context.go

package opencl

/*
#ifdef __APPLE__
#include <OpenCL/opencl.h>
#else
#include <CL/cl.h>
#endif

#include <stdlib.h>

extern void contextCallback(char *, void *, size_t, void *);
*/
import "C"
import (
	"fmt"
	"unsafe"
)

type Context struct {
	context  *C.cl_context
	callback func(string, unsafe.Pointer, uintptr, interface{})
	userdata interface{}
	devices  []*Device
}

type ContextProperties struct {
}

//export contextCallback
func contextCallback(errinfo *C.char, private_info unsafe.Pointer, cb C.size_t, user_data unsafe.Pointer) {
	context := *(*Context)(user_data)
	context.callback(C.GoString(errinfo), private_info, uintptr(cb), context.userdata)
}

func CreateContext(properties *ContextProperties, devices []*Device, notify func(string, unsafe.Pointer, uintptr, interface{}), userdata interface{}) (*Context, error) {
	context := Context{nil, notify, userdata, devices}
	context.context = (*C.cl_context)(C.malloc(C.sizeof_cl_context))

	ids := asCLDeviceIDs(devices)

	var callback *[0]byte
	var user unsafe.Pointer
	if notify != nil {
		callback = (*[0]byte)(unsafe.Pointer(C.contextCallback))
		user = unsafe.Pointer(&context)
	}

	var err C.cl_int
	*context.context = C.clCreateContext(nil, C.cl_uint(len(ids)), &ids[0], callback, user, &err)
	if err != C.CL_SUCCESS {
		C.free(unsafe.Pointer(context.context))
		return nil, fmt.Errorf("Error creating context: %d", err)
	}
	return &context, nil
}

func (c Context) Release() error {
	err := C.clReleaseContext(*c.context)
	if err != C.CL_SUCCESS {
		return fmt.Errorf("Error releasing context: %d", err)
	}
	C.free(unsafe.Pointer(c.context))
	return nil
}

func (c Context) Devices() []*Device {
	return c.devices
}

func (c Context) CreateCommandQueue(device Device, properties *CommandQueueProperties) (*CommandQueue, error) {
	return createCommandQueue(c, device, properties)
}

func (c Context) CreateBuffer(flags MemoryFlags, size uintptr, hostPtr unsafe.Pointer) (*Memory, error) {
	return createBuffer(c, flags, size, hostPtr)
}

func (c Context) CreateProgramWithSource(source []string) (*Program, error) {
	clSource := make([]*C.char, len(source))
	for i, s := range source {
		clSource[i] = C.CString(s)
		defer C.free(unsafe.Pointer(clSource[i]))
	}
	var clSourcePtr **C.char
	if len(source) > 0 {
		clSourcePtr = &clSource[0]
	}
	var err C.cl_int
	var program Program
	program.program = (*C.cl_program)(C.malloc(C.sizeof_cl_program))
	*program.program = C.clCreateProgramWithSource(*c.context, C.cl_uint(len(source)), clSourcePtr, nil, &err)
	if err != C.CL_SUCCESS {
		C.free(unsafe.Pointer(program.program))
		return nil, fmt.Errorf("failed to create program: %d", err)
	}
	return &program, nil
}