Applicable Products

Product	Supported (√/x)
Ascend 950PR / Ascend 950DT	√
Atlas A3 training products / Atlas A3 inference products	√
Atlas A2 training products / Atlas A2 inference products	√
Atlas training products	√
Atlas inference products	√
Atlas 200I/500 A2 inference products	√

Description

Records an event in a stream. When this API is called, the tasks that have been delivered in the current stream are captured and recorded in the event. Therefore, when the acl.rt.query_event_status or acl.rt.stream_wait_event API is called later, the system checks or waits until all the tasks captured in the event are complete.

For events created using acl rt.create_event_ex_with_flag:

This API supports event reuse for multiple records of the same event. Each record captures the tasks that have been delivered on the current stream and overwrites the tasks in the event. When acl.rt.stream_wait_event is called, the task saved in the latest event is used and will not be affected by subsequent calling of acl.rt.record_event.
Before this API is called for the first time, ACL_EVENT_RECORDED_STATUS_COMPLETE is returned when acl.rt.query_event_status is called because there is no task in the event.

Prototype

C Prototype

        
             aclError aclrtRecordEvent(aclrtEvent event, aclrtStream stream)

Python Function

        
             ret = acl.rt.record_event(event, stream)

Parameters

Parameter	Description
event	Int, pointer address of the event to be recorded.
stream	Int, the specified stream (pointer address) recording the event. 0 indicates the default stream.

Return Values

Return Value	Description
ret	Int, error code. 0 on success; else, failure.

Restrictions

This API is asynchronous. The API call delivers a task rather than executes a task. After this API is called, call the synchronization API (for example, acl.rt.synchronize_stream) to ensure that the task is complete.
acl.rt.record_event and acl.rt.stream_wait_event are used in conjunction for synchronization between streams. When acl.rt.record_event is called, an event resource is allocated. After acl.rt.stream_wait_event is called, acl.rt.reset_event should be called to free the event resource in a timely manner.
API call sequence: acl.rt.create_event-->acl.rt.record_event-->acl.rt.stream_wait_event-->acl.rt.reset_event

Reference

For the API call example, see Event Synchronization and Synchronous Wait of Tasks Between Streams (Implemented Using Events).