context.go

package cl

/*
#include "cl.h"

// this needs to come out
typedef void*	pVoid;
extern void	go_ctx_notify(char *errinfo, void *private_info, int cb,
		    void *user_data);

static void CL_CALLBACK	c_ctx_notify(const char *errinfo,
			    const void *private_info, size_t cb,
			    void *user_data)
{
	go_ctx_notify((char *)errinfo, (void *)private_info, cb, user_data);
}

static pVoid
*allocArray(size_t n)
{
	return (pVoid*)malloc(n * sizeof(pVoid));
}

static void
freeArray(pVoid* p)
{
	free(p);
}

static cl_context
CLCreateContext(const cl_context_properties *properties, cl_uint num_devices,
    const cl_device_id *devices, void *user_data, cl_int *errcode_ret)
{
	return clCreateContext(properties, num_devices, devices, c_ctx_notify,
	    user_data, errcode_ret);
}

static cl_context
CLCreateContextFromType(const cl_context_properties *properties,
    cl_device_type device_type, void *user_data, cl_int *errcode_ret)
{
	return clCreateContextFromType(properties, device_type, c_ctx_notify,
	    user_data, errcode_ret);
}

*/
import "C"
import "unsafe"

type CL_ctx_notify func(errinfo string, private_info unsafe.Pointer, cb int, user_data unsafe.Pointer)

var ctx_notify map[unsafe.Pointer]CL_ctx_notify

func init() {
	ctx_notify = make(map[unsafe.Pointer]CL_ctx_notify)
}

//export go_ctx_notify
func go_ctx_notify(errinfo *C.char, private_info unsafe.Pointer, cb C.int, user_data unsafe.Pointer) {
	var c_user_data []unsafe.Pointer
	c_user_data = *(*[]unsafe.Pointer)(user_data)
	ctx_notify[c_user_data[1]](C.GoString(errinfo), private_info, int(cb), c_user_data[0])
}

func CLCreateContext(properties []CL_context_properties,
	num_devices CL_uint,
	devices []CL_device_id,
	pfn_notify CL_ctx_notify,
	user_data unsafe.Pointer,
	errcode_ret *CL_int) CL_context {

	var c_errcode_ret C.cl_int
	var c_context C.cl_context

	if num_devices == 0 || devices == nil || (pfn_notify == nil && user_data != nil) {
		c_errcode_ret = CL_INVALID_VALUE
		c_context = nil
	} else {
		var c_properties []C.cl_context_properties
		var c_properties_ptr *C.cl_context_properties
		var c_devices []C.cl_device_id
		var c_devices_ptr *C.cl_device_id

		if properties != nil {
			c_properties = make([]C.cl_context_properties, len(properties))
			for i := 0; i < len(properties); i++ {
				c_properties[i] = C.cl_context_properties(properties[i])
			}
			c_properties_ptr = &c_properties[0]
		} else {
			c_properties_ptr = nil
		}

		if devices != nil {
			c_devices = make([]C.cl_device_id, len(devices))
			for i := 0; i < len(devices); i++ {
				c_devices[i] = C.cl_device_id(devices[i].cl_device_id)
			}
			c_devices_ptr = &c_devices[0]
		} else {
			c_devices_ptr = nil
		}

		if pfn_notify != nil {
			//var c_user_data []unsafe.Pointer
			//c_user_data = make([]unsafe.Pointer, 2)
			arr := C.allocArray(2)
			c_user_data := (*[2]C.pVoid)(unsafe.Pointer(arr))[:]
			c_user_data[0] = (C.pVoid)(user_data)
			c_user_data[1] = (C.pVoid)(unsafe.Pointer(&pfn_notify))

			ctx_notify[unsafe.Pointer(&pfn_notify)] = pfn_notify

			c_context = C.CLCreateContext(c_properties_ptr,
				C.cl_uint(len(c_devices)),
				c_devices_ptr,
				unsafe.Pointer(&c_user_data),
				&c_errcode_ret)

			C.freeArray(arr)
		} else {
			c_context = C.clCreateContext(c_properties_ptr,
				C.cl_uint(len(c_devices)),
				c_devices_ptr,
				nil,
				nil,
				&c_errcode_ret)

