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>

diff --git a/lib/tevent/tevent_poll.c b/lib/tevent/tevent_poll.c
index 9e2cf1ee05cdf85eb2aca4a8352bc3b438304e54..763a139c7c5fbc350431c3488a9f77aa3ec04b18 100644 (file)
--- 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