windows: hotplug implementation

sonatique · Feb 4, 2024 · 88583d5 · 88583d5
1 parent e8a3b16
commit 88583d5
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Showing 11 changed files with 393 additions and 44 deletions.
diff --git a/libusb/Makefile.am b/libusb/Makefile.am
@@ -28,7 +28,8 @@ OS_SUNOS_SRC = os/sunos_usb.h os/sunos_usb.c
 OS_WINDOWS_SRC = libusb-1.0.def libusb-1.0.rc \
 		 os/windows_common.h os/windows_common.c \
 		 os/windows_usbdk.h os/windows_usbdk.c \
-		 os/windows_winusb.h os/windows_winusb.c
+		 os/windows_winusb.h os/windows_winusb.c \
+		 os/windows_hotplug.h os/windows_hotplug.c
 
 if OS_DARWIN
 OS_SRC = $(OS_DARWIN_SRC)

diff --git a/libusb/core.c b/libusb/core.c
@@ -728,20 +728,24 @@ struct libusb_device *usbi_alloc_device(struct libusb_context *ctx,
 	return dev;
 }
 
-void usbi_connect_device(struct libusb_device *dev)
+void usbi_attach_device(struct libusb_device *dev)
 {
 	struct libusb_context *ctx = DEVICE_CTX(dev);
 
 	usbi_atomic_store(&dev->attached, 1);
 
-	usbi_mutex_lock(&dev->ctx->usb_devs_lock);
-	list_add(&dev->list, &dev->ctx->usb_devs);
-	usbi_mutex_unlock(&dev->ctx->usb_devs_lock);
+	usbi_mutex_lock(&ctx->usb_devs_lock);
+	list_add(&dev->list, &ctx->usb_devs);
+	usbi_mutex_unlock(&ctx->usb_devs_lock);
+}
 
-	usbi_hotplug_notification(ctx, dev, LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED);
+void usbi_connect_device(struct libusb_device *dev)
+{
+	usbi_attach_device(dev);
+	usbi_hotplug_notification(DEVICE_CTX(dev), dev, LIBUSB_HOTPLUG_EVENT_DEVICE_ARRIVED);
 }
 
-void usbi_disconnect_device(struct libusb_device *dev)
+void usbi_detach_device(struct libusb_device *dev)
 {
 	struct libusb_context *ctx = DEVICE_CTX(dev);
 
@@ -750,8 +754,12 @@ void usbi_disconnect_device(struct libusb_device *dev)
 	usbi_mutex_lock(&ctx->usb_devs_lock);
 	list_del(&dev->list);
 	usbi_mutex_unlock(&ctx->usb_devs_lock);
+}
 
-	usbi_hotplug_notification(ctx, dev, LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT);
+void usbi_disconnect_device(struct libusb_device *dev)
+{
+	usbi_detach_device(dev);
+	usbi_hotplug_notification(DEVICE_CTX(dev), dev, LIBUSB_HOTPLUG_EVENT_DEVICE_LEFT);
 }
 
 /* Perform some final sanity checks on a newly discovered device. If this

diff --git a/libusb/libusbi.h b/libusb/libusbi.h
@@ -809,6 +809,9 @@ int usbi_handle_transfer_completion(struct usbi_transfer *itransfer,
 int usbi_handle_transfer_cancellation(struct usbi_transfer *itransfer);
 void usbi_signal_transfer_completion(struct usbi_transfer *itransfer);
 
+void usbi_attach_device(struct libusb_device *dev);
+void usbi_detach_device(struct libusb_device *dev);
+
 void usbi_connect_device(struct libusb_device *dev);
 void usbi_disconnect_device(struct libusb_device *dev);
 

diff --git a/libusb/os/windows_common.c b/libusb/os/windows_common.c
@@ -28,6 +28,7 @@
 
 #include "libusbi.h"
 #include "windows_common.h"
+#include "windows_hotplug.h"
 
 #define EPOCH_TIME	UINT64_C(116444736000000000)	// 1970.01.01 00:00:000 in MS Filetime
 
@@ -565,6 +566,20 @@ static int windows_init(struct libusb_context *ctx)
 
 	r = LIBUSB_SUCCESS;
 
