func (this *command_queue) EnqueueCopyBuffer(src_buffer Buffer,
dst_buffer Buffer,
src_offset cl.CL_size_t,
dst_offset cl.CL_size_t,
cb cl.CL_size_t,
event_wait_list []Event) (Event, error) {
var errCode cl.CL_int
var event_id cl.CL_event
numEvents := cl.CL_uint(len(event_wait_list))
events := make([]cl.CL_event, numEvents)
for i := cl.CL_uint(0); i < numEvents; i++ {
events[i] = event_wait_list[i].GetID()
}
if errCode = cl.CLEnqueueCopyBuffer(this.command_queue_id,
src_buffer.GetID(),
dst_buffer.GetID(),
src_offset,
dst_offset,
cb,
numEvents,
events,
&event_id); errCode != cl.CL_SUCCESS {
return nil, fmt.Errorf("EnqueueCopyBuffer failure with errcode_ret %d: %s", errCode, cl.ERROR_CODES_STRINGS[-errCode])
} else {
return &event{event_id}, nil
}
}
func main() {
/* OpenCL data structures */
var device []cl.CL_device_id
var context cl.CL_context
var queue cl.CL_command_queue
var program *cl.CL_program
var kernel cl.CL_kernel
var err cl.CL_int
/* Data and buffers */
var data_one, data_two, result_array [100]float32
var buffer_one, buffer_two cl.CL_mem
var mapped_memory unsafe.Pointer
/* Initialize arrays */
for i := 0; i < 100; i++ {
data_one[i] = 1.0 * float32(i)
data_two[i] = -1.0 * float32(i)
result_array[i] = 0.0
}
/* Create a device and context */
device = utils.Create_device()
context = cl.CLCreateContext(nil, 1, device[:], nil, nil, &err)
if err < 0 {
println("Couldn't create a context")
return
}
/* Build the program and create the kernel */
program = utils.Build_program(context, device[:], PROGRAM_FILE, nil)
kernel = cl.CLCreateKernel(*program, []byte(KERNEL_FUNC), &err)
if err < 0 {
println("Couldn't create a kernel")
return
}
/* Create buffers */
buffer_one = cl.CLCreateBuffer(context, cl.CL_MEM_READ_WRITE|
cl.CL_MEM_COPY_HOST_PTR, cl.CL_size_t(unsafe.Sizeof(data_one)), unsafe.Pointer(&data_one[0]), &err)
if err < 0 {
println("Couldn't create buffer object 1")
return
}
buffer_two = cl.CLCreateBuffer(context, cl.CL_MEM_READ_WRITE|
cl.CL_MEM_COPY_HOST_PTR, cl.CL_size_t(unsafe.Sizeof(data_two)), unsafe.Pointer(&data_two), &err)
if err < 0 {
println("Couldn't create buffer object 2")
return
}
/* Set buffers as arguments to the kernel */
err = cl.CLSetKernelArg(kernel, 0, cl.CL_size_t(unsafe.Sizeof(buffer_one)), unsafe.Pointer(&buffer_one))
err |= cl.CLSetKernelArg(kernel, 1, cl.CL_size_t(unsafe.Sizeof(buffer_two)), unsafe.Pointer(&buffer_two))
if err < 0 {
println("Couldn't set the buffer as the kernel argument")
return
}
/* Create a command queue */
queue = cl.CLCreateCommandQueue(context, device[0], 0, &err)
if err < 0 {
println("Couldn't create a command queue")
return
}
/* Enqueue kernel */
err = cl.CLEnqueueTask(queue, kernel, 0, nil, nil)
if err < 0 {
println("Couldn't enqueue the kernel")
return
}
/* Enqueue command to copy buffer one to buffer two */
err = cl.CLEnqueueCopyBuffer(queue, buffer_one, buffer_two, 0, 0,
cl.CL_size_t(unsafe.Sizeof(data_one)), 0, nil, nil)
if err < 0 {
println("Couldn't perform the buffer copy")
return
}
/* Enqueue command to map buffer two to host memory */
mapped_memory = cl.CLEnqueueMapBuffer(queue, buffer_two, cl.CL_TRUE,
cl.CL_MAP_READ, 0, cl.CL_size_t(unsafe.Sizeof(data_two)), 0, nil, nil, &err)
if err < 0 {
println("Couldn't map the buffer to host memory")
return
}
/* Transfer memory and unmap the buffer */
C.memcpy(unsafe.Pointer(&result_array[0]), mapped_memory, C.size_t(unsafe.Sizeof(data_two)))
err = cl.CLEnqueueUnmapMemObject(queue, buffer_two, mapped_memory,
0, nil, nil)
if err < 0 {
println("Couldn't unmap the buffer")
return
}
/* Display updated buffer */
for i := 0; i < 10; i++ {
for j := 0; j < 10; j++ {
fmt.Printf("%6.1f", result_array[j+i*10])
}
fmt.Printf("\n")
}
/* Deallocate resources */
cl.CLReleaseMemObject(buffer_one)
cl.CLReleaseMemObject(buffer_two)
cl.CLReleaseKernel(kernel)
cl.CLReleaseCommandQueue(queue)
cl.CLReleaseProgram(*program)
cl.CLReleaseContext(context)
}
