hipEventCreateWithFlags(hipEvent_t *event, unsigned flags)¶
Create an event with the specified flags.
hipEventDefault : Default flag. The event will use active synchronization and will support timing. Blocking synchronization provides lowest possible latency at the expense of dedicating a CPU to poll on the eevent. hipEventBlockingSync : The event will use blocking synchronization : if hipEventSynchronize is called on this event, the thread will block until the event completes. This can increase latency for the synchroniation but can result in lower power and more resources for other CPU threads. hipEventDisableTiming : Disable recording of timing information. On ROCM platform, timing information is always recorded and this flag has no performance benefit.
[inout] event: Returns the newly created event.
[in] flags: Flags to control event behavior. Valid values are hipEventDefault, hipEventBlockingSync, hipEventDisableTiming, hipEventInterprocess
On HCC platform, hipEventInterprocess support is under development. Use of this flag will return an error.
#hipSuccess, #hipErrorInitializationError, #hipErrorInvalidValue, #hipErrorLaunchFailure, #hipErrorMemoryAllocation
Create an event.
hipEventRecord(hipEvent_t event, hipStream_t stream)¶
Record an event in the specified stream.
hipEventQuery() or hipEventSynchronize() must be used to determine when the event transitions from “recording” (after hipEventRecord() is called) to “recorded” (when timestamps are set, if requested).
#hipSuccess, #hipErrorInvalidValue, #hipErrorInitializationError, #hipErrorInvalidResourceHandle, #hipErrorLaunchFailure
[in] event: event to record.
[in] stream: stream in which to record event.
Events which are recorded in a non-NULL stream will transition to from recording to “recorded” state when they reach the head of the specified stream, after all previous commands in that stream have completed executing.
If hipEventRecord() has been previously called on this event, then this call will overwrite any existing state in event.
If this function is called on a an event that is currently being recorded, results are undefined
either outstanding recording may save state into the event, and the order is not guaranteed.
Destroy the specified event.
Releases memory associated with the event. If the event is recording but has not completed recording whenhipEventDestroy() is called, the function will return immediately and the completion_future resources will be released later, when the hipDevice is synchronized.
#hipSuccess, #hipErrorInitializationError, #hipErrorInvalidValue, #hipErrorLaunchFailure
[in] event: Event to destroy.
Wait for an event to complete.
This function will block until the event is ready, waiting for all previous work in the stream specified when event was recorded with hipEventRecord().
If hipEventRecord() has not been called on
event, this function returns immediately.
TODO-hcc - This function needs to support hipEventBlockingSync parameter.
hipEventElapsedTime(float *ms, hipEvent_t start, hipEvent_t stop)¶
Return the elapsed time between two events.
Computes the elapsed time between two events. Time is computed in ms, with a resolution of approximately 1 us.
#hipSuccess, #hipErrorInvalidValue, #hipErrorNotReady, #hipErrorInvalidResourceHandle, #hipErrorInitializationError, #hipErrorLaunchFailure
[out] ms: : Return time between start and stop in ms.
[in] start: : Start event.
[in] stop: : Stop event.
Events which are recorded in a NULL stream will block until all commands on all other streams complete execution, and then record the timestamp.
Events which are recorded in a non-NULL stream will record their timestamp when they reach the head of the specified stream, after all previous commands in that stream have completed executing. Thus the time that the event recorded may be significantly after the host calls hipEventRecord().
If hipEventRecord() has not been called on either event, then #hipErrorInvalidResourceHandle is returned. If hipEventRecord() has been called on both events, but the timestamp has not yet been recorded on one or both events (that is, hipEventQuery() would return #hipErrorNotReady on at least one of the events), then #hipErrorNotReady is returned.
Query event status.
Query the status of the specified event. This function will return #hipErrorNotReady if all commands in the appropriate stream (specified tohipEventRecord()) have completed. If that work has not completed, or if hipEventRecord() was not called on the event, then #hipSuccess is returned.
#hipSuccess, #hipErrorNotReady, #hipErrorInvalidResourceHandle, #hipErrorInvalidValue, #hipErrorInitializationError, #hipErrorLaunchFailure
[in] event: Event to query.