MEDIUM: applets: Don't process more than 200 active applets at once

Now, we process at most 200 active applets per call to applet_run_active. We use
the same limit as the tasks. With the cache filter and the SPOE, the number of
active applets can now be huge. So, it is important to limit the number of
applets processed in applet_run_active.
diff --git a/src/applet.c b/src/applet.c
index 84ffde6..77f984d 100644
--- a/src/applet.c
+++ b/src/applet.c
@@ -32,13 +32,18 @@
 	struct appctx *curr, *next;
 	struct stream_interface *si;
 	struct list applet_cur_queue = LIST_HEAD_INIT(applet_cur_queue);
+	int max_processed;
+
+	max_processed = applets_active_queue;
+	if (max_processed > 200)
+		max_processed = 200;
 
 	HA_SPIN_LOCK(APPLETS_LOCK, &applet_active_lock);
 	if (!(active_applets_mask & tid_bit)) {
 		HA_SPIN_UNLOCK(APPLETS_LOCK, &applet_active_lock);
 		return;
 	}
-
+	active_applets_mask &= ~tid_bit;
 	curr = LIST_NEXT(&applet_active_queue, typeof(curr), runq);
 	while (&curr->runq != &applet_active_queue) {
 		next = LIST_NEXT(&curr->runq, typeof(next), runq);
@@ -47,10 +52,14 @@
 			curr->state = APPLET_RUNNING;
 			LIST_ADDQ(&applet_cur_queue, &curr->runq);
 			applets_active_queue--;
+			max_processed--;
 		}
 		curr = next;
+		if (max_processed <= 0) {
+			active_applets_mask |= tid_bit;
+			break;
+		}
 	}
-	active_applets_mask &= ~tid_bit;
 	HA_SPIN_UNLOCK(APPLETS_LOCK, &applet_active_lock);
 
 	/* The list is only scanned from the head. This guarantees that if any