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)
Must be a valid host command-queue.
A valid memory (buffer or image) object. The OpenCL context associated with
memobjmust be the same.
Specify events that need to complete before
clEnqueueUnmapMemObjectcan be executed. If
event_wait_listis NULL, then
clEnqueueUnmapMemObjectdoes not wait on any event to complete. If
num_events_in_wait_listmust be 0. If
event_wait_listis not NULL, the list of events pointed to by
event_wait_listmust be valid and
num_events_in_wait_listmust be greater than 0. The events specified in
event_wait_listact as synchronization points. The context associated with events in
command_queuemust be the same. The memory associated with
event_wait_listcan be reused or freed after the function returns.
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.
eventcan 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.
clEnqueueBarrierWithWaitListcan be used instead. If the
eventarguments are not NULL, the
eventargument should not refer to an element of the
clEnqueueMapImage increment the mapped count of the memory object.
The initial mapped count value of a memory object is zero.
Multiple calls to
clEnqueueMapImage on the same memory object will increment this mapped count by appropriate number of calls.
clEnqueueUnmapMemObject decrements the mapped count of the memory object.
This section describes the behavior of OpenCL commands that access mapped regions of a memory object.
The contents of the region of a memory object and associated memory objects (sub-buffer objects or 1D image buffer objects that overlap this region) mapped for writing (i.e.
CL_MAP_WRITE_INVALIDATE_REGION is set in
map_flags argument to
clEnqueueMapImage) are considered to be undefined until this region is unmapped.
Multiple commands in command-queues can map a region or overlapping regions of a memory object and associated memory objects (sub-buffer objects or 1D image buffer objects that overlap this region) for reading (i.e.
The contents of the regions of a memory object mapped for reading can also be read by kernels and other OpenCL commands (such as
clEnqueueCopyBuffer) executing on a device(s).
Mapping (and unmapping) overlapped regions in a memory object and/or associated memory objects (sub-buffer objects or 1D image buffer objects that overlap this region) for writing is an error and will result in
CL_INVALID_OPERATION error returned by
If a memory object is currently mapped for writing, the application must ensure that the memory object is unmapped before any enqueued kernels or commands that read from or write to this memory object or any of its associated memory objects (sub-buffer or 1D image buffer objects) or its parent object (if the memory object is a sub-buffer or 1D image buffer object) begin execution; otherwise the behavior is undefined.
If a memory object is currently mapped for reading, the application must ensure that the memory object is unmapped before any enqueued kernels or commands that write to this memory object or any of its associated memory objects (sub-buffer or 1D image buffer objects) or its parent object (if the memory object is a sub-buffer or 1D image buffer object) begin execution; otherwise the behavior is undefined.
A memory object is considered as mapped if there are one or more active mappings for the memory object irrespective of whether the mapped regions span the entire memory object.
Accessing the contents of the memory region referred to by the mapped pointer that has been unmapped is undefined.
CL_SUCCESS if the function is executed successfully.
Otherwise, it returns one of the following errors:.
command_queueis not a valid host command-queue.
memobjis not a valid memory object or is a pipe object.
event_wait_listis NULL and
num_events_in_wait_list> 0, or
event_wait_listis not NULL and
num_events_in_wait_listis 0, or if event objects in
event_wait_listare not valid events.
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.
CL_INVALID_CONTEXTif the context associated with
memobjare not the same or if the context associated with
command_queueand events in
event_wait_listare not the same.