From 57b0cdf152b7266e68bfa3e84635d4bdb64ef2cd Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" Date: Mon, 9 Oct 2017 15:34:06 +0100 Subject: io: simplify websocket ping reply handling We must ensure we don't get flooded with ping replies if the outbound channel is slow. Currently we do this by keeping the ping reply in a separate temporary buffer and only writing it if the encoutput buffer is completely empty. This is overly pessimistic, as it is reasonable to add a ping reply to the encoutput buffer even if it has previous data in it, as long as that previous data doesn't include a ping reply. To track this better, put the ping reply directly into the encoutput buffer, and then record the size of encoutput at this time in pong_remain. As we write encoutput to the underlying channel, we can decrement the pong_remain counter. Once it hits zero, we can accept further ping replies for transmission. Reviewed-by: Eric Blake Signed-off-by: Daniel P. Berrange --- include/io/channel-websock.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/io') diff --git a/include/io/channel-websock.h b/include/io/channel-websock.h index ff32d8651b..3762707b9c 100644 --- a/include/io/channel-websock.h +++ b/include/io/channel-websock.h @@ -60,8 +60,8 @@ struct QIOChannelWebsock { Buffer encoutput; Buffer rawinput; Buffer rawoutput; - Buffer ping_reply; size_t payload_remain; + size_t pong_remain; QIOChannelWebsockMask mask; guint io_tag; Error *io_err; -- cgit v1.2.3