Enable enumeration of devices

cmd/go-opencl-info/main.go

@@ -41,5 +41,14 @@ func main() {
 		log.Printf("  Profile: %s", profile)
 		log.Printf("  Version: %s", version)
 		log.Printf("  Extensions: %s", strings.Join(extensions, ", "))
+
+		devices, err := p.Devices(opencl.DeviceTypeAll)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		for i := range devices {
+			log.Printf("  Device %d", i)
+		}
 	}
 }

device.go

+package opencl
+
+/*
+#ifdef __APPLE__
+#include <OpenCL/opencl.h>
+#else
+#include <CL/cl.h>
+#endif
+*/
+import "C"
+import (
+	"fmt"
+	"unsafe"
+)
+
+type Device struct {
+	id C.cl_device_id
+}
+
+type DeviceType C.cl_device_type
+
+const (
+	DeviceTypeCPU         = DeviceType(C.CL_DEVICE_TYPE_CPU)
+	DeviceTypeGPU         = DeviceType(C.CL_DEVICE_TYPE_GPU)
+	DeviceTypeAccelerator = DeviceType(C.CL_DEVICE_TYPE_ACCELERATOR)
+	DeviceTypeCustom      = DeviceType(C.CL_DEVICE_TYPE_CUSTOM)
+	DeviceTypeDefault     = DeviceType(C.CL_DEVICE_TYPE_DEFAULT)
+	DeviceTypeAll         = DeviceType(C.CL_DEVICE_TYPE_ALL)
+)
+
+func (t DeviceType) String() string {
+	switch t {
+	case DeviceTypeCPU:
+		return "CPU"
+	case DeviceTypeGPU:
+		return "GPU"
+	case DeviceTypeAccelerator:
+		return "accelereator"
+	case DeviceTypeCustom:
+		return "custom"
+	case DeviceTypeDefault:
+		return "default"
+	case DeviceTypeAll:
+		return "all"
+	}
+	return fmt.Sprintf("unknown type %d", t)
+}
+
+func getDevices(platform Platform, deviceType DeviceType) ([]Device, error) {
+	var n C.cl_uint
+	if err := C.clGetDeviceIDs(platform.id, C.cl_device_type(deviceType), 0, nil, &n); err != C.CL_SUCCESS {
+		return nil, fmt.Errorf("error getting number of devices: %d", err)
+	}
+
+	ids := make([]C.cl_device_id, n)
+	if err := C.clGetDeviceIDs(platform.id, C.cl_device_type(deviceType), n, unsafe.Pointer(&ids[0]), nil); err != C.CL_SUCCESS {
+		return nil, fmt.Errorf("error getting devices: %d", err)
+	}
+
+	devices := make([]Device, n)
+	for i, id := range ids {
+		devices[i].id = id
+	}
+
+	return devices, nil
+}

platform.go

@@ -8,7 +8,9 @@ package opencl
 #endif
 */
 import "C"
-import "fmt"
+import (
+	"fmt"
+)
 
 type Platform struct {
 	id C.cl_platform_id
@@ -32,3 +34,7 @@ func GetPlatforms() ([]Platform, error) {
 
 	return platforms, nil
 }
+
+func (p Platform) Devices(deviceType DeviceType) ([]Device, error) {
+	return getDevices(p, deviceType)
+}