+
+#ifdef _WIN32
+static gpointer usb_thread(gpointer data)
+{
+ struct sr_context *ctx = data;
+
+ while (ctx->usb_thread_running) {
+ g_mutex_lock(&ctx->usb_mutex);
+ libusb_wait_for_event(ctx->libusb_ctx, NULL);
+ SetEvent(ctx->usb_event);
+ g_mutex_unlock(&ctx->usb_mutex);
+ g_thread_yield();
+ }
+
+ return NULL;
+}
+
+static int usb_callback(int fd, int revents, void *cb_data)
+{
+ struct sr_context *ctx = cb_data;
+ int ret;
+
+ g_mutex_lock(&ctx->usb_mutex);
+ ret = ctx->usb_cb(fd, revents, ctx->usb_cb_data);
+
+ if (ctx->usb_thread_running) {
+ ResetEvent(ctx->usb_event);
+ g_mutex_unlock(&ctx->usb_mutex);
+ }
+
+ return ret;
+}
+#endif
+
+SR_PRIV int usb_source_add(struct sr_context *ctx, int timeout,
+ sr_receive_data_callback_t cb, void *cb_data)
+{
+ if (ctx->usb_source_present) {
+ sr_err("A USB event source is already present.");
+ return SR_ERR;
+ }
+
+#ifdef _WIN32
+ ctx->usb_event = CreateEvent(NULL, TRUE, FALSE, NULL);
+ g_mutex_init(&ctx->usb_mutex);
+ ctx->usb_thread_running = TRUE;
+ ctx->usb_thread = g_thread_new("usb", usb_thread, ctx);
+ ctx->usb_pollfd.fd = ctx->usb_event;
+ ctx->usb_pollfd.events = G_IO_IN;
+ ctx->usb_cb = cb;
+ ctx->usb_cb_data = cb_data;
+ sr_session_source_add_pollfd(&ctx->usb_pollfd, timeout, usb_callback, ctx);
+#else
+ const struct libusb_pollfd **lupfd;
+ unsigned int i;
+
+ lupfd = libusb_get_pollfds(ctx->libusb_ctx);
+ for (i = 0; lupfd[i]; i++)
+ sr_source_add(lupfd[i]->fd, lupfd[i]->events, timeout, cb, cb_data);
+ free(lupfd);
+#endif
+ ctx->usb_source_present = TRUE;
+
+ return SR_OK;
+}
+
+SR_PRIV int usb_source_remove(struct sr_context *ctx)
+{
+ if (!ctx->usb_source_present)
+ return SR_OK;
+
+#ifdef _WIN32
+ ctx->usb_thread_running = FALSE;
+ g_mutex_unlock(&ctx->usb_mutex);
+ libusb_unlock_events(ctx->libusb_ctx);
+ g_thread_join(ctx->usb_thread);
+ g_mutex_clear(&ctx->usb_mutex);
+ sr_session_source_remove_pollfd(&ctx->usb_pollfd);
+ CloseHandle(ctx->usb_event);
+#else
+ const struct libusb_pollfd **lupfd;
+ unsigned int i;
+
+ lupfd = libusb_get_pollfds(ctx->libusb_ctx);
+ for (i = 0; lupfd[i]; i++)
+ sr_source_remove(lupfd[i]->fd);
+ free(lupfd);
+#endif
+ ctx->usb_source_present = FALSE;
+
+ return SR_OK;
+}