Enqueues a command to execute a kernel on a device.

cl_int clEnqueueTask ( cl_command_queue command_queue,
  cl_kernel kernel,
  cl_uint num_events_in_wait_list,
  const cl_event *event_wait_list,
  cl_event *event)



A valid command-queue. The kernel will be queued for execution on the device associated with command_queue.


A valid kernel object. The OpenCL context associated with kernel and command_queue must be the same.

num_events_in_wait_list and event_wait_list

Specify events that need to complete before this particular command can be executed. If event_wait_list is NULL, then this particular command does not wait on any event to complete. If event_wait_list is NULL, num_events_in_wait_list must be 0. If event_wait_list is not NULL, the list of events pointed to by event_wait_list must be valid and num_events_in_wait_list must be greater than 0. The events specified in event_wait_list act as synchronization points. The context associated with events in event_wait_list and command_queue must be the same.


Returns an event object that identifies this particular kernel execution instance. Event objects are unique and can be used to identify a particular kernel execution instance later on. If event is NULL, no event will be created for this kernel execution instance and therefore it will not be possible for the application to query or queue a wait for this particular kernel execution instance.


The kernel is executed using a single work-item.

clEnqueueTask is equivalent to calling clEnqueueNDRangeKernel with work_dim = 1, global_work_offset = NULL, global_work_size[0] set to 1, and local_work_size[0] set to 1.


Returns CL_SUCCESS if the kernel execution was successfully queued, or one of the errors below:

  • CL_INVALID_PROGRAM_EXECUTABLE if there is no successfully built program executable available for device associated with command_queue.
  • CL_INVALID_COMMAND_QUEUE if command_queue is not a valid command-queue.
  • CL_INVALID_KERNEL if kernel is not a valid kernel object.
  • CL_INVALID_CONTEXT if context associated with command_queue and kernel is not the same or if the context associated with command_queue and events in event_wait_list are not the same.
  • CL_INVALID_KERNEL_ARGS if the kernel argument values have not been specified.
  • CL_INVALID_WORK_GROUP_SIZE if a work-group size is specified for kernel using the __attribute__((reqd_work_group_size(X, Y, Z))) qualifier in program source and is not (1, 1, 1).
  • CL_MISALIGNED_SUB_BUFFER_OFFSET if a sub-buffer object is specified as the value for an argument that is a buffer object and the offset specified when the sub-buffer object is created is not aligned to CL_DEVICE_MEM_BASE_ADDR_ALIGN value for device associated with queue.
  • CL_INVALID_IMAGE_SIZE if an image object is specified as an argument value and the image dimensions (image width, height, specified or compute row and/or slice pitch) are not supported by device associated with queue.
  • CL_OUT_OF_RESOURCES if there is a failure to queue the execution instance of kernel on the command-queue because of insufficient resources needed to execute the kernel.
  • CL_OUT_OF_RESOURCES if there is a failure to allocate resources required by the OpenCL implementation on the device.
  • CL_MEM_OBJECT_ALLOCATION_FAILURE if there is a failure to allocate memory for data store associated with image or buffer objects specified as arguments to kernel.
  • CL_INVALID_EVENT_WAIT_LIST if event_wait_list is NULL and num_events_in_wait_list is greater than 0, or event_wait_list is not NULL and num_events_in_wait_list is 0, or if event objects in event_wait_list are not valid events.
  • CL_OUT_OF_HOST_MEMORY if there is a failure to allocate resources required by the OpenCL implementation on the host.


OpenCL Specification

Also see

clEnqueueNDRangeKernel, clEnqueueNativeKernel

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