Stream¶

class paddle.device. Stream ( device=None, priority=2, stream_base=None ) [source]

A device stream wrapper around StreamBase.

Parameters

device (str|paddle.CUDAPlace(n)|paddle.CustomPlace(n)) – Which device the stream run on. If device is None, the device is the current device. Default: None. It can be gpu, gpu:x, custom_device, custom_device:x, where custom_device is the name of CustomDevice, where x is the index of the GPUs, XPUs. And it can be paddle.CUDAPlace(n) or paddle.CustomPlace(n).
priority (int, optional) – priority of the CUDA stream. Can be either 1 (high priority) or 2 (low priority). By default, streams have priority 2.

Returns

The stream.

Return type

Stream

Examples

           >>> 
>>> import paddle

>>> paddle.set_device('custom_cpu')
>>> s1 = paddle.device.Stream()
>>> s2 = paddle.device.Stream('custom_cpu')
>>> s3 = paddle.device.Stream('custom_cpu:0')
>>> s4 = paddle.device.Stream(paddle.CustomPlace('custom_cpu', 0))

          

wait_event ( event ) wait_event¶

Makes all future work submitted to the stream wait for an event.

Parameters: event (Event) – an event to wait for.
Returns: None.

Examples

             >>> 
>>> import paddle

>>> paddle.set_device('custom_cpu')
>>> s1 = paddle.device.Stream()
>>> s2 = paddle.device.Stream()
>>> e = paddle.device.Event()
>>> e.record(s1)
>>> s2.wait_event(e)

            

wait_stream ( stream ) wait_stream¶

Synchronizes with another stream. All future work submitted to this stream will wait until all kernels submitted to a given stream at the time of call complete.

Parameters: stream (Stream) – a stream to synchronize.
Returns: None.

Examples

             >>> 
>>> import paddle

>>> paddle.set_device('custom_cpu')
>>> s1 = paddle.device.Stream()
>>> s2 = paddle.device.Stream()
>>> s1.wait_stream(s2)

            

record_event ( event=None ) record_event¶

Records an event.

Parameters

event (Event, optional) – event to record. If not given, a new one
allocated. (will be) –

Returns

Recorded event.

Return type

Event

Examples

             >>> 
>>> import paddle

>>> paddle.set_device('custom_cpu')
>>> s = paddle.device.Stream()
>>> e1 = s.record_event()

>>> e2 = paddle.device.Event()
>>> s.record_event(e2)

            

query ( ) query¶

Checks if all the work submitted has been completed.

Returns: Whether all kernels in this stream are completed.
Return type: bool

Examples

             >>> 
>>> import paddle

>>> paddle.set_device('custom_cpu')
>>> s = paddle.device.Stream()
>>> s.query()

            

synchronize ( ) [source] synchronize¶

Wait for all the kernels in this stream to complete.

Returns: None.

Examples

             >>> 
>>> import paddle

>>> paddle.set_device('custom_cpu')
>>> s = paddle.device.Stream()
>>> s.synchronize()

            