BUG/MEDIUM: h2: Don't attempt to recv from h2_process_demux if we subscribed.
Modify h2c_restart_reading() to add a new parameter, to let it know if it
should consider if the buffer isn't empty when retrying to read or not, and
call h2c_restart_reading() using 0 as a parameter from h2_process_demux().
If we're leaving h2_process_demux() with a non-empty buffer, it means the
frame is incomplete, and we're waiting for more data, and if we already
subscribed, we'll be waken when more data are available.
Failing to do so means we'll be waken up in a loop until more data are
available.
This should be backported to 1.9.
diff --git a/src/mux_h2.c b/src/mux_h2.c
index 9894592..7634361 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -332,11 +332,12 @@
}
/* restarts reading on the connection if it was not enabled */
-static inline void h2c_restart_reading(const struct h2c *h2c)
+static inline void h2c_restart_reading(const struct h2c *h2c, int consider_buffer)
{
if (!h2_recv_allowed(h2c))
return;
- if (!b_data(&h2c->dbuf) && (h2c->wait_event.events & SUB_RETRY_RECV))
+ if ((!consider_buffer || !b_data(&h2c->dbuf))
+ && (h2c->wait_event.events & SUB_RETRY_RECV))
return;
tasklet_wakeup(h2c->wait_event.task);
}
@@ -360,7 +361,7 @@
if ((h2c->flags & H2_CF_DEM_DALLOC) && b_alloc_margin(&h2c->dbuf, 0)) {
h2c->flags &= ~H2_CF_DEM_DALLOC;
- h2c_restart_reading(h2c);
+ h2c_restart_reading(h2c, 1);
return 1;
}
@@ -369,7 +370,7 @@
if (h2c->flags & H2_CF_DEM_MROOM) {
h2c->flags &= ~H2_CF_DEM_MROOM;
- h2c_restart_reading(h2c);
+ h2c_restart_reading(h2c, 1);
}
return 1;
}
@@ -378,7 +379,7 @@
(h2s = h2c_st_by_id(h2c, h2c->dsi)) && h2s->cs &&
b_alloc_margin(&h2s->rxbuf, 0)) {
h2c->flags &= ~H2_CF_DEM_SALLOC;
- h2c_restart_reading(h2c);
+ h2c_restart_reading(h2c, 1);
return 1;
}
@@ -567,7 +568,7 @@
conn->ctx = h2c;
/* prepare to read something */
- h2c_restart_reading(h2c);
+ h2c_restart_reading(h2c, 1);
return 0;
fail_stream:
hpack_dht_free(h2c->ddht);
@@ -2529,7 +2530,7 @@
h2s_notify_recv(h2s);
}
- h2c_restart_reading(h2c);
+ h2c_restart_reading(h2c, 0);
}
/* process Tx frames from streams to be multiplexed. Returns > 0 if it reached
@@ -3011,7 +3012,7 @@
!h2_frt_has_too_many_cs(h2c)) {
/* frontend connection was blocking new streams creation */
h2c->flags &= ~H2_CF_DEM_TOOMANY;
- h2c_restart_reading(h2c);
+ h2c_restart_reading(h2c, 1);
}
/* this stream may be blocked waiting for some data to leave (possibly
@@ -3029,7 +3030,7 @@
*/
h2c->flags &= ~H2_CF_DEM_BLOCK_ANY;
h2c->flags &= ~H2_CF_MUX_BLOCK_ANY;
- h2c_restart_reading(h2c);
+ h2c_restart_reading(h2c, 1);
}
h2s_destroy(h2s);
@@ -5258,7 +5259,7 @@
if (ret && h2c->dsi == h2s->id) {
/* demux is blocking on this stream's buffer */
h2c->flags &= ~H2_CF_DEM_SFULL;
- h2c_restart_reading(h2c);
+ h2c_restart_reading(h2c, 1);
}
return ret;