From: Willy Tarreau <w@1wt.eu>
Date: Mon, 13 Apr 2015 18:44:19 +0000 (+0200)
Subject: CLEANUP: poll: move the conditions for waiting out of the poll functions
X-Git-Tag: v1.6-dev2~211
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=10146c9c51e17272970b19434be2e0bca0c7cf8f;p=thirdparty%2Fhaproxy.git

CLEANUP: poll: move the conditions for waiting out of the poll functions

The poll() functions have become a bit dirty because they now check the
size of the signal queue, the FD cache and the number of tasks. It's not
their job, this must be moved to the caller. In the end it simplifies the
code because the expiration date is now set to now_ms if we must not wait,
and this achieves in exactly the same result and is cleaner. The change
looks large due to the change of indent for blocks which were inside an
"if" block.
---

diff --git a/src/ev_epoll.c b/src/ev_epoll.c
index c52d07521a..ccb7c33772 100644
--- a/src/ev_epoll.c
+++ b/src/ev_epoll.c
@@ -25,9 +25,6 @@
 #include <types/global.h>
 
 #include <proto/fd.h>
-#include <proto/signal.h>
-#include <proto/task.h>
-
 
 
 /* private data */
@@ -112,25 +109,14 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
 	fd_nbupdt = 0;
 
 	/* compute the epoll_wait() timeout */
-
-	if (fd_cache_num || run_queue || signal_queue_len) {
-		/* Maybe we still have events in the spec list, or there are
-		 * some tasks left pending in the run_queue, so we must not
-		 * wait in epoll() otherwise we would delay their delivery by
-		 * the next timeout.
-		 */
+	if (!exp)
+		wait_time = MAX_DELAY_MS;
+	else if (tick_is_expired(exp, now_ms))
 		wait_time = 0;
-	}
 	else {
-		if (!exp)
+		wait_time = TICKS_TO_MS(tick_remain(now_ms, exp)) + 1;
+		if (wait_time > MAX_DELAY_MS)
 			wait_time = MAX_DELAY_MS;
-		else if (tick_is_expired(exp, now_ms))
-			wait_time = 0;
-		else {
-			wait_time = TICKS_TO_MS(tick_remain(now_ms, exp)) + 1;
-			if (wait_time > MAX_DELAY_MS)
-				wait_time = MAX_DELAY_MS;
-		}
 	}
 
 	/* now let's wait for polled events */
diff --git a/src/ev_kqueue.c b/src/ev_kqueue.c
index 2af94b647c..007336fa7c 100644
--- a/src/ev_kqueue.c
+++ b/src/ev_kqueue.c
@@ -26,8 +26,7 @@
 #include <types/global.h>
 
 #include <proto/fd.h>
-#include <proto/signal.h>
-#include <proto/task.h>
+
 
 /* private data */
 static int kqueue_fd;
@@ -93,19 +92,17 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
 	timeout.tv_sec  = 0;
 	timeout.tv_nsec = 0;
 
-	if (!fd_cache_num && !run_queue && !signal_queue_len) {
-		if (!exp) {
-			delta_ms        = MAX_DELAY_MS;
-			timeout.tv_sec  = (MAX_DELAY_MS / 1000);
-			timeout.tv_nsec = (MAX_DELAY_MS % 1000) * 1000000;
-		}
-		else if (!tick_is_expired(exp, now_ms)) {
-			delta_ms = TICKS_TO_MS(tick_remain(now_ms, exp)) + 1;
-			if (delta_ms > MAX_DELAY_MS)
-				delta_ms = MAX_DELAY_MS;
-			timeout.tv_sec  = (delta_ms / 1000);
-			timeout.tv_nsec = (delta_ms % 1000) * 1000000;
-		}
+	if (!exp) {
+		delta_ms        = MAX_DELAY_MS;
+		timeout.tv_sec  = (MAX_DELAY_MS / 1000);
+		timeout.tv_nsec = (MAX_DELAY_MS % 1000) * 1000000;
+	}
+	else if (!tick_is_expired(exp, now_ms)) {
+		delta_ms = TICKS_TO_MS(tick_remain(now_ms, exp)) + 1;
+		if (delta_ms > MAX_DELAY_MS)
+			delta_ms = MAX_DELAY_MS;
+		timeout.tv_sec  = (delta_ms / 1000);
+		timeout.tv_nsec = (delta_ms % 1000) * 1000000;
 	}
 
