MINOR: pollers: Add a fixup_tgid_takeover() method.

Add a fixup_tgid_takeover() method to pollers for which it makes sense
(epoll, kqueue and evport). That method can be called after a takeover
of a fd from a different thread group, to make sure the poller's
internal structure reflects the new state.

include/haproxy/fd-t.h

@@ -242,6 +242,7 @@ struct poller {
 	void   (*term)(struct poller *p);            /* termination of this poller */
 	int    (*test)(struct poller *p);            /* pre-init check of the poller */
 	int    (*fork)(struct poller *p);            /* post-fork re-opening */
+	void   (*fixup_tgid_takeover)(struct poller *p, const int fd, const int old_tid, const int old_tgid); /* Fixup anything necessary after a FD takeover across tgids */
 	const char   *name;                                  /* poller name */
 	unsigned int flags;                                  /* HAP_POLL_F_* */
 	int    pref;                                         /* try pollers with higher preference first */

src/ev_epoll.c

@@ -69,6 +69,14 @@ static void __fd_clo(int fd)
 	}
 }
 
+static void _do_fixup_tgid_takeover(struct poller *poller, const int fd, const int old_ltid, const int old_tgid)
+{
+
+	polled_mask[fd].poll_recv = 0;
+	polled_mask[fd].poll_send = 0;
+	fdtab[fd].update_mask = 0;
+}
+
 static void _update_fd(int fd)
 {
 	int en, opcode;
@@ -463,6 +471,7 @@ static void _do_register(void)
 	p->term = _do_term;
 	p->poll = _do_poll;
 	p->fork = _do_fork;
+	p->fixup_tgid_takeover = _do_fixup_tgid_takeover;
 }
 
 /* config parser for global "tune.epoll.mask-events", accepts "err", "hup", "rdhup" */

src/ev_evports.c

@@ -105,6 +105,14 @@ static void _update_fd(int fd)
 	evports_resync_fd(fd, events);
 }
 
+static void _do_fixup_tgid_takeover(struct poller *poller, const int fd, const int old_ltid, const int old_tgid)
+{
+
+	polled_mask[fd].poll_recv = 0;
+	polled_mask[fd].poll_send = 0;
+	fdtab[fd].update_mask = 0;
+}
+
 /*
  * Event Ports poller.  This routine interacts with the file descriptor
  * management data structures and routines; see the large block comment in
@@ -450,6 +458,7 @@ static void _do_register(void)
 	p->term = _do_term;
 	p->poll = _do_poll;
 	p->fork = _do_fork;
+	p->fixup_tgid_takeover = _do_fixup_tgid_takeover;
 }
 
 INITCALL0(STG_REGISTER, _do_register);

src/ev_kqueue.c

@@ -84,6 +84,14 @@ static int _update_fd(int fd, int start)
 	return changes;
 }
 
+static void _do_fixup_tgid_takeover(struct poller *poller, const int fd, const int old_ltid, const int old_tgid)
+{
+
+	polled_mask[fd].poll_recv = 0;
+	polled_mask[fd].poll_send = 0;
+	fdtab[fd].update_mask = 0;
+}
+
 /*
  * kqueue() poller
  */
@@ -368,6 +376,7 @@ static void _do_register(void)
 	p->term = _do_term;
 	p->poll = _do_poll;
 	p->fork = _do_fork;
+	p->fixup_tgid_takeover = _do_fixup_tgid_takeover;
 }
 
 INITCALL0(STG_REGISTER, _do_register);