Event Timestamp Recording

The event created in Event Creation and Destruction can be used to collect statistics on the time consumed by compute tasks in a stream. The sample code is as follows: This sample code is used only to describe how to use events and cannot be directly copied for compilation or running. For the complete sample code, click here.

uint64_t time = 0;
float useTime = 0;

// Create a stream.
aclrtStream stream;
aclrtCreateStream(&stream);

aclrtEvent startEvent;
aclrtEvent endEvent;
// Create an event. Pass the ACL_EVENT_TIME_LINE parameter to the API, indicating that the created event is used for recording.
aclrtCreateEventExWithFlag(&startEvent, ACL_EVENT_TIME_LINE);
aclrtCreateEventExWithFlag(&endEvent, ACL_EVENT_TIME_LINE);

// Insert startEvent.
aclrtRecordEvent(startEvent, stream);
// Deliver compute tasks to the stream.
kernel<<< grid, block, 0, stream>>>(...);
// Insert endEvent.
aclrtRecordEvent(endEvent, stream);
aclrtSynchronizeStream(stream);

// Obtain the timestamp and calculate the time consumed.
aclrtEventElapsedTime(&useTime, startEvent, endEvent);

Parent topic: Event-based synchronization