org.bytedeco.opencv.opencv_core

Class Stream

java.lang.Object

org.bytedeco.javacpp.Pointer

org.bytedeco.opencv.opencv_core.Stream

All Implemented Interfaces:

AutoCloseable

@Namespace(value="cv::cuda")
 @NoOffset
 @Properties(inherit=opencv_core.class)
public class Stream
extends Pointer

\brief This class encapsulates a queue of asynchronous calls.

\note Currently, you may face problems if an operation is enqueued twice with different data. Some functions use the constant GPU memory, and next call may update the memory before the previous one has been finished. But calling different operations asynchronously is safe because each operation has its own constant buffer. Memory copy/upload/download/set operations to the buffers you hold are also safe.

\note The Stream class is not thread-safe. Please use different Stream objects for different CPU threads.

void thread1()
{
    cv::cuda::Stream stream1;
    cv::cuda::func1(..., stream1);
}

void thread2()
{
    cv::cuda::Stream stream2;
    cv::cuda::func2(..., stream2);
}

\note By default all CUDA routines are launched in Stream::Null() object, if the stream is not specified by user. In multi-threading environment the stream objects must be passed explicitly (see previous note).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Stream.Impl
static class	Stream.StreamCallback

Nested classes/interfaces inherited from class org.bytedeco.javacpp.Pointer

Pointer.CustomDeallocator, Pointer.Deallocator, Pointer.NativeDeallocator, Pointer.ReferenceCounter

Field Summary

Fields inherited from class org.bytedeco.javacpp.Pointer

address, capacity, limit, position

Constructor Summary

Constructors

Constructor and Description
Stream() creates a new asynchronous stream
Stream(GpuMat.Allocator allocator) creates a new asynchronous stream with custom allocator
Stream(long size) Native array allocator.
Stream(Pointer p) Pointer cast constructor.

Method Summary

Modifier and Type	Method and Description
Pointer	cudaPtr() return Pointer to CUDA stream
void	enqueueHostCallback(Stream.StreamCallback callback, Pointer userData) \brief Adds a callback to be called on the host after all currently enqueued items in the stream have completed.
static Stream	Null() return Stream object for default CUDA stream
Stream	position(long position)
boolean	queryIfComplete() \brief Returns true if the current stream queue is finished.
void	waitEvent(Event event) \brief Makes a compute stream wait on an event.
void	waitForCompletion() \brief Blocks the current CPU thread until all operations in the stream are complete.

Methods inherited from class org.bytedeco.javacpp.Pointer

address, asBuffer, asByteBuffer, availablePhysicalBytes, calloc, capacity, capacity, close, deallocate, deallocate, deallocateReferences, deallocator, deallocator, equals, fill, formatBytes, free, hashCode, isNull, isNull, limit, limit, malloc, maxBytes, maxPhysicalBytes, memchr, memcmp, memcpy, memmove, memset, offsetof, parseBytes, physicalBytes, position, put, realloc, referenceCount, releaseReference, retainReference, setNull, sizeof, toString, totalBytes, totalPhysicalBytes, withDeallocator, zero

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Stream

public Stream(Pointer p)

Pointer cast constructor. Invokes Pointer.Pointer(Pointer).

Stream

public Stream(long size)

Native array allocator. Access with Pointer.position(long).

Stream

public Stream()

creates a new asynchronous stream

Stream

public Stream(@opencv_core.Ptr
              GpuMat.Allocator allocator)

creates a new asynchronous stream with custom allocator

Method Detail

position

public Stream position(long position)

Overrides:

position in class Pointer

queryIfComplete

@Cast(value="bool")
public boolean queryIfComplete()

\brief Returns true if the current stream queue is finished. Otherwise, it returns false.

waitForCompletion

public void waitForCompletion()

\brief Blocks the current CPU thread until all operations in the stream are complete.

waitEvent

public void waitEvent(@Const @ByRef
                      Event event)

\brief Makes a compute stream wait on an event.

enqueueHostCallback

public void enqueueHostCallback(Stream.StreamCallback callback,
                                Pointer userData)

\brief Adds a callback to be called on the host after all currently enqueued items in the stream have completed.

\note Callbacks must not make any CUDA API calls. Callbacks must not perform any synchronization that may depend on outstanding device work or other callbacks that are not mandated to run earlier. Callbacks without a mandated order (in independent streams) execute in undefined order and may be serialized.

Null

@ByRef
public static Stream Null()

return Stream object for default CUDA stream

cudaPtr

public Pointer cudaPtr()

return Pointer to CUDA stream