[libsoup] SoupHTTPInputStream: don't burn through GCancellable fds

[Dan Winship <danw src gnome org>]

commit 856df33301221711789f0db744fce951eb70ba76
Author: Dan Winship <danw gnome org>
Date:   Mon Jan 23 12:34:12 2012 -0500

    SoupHTTPInputStream: don't burn through GCancellable fds
    
    SoupSession limits the number of outgoing TCP connections, but
    SoupRequestHTTP/SoupHTTPInputStream were still using a file descriptor
    for the GCancellable of each request that got queued, even before it
    was sent. This meant that if the app queued 1000ish requests all at
    once (eg, while rendering an HTML page with *lots* of images), we
    would run out of file descriptors.
    
    Fix this by just using the GCancellable::cancelled signal rather than
    g_cancellable_get_fd().
    
    https://bugzilla.gnome.org/show_bug.cgi?id=668508

 libsoup/soup-http-input-stream.c |   38 ++++++++++++++++----------------------
 1 files changed, 16 insertions(+), 22 deletions(-)
---
diff --git a/libsoup/soup-http-input-stream.c b/libsoup/soup-http-input-stream.c
index 45f181c..c0337e9 100644
--- a/libsoup/soup-http-input-stream.c
+++ b/libsoup/soup-http-input-stream.c
@@ -43,7 +43,7 @@ typedef struct {
 	goffset offset;
 
 	GCancellable *cancellable;
-	GSource *cancel_watch;
+	guint cancel_id;
 	SoupHTTPInputStreamCallback got_headers_cb;
 	SoupHTTPInputStreamCallback got_chunk_cb;
 	SoupHTTPInputStreamCallback finished_cb;
@@ -323,39 +323,34 @@ soup_http_input_stream_finished (SoupMessage *msg, gpointer stream)
 		priv->finished_cb (stream);
 }
 
-static gboolean
-soup_http_input_stream_cancelled (GIOChannel *chan, GIOCondition condition,
-					 gpointer stream)
+static void
+soup_http_input_stream_cancelled (GCancellable *cancellable,
+				  gpointer      user_data)
 {
+	SoupHTTPInputStream *stream = user_data;
 	SoupHTTPInputStreamPrivate *priv = SOUP_HTTP_INPUT_STREAM_GET_PRIVATE (stream);
 
-	priv->cancel_watch = NULL;
+	g_signal_handler_disconnect (cancellable, priv->cancel_id);
+	priv->cancel_id = 0;
 
 	soup_session_pause_message (priv->session, priv->msg);
 	if (priv->cancelled_cb)
-		priv->cancelled_cb (stream);
-
-	return FALSE;
+		priv->cancelled_cb (G_INPUT_STREAM (stream));
 }
 
 static void
 soup_http_input_stream_prepare_for_io (GInputStream *stream,
 				       GCancellable *cancellable,
 				       guchar       *buffer,
-				       gsize count)
+				       gsize         count)
 {
 	SoupHTTPInputStreamPrivate *priv = SOUP_HTTP_INPUT_STREAM_GET_PRIVATE (stream);
-	int cancel_fd;
 
 	priv->cancellable = cancellable;
-	cancel_fd = g_cancellable_get_fd (cancellable);
-	if (cancel_fd != -1) {
-		GIOChannel *chan = g_io_channel_unix_new (cancel_fd);
-		priv->cancel_watch = soup_add_io_watch (priv->async_context, chan,
-							G_IO_IN | G_IO_ERR | G_IO_HUP,
-							soup_http_input_stream_cancelled,
-							stream);
-		g_io_channel_unref (chan);
+	if (cancellable) {
+		priv->cancel_id = g_signal_connect (cancellable, "cancelled",
+						    G_CALLBACK (soup_http_input_stream_cancelled),
+						    stream);
 	}
 
 	priv->caller_buffer = buffer;
@@ -371,10 +366,9 @@ soup_http_input_stream_done_io (GInputStream *stream)
 {
 	SoupHTTPInputStreamPrivate *priv = SOUP_HTTP_INPUT_STREAM_GET_PRIVATE (stream);
 
-	if (priv->cancel_watch) {
-		g_source_destroy (priv->cancel_watch);
-		priv->cancel_watch = NULL;
-		g_cancellable_release_fd (priv->cancellable);
+	if (priv->cancel_id) {
+		g_signal_handler_disconnect (priv->cancellable, priv->cancel_id);
+		priv->cancel_id = 0;
 	}
 	priv->cancellable = NULL;