talloc: use the system pytalloc-util for python3 as well
[sfrench/samba-autobuild/.git] / lib / tevent / tevent_select.c
index e21b3c44b9477394315b4a0841403bcafc5ff352..55dd0b66f66c52eb8fea3e3ed78e973ca643c6bb 100644 (file)
@@ -2,25 +2,24 @@
    Unix SMB/CIFS implementation.
    main select loop and event handling
    Copyright (C) Andrew Tridgell       2003-2005
-   Copyright (C) Stefan Metzmacher     2005
-   
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 3 of the License, or
-   (at your option) any later version.
-   
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-   
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
+   Copyright (C) Stefan Metzmacher     2005-2009
 
-/*
-  This is SAMBA's default event loop code
+     ** NOTE! The following LGPL license applies to the tevent
+     ** library. This does NOT imply that all of Samba is released
+     ** under the LGPL
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
 
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "replace.h"
@@ -34,21 +33,8 @@ struct select_event_context {
        /* a pointer back to the generic event_context */
        struct tevent_context *ev;
 
-       /* list of filedescriptor events */
-       struct tevent_fd *fd_events;
-
-       /* list of timed events */
-       struct tevent_timer *timed_events;
-
        /* the maximum file descriptor number in fd_events */
        int maxfd;
-
-       /* information for exiting from the event loop */
-       int exit_code;
-
-       /* this is incremented when the loop over events causes something which
-          could change the events yet to be processed */
-       uint32_t destruction_count;
 };
 
 /*
@@ -58,6 +44,12 @@ static int select_event_context_init(struct tevent_context *ev)
 {
        struct select_event_context *select_ev;
 
+       /*
+        * We might be called during tevent_re_initialise()
+        * which means we need to free our old additional_data.
+        */
+       TALLOC_FREE(ev->additional_data);
+
        select_ev = talloc_zero(ev, struct select_event_context);
        if (!select_ev) return -1;
        select_ev->ev = ev;
@@ -74,7 +66,7 @@ static void calc_maxfd(struct select_event_context *select_ev)
        struct tevent_fd *fde;
 
        select_ev->maxfd = 0;
-       for (fde = select_ev->fd_events; fde; fde = fde->next) {
+       for (fde = select_ev->ev->fd_events; fde; fde = fde->next) {
                if (fde->fd > select_ev->maxfd) {
                        select_ev->maxfd = fde->fd;
                }
@@ -93,22 +85,18 @@ static void calc_maxfd(struct select_event_context *select_ev)
 static int select_event_fd_destructor(struct tevent_fd *fde)
 {
        struct tevent_context *ev = fde->event_ctx;
-       struct select_event_context *select_ev = talloc_get_type(ev->additional_data,
-                                                          struct select_event_context);
-
-       if (select_ev->maxfd == fde->fd) {
-               select_ev->maxfd = EVENT_INVALID_MAXFD;
-       }
+       struct select_event_context *select_ev = NULL;
 
-       DLIST_REMOVE(select_ev->fd_events, fde);
-       select_ev->destruction_count++;
+       if (ev) {
+               select_ev = talloc_get_type_abort(ev->additional_data,
+                                                 struct select_event_context);
 
-       if (fde->flags & TEVENT_FD_AUTOCLOSE) {
-               close(fde->fd);
-               fde->fd = -1;
+               if (select_ev->maxfd == fde->fd) {
+                       select_ev->maxfd = EVENT_INVALID_MAXFD;
+               }
        }
 
-       return 0;
+       return tevent_common_fd_destructor(fde);
 }
 
 /*
@@ -122,25 +110,23 @@ static struct tevent_fd *select_event_add_fd(struct tevent_context *ev, TALLOC_C
                                             const char *handler_name,
                                             const char *location)
 {
-       struct select_event_context *select_ev = talloc_get_type(ev->additional_data,
-                                                          struct select_event_context);
+       struct select_event_context *select_ev =
+               talloc_get_type_abort(ev->additional_data,
+               struct select_event_context);
        struct tevent_fd *fde;
 
-       fde = talloc(mem_ctx?mem_ctx:ev, struct tevent_fd);
+       if (fd < 0 || fd >= FD_SETSIZE) {
+               errno = EBADF;
+               return NULL;
+       }
+
+       fde = tevent_common_add_fd(ev, mem_ctx, fd, flags,
+                                  handler, private_data,
+                                  handler_name, location);
        if (!fde) return NULL;
 
