[MEDIUM] session: limit the number of analyser loops

The initial code's intention was to loop on the analysers as long
as an analyser is added by another one. [This code was wrong due to
the while(0) which breaks even on a continue statement, but the
initial intention must be changed too]. In fact we should limit the
number of times we loop on analysers in order to limit latency.
Using maxpollevents as a limit makes sense since this tunable is
used for the exact same purposes. We may add another tunable later
if that ever makes sense, so it's very unlikely.

diff --git a/src/session.c b/src/session.c
index 48c8ce9c978528cf693abee160d1b9d7feedeadd..5e8c990abf746405d382bb914eb335ceaa49b7ff 100644 (file)
--- a/src/session.c
+++ b/src/session.c
@@ -790,6 +790,7 @@ resync_stream_interface:
                unsigned int flags = s->req->flags;
 
                if (s->req->prod->state >= SI_ST_EST) {
+                       int max_loops = global.tune.maxpollevents;
                        unsigned int ana_list;
                        unsigned int ana_back;
 
@@ -838,10 +839,7 @@ resync_stream_interface:
                         */
 
                        ana_list = ana_back = s->req->analysers;
-                       do {
-                               if (!ana_list)
-                                       break;
-
+                       while (ana_list && max_loops--) {
                                /* Warning! ensure that analysers are always placed in ascending order! */
 
                                if (ana_list & AN_REQ_INSPECT) {
@@ -903,7 +901,8 @@ resync_stream_interface:
                                                break;
                                        UPDATE_ANALYSERS(s->req->analysers, ana_list, ana_back, AN_REQ_HTTP_XFER_BODY);
                                }
-                       } while (0);
+                               break;
+                       }
                }
 
                if ((s->req->flags ^ flags) & BF_MASK_STATIC) {
@@ -942,6 +941,7 @@ resync_stream_interface:
                unsigned int flags = s->rep->flags;
 
                if (s->rep->prod->state >= SI_ST_EST) {
+                       int max_loops = global.tune.maxpollevents;
                        unsigned int ana_list;
                        unsigned int ana_back;
 
@@ -966,7 +966,7 @@ resync_stream_interface:
                         */
 
                        ana_list = ana_back = s->rep->analysers;
-                       do {
+                       while (ana_list && max_loops--) {
                                if (!ana_list)
                                        break;
 
@@ -989,7 +989,8 @@ resync_stream_interface:
                                                break;
                                        UPDATE_ANALYSERS(s->rep->analysers, ana_list, ana_back, AN_RES_HTTP_XFER_BODY);
                                }
-                       } while (0);
+                               break;
+                       }
                }
 
                if ((s->rep->flags ^ flags) & BF_MASK_STATIC) {