Unix SMB/CIFS implementation.
main select loop and event handling
Copyright (C) Andrew Tridgell 2003
-
- 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,
+ Copyright (C) Stefan Metzmacher 2009
+
+ ** 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 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/>.
+ 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"
#include "system/filesys.h"
+#define TEVENT_DEPRECATED 1
#include "tevent.h"
#include "tevent_internal.h"
#include "tevent_util.h"
}
}
- e = talloc(talloc_autofree_context(), struct tevent_ops_list);
+ e = talloc(NULL, struct tevent_ops_list);
if (e == NULL) return false;
e->name = name;
void tevent_set_default_backend(const char *backend)
{
talloc_free(tevent_default_backend);
- tevent_default_backend = talloc_strdup(talloc_autofree_context(),
- backend);
+ tevent_default_backend = talloc_strdup(NULL, backend);
}
/*
*/
static void tevent_backend_init(void)
{
+ static bool done;
+
+ if (done) {
+ return;
+ }
+
+ done = true;
+
tevent_select_init();
- tevent_standard_init();
+ tevent_poll_init();
+ tevent_poll_mt_init();
#ifdef HAVE_EPOLL
tevent_epoll_init();
#endif
-#ifdef HAVE_LINUX_AIO
- tevent_aio_init();
+#ifdef HAVE_KQUEUE
+ tevent_kqueue_init();
#endif
+ tevent_standard_init();
+}
+
+_PRIVATE_ const struct tevent_ops *tevent_find_ops_byname(const char *name)
+{
+ struct tevent_ops_list *e;
+
+ tevent_backend_init();
+
+ if (name == NULL) {
+ name = tevent_default_backend;
+ }
+ if (name == NULL) {
+ name = "standard";
+ }
+
+ for (e = tevent_backends; e != NULL; e = e->next) {
+ if (0 == strcmp(e->name, name)) {
+ return e->ops;
+ }
+ }
+
+ return NULL;
}
/*
{
struct tevent_fd *fd, *fn;
struct tevent_timer *te, *tn;
+ struct tevent_immediate *ie, *in;
struct tevent_signal *se, *sn;
if (ev->pipe_fde) {
talloc_free(ev->pipe_fde);
+ close(ev->pipe_fds[0]);
+ close(ev->pipe_fds[1]);
ev->pipe_fde = NULL;
}
DLIST_REMOVE(ev->fd_events, fd);
}
+ ev->last_zero_timer = NULL;
for (te = ev->timer_events; te; te = tn) {
tn = te->next;
te->event_ctx = NULL;
DLIST_REMOVE(ev->timer_events, te);
}
+ for (ie = ev->immediate_events; ie; ie = in) {
+ in = ie->next;
+ ie->event_ctx = NULL;
+ ie->cancel_fn = NULL;
+ DLIST_REMOVE(ev->immediate_events, ie);
+ }
+
for (se = ev->signal_events; se; se = sn) {
sn = se->next;
se->event_ctx = NULL;
DLIST_REMOVE(ev->signal_events, se);
+ /*
+ * This is important, Otherwise signals
+ * are handled twice in child. eg, SIGHUP.
+ * one added in parent, and another one in
+ * the child. -- BoYang
+ */
+ tevent_cleanup_pending_signal_handlers(se);
}
+ /* removing nesting hook or we get an abort when nesting is
+ * not allowed. -- SSS
+ * Note that we need to leave the allowed flag at its current
+ * value, otherwise the use in tevent_re_initialise() will
+ * leave the event context with allowed forced to false, which
+ * will break users that expect nesting to be allowed
+ */
+ ev->nesting.level = 0;
+ ev->nesting.hook_fn = NULL;
+ ev->nesting.hook_private = NULL;
+
return 0;
}
NOTE: use tevent_context_init() inside of samba!
