clEnqueueUnmapMemObject - Enqueues a command to unmap a previously
mapped region of a memory object.
cl_int
clEnqueueUnmapMemObject(cl_command_queue command_queue,
cl_mem memobj, void *mapped_ptr,
cl_uint num_events_in_wait_list,
const cl_event *event_wait_list,
cl_event *event);
command_queue
Must be a valid command-queue.
memobj
A valid memory object. The OpenCL context associated with
command_queue and memobj must be the same.
mapped_ptr
The host address returned by a previous call to
clEnqueueMapBuffer(3clc) or clEnqueueMapImage(3clc) for
memobj.
event_wait_list , num_events_in_wait_list
Specify events that need to complete before
clEnqueueUnmapMemObject can be executed. If event_wait_list is
NULL, then clEnqueueUnmapMemObject 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. The memory
associated with event_wait_list can be reused or freed after the
function returns.
event
Returns an event object that identifies this particular
copy command and can be used to query or queue a wait for this particular
command to complete. event can be NULL in which case it will not be
possible for the application to query the status of this command or queue a
wait for this command to complete. clEnqueueBarrierWithWaitList(3clc)
can be used instead.
Reads or writes from the host using the pointer returned by
clEnqueueMapBuffer(3clc) or clEnqueueMapImage(3clc) are
considered to be complete.
clEnqueueMapBuffer(3clc) and clEnqueueMapImage(3clc)
increment the mapped count of the memory object. The initial mapped count
value of a memory object is zero. Multiple calls to
clEnqueueMapBuffer(3clc) or clEnqueueMapImage(3clc) on the
same memory object will increment this mapped count by appropriate number of
calls. clEnqueueUnmapMemObject decrements the mapped count of the
memory object.
clEnqueueMapBuffer(3clc) and clEnqueueMapImage(3clc)
act as synchronization points for a region of the buffer object being
mapped.
clEnqueueUnmapMemObject returns CL_SUCCESS if the function
is executed successfully. Otherwise, it returns one of the following
errors:.
•CL_INVALID_COMMAND_QUEUE if command_queue
is not a valid command-queue.
•CL_INVALID_MEM_OBJECT if memobj is not a
valid memory object.
•CL_INVALID_VALUE if mapped_ptr is not a
valid pointer returned by clEnqueueMapBuffer(3clc) or
clEnqueueMapImage(3clc) for memobj.
•CL_INVALID_EVENT_WAIT_LIST if
event_wait_list is NULL and num_events_in_wait_list > 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_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.
•CL_INVALID_CONTEXT if the context associated with
command_queue and memobj are not the same or if the context
associated with command_queue and events in event_wait_list are
not the same.
clEnqueueMapBuffer(3clc),
clEnqueueMapImage(3clc)
Copyright © 2007-2011 The Khronos Group Inc.
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and/or associated documentation files (the
"Materials"), to deal in the Materials without restriction,
including without limitation the rights to use, copy, modify, merge,
publish, distribute, sublicense, and/or sell copies of the Materials, and to
permit persons to whom the Materials are furnished to do so, subject to the
condition that this copyright notice and permission notice shall be included
in all copies or substantial portions of the Materials.
- 1.
- OpenCL Specification
page 120, section 5.4.2 - Unmapping Mapped Memory
Objects