MEDIUM: h2: send WINDOW_UPDATE frames for connection

When it is detected that the number of received bytes is > 0 on the
connection at the end of the demux call or before starting to process
pending output data, an attempt is made at sending a WINDOW UPDATE on
the connection. In case of failure, it's attempted later.
This commit is contained in:
Willy Tarreau 2017-10-26 16:55:59 +02:00
parent c199faf5bd
commit cc0b8c34a6

View File

@ -966,6 +966,87 @@ static int h2c_handle_ping(struct h2c *h2c)
return 1;
}
/* Try to send a window update for stream id <sid> and value <increment>.
* Returns > 0 on success or zero on missing room or failure. It may return an
* error in h2c.
*/
static int h2c_send_window_update(struct h2c *h2c, int sid, uint32_t increment)
{
struct buffer *res;
char str[13];
int ret = -1;
if (h2c_mux_busy(h2c, NULL)) {
h2c->flags |= H2_CF_DEM_MBUSY;
return 0;
}
res = h2_get_mbuf(h2c);
if (!res) {
h2c->flags |= H2_CF_MUX_MALLOC;
h2c->flags |= H2_CF_DEM_MROOM;
return 0;
}
/* length: 4, type: 8, flags: none */
memcpy(str, "\x00\x00\x04\x08\x00", 5);
write_n32(str + 5, sid);
write_n32(str + 9, increment);
ret = bo_istput(res, ist2(str, 13));
if (unlikely(ret <= 0)) {
if (!ret) {
h2c->flags |= H2_CF_MUX_MFULL;
h2c->flags |= H2_CF_DEM_MROOM;
return 0;
}
else {
h2c_error(h2c, H2_ERR_INTERNAL_ERROR);
return 0;
}
}
return ret;
}
/* try to send pending window update for the connection. It's safe to call it
* with no pending updates. Returns > 0 on success or zero on missing room or
* failure. It may return an error in h2c.
*/
static int h2c_send_conn_wu(struct h2c *h2c)
{
int ret = 1;
if (h2c->rcvd_c <= 0)
return 1;
/* send WU for the connection */
ret = h2c_send_window_update(h2c, 0, h2c->rcvd_c);
if (ret > 0)
h2c->rcvd_c = 0;
return ret;
}
/* try to send pending window update for the current dmux stream. It's safe to
* call it with no pending updates. Returns > 0 on success or zero on missing
* room or failure. It may return an error in h2c.
*/
static int h2c_send_strm_wu(struct h2c *h2c)
{
int ret = 1;
if (h2c->rcvd_s <= 0)
return 1;
/* send WU for the stream */
ret = h2c_send_window_update(h2c, h2c->dsi, h2c->rcvd_s);
if (ret > 0)
h2c->rcvd_s = 0;
return ret;
}
/* try to send an ACK for a ping frame on the connection. Returns > 0 on
* success, 0 on missing data or one of the h2_status values.
*/
@ -1335,6 +1416,10 @@ static void h2_process_demux(struct h2c *h2c)
}
}
if (h2c->rcvd_c > 0 &&
!(h2c->flags & (H2_CF_MUX_MFULL | H2_CF_DEM_MBUSY | H2_CF_DEM_MROOM)))
h2c_send_conn_wu(h2c);
fail:
/* we can go here on missing data, blocked response or error */
return;
@ -1347,6 +1432,12 @@ static int h2_process_mux(struct h2c *h2c)
{
struct h2s *h2s, *h2s_back;
/* start by sending possibly pending window updates */
if (h2c->rcvd_c > 0 &&
!(h2c->flags & (H2_CF_MUX_MFULL | H2_CF_MUX_MALLOC)) &&
h2c_send_conn_wu(h2c) < 0)
goto fail;
/* First we always process the flow control list because the streams
* waiting there were already elected for immediate emission but were
* blocked just on this.
@ -1427,6 +1518,7 @@ static int h2_process_mux(struct h2c *h2c)
}
}
fail:
if (unlikely(h2c->st0 > H2_CS_ERROR)) {
if (h2c->st0 == H2_CS_ERROR) {
if (h2c->max_id >= 0) {