Remove (*Config).Close()

lsusb/main.go

@@ -64,11 +64,6 @@ func main() {
 		// be set once the device is opened.  All configuration references must be closed,
 		// to free up the memory in libusb.
 		cfgs, err := dev.Configurations()
-		defer func() {
-			for _, cfg := range cfgs {
-				cfg.Close()
-			}
-		}()
 		if err != nil {
 			log.Printf("  - configs: %s", err)
 			continue

usb/config.go

@@ -7,7 +7,6 @@ import "C"
 import (
 	"fmt"
 	"reflect"
-	"runtime"
 	"unsafe"
 )
 
@@ -53,8 +52,6 @@ func (i InterfaceInfo) String() string {
 }
 
 type Config struct {
-	cfg *C.struct_libusb_config_descriptor
-
 	Type       DescriptorType
 	Config     uint8
 	Attributes uint8
@@ -68,7 +65,6 @@ func (c Config) String() string {
 
 func newConfig(cfg *C.struct_libusb_config_descriptor) *Config {
 	c := &Config{
-		cfg:        cfg,
 		Type:       DescriptorType(cfg.bDescriptorType),
 		Config:     uint8(cfg.bConfigurationValue),
 		Attributes: uint8(cfg.bmAttributes),
@@ -121,24 +117,5 @@ func newConfig(cfg *C.struct_libusb_config_descriptor) *Config {
 		}
 		c.Interfaces = append(c.Interfaces, descs)
 	}
-
-	// *sigh*
-	runtime.SetFinalizer(c, (*Config).Close)
-
-	//log.Printf("config %p initialized", c.cfg)
 	return c
 }
-
-// Close decrements the reference count for the device in the libusb driver
-// code.  It should be called exactly once!
-//
-// TODO(kevlar): This information can probably be cached at creation time
-// and then immediately closed.
-func (c *Config) Close() error {
-	if c.cfg != nil {
-		//log.Printf("config %p closed", c.cfg)
-		C.libusb_free_config_descriptor(c.cfg)
-	}
-	c.cfg = nil
-	return nil
-}

usb/descriptor.go

@@ -37,27 +37,20 @@ func newDescriptor(dev *C.libusb_device) (*Descriptor, error) {
 
 // Configurations returns a list of configurations configured on this
 // device.  Each config must be Closed.
-func (d *DeviceInfo) Configurations() (_c []*Config, _e error) {
+func (d *DeviceInfo) Configurations() ([]*Config, error) {
 	var desc C.struct_libusb_device_descriptor
 	if errno := C.libusb_get_device_descriptor(d.dev, &desc); errno < 0 {
 		return nil, usbError(errno)
 	}
 
 	var cfgs []*Config
-	defer func() {
-		if _e != nil {
-			for _, c := range cfgs {
-				c.Close()
-			}
-		}
-	}()
-
 	for i := 0; i < int(desc.bNumConfigurations); i++ {
 		var cfg *C.struct_libusb_config_descriptor
 		if errno := C.libusb_get_config_descriptor(d.dev, C.uint8_t(i), &cfg); errno < 0 {
 			return nil, usbError(errno)
 		}
 		cfgs = append(cfgs, newConfig(cfg))
+		C.libusb_free_config_descriptor(cfg)
 	}
 	return cfgs, nil
 }

usb/usb_test.go

@@ -49,11 +49,6 @@ func TestEnum(t *testing.T) {
 		t.Logf("- Protocol: %s", usbid.Classify(desc))
 
 		cfgs, err := dev.Configurations()
-		defer func() {
-			for _, cfg := range cfgs {
-				cfg.Close()
-			}
-		}()
 		if err != nil {
 			t.Errorf("  - configs: %s", err)
 			continue