clLinkProgram

Links a set of compiled program objects and libraries for all the devices or a specific device(s) in the OpenCL context and creates an executable.

cl_program clLinkProgram ( cl_context context,
  cl_uint num_devices,
  const cl_device_id *device_list,
  const char *options,
  cl_uint num_input_programs,
  const cl_program *input_programs,
  void (CL_CALLBACK *pfn_notify) (cl_program program, void *user_data),
  void *user_data,
  cl_int *errcode_ret)

Parameters

context

Must be a valid OpenCL context.

device_list

A pointer to a list of devices that are in context. If device_list is a NULL value, the link is performed for all devices associated with context for which a compiled object is available. If device_list is a non-NULL value, the compile is performed for devices specified in this list for which a compiled object is available.

num_devices

The number of devices listed in device_list.

options

A pointer to a null-terminated string of characters that describes the link options to be used for building the program executable. See clBuildProgram for a list of supported compiler and linker options.

num_input_programs

Specifies the number of programs in array referenced by input_programs.

input_programs

An array of program objects that are compiled binaries or libraries that are to be linked to create the program executable. For each device in device_list or if device_list is NULL the list of devices associated with context, the following cases occur:

  • All programs specified by input_programs contain a compiled binary or library for the device. In this case, a link is performed to generate a program executable for this device.

  • None of the programs contain a compiled binary or library for that device. In this case, no link is performed and there will be no program executable generated for this device.

  • All other cases will return a CL_INVALID_OPERATION error.

pfn_notify

A function pointer to a notification routine. The notification routine is a callback function that an application can register and which will be called when the program executable has been built (successfully or unsuccessfully).

If pfn_notify is not NULL, clLinkProgram does not need to wait for the linker to complete and can return immediately once the linking operation can begin. Once the linker has completed, the pfn_notify callback function is called which returns the program object returned by clLinkProgram. The application can query the link status and log for this program object. This callback function may be called asynchronously by the OpenCL implementation. It is the application’s responsibility to ensure that the callback function is thread-safe.

If pfn_notify is NULL, clLinkProgram does not return until the linker has completed.

user_data

Will be passed as an argument when pfn_notify is called. user_data can be NULL.

Notes

clLinkProgram creates a new program object which contains this executable. The executable binary can be queried using clGetProgramInfo(program, CL_PROGRAM_BINARIES, ...) and can be specified to clCreateProgramWithBinary to create a new program object.

The devices associated with the returned program object will be the list of devices specified by device_list or if device_list is NULL it will be the list of devices associated with context.

The linking operation can begin if the context, list of devices, input programs and linker options specified are all valid and appropriate host and device resources needed to perform the link are available. If the linking operation can begin, clLinkProgram returns a valid non-zero program object.

Errors

If pfn_notify is NULL, the errcode_ret will be set to CL_SUCCESS if the link operation was successful and CL_LINK_FAILURE if there is a failure to link the compiled binaries and/or libraries.

If pfn_notify is not NULL, clLinkProgram does not have to wait until the linker to complete and can return CL_SUCCESS in errcode_ret if the linking operation can begin. The pfn_notify callback function will return a CL_SUCCESS or CL_LINK_FAILURE if the linking operation was successful or not.

Otherwise clLinkProgram returns a NULL program object with an appropriate error in errcode_ret. The application should query the linker status of this program object to check if the link was successful or not. The list of errors that can be returned are:

  • CL_INVALID_CONTEXT if context is not a valid context.
  • CL_INVALID_VALUE if device_list is NULL and num_devices is greater than zero, or if device_list is not NULL and num_devices is zero.
  • CL_INVALID_VALUE if num_input_programs is zero and input_programs is NULL or if num_input_programs is zero and input_programs is not NULL or if num_input_programs is not zero and input_programs is NULL.
  • CL_INVALID_PROGRAM if programs specified in input_programs are not valid program objects.
  • CL_INVALID_VALUE if pfn_notify is NULL but user_data is not NULL.
  • CL_INVALID_DEVICE if OpenCL devices listed in device_list are not in the list of devices associated with context.
  • CL_INVALID_LINKER_OPTIONS if the linker options specified by options are invalid
  • CL_INVALID_OPERATION if the compilation or build of a program executable for any of the devices listed in device_list by a previous call to clCompileProgram or clBuildProgram for program has not completed.
  • CL_INVALID_OPERATION if the rules for devices containing compiled binaries or libraries as described in input_programs argument above are not followed.
  • CL_LINKER_NOT_AVAILABLE if a linker is not available i.e. CL_DEVICE_LINKER_AVAILABLE specified in the table of allowed values for param_name for clGetDeviceInfo is set to CL_FALSE.
  • CL_LINK_PROGRAM_FAILURE if there is a failure to link the compiled binaries and/or libraries.
  • CL_OUT_OF_RESOURCES if there is a failure to allocate resources required by the OpenCL implementation on the device.
  • CL_OUT_OF_HOST_MEMORY if there is a failure to allocate resources required by the OpenCL implementation on the host.

Specification

OpenCL Specification

Also see

clGetDeviceInfo

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