From a805519ceedc53afa5453a6d8a7d80038d885d9f Mon Sep 17 00:00:00 2001 From: Mike Lockwood Date: Mon, 19 Jul 2010 20:15:15 -0400 Subject: libusbhost: Add callback to usb_host_run to notify when initial device discovery is done This can be used to eliminate race conditions in clients that operate immediately on the currently connected device list. Signed-off-by: Mike Lockwood Change-Id: I14954b9fcc84239950ead6bdc1a0a888882c2226 --- include/usbhost/usbhost.h | 8 ++++++++ libusbhost/usbhost.c | 3 +++ 2 files changed, 11 insertions(+) diff --git a/include/usbhost/usbhost.h b/include/usbhost/usbhost.h index c6a443c..7432277 100644 --- a/include/usbhost/usbhost.h +++ b/include/usbhost/usbhost.h @@ -42,6 +42,11 @@ typedef int (* usb_device_added_cb)(const char *dev_name, void *client_data); */ typedef int (* usb_device_removed_cb)(const char *dev_name, void *client_data); +/* Callback indicating that initial device discovery is done. + * Return true to exit from usb_host_run. + */ +typedef int (* usb_discovery_done_cb)(void *client_data); + /* Call this to initialize the USB host library. */ struct usb_host_context *usb_host_init(void); @@ -54,10 +59,13 @@ void usb_host_cleanup(struct usb_host_context *context); * added_cb will be called immediately for each existing USB device, * and subsequently each time a new device is added. * removed_cb is called when USB devices are removed from the bus. + * discovery_done_cb is called after the initial discovery of already + * connected devices is complete. */ void usb_host_run(struct usb_host_context *context, usb_device_added_cb added_cb, usb_device_removed_cb removed_cb, + usb_discovery_done_cb discovery_done_cb, void *client_data); /* Creates a usb_device object for a USB device */ diff --git a/libusbhost/usbhost.c b/libusbhost/usbhost.c index efd3103..f5ec140 100644 --- a/libusbhost/usbhost.c +++ b/libusbhost/usbhost.c @@ -144,6 +144,7 @@ void usb_host_cleanup(struct usb_host_context *context) void usb_host_run(struct usb_host_context *context, usb_device_added_cb added_cb, usb_device_removed_cb removed_cb, + usb_discovery_done_cb discovery_done_cb, void *client_data) { struct inotify_event* event; @@ -174,6 +175,8 @@ void usb_host_run(struct usb_host_context *context, /* check for existing devices first, after we have inotify set up */ done = find_existing_devices(added_cb, removed_cb, client_data); + if (discovery_done_cb) + done |= discovery_done_cb(client_data); while (!done) { ret = read(context->fd, event_buf, sizeof(event_buf)); -- cgit v1.1