Creates an event.

phEvent

- Returns newly created event

Flags

- Event creation flags

Destroys an event.

hEvent

- Event to destroy

Computes the elapsed time between two events.

pMilliseconds

- Time between hStart and hEnd in ms

hStart

- Starting event

hEnd

- Ending event

Computes the elapsed time between two events (in milliseconds with a resolution of around 0.5 microseconds). Note this API is not guaranteed to return the latest errors for pending work. As such this API is intended to serve as an elapsed time calculation only and any polling for completion on the events to be compared should be done with cuEventQuery instead.

If either event was last recorded in a non-NULL stream, the resulting time may be greater than expected (even if both used the same stream handle). This happens because the cuEventRecord() operation takes place asynchronously and there is no guarantee that the measured latency is actually just between the two events. Any number of other different stream operations could execute in between the two measured events, thus altering the timing in a significant way.

If cuEventRecord() has not been called on either event then CUDA_ERROR_INVALID_HANDLE is returned. If cuEventRecord() has been called on both events but one or both of them has not yet been completed (that is, cuEventQuery() would return CUDA_ERROR_NOT_READY on at least one of the events), CUDA_ERROR_NOT_READY is returned. If either event was created with the CU_EVENT_DISABLE_TIMING flag, then this function will return CUDA_ERROR_INVALID_HANDLE.

Note that this function may also return error codes from previous, asynchronous launches.

See also:

cuEventCreate, cuEventRecord, cuEventQuery, cuEventSynchronize, cuEventDestroy, cudaEventElapsedTime

Queries an event's status.

Records an event.

hEvent

- Event to record

hStream

- Stream to record event for

Captures in hEvent the contents of hStream at the time of this call. hEvent and hStream must be from the same context otherwise CUDA_ERROR_INVALID_HANDLE is returned. Calls such as cuEventQuery() or cuStreamWaitEvent() will then examine or wait for completion of the work that was captured. Uses of hStream after this call do not modify hEvent. See note on default stream behavior for what is captured in the default case.

cuEventRecord() can be called multiple times on the same event and will overwrite the previously captured state. Other APIs such as cuStreamWaitEvent() use the most recently captured state at the time of the API call, and are not affected by later calls to cuEventRecord(). Before the first call to cuEventRecord(), an event represents an empty set of work, so for example cuEventQuery() would return CUDA_SUCCESS.

• This function uses standard default stream semantics.

• Note that this function may also return error codes from previous, asynchronous launches.

See also:

cuEventCreate, cuEventQuery, cuEventSynchronize, cuStreamWaitEvent, cuEventDestroy, cuEventElapsedTime, cudaEventRecord, cuEventRecordWithFlags

Records an event.

hEvent

- Event to record

hStream

- Stream to record event for

flags

- See CUevent_capture_flags

Captures in hEvent the contents of hStream at the time of this call. hEvent and hStream must be from the same context otherwise CUDA_ERROR_INVALID_HANDLE is returned. Calls such as cuEventQuery() or cuStreamWaitEvent() will then examine or wait for completion of the work that was captured. Uses of hStream after this call do not modify hEvent. See note on default stream behavior for what is captured in the default case.

cuEventRecordWithFlags() can be called multiple times on the same event and will overwrite the previously captured state. Other APIs such as cuStreamWaitEvent() use the most recently captured state at the time of the API call, and are not affected by later calls to cuEventRecordWithFlags(). Before the first call to cuEventRecordWithFlags(), an event represents an empty set of work, so for example cuEventQuery() would return CUDA_SUCCESS.

flags include:

• CU_EVENT_RECORD_DEFAULT: Default event creation flag.

• CU_EVENT_RECORD_EXTERNAL: Event is captured in the graph as an external event node when performing stream capture. This flag is invalid outside of stream capture.

• This function uses standard default stream semantics.

• Note that this function may also return error codes from previous, asynchronous launches.

See also:

cuEventCreate, cuEventQuery, cuEventSynchronize, cuStreamWaitEvent, cuEventDestroy, cuEventElapsedTime, cuEventRecord, cudaEventRecord

Waits for an event to complete.

hEvent

- Event to wait for