Stream Management#
Typedefs | |
typedef void(* | hipStreamCallback_t) (hipStream_t stream, hipError_t status, void *userData) |
Functions | |
hipError_t | hipStreamCreate (hipStream_t *stream) |
Create an asynchronous stream. | |
hipError_t | hipStreamCreateWithFlags (hipStream_t *stream, unsigned int flags) |
Create an asynchronous stream. | |
hipError_t | hipStreamCreateWithPriority (hipStream_t *stream, unsigned int flags, int priority) |
Create an asynchronous stream with the specified priority. | |
hipError_t | hipDeviceGetStreamPriorityRange (int *leastPriority, int *greatestPriority) |
Returns numerical values that correspond to the least and greatest stream priority. | |
hipError_t | hipStreamDestroy (hipStream_t stream) |
Destroys the specified stream. | |
hipError_t | hipStreamQuery (hipStream_t stream) |
Return hipSuccess if all of the operations in the specified stream have completed, or hipErrorNotReady if not. | |
hipError_t | hipStreamSynchronize (hipStream_t stream) |
Wait for all commands in stream to complete. | |
hipError_t | hipStreamWaitEvent (hipStream_t stream, hipEvent_t event, unsigned int flags) |
Make the specified compute stream wait for an event. | |
hipError_t | hipStreamGetFlags (hipStream_t stream, unsigned int *flags) |
Return flags associated with this stream. | |
hipError_t | hipStreamGetPriority (hipStream_t stream, int *priority) |
Query the priority of a stream. | |
hipError_t | hipStreamGetDevice (hipStream_t stream, hipDevice_t *device) |
Get the device assocaited with the stream. | |
hipError_t | hipExtStreamCreateWithCUMask (hipStream_t *stream, uint32_t cuMaskSize, const uint32_t *cuMask) |
Create an asynchronous stream with the specified CU mask. | |
hipError_t | hipExtStreamGetCUMask (hipStream_t stream, uint32_t cuMaskSize, uint32_t *cuMask) |
Get CU mask associated with an asynchronous stream. | |
hipError_t | hipStreamAddCallback (hipStream_t stream, hipStreamCallback_t callback, void *userData, unsigned int flags) |
Adds a callback to be called on the host after all currently enqueued items in the stream have completed. For each hipStreamAddCallback call, a callback will be executed exactly once. The callback will block later work in the stream until it is finished. | |
Detailed Description
This section describes the stream management functions of HIP runtime API. The following Stream APIs are not (yet) supported in HIP:
- hipStreamAttachMemAsync is a nop
Typedef Documentation
◆ hipStreamCallback_t
typedef void(* hipStreamCallback_t) (hipStream_t stream, hipError_t status, void *userData) |
Stream CallBack struct
Function Documentation
◆ hipDeviceGetStreamPriorityRange()
hipError_t hipDeviceGetStreamPriorityRange | ( | int * | leastPriority, |
int * | greatestPriority | ||
) |
Returns numerical values that correspond to the least and greatest stream priority.
- Parameters
-
[in,out] leastPriority pointer in which value corresponding to least priority is returned. [in,out] greatestPriority pointer in which value corresponding to greatest priority is returned.
- Returns
- hipSuccess
Returns in *leastPriority and *greatestPriority the numerical values that correspond to the least and greatest stream priority respectively. Stream priorities follow a convention where lower numbers imply greater priorities. The range of meaningful stream priorities is given by [*greatestPriority, *leastPriority]. If the user attempts to create a stream with a priority value that is outside the meaningful range as specified by this API, the priority is automatically clamped to within the valid range.
◆ hipExtStreamCreateWithCUMask()
hipError_t hipExtStreamCreateWithCUMask | ( | hipStream_t * | stream, |
uint32_t | cuMaskSize, | ||
const uint32_t * | cuMask | ||
) |
Create an asynchronous stream with the specified CU mask.
- Parameters
-
[in,out] stream Pointer to new stream [in] cuMaskSize Size of CU mask bit array passed in. [in] cuMask Bit-vector representing the CU mask. Each active bit represents using one CU. The first 32 bits represent the first 32 CUs, and so on. If its size is greater than physical CU number (i.e., multiProcessorCount member of hipDeviceProp_t), the extra elements are ignored. It is user's responsibility to make sure the input is meaningful.
Create a new asynchronous stream with the specified CU mask. stream
returns an opaque handle that can be used to reference the newly created stream in subsequent hipStream* commands. The stream is allocated on the heap and will remain allocated even if the handle goes out-of-scope. To release the memory used by the stream, application must call hipStreamDestroy.
◆ hipExtStreamGetCUMask()
hipError_t hipExtStreamGetCUMask | ( | hipStream_t | stream, |
uint32_t | cuMaskSize, | ||
uint32_t * | cuMask | ||
) |
Get CU mask associated with an asynchronous stream.
- Parameters
-
[in] stream stream to be queried [in] cuMaskSize number of the block of memories (uint32_t *) allocated by user [out] cuMask Pointer to a pre-allocated block of memories (uint32_t *) in which the stream's CU mask is returned. The CU mask is returned in a chunck of 32 bits where each active bit represents one active CU
◆ hipStreamAddCallback()
hipError_t hipStreamAddCallback | ( | hipStream_t | stream, |
hipStreamCallback_t | callback, | ||
void * | userData, | ||
unsigned int | flags | ||
) |
Adds a callback to be called on the host after all currently enqueued items in the stream have completed. For each hipStreamAddCallback call, a callback will be executed exactly once. The callback will block later work in the stream until it is finished.
- Parameters
-
[in] stream - Stream to add callback to [in] callback - The function to call once preceding stream operations are complete [in] userData - User specified data to be passed to the callback function [in] flags - Reserved for future use, must be 0
◆ hipStreamCreate()
hipError_t hipStreamCreate | ( | hipStream_t * | stream | ) |
Create an asynchronous stream.