-       fde->event_ctx          = ev;
-       fde->fd                 = fd;
-       fde->flags              = flags;
-       fde->handler            = handler;
-       fde->private_data       = private_data;
-       fde->handler_name       = handler_name;
-       fde->location           = location;
-       fde->additional_flags   = 0;
-       fde->additional_data    = NULL;
-
-       DLIST_ADD(select_ev->fd_events, fde);
-       if (fde->fd > select_ev->maxfd) {
+       if ((select_ev->maxfd != EVENT_INVALID_MAXFD)
+           && (fde->fd > select_ev->maxfd)) {
                select_ev->maxfd = fde->fd;
        }
        talloc_set_destructor(fde, select_event_fd_destructor);
@@ -148,31 +134,6 @@ static struct tevent_fd *select_event_add_fd(struct tevent_context *ev, TALLOC_C
        return fde;
 }
 
-
-/*
-  return the fd event flags
-*/
-static uint16_t select_event_get_fd_flags(struct tevent_fd *fde)
-{
-       return fde->flags;
-}
-
-/*
-  set the fd event flags
-*/
-static void select_event_set_fd_flags(struct tevent_fd *fde, uint16_t flags)
-{
-       struct tevent_context *ev;
-       struct select_event_context *select_ev;
-
-       if (fde->flags == flags) return;
-
-       ev = fde->event_ctx;
-       select_ev = talloc_get_type(ev->additional_data, struct select_event_context);
-
-       fde->flags = flags;
-}
-
 /*
   event loop handling using select()
 */
@@ -181,7 +142,7 @@ static int select_event_loop_select(struct select_event_context *select_ev, stru
        fd_set r_fds, w_fds;
        struct tevent_fd *fde;
        int selrtn;
-       uint32_t destruction_count = ++select_ev->destruction_count;
+       int select_errno;
 
        /* we maybe need to recalculate the maxfd */
        if (select_ev->maxfd == EVENT_INVALID_MAXFD) {
@@ -192,7 +153,16 @@ static int select_event_loop_select(struct select_event_context *select_ev, stru
        FD_ZERO(&w_fds);
 
        /* setup any fd events */
-       for (fde = select_ev->fd_events; fde; fde = fde->next) {
+       for (fde = select_ev->ev->fd_events; fde; fde = fde->next) {
+               if (fde->fd < 0 || fde->fd >= FD_SETSIZE) {
+                       tevent_debug(select_ev->ev, TEVENT_DEBUG_FATAL,
+                                    "ERROR: EBADF fd[%d] >= %d "
+                                    "select_event_loop_once\n",
+                                    fde->fd, FD_SETSIZE);
+                       errno = EBADF;
+                       return -1;
+               }
+
                if (fde->flags & TEVENT_FD_READ) {
                        FD_SET(fde->fd, &r_fds);
                }
@@ -201,20 +171,23 @@ static int select_event_loop_select(struct select_event_context *select_ev, stru
                }
        }
 
-       if (select_ev->ev->num_signal_handlers && 
+       if (select_ev->ev->signal_events &&
            tevent_common_check_signal(select_ev->ev)) {
                return 0;
        }
 
+       tevent_trace_point_callback(select_ev->ev, TEVENT_TRACE_BEFORE_WAIT);
        selrtn = select(select_ev->maxfd+1, &r_fds, &w_fds, NULL, tvalp);
+       select_errno = errno;
+       tevent_trace_point_callback(select_ev->ev, TEVENT_TRACE_AFTER_WAIT);
 
-       if (selrtn == -1 && errno == EINTR && 
-           select_ev->ev->num_signal_handlers) {
+       if (selrtn == -1 && select_errno == EINTR &&
+           select_ev->ev->signal_events) {
                tevent_common_check_signal(select_ev->ev);
                return 0;
        }
 
-       if (selrtn == -1 && errno == EBADF) {
+       if (selrtn == -1 && select_errno == EBADF) {
                /* the socket is dead! this should never
                   happen as the socket should have first been
                   made readable and that should have removed
@@ -222,7 +195,7 @@ static int select_event_loop_select(struct select_event_context *select_ev, stru
                   fatal error. */
                tevent_debug(select_ev->ev, TEVENT_DEBUG_FATAL,
                             "ERROR: EBADF on select_event_loop_once\n");
-               select_ev->exit_code = EBADF;
+               errno = select_errno;
                return -1;
        }
 
