libusbhost: The client is now responsible for creating the thread that monitors the bus
This is to allow using a thread that is capable of calling through JNI to Java code
to report USB device attached/removed events.
Change-Id: Ia58592607a2c1f4357b31072044f5db5617d7f5b
Signed-off-by: Mike Lockwood <lockwood@android.com>
diff --git a/libusbhost/usbhost.c b/libusbhost/usbhost.c
index 1d83a39..efd3103 100644
--- a/libusbhost/usbhost.c
+++ b/libusbhost/usbhost.c
@@ -60,9 +60,7 @@
struct usb_host_context {
- usb_device_added_cb added_cb;
- usb_device_removed_cb removed_cb;
- void *client_data;
+ int fd;
};
struct usb_device {
@@ -88,73 +86,97 @@
return 0;
}
-static void find_existing_devices(struct usb_host_context *context)
+/* returns true if one of the callbacks indicates we are done */
+static int find_existing_devices(usb_device_added_cb added_cb,
+ usb_device_removed_cb removed_cb,
+ void *client_data)
{
char busname[32], devname[32];
DIR *busdir , *devdir ;
struct dirent *de;
+ int done = 0;
busdir = opendir(USB_FS_DIR);
- if(busdir == 0) return;
+ if(busdir == 0) return 1;
- while((de = readdir(busdir)) != 0) {
+ while ((de = readdir(busdir)) != 0 && !done) {
if(badname(de->d_name)) continue;
snprintf(busname, sizeof busname, "%s/%s", USB_FS_DIR, de->d_name);
devdir = opendir(busname);
if(devdir == 0) continue;
- while((de = readdir(devdir))) {
+ while ((de = readdir(devdir)) && !done) {
if(badname(de->d_name)) continue;
snprintf(devname, sizeof devname, "%s/%s", busname, de->d_name);
- context->added_cb(devname, context->client_data);
+ done = added_cb(devname, client_data);
} // end of devdir while
closedir(devdir);
} //end of busdir while
closedir(busdir);
+
+ return done;
}
-static void* device_discovery_thread(void *client_data)
+struct usb_host_context *usb_host_init()
{
- struct usb_host_context *context = (struct usb_host_context *)client_data;
+ struct usb_host_context *context = calloc(1, sizeof(struct usb_host_context));
+ if (!context) {
+ fprintf(stderr, "out of memory in usb_host_context\n");
+ return NULL;
+ }
+ context->fd = inotify_init();
+ if (context->fd < 0) {
+ fprintf(stderr, "inotify_init failed\n");
+ free(context);
+ return NULL;
+ }
+ return context;
+}
+
+void usb_host_cleanup(struct usb_host_context *context)
+{
+ close(context->fd);
+ free(context);
+}
+
+void usb_host_run(struct usb_host_context *context,
+ usb_device_added_cb added_cb,
+ usb_device_removed_cb removed_cb,
+ void *client_data)
+{
struct inotify_event* event;
char event_buf[512];
char path[100];
- int i, fd, ret;
+ int i, ret, done = 0;
int wd, wds[10];
int wd_count = sizeof(wds) / sizeof(wds[0]);
D("Created device discovery thread\n");
- fd = inotify_init();
- if (fd < 0) {
- fprintf(stderr, "inotify_init failed\n");
- return NULL;
- }
-
/* watch for files added and deleted within USB_FS_DIR */
memset(wds, 0, sizeof(wds));
/* watch the root for new subdirectories */
- wds[0] = inotify_add_watch(fd, USB_FS_DIR, IN_CREATE | IN_DELETE);
+ wds[0] = inotify_add_watch(context->fd, USB_FS_DIR, IN_CREATE | IN_DELETE);
if (wds[0] < 0) {
fprintf(stderr, "inotify_add_watch failed\n");
- return NULL;
+ return;
}
/* watch existing subdirectories of USB_FS_DIR */
for (i = 1; i < wd_count; i++) {
snprintf(path, sizeof(path), "%s/%03d", USB_FS_DIR, i);
- ret = inotify_add_watch(fd, path, IN_CREATE | IN_DELETE);
+ ret = inotify_add_watch(context->fd, path, IN_CREATE | IN_DELETE);
if (ret > 0)
wds[i] = ret;
}
/* check for existing devices first, after we have inotify set up */
- find_existing_devices(context);
+ done = find_existing_devices(added_cb, removed_cb, client_data);
- while (1) {
- ret = read(fd, event_buf, sizeof(event_buf));
+ while (!done) {
+ ret = read(context->fd, event_buf, sizeof(event_buf));
if (ret >= (int)sizeof(struct inotify_event)) {
event = (struct inotify_event *)event_buf;
wd = event->wd;
@@ -163,46 +185,26 @@
snprintf(path, sizeof(path), "%s/%s", USB_FS_DIR, event->name);
D("new subdirectory %s: index: %d\n", path, i);
if (i > 0 && i < wd_count) {
- ret = inotify_add_watch(fd, path, IN_CREATE | IN_DELETE);
+ ret = inotify_add_watch(context->fd, path, IN_CREATE | IN_DELETE);
if (ret > 0)
wds[i] = ret;
}
} else {
- for (i = 1; i < wd_count; i++) {
+ for (i = 1; i < wd_count && !done; i++) {
if (wd == wds[i]) {
snprintf(path, sizeof(path), "%s/%03d/%s", USB_FS_DIR, i, event->name);
if (event->mask == IN_CREATE) {
D("new device %s\n", path);
- context->added_cb(path, context->client_data);
+ done = added_cb(path, client_data);
} else if (event->mask == IN_DELETE) {
D("gone device %s\n", path);
- context->removed_cb(path, context->client_data);
+ done = removed_cb(path, client_data);
}
}
}
}
}
}
- return NULL;
-}
-
-int usb_host_init(usb_device_added_cb added_cb, usb_device_removed_cb removed_cb, void *client_data)
-{
- struct usb_host_context *context;
- pthread_t tid;
- pthread_attr_t attr;
-
- if (!added_cb || !removed_cb)
- return -EINVAL;
-
- context = calloc(1, sizeof(struct usb_host_context));
- context->added_cb = added_cb;
- context->removed_cb = removed_cb;
- context->client_data = client_data;
-
- pthread_attr_init(&attr);
- pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
- return pthread_create(&tid, &attr, device_discovery_thread, context);
}
struct usb_device *usb_device_open(const char *dev_name)