From 242617c3161f7d50a592ab21607301aacd4e8f8c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jonas=20=C3=85dahl?= Date: Mon, 28 Dec 2015 14:50:12 +0800 Subject: [PATCH] client: Fully flush during blocking dispatch MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit wl_display_flush() may fail with EAGAIN which means that not all data waiting in the buffer has been flushed. We later block until there is data to read, which could mean that we block on input from the compositor without having sent out all data from the client. Avoid this by fully flushing the socket before starting to wait. This commit also changes the array length of the struct pollfd array from 2 to 1, as only one element was ever used. Signed-off-by: Jonas Ådahl Reviewed-by: Daniel Stone --- src/wayland-client.c | 39 +++++++++++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 10 deletions(-) diff --git a/src/wayland-client.c b/src/wayland-client.c index 18a837a6..55483c64 100644 --- a/src/wayland-client.c +++ b/src/wayland-client.c @@ -1442,6 +1442,21 @@ wl_display_cancel_read(struct wl_display *display) pthread_mutex_unlock(&display->mutex); } +static int +wl_display_poll(struct wl_display *display, short int events) +{ + int ret; + struct pollfd pfd[1]; + + pfd[0].fd = display->fd; + pfd[0].events = events; + do { + ret = poll(pfd, 1, -1); + } while (ret == -1 && errno == EINTR); + + return ret; +} + /** Dispatch events in an event queue * * \param display The display context object @@ -1485,27 +1500,31 @@ WL_EXPORT int wl_display_dispatch_queue(struct wl_display *display, struct wl_event_queue *queue) { - struct pollfd pfd[2]; int ret; if (wl_display_prepare_read_queue(display, queue) == -1) return wl_display_dispatch_queue_pending(display, queue); + while (true) { + ret = wl_display_flush(display); + + if (ret != -1 || errno != EAGAIN) + break; + + if (wl_display_poll(display, POLLOUT) == -1) { + wl_display_cancel_read(display); + return -1; + } + } + /* Don't stop if flushing hits an EPIPE; continue so we can read any * protocol error that may have triggered it. */ - ret = wl_display_flush(display); - if (ret < 0 && errno != EAGAIN && errno != EPIPE) { + if (ret < 0 && errno != EPIPE) { wl_display_cancel_read(display); return -1; } - pfd[0].fd = display->fd; - pfd[0].events = POLLIN; - do { - ret = poll(pfd, 1, -1); - } while (ret == -1 && errno == EINTR); - - if (ret == -1) { + if (wl_display_poll(display, POLLIN) == -1) { wl_display_cancel_read(display); return -1; }