event_pipe: use g_io_channel_read_chars() to drain the pipe

For some unknown reason, read() blocks on WIN32, even though it was
invoked inside the G_IO_IN callback.  By switching to GIOChannel
functions, this problem is solved, and it works on both Linux and
Windows.

1 files changed, 14 insertions, 6 deletions

diff --git a/src/event_pipe.c b/src/event_pipe.c
index 5f69ee95c..af6517cd4 100644
--- a/src/event_pipe.c
+++ b/src/event_pipe.c
@@ -38,6 +38,7 @@
 #define G_LOG_DOMAIN "event_pipe"
 
 static int event_pipe[2];
+static GIOChannel *event_channel;
 static guint event_pipe_source_id;
 static GMutex *event_pipe_mutex;
 static bool pipe_events[PIPE_EVENT_MAX];
@@ -61,12 +62,15 @@ main_notify_event(G_GNUC_UNUSED GIOChannel *source,
 		  G_GNUC_UNUSED gpointer data)
 {
 	char buffer[256];
-	ssize_t r = read(event_pipe[0], buffer, sizeof(buffer));
-	bool events[PIPE_EVENT_MAX];
-
-	if (r < 0 && errno != EAGAIN && errno != EINTR)
-		g_error("error reading from pipe: %s", strerror(errno));
+	gsize bytes_read;
+	GError *error = NULL;
+	GIOStatus status = g_io_channel_read_chars(event_channel,
+						   buffer, sizeof(buffer),
+						   &bytes_read, &error);
+	if (status == G_IO_STATUS_ERROR)
+		g_error("error reading from pipe: %s", error->message);
 
+	bool events[PIPE_EVENT_MAX];
 	g_mutex_lock(event_pipe_mutex);
 	memcpy(events, pipe_events, sizeof(events));
 	memset(pipe_events, 0, sizeof(pipe_events));
@@ -94,10 +98,13 @@ void event_pipe_init(void)
 #else
 	channel = g_io_channel_win32_new_fd(event_pipe[0]);
 #endif
+	g_io_channel_set_encoding(channel, NULL, NULL);
+	g_io_channel_set_buffered(channel, false);
 
 	event_pipe_source_id = g_io_add_watch(channel, G_IO_IN,
 					      main_notify_event, NULL);
-	g_io_channel_unref(channel);
+
+	event_channel = channel;
 
 	event_pipe_mutex = g_mutex_new();
 }
@@ -107,6 +114,7 @@ void event_pipe_deinit(void)
 	g_mutex_free(event_pipe_mutex);
 
 	g_source_remove(event_pipe_source_id);
+	g_io_channel_unref(event_channel);
 
 	close(event_pipe[0]);
 	close(event_pipe[1]);