improve issue that libusb_device instance leaked

libuvccamera/src/main/jni/libusb/libusb/core.c

@@ -1071,11 +1071,13 @@ int API_EXPORTED libusb_get_max_iso_packet_size(libusb_device *dev,
 DEFAULT_VISIBILITY
 libusb_device * LIBUSB_CALL libusb_ref_device(libusb_device *dev) {
 
+	int refcnt;
 	usbi_mutex_lock(&dev->lock);
 	{
-		dev->refcnt++;
+		refcnt = ++dev->refcnt;
 	}
 	usbi_mutex_unlock(&dev->lock);
+//	LOGI("refcnt=%d", refcnt);
 	return dev;
 }
 
@@ -1096,6 +1098,7 @@ void API_EXPORTED libusb_unref_device(libusb_device *dev) {
 		refcnt = --dev->refcnt;
 	}
 	usbi_mutex_unlock(&dev->lock);
+//	LOGI("refcnt=%d", dev->refcnt);
 
 	if (refcnt == 0) {
 		usbi_dbg("destroy device %d.%d", dev->bus_number, dev->device_address);
@@ -1249,9 +1252,11 @@ libusb_device * LIBUSB_CALL libusb_get_device_with_fd(libusb_context *ctx,
 	ENTER();
 
 	struct libusb_device *device = NULL;
+	// android_generate_device内でusbi_alloc_deviceが呼ばれた時に参照カウンタは1
 	int ret = android_generate_device(ctx, &device, vid, pid, serial, fd, busnum, devaddr);
-	if (LIKELY(!ret)) {
-		libusb_ref_device(device);	// これいるんかな? usbi_alloc_device内で既に呼ばれとるんやけど
+	if (ret) {
+		LOGD("android_generate_device failed:err=%d", ret);
+		device = NULL;
 	}
 
 	RET(device);

libuvccamera/src/main/jni/libusb/libusb/os/android_usbfs.c

@@ -1300,7 +1300,6 @@ static int android_initialize_device(struct libusb_device *dev,
 	struct android_device_priv *priv = _device_priv(dev);
 	struct libusb_context *ctx = DEVICE_CTX(dev);
 	uint8_t desc[4096]; // max descriptor size is 4096 bytes
-	int descriptors_size = 512; /* Begin with a 1024 byte alloc */
 	int speed;
 	ssize_t r;
 
@@ -1310,15 +1309,15 @@ static int android_initialize_device(struct libusb_device *dev,
 	LOGD("cache descriptors in memory");
 
 	priv->descriptors_len = 0;
+	priv->fd = 0;
 	memset(desc, 0, sizeof(desc));
     if (!lseek(fd, 0, SEEK_SET)) {
         // ディスクリプタを読み込んでローカルキャッシュする
         int length = read(fd, desc, sizeof(desc));
         LOGD("Device::init read returned %d errno %d\n", length, errno);
 		if (length > 0) {
 			priv->fd = fd;
-			descriptors_size = length;
-			priv->descriptors = usbi_reallocf(priv->descriptors, descriptors_size);
+			priv->descriptors = usbi_reallocf(priv->descriptors, length);
 			if (UNLIKELY(!priv->descriptors)) {
 				RETURN(LIBUSB_ERROR_NO_MEM, int);
 			}
@@ -1389,7 +1388,7 @@ int android_generate_device(struct libusb_context *ctx, struct libusb_device **d
  	 * a session ID. */
 	session_id = busnum << 8 | devaddr;
  	LOGD("allocating new device for %d/%d (session %ld)", busnum, devaddr, session_id);
- 	*dev = usbi_alloc_device(ctx, session_id);
+ 	*dev = usbi_alloc_device(ctx, session_id);	// この時点で参照カウンタ=1
  	if (UNLIKELY(!dev)) {
  		RETURN(LIBUSB_ERROR_NO_MEM, int);
  	}
@@ -1407,7 +1406,8 @@ int android_generate_device(struct libusb_context *ctx, struct libusb_device **d
 
 out:
  	if (UNLIKELY(r < 0)) {
- 		libusb_unref_device(*dev);
+ 		libusb_unref_device(*dev);	// ここで参照カウンタが0になって破棄される
+ 		*dev = NULL;
  	} else {
  		usbi_connect_device(*dev);
  	}

libuvccamera/src/main/jni/libuvc/android/jni/Android.mk

@@ -74,7 +74,7 @@ LOCAL_MODULE := libuvc_static
 include $(BUILD_STATIC_LIBRARY)
 
 ######################################################################
-# libuvc.so (shared library with static link to libjpeg-turbo)
+# libuvc.so
 ######################################################################
 include $(CLEAR_VARS)
 LOCAL_MODULE_TAGS := optional

libuvccamera/src/main/jni/libuvc/src/device.c

@@ -228,7 +228,7 @@ uvc_error_t uvc_get_device_with_fd(uvc_context_t *ctx, uvc_device_t **device,
 	LOGD("call libusb_get_device_with_fd");
 	struct libusb_device *usb_dev = libusb_get_device_with_fd(ctx->usb_ctx, vid, pid, serial, fd, busnum, devaddr);
 
-	if (usb_dev) {
+	if (LIKELY(usb_dev)) {
 		*device = malloc(sizeof(uvc_device_t/* *device */));
 		(*device)->ctx = ctx;
 		(*device)->ref = 0;
@@ -240,9 +240,9 @@ uvc_error_t uvc_get_device_with_fd(uvc_context_t *ctx, uvc_device_t **device,
 	} else {
 		LOGE("could not find specific device");
 		*device = NULL;
+		RETURN(UVC_ERROR_NO_DEVICE, int);
 	}
 
-	RETURN(UVC_ERROR_NO_DEVICE, int);
 }
 
 /** @brief Get the number of the bus to which the device is attached
@@ -791,7 +791,8 @@ const uvc_extension_unit_t *uvc_get_extension_units(uvc_device_handle_t *devh) {
 void uvc_ref_device(uvc_device_t *dev) {
 	UVC_ENTER();
 
-	dev->ref++;
+	dev->ref++;	// これ排他制御要るんちゃうかなぁ(｡･_･｡)
+//	LOGI("ref=%d", dev->ref);
 	libusb_ref_device(dev->usb_dev);
 
 	UVC_EXIT_VOID();
@@ -808,8 +809,9 @@ void uvc_unref_device(uvc_device_t *dev) {
 	UVC_ENTER();
 
 	libusb_unref_device(dev->usb_dev);
-	dev->ref--;
+	dev->ref--;	// これ排他制御要るんちゃうかなぁ(｡･_･｡)
 
+//	LOGI("ref=%d", dev->ref);
 	if (dev->ref == 0) {
 		free(dev);
 		dev = NULL;