USB: Handle live changes to the set of FDs to poll

[libsigrok.git] / src / usb.c

diff --git a/src/usb.c b/src/usb.c
index cc63b86096a65683f4d97ebb52663ae654757a22..122371f6268f2008d31a48b24e61b0c94279d05d 100644 (file)
--- a/src/usb.c
+++ b/src/usb.c
@@ -184,55 +184,88 @@ SR_PRIV void sr_usb_close(struct sr_usb_dev_inst *usb)
        sr_dbg("Closed USB device %d.%d.", usb->bus, usb->address);
 }
 
+#if (LIBUSB_API_VERSION < 0x01000104)
+typedef int libusb_os_handle;
+#endif
+
+static LIBUSB_CALL void usb_pollfd_added(libusb_os_handle fd,
+               short events, void *user_data)
+{
+       struct sr_session *session;
+       gintptr tag;
+
+       session = user_data;
+       tag = (gintptr)session->ctx->libusb_ctx;
+#ifdef G_OS_WIN32
+       events = G_IO_IN;
+#endif
+       sr_session_source_poll_add(session, tag, (gintptr)fd, events);
+}
+
+static LIBUSB_CALL void usb_pollfd_removed(libusb_os_handle fd, void *user_data)
+{
+       struct sr_session *session;
+       gintptr tag;
+
+       session = user_data;
+       tag = (gintptr)session->ctx->libusb_ctx;
+
+       sr_session_source_poll_remove(session, tag, (gintptr)fd);
+}
+
 SR_PRIV int usb_source_add(struct sr_session *session, struct sr_context *ctx,
                int timeout, sr_receive_data_callback cb, void *cb_data)
 {
-       const struct libusb_pollfd **lupfd;
-       GPollFD *pollfds;
+       const struct libusb_pollfd **pollfds;
+       gintptr tag;
        int i;
-       int num_fds = 0;
        int ret;
+       int events;
 
        if (ctx->usb_source_present) {
                sr_err("A USB event source is already present.");
                return SR_ERR;
        }
-       lupfd = libusb_get_pollfds(ctx->libusb_ctx);
-       if (!lupfd || !lupfd[0]) {
-               free(lupfd);
+       pollfds = libusb_get_pollfds(ctx->libusb_ctx);
+       if (!pollfds) {
                sr_err("Failed to get libusb file descriptors.");
                return SR_ERR;
        }
-       while (lupfd[num_fds])
-               ++num_fds;
-       pollfds = g_new(GPollFD, num_fds);
-
-       for (i = 0; i < num_fds; ++i) {
-#if defined(G_OS_WIN32) && (GLIB_SIZEOF_VOID_P == 4)
-               /* Avoid a warning on 32-bit Windows. */
-               pollfds[i].fd = (gintptr)lupfd[i]->fd;
-#else
-               pollfds[i].fd = lupfd[i]->fd;
-#endif
+       tag = (gintptr)ctx->libusb_ctx;
+       ret = sr_session_source_add_internal(session,
+                       timeout, cb, cb_data, tag);
+
+       ctx->usb_source_present = (ret == SR_OK);
+
+       for (i = 0; ret == SR_OK && pollfds[i]; ++i) {
 #ifdef G_OS_WIN32
-               pollfds[i].events = G_IO_IN;
+               events = G_IO_IN;
 #else
-               pollfds[i].events = lupfd[i]->events;
+               events = pollfds[i]->events;
 #endif
-               pollfds[i].revents = 0;
+               ret = sr_session_source_poll_add(session, tag,
+                               (gintptr)pollfds[i]->fd, events);
        }
-       free(lupfd);
-       ret = sr_session_source_add_internal(session, pollfds, num_fds,
-                       timeout, cb, cb_data, (gintptr)ctx->libusb_ctx);
-       g_free(pollfds);
+#if (LIBUSB_API_VERSION >= 0x01000104)
+       libusb_free_pollfds(pollfds);
+#else
+       free(pollfds);
+#endif
+       if (ret != SR_OK)
+               return ret;
 
-       ctx->usb_source_present = (ret == SR_OK);
+       libusb_set_pollfd_notifiers(ctx->libusb_ctx,
+               &usb_pollfd_added, &usb_pollfd_removed, session);
 
-       return ret;
+       return SR_OK;
 }
 
 SR_PRIV int usb_source_remove(struct sr_session *session, struct sr_context *ctx)
 {
+       ctx->usb_source_present = FALSE;
+
+       libusb_set_pollfd_notifiers(ctx->libusb_ctx, NULL, NULL, NULL);
+
        return sr_session_source_remove_internal(session,
                        (gintptr)ctx->libusb_ctx);
 }