 	fd = MIN(maxfd, global.tune.maxpollevents);
diff --git a/src/ev_poll.c b/src/ev_poll.c
index 866906c3a3..44a2b9b641 100644
--- a/src/ev_poll.c
+++ b/src/ev_poll.c
@@ -23,8 +23,6 @@
 #include <types/global.h>
 
 #include <proto/fd.h>
-#include <proto/signal.h>
-#include <proto/task.h>
 
 
 static unsigned int *fd_evts[2];
@@ -116,9 +114,7 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
 	}
       
 	/* now let's wait for events */
-	if (fd_cache_num || run_queue || signal_queue_len)
-		wait_time = 0;
-	else if (!exp)
+	if (!exp)
 		wait_time = MAX_DELAY_MS;
 	else if (tick_is_expired(exp, now_ms))
 		wait_time = 0;
diff --git a/src/ev_select.c b/src/ev_select.c
index 73fe327aa8..35d3c77db7 100644
--- a/src/ev_select.c
+++ b/src/ev_select.c
@@ -22,8 +22,6 @@
 #include <types/global.h>
 
 #include <proto/fd.h>
-#include <proto/signal.h>
-#include <proto/task.h>
 
 
 static fd_set *fd_evts[2];
@@ -83,19 +81,17 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
 	delta.tv_sec  = 0;
 	delta.tv_usec = 0;
 
-	if (!fd_cache_num && !run_queue && !signal_queue_len) {
-		if (!exp) {
-			delta_ms      = MAX_DELAY_MS;
-			delta.tv_sec  = (MAX_DELAY_MS / 1000);
-			delta.tv_usec = (MAX_DELAY_MS % 1000) * 1000;
-		}
-		else if (!tick_is_expired(exp, now_ms)) {
-			delta_ms = TICKS_TO_MS(tick_remain(now_ms, exp)) + SCHEDULER_RESOLUTION;
-			if (delta_ms > MAX_DELAY_MS)
-				delta_ms = MAX_DELAY_MS;
-			delta.tv_sec  = (delta_ms / 1000);
-			delta.tv_usec = (delta_ms % 1000) * 1000;
-		}
+	if (!exp) {
+		delta_ms      = MAX_DELAY_MS;
+		delta.tv_sec  = (MAX_DELAY_MS / 1000);
+		delta.tv_usec = (MAX_DELAY_MS % 1000) * 1000;
+	}
+	else if (!tick_is_expired(exp, now_ms)) {
+		delta_ms = TICKS_TO_MS(tick_remain(now_ms, exp)) + SCHEDULER_RESOLUTION;
+		if (delta_ms > MAX_DELAY_MS)
+			delta_ms = MAX_DELAY_MS;
+		delta.tv_sec  = (delta_ms / 1000);
+		delta.tv_usec = (delta_ms % 1000) * 1000;
 	}
 
 	/* let's restore fdset state */
diff --git a/src/haproxy.c b/src/haproxy.c
index b2f3e367aa..752c4a2d02 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -1486,6 +1486,10 @@ void run_poll_loop()
 		if (jobs == 0)
 			break;
 
+		/* expire immediately if events are pending */
+		if (fd_cache_num || run_queue || signal_queue_len)
+			next = now_ms;
+
 		/* The poller will ensure it returns around <next> */
 		cur_poller.poll(&cur_poller, next);
 		fd_process_cached_events();