		}
	}

	if errcode_ret != nil {
		*errcode_ret = CL_int(c_errcode_ret)
	}

	return CL_context{c_context}
}

func CLCreateContextFromType(properties []CL_context_properties,
	device_type CL_device_type,
	pfn_notify CL_ctx_notify,
	user_data unsafe.Pointer,
	errcode_ret *CL_int) CL_context {

	var c_errcode_ret C.cl_int
	var c_context C.cl_context

	if pfn_notify == nil && user_data != nil {
		c_errcode_ret = CL_INVALID_VALUE
		c_context = nil
	} else {
		var c_properties []C.cl_context_properties
		var c_properties_ptr *C.cl_context_properties

		if properties != nil {
			c_properties = make([]C.cl_context_properties, len(properties))
			for i := 0; i < len(properties); i++ {
				c_properties[i] = C.cl_context_properties(properties[i])
			}
			c_properties_ptr = &c_properties[0]
		} else {
			c_properties_ptr = nil
		}

		if pfn_notify != nil {
			//var c_user_data []unsafe.Pointer
			//c_user_data = make([]unsafe.Pointer, 2)
			arr := C.allocArray(2)
			c_user_data := (*[2]C.pVoid)(unsafe.Pointer(arr))[:]
			c_user_data[0] = (C.pVoid)(user_data)
			c_user_data[1] = (C.pVoid)(unsafe.Pointer(&pfn_notify))

			ctx_notify[unsafe.Pointer(&pfn_notify)] = pfn_notify

			c_context = C.CLCreateContextFromType(c_properties_ptr,
				C.cl_device_type(device_type),
				unsafe.Pointer(&c_user_data),
				&c_errcode_ret)

			C.freeArray(arr)
		} else {
			c_context = C.clCreateContextFromType(c_properties_ptr,
				C.cl_device_type(device_type),
				nil,
				nil,
				&c_errcode_ret)
		}
	}

	if errcode_ret != nil {
		*errcode_ret = CL_int(c_errcode_ret)
	}

	return CL_context{c_context}
}

func CLGetContextInfo(context CL_context,
	param_name CL_context_info,
	param_value_size CL_size_t,
	param_value *interface{},
	param_value_size_ret *CL_size_t) CL_int {

	if (param_value_size == 0 || param_value == nil) && param_value_size_ret == nil {
		return CL_INVALID_VALUE
	} else {
		var c_param_value_size_ret C.size_t
		var c_errcode_ret C.cl_int

		if param_value_size == 0 || param_value == nil {
			c_errcode_ret = C.clGetContextInfo(context.cl_context,
				C.cl_context_info(param_name),
				C.size_t(param_value_size),
				nil,
				&c_param_value_size_ret)
		} else {
			switch param_name {
			case CL_CONTEXT_REFERENCE_COUNT,
				CL_CONTEXT_NUM_DEVICES:

				var value C.cl_uint
				c_errcode_ret = C.clGetContextInfo(context.cl_context,
					C.cl_context_info(param_name),
					C.size_t(param_value_size),
					unsafe.Pointer(&value),
					&c_param_value_size_ret)

				*param_value = CL_uint(value)

			case CL_CONTEXT_DEVICES:
				var param C.cl_device_id
				length := int(C.size_t(param_value_size) / C.size_t(unsafe.Sizeof(param)))

				value1 := make([]C.cl_device_id, length)
				value2 := make([]CL_device_id, length)

				c_errcode_ret = C.clGetContextInfo(context.cl_context,
					C.cl_context_info(param_name),
					C.size_t(param_value_size),
					unsafe.Pointer(&value1[0]),
					&c_param_value_size_ret)

				for i := 0; i < length; i++ {
					value2[i].cl_device_id = value1[i]
				}

				*param_value = value2

			default:
				return CL_INVALID_VALUE
			}
		}

		if param_value_size_ret != nil {
			*param_value_size_ret = CL_size_t(c_param_value_size_ret)
		}

		return CL_int(c_errcode_ret)
	}
}

func CLRetainContext(context CL_context) CL_int {
	return CL_int(C.clRetainContext(context.cl_context))
}

func CLReleaseContext(context CL_context) CL_int {
	return CL_int(C.clReleaseContext(context.cl_context))
}