From: Willy Tarreau <w@1wt.eu>
Date: Sun, 11 Nov 2012 15:53:50 +0000 (+0100)
Subject: MAJOR: ev_select: make the poller support speculative events
X-Git-Tag: v1.5-dev13~53
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4d31fb2643cc10602b859309eb7913ee3fb33f2a;p=thirdparty%2Fhaproxy.git

MAJOR: ev_select: make the poller support speculative events

The poller was updated to support speculative events. We'll need this
to fully support SSL.
---

diff --git a/src/ev_select.c b/src/ev_select.c
index 100bc57565..a4fe3d7398 100644
--- a/src/ev_select.c
+++ b/src/ev_select.c
@@ -1,7 +1,7 @@
 /*
  * FD polling functions for generic select()
  *
- * Copyright 2000-2008 Willy Tarreau <w@1wt.eu>
+ * Copyright 2000-2012 Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -29,28 +29,8 @@
 static fd_set *fd_evts[2];
 static fd_set *tmp_evts[2];
 
-
-/*
- * Benchmarks performed on a Pentium-M notebook show that using functions
- * instead of the usual macros improve the FD_* performance by about 80%,
- * and that marking them regparm(2) adds another 20%.
- */
-REGPRM2 static int __fd_is_set(const int fd, int dir)
-{
-	return FD_ISSET(fd, fd_evts[dir]);
-}
-
-REGPRM2 static void __fd_set(const int fd, int dir)
-{
-	FD_SET(fd, fd_evts[dir]);
-}
-
-REGPRM2 static void __fd_clr(const int fd, int dir)
-{
-	FD_CLR(fd, fd_evts[dir]);
-}
-
-REGPRM1 static void __fd_rem(int fd)
+/* Immediately remove the entry upon close() */
+REGPRM1 static void __fd_clo(int fd)
 {
 	FD_CLR(fd, fd_evts[DIR_RD]);
 	FD_CLR(fd, fd_evts[DIR_WR]);
@@ -67,13 +47,53 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
 	int delta_ms;
 	int readnotnull, writenotnull;
 	int fds;
+	int updt_idx, en, eo;
 	char count;
 		
+	/* first, scan the update list to find changes */
+	for (updt_idx = 0; updt_idx < fd_nbupdt; updt_idx++) {
+		fd = fd_updt[updt_idx];
+		en = fdtab[fd].spec_e & 15;  /* new events */
+		eo = fdtab[fd].spec_e >> 4;  /* previous events */
+
+		if (fdtab[fd].owner && (eo ^ en)) {
+			if ((eo ^ en) & FD_EV_POLLED_RW) {
+				/* poll status changed, update the lists */
+				if ((eo & ~en) & FD_EV_POLLED_R)
+					FD_CLR(fd, fd_evts[DIR_RD]);
+				else if ((en & ~eo) & FD_EV_POLLED_R)
+					FD_SET(fd, fd_evts[DIR_RD]);
+
+				if ((eo & ~en) & FD_EV_POLLED_W)
+					FD_CLR(fd, fd_evts[DIR_WR]);
+				else if ((en & ~eo) & FD_EV_POLLED_W)
+					FD_SET(fd, fd_evts[DIR_WR]);
+			}
+
+			fdtab[fd].spec_e = (en << 4) + en;  /* save new events */
+
+			if (!(en & FD_EV_ACTIVE_RW)) {
+				/* This fd doesn't use any active entry anymore, we can
+				 * kill its entry.
+				 */
+				release_spec_entry(fd);
+			}
+			else if ((en & ~eo) & FD_EV_ACTIVE_RW) {
+				/* we need a new spec entry now */
+				alloc_spec_entry(fd);
+			}
+
+		}
+		fdtab[fd].updated = 0;
+		fdtab[fd].new = 0;
+	}
+	fd_nbupdt = 0;
+
 	delta_ms      = 0;
 	delta.tv_sec  = 0;
 	delta.tv_usec = 0;
 
-	if (!run_queue && !signal_queue_len) {
+	if (!fd_nbspec && !run_queue && !signal_queue_len) {
 		if (!exp) {
 			delta_ms      = MAX_DELAY_MS;
 			delta.tv_sec  = (MAX_DELAY_MS / 1000);
@@ -136,8 +156,19 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
 			if (FD_ISSET(fd, tmp_evts[DIR_WR]))
 				fdtab[fd].ev |= FD_POLL_OUT;
 
-			if (fdtab[fd].iocb && fdtab[fd].owner && fdtab[fd].ev)
+			if (fdtab[fd].iocb && fdtab[fd].owner && fdtab[fd].ev) {
+				/* Mark the events as speculative before processing
+				 * them so that if nothing can be done we don't need
+				 * to poll again.
+				 */
+				if (fdtab[fd].ev & (FD_POLL_IN|FD_POLL_HUP|FD_POLL_ERR))
+					fd_ev_set(fd, DIR_RD);
+
+				if (fdtab[fd].ev & (FD_POLL_OUT|FD_POLL_ERR))
+					fd_ev_set(fd, DIR_WR);
+
 				fdtab[fd].iocb(fd);
+			}
 		}
 	}
 }
@@ -225,11 +256,12 @@ static void _do_register(void)
 	p->init = _do_init;
 	p->term = _do_term;
 	p->poll = _do_poll;
-	p->is_set = __fd_is_set;
-	p->set = __fd_set;
-	p->wai = __fd_set;
-	p->clr = __fd_clr;
-	p->clo = p->rem = __fd_rem;
+	p->is_set = NULL;
+	p->set = NULL;
+	p->wai = NULL;
+	p->clr = NULL;
+	p->rem = NULL;
+	p->clo = __fd_clo;
 }