenceFd has a signal triggered. Returns false in the following cases: 1. The input fenceFd is a negative integer. 2. No signal is triggered within the specified timeout period. 3. The underlying poll API fails to be called. 4. The timeout period is set to 0. 5. The file descriptor fails to be copied in the API.

bool OH_NativeFence_WaitForever(int fenceFd)

Description

Permanently blocks the input fenceFd. The input fenceFd needs to be closed by yourself.

Since: 20

Parameters

Name	Description
int fenceFd	File descriptor for periodic sync.

Returns

Type	Description
bool	Returns true if the corresponding fenceFd has a signal triggered. Returns false in the following cases: 1. The input fenceFd is a negative integer. 2. No signal is triggered within the specified timeout period, and the API waits permanently. 3. The file descriptor fails to be copied in the API.