- Parameters
-
[in,out] stream Valid pointer to hipStream_t. This function writes the memory with the newly created stream.
- Returns
- hipSuccess, hipErrorInvalidValue
Create a new asynchronous stream. stream
returns an opaque handle that can be used to reference the newly created stream in subsequent hipStream* commands. The stream is allocated on the heap and will remain allocated even if the handle goes out-of-scope. To release the memory used by the stream, application must call hipStreamDestroy.
- Returns
- hipSuccess, hipErrorInvalidValue
◆ hipStreamCreateWithFlags()
hipError_t hipStreamCreateWithFlags | ( | hipStream_t * | stream, |
unsigned int | flags | ||
) |
Create an asynchronous stream.
- Parameters
-
[in,out] stream Pointer to new stream [in] flags to control stream creation.
- Returns
- hipSuccess, hipErrorInvalidValue
Create a new asynchronous stream. stream
returns an opaque handle that can be used to reference the newly created stream in subsequent hipStream* commands. The stream is allocated on the heap and will remain allocated even if the handle goes out-of-scope. To release the memory used by the stream, application must call hipStreamDestroy. Flags controls behavior of the stream. See hipStreamDefault, hipStreamNonBlocking.
◆ hipStreamCreateWithPriority()
hipError_t hipStreamCreateWithPriority | ( | hipStream_t * | stream, |
unsigned int | flags, | ||
int | priority | ||
) |
Create an asynchronous stream with the specified priority.
- Parameters
-
[in,out] stream Pointer to new stream [in] flags to control stream creation. [in] priority of the stream. Lower numbers represent higher priorities.
- Returns
- hipSuccess, hipErrorInvalidValue
Create a new asynchronous stream with the specified priority. stream
returns an opaque handle that can be used to reference the newly created stream in subsequent hipStream* commands. The stream is allocated on the heap and will remain allocated even if the handle goes out-of-scope. To release the memory used by the stream, application must call hipStreamDestroy. Flags controls behavior of the stream. See hipStreamDefault, hipStreamNonBlocking.
◆ hipStreamDestroy()
hipError_t hipStreamDestroy | ( | hipStream_t | stream | ) |
Destroys the specified stream.
- Parameters
-
[in] stream stream identifier.
- Returns
- hipSuccess hipErrorInvalidHandle
Destroys the specified stream.
If commands are still executing on the specified stream, some may complete execution before the queue is deleted.
The queue may be destroyed while some commands are still inflight, or may wait for all commands queued to the stream before destroying it.
◆ hipStreamGetDevice()
hipError_t hipStreamGetDevice | ( | hipStream_t | stream, |
hipDevice_t * | device | ||
) |
Get the device assocaited with the stream.
- Parameters
-
[in] stream stream to be queried [out] device device associated with the stream
◆ hipStreamGetFlags()
hipError_t hipStreamGetFlags | ( | hipStream_t | stream, |
unsigned int * | flags | ||
) |
Return flags associated with this stream.
- Parameters
-
[in] stream stream to be queried [in,out] flags Pointer to an unsigned integer in which the stream's flags are returned
- Returns
- hipSuccess, hipErrorInvalidValue, hipErrorInvalidHandle
- hipSuccess hipErrorInvalidValue hipErrorInvalidHandle
Return flags associated with this stream in *flags
.
- See also
- hipStreamCreateWithFlags
◆ hipStreamGetPriority()
hipError_t hipStreamGetPriority | ( | hipStream_t | stream, |
int * | priority | ||
) |
Query the priority of a stream.
- Parameters
-
[in] stream stream to be queried [in,out] priority Pointer to an unsigned integer in which the stream's priority is returned
- Returns
- hipSuccess, hipErrorInvalidValue, hipErrorInvalidHandle
- hipSuccess hipErrorInvalidValue hipErrorInvalidHandle
Query the priority of a stream. The priority is returned in in priority.
- See also
- hipStreamCreateWithFlags
◆ hipStreamQuery()
hipError_t hipStreamQuery | ( | hipStream_t | stream | ) |
Return hipSuccess if all of the operations in the specified stream
have completed, or hipErrorNotReady if not.
- Parameters
-
[in] stream stream to query
This is thread-safe and returns a snapshot of the current state of the queue. However, if other host threads are sending work to the stream, the status may change immediately after the function is called. It is typically used for debug.
◆ hipStreamSynchronize()
hipError_t hipStreamSynchronize | ( | hipStream_t | stream | ) |
Wait for all commands in stream to complete.
- Parameters
-
[in] stream stream identifier.
- Returns
- hipSuccess, hipErrorInvalidHandle
This command is host-synchronous : the host will block until the specified stream is empty.
This command follows standard null-stream semantics. Specifically, specifying the null stream will cause the command to wait for other streams on the same device to complete all pending operations.
This command honors the hipDeviceLaunchBlocking flag, which controls whether the wait is active or blocking.
◆ hipStreamWaitEvent()
hipError_t hipStreamWaitEvent | ( | hipStream_t | stream, |
hipEvent_t | event, | ||
unsigned int | flags | ||
) |
Make the specified compute stream wait for an event.
- Parameters
-
[in] stream stream to make wait. [in] event event to wait on [in] flags control operation [must be 0]
- Returns
- hipSuccess, hipErrorInvalidHandle
This function inserts a wait operation into the specified stream. All future work submitted to stream
will wait until event
reports completion before beginning execution.
This function only waits for commands in the current stream to complete. Notably, this function does not implicitly wait for commands in the default stream to complete, even if the specified stream is created with hipStreamNonBlocking = 0.