Provided by: nvidia-cuda-dev_7.5.18-0ubuntu1_amd64 
NAME
Event Management -
Functions
CUresult cuEventCreate (CUevent *phEvent, unsigned int Flags)
Creates an event.
CUresult cuEventDestroy (CUevent hEvent)
Destroys an event.
CUresult cuEventElapsedTime (float *pMilliseconds, CUevent hStart, CUevent hEnd)
Computes the elapsed time between two events.
CUresult cuEventQuery (CUevent hEvent)
Queries an event's status.
CUresult cuEventRecord (CUevent hEvent, CUstream hStream)
Records an event.
CUresult cuEventSynchronize (CUevent hEvent)
Waits for an event to complete.
Detailed Description
\brief event management functions of the low-level CUDA driver API (cuda.h)
This section describes the event management functions of the low-level CUDA driver application
programming interface.
Function Documentation
CUresult cuEventCreate (CUevent * phEvent, unsigned int Flags)
Creates an event *phEvent with the flags specified via Flags. Valid flags include:
• CU_EVENT_DEFAULT: Default event creation flag.
• CU_EVENT_BLOCKING_SYNC: Specifies that the created event should use blocking synchronization. A CPU
thread that uses cuEventSynchronize() to wait on an event created with this flag will block until the
event has actually been recorded.
• CU_EVENT_DISABLE_TIMING: Specifies that the created event does not need to record timing data. Events
created with this flag specified and the CU_EVENT_BLOCKING_SYNC flag not specified will provide the
best performance when used with cuStreamWaitEvent() and cuEventQuery().
• CU_EVENT_INTERPROCESS: Specifies that the created event may be used as an interprocess event by
cuIpcGetEventHandle(). CU_EVENT_INTERPROCESS must be specified along with CU_EVENT_DISABLE_TIMING.
Parameters:
phEvent - Returns newly created event
Flags - Event creation flags
Returns:
CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_CONTEXT,
CUDA_ERROR_INVALID_VALUE, CUDA_ERROR_OUT_OF_MEMORY
Note:
Note that this function may also return error codes from previous, asynchronous launches.
See also:
cuEventRecord, cuEventQuery, cuEventSynchronize, cuEventDestroy, cuEventElapsedTime
CUresult cuEventDestroy (CUevent hEvent)
Destroys the event specified by hEvent.
In case hEvent has been recorded but has not yet been completed when cuEventDestroy() is called, the
function will return immediately and the resources associated with hEvent will be released automatically
once the device has completed hEvent.
Parameters:
hEvent - Event to destroy
Returns:
CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_CONTEXT,
CUDA_ERROR_INVALID_HANDLE
Note:
Note that this function may also return error codes from previous, asynchronous launches.
See also:
cuEventCreate, cuEventRecord, cuEventQuery, cuEventSynchronize, cuEventElapsedTime
CUresult cuEventElapsedTime (float * pMilliseconds, CUevent hStart, CUevent hEnd)
Computes the elapsed time between two events (in milliseconds with a resolution of around 0.5
microseconds).
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.
Parameters:
pMilliseconds - Time between hStart and hEnd in ms
hStart - Starting event
hEnd - Ending event
Returns:
CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_CONTEXT,
CUDA_ERROR_INVALID_HANDLE, CUDA_ERROR_NOT_READY
Note:
Note that this function may also return error codes from previous, asynchronous launches.
See also:
cuEventCreate, cuEventRecord, cuEventQuery, cuEventSynchronize, cuEventDestroy
CUresult cuEventQuery (CUevent hEvent)
Query the status of all device work preceding the most recent call to cuEventRecord() (in the appropriate
compute streams, as specified by the arguments to cuEventRecord()).
If this work has successfully been completed by the device, or if cuEventRecord() has not been called on
hEvent, then CUDA_SUCCESS is returned. If this work has not yet been completed by the device then
CUDA_ERROR_NOT_READY is returned.
For the purposes of Unified Memory, a return value of CUDA_SUCCESS is equivalent to having called
cuEventSynchronize().
Parameters:
hEvent - Event to query
Returns:
CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_HANDLE,
CUDA_ERROR_INVALID_VALUE, CUDA_ERROR_NOT_READY
Note:
Note that this function may also return error codes from previous, asynchronous launches.
See also:
cuEventCreate, cuEventRecord, cuEventSynchronize, cuEventDestroy, cuEventElapsedTime
CUresult cuEventRecord (CUevent hEvent, CUstream hStream)
Records an event. See note on NULL stream behavior. Since operation is asynchronous, cuEventQuery or
cuEventSynchronize() must be used to determine when the event has actually been recorded.
If cuEventRecord() has previously been called on hEvent, then this call will overwrite any existing state
in hEvent. Any subsequent calls which examine the status of hEvent will only examine the completion of
this most recent call to cuEventRecord().
It is necessary that hEvent and hStream be created on the same context.
Parameters:
hEvent - Event to record
hStream - Stream to record event for
Returns:
CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_CONTEXT,
CUDA_ERROR_INVALID_HANDLE, CUDA_ERROR_INVALID_VALUE
Note:
This function uses standard semantics.
Note that this function may also return error codes from previous, asynchronous launches.
See also:
cuEventCreate, cuEventQuery, cuEventSynchronize, cuStreamWaitEvent, cuEventDestroy,
cuEventElapsedTime
CUresult cuEventSynchronize (CUevent hEvent)
Wait until the completion of all device work preceding the most recent call to cuEventRecord() (in the
appropriate compute streams, as specified by the arguments to cuEventRecord()).
If cuEventRecord() has not been called on hEvent, CUDA_SUCCESS is returned immediately.
Waiting for an event that was created with the CU_EVENT_BLOCKING_SYNC flag will cause the calling CPU
thread to block until the event has been completed by the device. If the CU_EVENT_BLOCKING_SYNC flag has
not been set, then the CPU thread will busy-wait until the event has been completed by the device.
Parameters:
hEvent - Event to wait for
Returns:
CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_CONTEXT,
CUDA_ERROR_INVALID_HANDLE
Note:
Note that this function may also return error codes from previous, asynchronous launches.
See also:
cuEventCreate, cuEventRecord, cuEventQuery, cuEventDestroy, cuEventElapsedTime
Author
Generated automatically by Doxygen from the source code.
Version 6.0 15 Aug 2015 Event Management(3)