+	if (init_count == 1) {
+		r = windows_start_event_monitor();
+	}
+	if (r != LIBUSB_SUCCESS) {
+		usbi_err(ctx, "error starting hotplug event monitor");
+
+		if (init_count == 1) {
+			windows_stop_event_monitor();
+		}
+		goto init_exit;
+	}
+
+	windows_initial_scan_devices(ctx);
+
 init_exit: // Holds semaphore here
 	if ((init_count == 1) && (r != LIBUSB_SUCCESS)) { // First init failed?
 		if (usbdk_available) {
@@ -596,6 +611,7 @@ static void windows_exit(struct libusb_context *ctx)
 
 	// Only works if exits and inits are balanced exactly
 	if (--init_count == 0) { // Last exit
+		windows_stop_event_monitor();
 		if (usbdk_available) {
 			usbdk_backend.exit(ctx);
 			usbdk_available = false;
@@ -624,12 +640,6 @@ static int windows_set_option(struct libusb_context *ctx, enum libusb_option opt
 	return LIBUSB_ERROR_NOT_SUPPORTED;
 }
 
-static int windows_get_device_list(struct libusb_context *ctx, struct discovered_devs **discdevs)
-{
-	struct windows_context_priv *priv = usbi_get_context_priv(ctx);
-	return priv->backend->get_device_list(ctx, discdevs);
-}
-
 static int windows_open(struct libusb_device_handle *dev_handle)
 {
 	struct windows_context_priv *priv = usbi_get_context_priv(HANDLE_CTX(dev_handle));
@@ -888,7 +898,7 @@ const struct usbi_os_backend usbi_backend = {
 	windows_init,
 	windows_exit,
 	windows_set_option,
-	windows_get_device_list,
+	NULL, /* get_device_list */
 	NULL,	/* hotplug_poll */
 	NULL,	/* wrap_sys_device */
 	windows_open,

diff --git a/libusb/os/windows_common.h b/libusb/os/windows_common.h
@@ -232,12 +232,29 @@ typedef struct USB_DK_TRANSFER_REQUEST {
 	USB_DK_TRANSFER_RESULT Result;
 } USB_DK_TRANSFER_REQUEST, *PUSB_DK_TRANSFER_REQUEST;
 
+/* track devices that are removed, kept unchanged, or added when updating device list
+ * using system enumeration, in response to low-level hotplug related events */
+ enum enumeration_status {
+	/* device is no longer present in system enumeration.
+	 * A hotplug "device left" event shall be triggered and the device removed from the list */
+	NO_LONGER_ENUMERATED,
+
+	/* device is still in system enumeration as it was in previous enumeration.
+	 * There is no need to take any action */
+	STILL_ENUMERATED,
+
+ 	/* device is newly added to the list, meaning it just appeared in system enumeration.
+ 	 * A hotplug "device arrived" event shall be triggered */
+	NEWLY_ENUMERATED
+};
+
 struct usbdk_device_priv {
 	USB_DK_DEVICE_ID ID;
 	PUSB_CONFIGURATION_DESCRIPTOR *config_descriptors;
 	HANDLE redirector_handle;
 	HANDLE system_handle;
 	uint8_t active_configuration;
+	enum enumeration_status discovery_status; /* updated while getting current device list */
 };
 
 struct winusb_device_priv {
@@ -269,6 +286,7 @@ struct winusb_device_priv {
 	struct hid_device_priv *hid;
 	PUSB_CONFIGURATION_DESCRIPTOR *config_descriptor; // list of pointers to the cached config descriptors
 	GUID class_guid; // checked for change during re-enumeration
+	enum enumeration_status discovery_status;
 };
 
 struct usbdk_device_handle_priv {
@@ -318,8 +336,7 @@ struct winusb_transfer_priv {
 struct windows_backend {
 	int (*init)(struct libusb_context *ctx);
 	void (*exit)(struct libusb_context *ctx);
-	int (*get_device_list)(struct libusb_context *ctx,
-		struct discovered_devs **discdevs);
+	int (*get_device_list)(struct libusb_context *ctx);
 	int (*open)(struct libusb_device_handle *dev_handle);
 	void (*close)(struct libusb_device_handle *dev_handle);
 	int (*get_active_config_descriptor)(struct libusb_device *device,