tevent: traverse the ev->fd_event list instead of the poll_ev->fds array

That has the same complexity but simplifies the code.

It also seems to fix a real problem, which was found
by the following test failure in Samba's autobuild,
while removing the epoll support from the "standard" backend.

    [402/1555 in 19m8s] samba3.raw.composite(plugin_s4_dc)
    smbtorture 4.1.0pre1-DEVELOPERBUILD
    Using seed 1361531675
    Testing savefile
    Testing parallel fetchfile with 10 ops
    waiting for completion
    maximum runtime exceeded for smbtorture - terminating
    UNEXPECTED(error): samba3.raw.composite.fetchfile (subunit.RemotedTestCase)(plugin_s4_dc)
    REASON: _StringException: _StringException: was started but never finished!
    UNEXPECTED(error): samba3.raw.composite.fetchfile(plugin_s4_dc) (subunit.RemotedTestCase)
    REASON: was started but never finished!

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

1 files changed, 5 insertions, 26 deletions

diff --git a/lib/tevent/tevent_poll.c b/lib/tevent/tevent_poll.c
index 9e2cf1ee05..763a139c7c 100644
--- a/lib/tevent/tevent_poll.c
+++ b/lib/tevent/tevent_poll.c
@@ -499,9 +499,8 @@ static int poll_event_loop_poll(struct tevent_context *ev,
 		ev->additional_data, struct poll_event_context);
 	int pollrtn;
 	int timeout = -1;
-	unsigned first_fd;
-	unsigned i, next_i;
 	int poll_errno;
+	struct tevent_fd *fde = NULL;
 
 	if (ev->signal_events && tevent_common_check_signal(ev)) {
 		return 0;
@@ -541,40 +540,20 @@ static int poll_event_loop_poll(struct tevent_context *ev,
 		return 0;
 	}
 
-	first_fd = (poll_ev->signal_fd != -1) ? 1 : 0;
-
 	/* at least one file descriptor is ready - check
 	   which ones and call the handler, being careful to allow
 	   the handler to remove itself when called */
 
-	for (i=first_fd; i<poll_ev->num_fds; i = next_i) {
+	for (fde = ev->fd_events; fde; fde = fde->next) {
+		unsigned idx = fde->additional_flags;
 		struct pollfd *pfd;
-		struct tevent_fd *fde;
 		uint16_t flags = 0;
 
-		next_i = i + 1;
-
-		fde = poll_ev->fdes[i];
-		if (fde == NULL) {
-			/*
-			 * This fde was talloc_free()'ed. Delete it
-			 * from the arrays
-			 */
-			poll_ev->num_fds -= 1;
-			if (poll_ev->num_fds == i) {
-				break;
-			}
-			poll_ev->fds[i] = poll_ev->fds[poll_ev->num_fds];
-			poll_ev->fdes[i] = poll_ev->fdes[poll_ev->num_fds];
-			if (poll_ev->fdes[i] != NULL) {
-				poll_ev->fdes[i]->additional_flags = i;
-			}
-			/* we have to reprocess position 'i' */
-			next_i = i;
+		if (idx == UINT64_MAX) {
 			continue;
 		}
 
-		pfd = &poll_ev->fds[i];
+		pfd = &poll_ev->fds[idx];
 
 		if (pfd->revents & (POLLHUP|POLLERR)) {
 			/* If we only wait for TEVENT_FD_WRITE, we