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mirror of https://github.com/moparisthebest/spdylay synced 2024-12-22 15:48:53 -05:00

Fixed the potential dead lock in flow control.

This commit is contained in:
Tatsuhiro Tsujikawa 2012-02-28 21:40:19 +09:00
parent 3d1b411895
commit a452893068

View File

@ -489,20 +489,20 @@ static int spdylay_session_is_window_update_allowed(spdylay_session *session,
}
/*
* Returns the available window size.
* Returns the maximum length of next data read. If the flow control
* is enabled, the return value takes into account the current window
* size.
*/
static size_t spdylay_session_avail_window(spdylay_session *session,
spdylay_stream *stream)
static size_t spdylay_session_next_data_read(spdylay_session *session,
spdylay_stream *stream)
{
if(session->flow_control == 0) {
return SPDYLAY_DATA_PAYLOAD_LENGTH;
} else if(stream->window_size > 0) {
return stream->window_size < SPDYLAY_DATA_PAYLOAD_LENGTH ?
stream->window_size : SPDYLAY_DATA_PAYLOAD_LENGTH;
} else {
if(stream->window_size >= SPDYLAY_DATA_PAYLOAD_LENGTH ||
stream->initial_window_size < stream->window_size*2) {
return stream->window_size;
} else {
return 0;
}
return 0;
}
}
@ -660,7 +660,7 @@ static ssize_t spdylay_session_prep_frame(spdylay_session *session,
}
break;
case SPDYLAY_DATA: {
size_t avail_window;
size_t next_readmax;
spdylay_stream *stream;
if(!spdylay_session_is_data_allowed(session, item->frame->data.stream_id)) {
return SPDYLAY_ERR_INVALID_FRAME;
@ -668,18 +668,16 @@ static ssize_t spdylay_session_prep_frame(spdylay_session *session,
stream = spdylay_session_get_stream(session, item->frame->data.stream_id);
/* Assuming stream is not NULL */
assert(stream);
avail_window = spdylay_session_avail_window(session, stream);
if(avail_window == 0) {
next_readmax = spdylay_session_next_data_read(session, stream);
if(next_readmax == 0) {
spdylay_stream_defer_data(stream, item, SPDYLAY_DEFERRED_FLOW_CONTROL);
return SPDYLAY_ERR_DEFERRED;
}
framebuflen = spdylay_session_pack_data
(session,
&session->aob.framebuf,
&session->aob.framebufmax,
(avail_window < SPDYLAY_DATA_PAYLOAD_LENGTH) ?
avail_window : SPDYLAY_DATA_PAYLOAD_LENGTH,
&item->frame->data);
framebuflen = spdylay_session_pack_data(session,
&session->aob.framebuf,
&session->aob.framebufmax,
next_readmax,
&item->frame->data);
if(framebuflen == SPDYLAY_ERR_DEFERRED) {
spdylay_stream_defer_data(stream, item, SPDYLAY_DEFERRED_NONE);
return SPDYLAY_ERR_DEFERRED;
@ -927,26 +925,24 @@ static int spdylay_session_after_frame_sent(spdylay_session *session)
waiting at the top of the queue, we continue to send this
data. */
if(item == NULL || session->aob.item->pri <= item->pri) {
size_t avail_window;
size_t next_readmax;
spdylay_stream *stream;
stream = spdylay_session_get_stream(session, frame->data.stream_id);
/* Assuming stream is not NULL */
assert(stream);
avail_window = spdylay_session_avail_window(session, stream);
if(avail_window == 0) {
next_readmax = spdylay_session_next_data_read(session, stream);
if(next_readmax == 0) {
spdylay_stream_defer_data(stream, session->aob.item,
SPDYLAY_DEFERRED_FLOW_CONTROL);
session->aob.item = NULL;
spdylay_active_outbound_item_reset(&session->aob);
return 0;
}
r = spdylay_session_pack_data
(session,
&session->aob.framebuf,
&session->aob.framebufmax,
(avail_window < SPDYLAY_DATA_PAYLOAD_LENGTH ?
avail_window : SPDYLAY_DATA_PAYLOAD_LENGTH),
&frame->data);
r = spdylay_session_pack_data(session,
&session->aob.framebuf,
&session->aob.framebufmax,
next_readmax,
&frame->data);
if(r == SPDYLAY_ERR_DEFERRED) {
spdylay_stream_defer_data(stream, session->aob.item,
SPDYLAY_DEFERRED_NONE);