To create a pipe object, call the function
cl_mem clCreatePipe( cl_context context, cl_mem_flags flags, cl_uint pipe_packet_size, cl_uint pipe_max_packets, const cl_pipe_properties* properties, cl_int* errcode_ret);
context is a valid OpenCL context used to create the pipe object.
flags is a bit-field that is used to specify allocation and usage information such as the memory arena that should be used to allocate the pipe object and how it will be used. The Memory Flags table describes the possible values for flags. Only
CL_MEM_HOST_NO_ACCESScan be specified when creating a pipe object. If the value specified for flags is 0, the default is used which is
pipe_packet_size is the size in bytes of a pipe packet.
pipe_max_packets specifies the pipe capacity by specifying the maximum number of packets the pipe can hold.
properties specifies a list of properties for the pipe and their corresponding values. Each property name is immediately followed by the corresponding desired value. The list is terminated with 0. Currently, in all OpenCL versions, properties must be
errcode_ret will return an appropriate error code. If errcode_ret is
NULL, no error code is returned.
clCreatePipe returns a valid non-zero pipe object and errcode_ret is set
CL_SUCCESS if the pipe object is created successfully.
Otherwise, it returns a
NULL value with one of the following error values
returned in errcode_ret:
CL_INVALID_CONTEXTif context is not a valid context.
CL_INVALID_VALUEif values specified in flags are not as defined above.
CL_INVALID_VALUEif properties is not
CL_INVALID_PIPE_SIZEif pipe_packet_size is 0 or the pipe_packet_size exceeds
CL_DEVICE_PIPE_MAX_PACKET_SIZEvalue specified in the Device Queries table for all devices in context or if pipe_max_packets is 0.
CL_MEM_OBJECT_ALLOCATION_FAILUREif there is a failure to allocate memory for the pipe object.
CL_OUT_OF_RESOURCESif there is a failure to allocate resources required by the OpenCL implementation on the device.
CL_OUT_OF_HOST_MEMORYif there is a failure to allocate resources required by the OpenCL implementation on the host.
Pipes follow the same memory consistency model as defined for buffer and image objects. The pipe state i.e. contents of the pipe across kernel-instances (on the same or different devices) is enforced at a synchronization point.
For more information, see the OpenCL Specification
This page is extracted from the OpenCL Specification. Fixes and changes should be made to the Specification, not directly.
Copyright (c) 2014-2020 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.