@@ -236,70 +209,72 @@ static int select_event_loop_select(struct select_event_context *select_ev, stru
                /* 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 (fde = select_ev->fd_events; fde; fde = fde->next) {
+               for (fde = select_ev->ev->fd_events; fde; fde = fde->next) {
                        uint16_t flags = 0;
 
-                       if (FD_ISSET(fde->fd, &r_fds)) flags |= TEVENT_FD_READ;
-                       if (FD_ISSET(fde->fd, &w_fds)) flags |= TEVENT_FD_WRITE;
+                       if (FD_ISSET(fde->fd, &r_fds) && (fde->flags & TEVENT_FD_READ)) {
+                               flags |= TEVENT_FD_READ;
+                       }
+                       if (FD_ISSET(fde->fd, &w_fds) && (fde->flags & TEVENT_FD_WRITE)) {
+                               flags |= TEVENT_FD_WRITE;
+                       }
                        if (flags) {
+                               DLIST_DEMOTE(select_ev->ev->fd_events, fde);
                                fde->handler(select_ev->ev, fde, flags, fde->private_data);
-                               if (destruction_count != select_ev->destruction_count) {
-                                       break;
-                               }
+                               break;
                        }
                }
        }
 
        return 0;
-}              
+}
 
 /*
   do a single event loop using the events defined in ev 
 */
-static int select_event_loop_once(struct tevent_context *ev)
+static int select_event_loop_once(struct tevent_context *ev, const char *location)
 {
-       struct select_event_context *select_ev = talloc_get_type(ev->additional_data,
-                                                          struct select_event_context);
+       struct select_event_context *select_ev =
+               talloc_get_type_abort(ev->additional_data,
+               struct select_event_context);
        struct timeval tval;
 
-       tval = tevent_common_loop_timer_delay(ev);
-       if (ev_timeval_is_zero(&tval)) {
+       if (ev->signal_events &&
+           tevent_common_check_signal(ev)) {
                return 0;
        }
 
-       return select_event_loop_select(select_ev, &tval);
-}
+       if (ev->threaded_contexts != NULL) {
+               tevent_common_threaded_activate_immediate(ev);
+       }
 
-/*
-  return on failure or (with 0) if all fd events are removed
-*/
-static int select_event_loop_wait(struct tevent_context *ev)
-{
-       struct select_event_context *select_ev = talloc_get_type(ev->additional_data,
-                                                          struct select_event_context);
-       select_ev->exit_code = 0;
+       if (ev->immediate_events &&
+           tevent_common_loop_immediate(ev)) {
+               return 0;
+       }
 
-       while (select_ev->fd_events && select_ev->exit_code == 0) {
-               if (select_event_loop_once(ev) != 0) {
-                       break;
-               }
+       tval = tevent_common_loop_timer_delay(ev);
+       if (tevent_timeval_is_zero(&tval)) {
+               return 0;
        }
 
-       return select_ev->exit_code;
+       return select_event_loop_select(select_ev, &tval);
 }
 
 static const struct tevent_ops select_event_ops = {
-       .context_init   = select_event_context_init,
-       .add_fd         = select_event_add_fd,
-       .get_fd_flags   = select_event_get_fd_flags,
-       .set_fd_flags   = select_event_set_fd_flags,
-       .add_timer      = tevent_common_add_timer,
-       .add_signal     = tevent_common_add_signal,
-       .loop_once      = select_event_loop_once,
-       .loop_wait      = select_event_loop_wait,
+       .context_init           = select_event_context_init,
+       .add_fd                 = select_event_add_fd,
+       .set_fd_close_fn        = tevent_common_fd_set_close_fn,
+       .get_fd_flags           = tevent_common_fd_get_flags,
+       .set_fd_flags           = tevent_common_fd_set_flags,
+       .add_timer              = tevent_common_add_timer_v2,
+       .schedule_immediate     = tevent_common_schedule_immediate,
+       .add_signal             = tevent_common_add_signal,
+       .loop_once              = select_event_loop_once,
+       .loop_wait              = tevent_common_loop_wait,
 };
 
-bool tevent_select_init(void)
+_PRIVATE_ bool tevent_select_init(void)
 {
        return tevent_register_backend("select", &select_event_ops);
 }