*/
-static struct tevent_context *tevent_context_init_ops(TALLOC_CTX *mem_ctx,
- const struct tevent_ops *ops)
+struct tevent_context *tevent_context_init_ops(TALLOC_CTX *mem_ctx,
+ const struct tevent_ops *ops,
+ void *additional_data)
{
struct tevent_context *ev;
int ret;
talloc_set_destructor(ev, tevent_common_context_destructor);
ev->ops = ops;
+ ev->additional_data = additional_data;
ret = ev->ops->context_init(ev);
if (ret != 0) {
struct tevent_context *tevent_context_init_byname(TALLOC_CTX *mem_ctx,
const char *name)
{
- struct tevent_ops_list *e;
-
- tevent_backend_init();
+ const struct tevent_ops *ops;
- if (name == NULL) {
- name = tevent_default_backend;
- }
- if (name == NULL) {
- name = "standard";
+ ops = tevent_find_ops_byname(name);
+ if (ops == NULL) {
+ return NULL;
}
- for (e=tevent_backends;e;e=e->next) {
- if (strcmp(name, e->name) == 0) {
- return tevent_context_init_ops(mem_ctx, e->ops);
- }
- }
- return NULL;
+ return tevent_context_init_ops(mem_ctx, ops, NULL);
}
/*
add a fd based event
return NULL on failure (memory allocation error)
-
- if flags contains TEVENT_FD_AUTOCLOSE then the fd will be closed when
- the returned fd_event context is freed
*/
struct tevent_fd *_tevent_add_fd(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
handler_name, location);
}
-/*
- add a disk aio event
-*/
-struct tevent_aio *_tevent_add_aio(struct tevent_context *ev,
- TALLOC_CTX *mem_ctx,
- struct iocb *iocb,
- tevent_aio_handler_t handler,
- void *private_data,
- const char *handler_name,
- const char *location)
-{
- if (ev->ops->add_aio == NULL) return NULL;
- return ev->ops->add_aio(ev, mem_ctx, iocb, handler, private_data,
- handler_name, location);
-}
-
/*
set a close function on the fd event
*/
fde->event_ctx->ops->set_fd_flags(fde, flags);
}
+bool tevent_signal_support(struct tevent_context *ev)
+{
+ if (ev->ops->add_signal) {
+ return true;
+ }
+ return false;
+}
+
+static void (*tevent_abort_fn)(const char *reason);
+
+void tevent_set_abort_fn(void (*abort_fn)(const char *reason))
+{
+ tevent_abort_fn = abort_fn;
+}
+
+static void tevent_abort(struct tevent_context *ev, const char *reason)
+{
+ tevent_debug(ev, TEVENT_DEBUG_FATAL,
+ "abort: %s\n", reason);
+
+ if (!tevent_abort_fn) {
+ abort();
+ }
+
+ tevent_abort_fn(reason);
+}
+
/*
add a timer event
return NULL on failure
handler_name, location);
}
+/*
+ allocate an immediate event
+ return NULL on failure (memory allocation error)
+*/
+struct tevent_immediate *_tevent_create_immediate(TALLOC_CTX *mem_ctx,
+ const char *location)
+{
+ struct tevent_immediate *im;
+
+ im = talloc(mem_ctx, struct tevent_immediate);
+ if (im == NULL) return NULL;
+
+ im->prev = NULL;
+ im->next = NULL;
+ im->event_ctx = NULL;
+ im->create_location = location;
+ im->handler = NULL;
+ im->private_data = NULL;
+ im->handler_name = NULL;
+ im->schedule_location = NULL;
+ im->cancel_fn = NULL;
+ im->additional_data = NULL;
+
+ return im;
+}
+
+/*
+ schedule an immediate event
+*/
+void _tevent_schedule_immediate(struct tevent_immediate *im,
+ struct tevent_context *ev,
+ tevent_immediate_handler_t handler,
+ void *private_data,
+ const char *handler_name,
+ const char *location)
+{
+ ev->ops->schedule_immediate(im, ev, handler, private_data,
+ handler_name, location);
+}
+
/*
add a signal event
handler_name, location);
}
+void tevent_loop_allow_nesting(struct tevent_context *ev)
+{
+ ev->nesting.allowed = true;
+}
+
+void tevent_loop_set_nesting_hook(struct tevent_context *ev,
+ tevent_nesting_hook hook,
+ void *private_data)
+{
+ if (ev->nesting.hook_fn &&
+ (ev->nesting.hook_fn != hook ||
+ ev->nesting.hook_private != private_data)) {
+ /* the way the nesting hook code is currently written
+ we cannot support two different nesting hooks at the
+ same time. */
+ tevent_abort(ev, "tevent: Violation of nesting hook rules\n");
+ }
+ ev->nesting.hook_fn = hook;
+ ev->nesting.hook_private = private_data;
+}
+
+static void tevent_abort_nesting(struct tevent_context *ev, const char *location)
+{
+ const char *reason;
+
+ reason = talloc_asprintf(NULL, "tevent_loop_once() nesting at %s",
+ location);
+ if (!reason) {
+ reason = "tevent_loop_once() nesting";
+ }
+
+ tevent_abort(ev, reason);
+}
+
/*
do a single event loop using the events defined in ev
*/
-int tevent_loop_once(struct tevent_context *ev)
+int _tevent_loop_once(struct tevent_context *ev, const char *location)
{
- return ev->ops->loop_once(ev);
+ int ret;
+ void *nesting_stack_ptr = NULL;
+
+ ev->nesting.level++;
+
+ if (ev->nesting.level > 1) {
+ if (!ev->nesting.allowed) {
+ tevent_abort_nesting(ev, location);
+ errno = ELOOP;
+ return -1;
+ }
+ }
+ if (ev->nesting.level > 0) {
+ if (ev->nesting.hook_fn) {
+ int ret2;
+ ret2 = ev->nesting.hook_fn(ev,
+ ev->nesting.hook_private,
+ ev->nesting.level,
+ true,
+ (void *)&nesting_stack_ptr,
+ location);
+ if (ret2 != 0) {
+ ret = ret2;
+ goto done;
+ }
+ }
+ }
+
+ tevent_trace_point_callback(ev, TEVENT_TRACE_BEFORE_LOOP_ONCE);
+ ret = ev->ops->loop_once(ev, location);
+ tevent_trace_point_callback(ev, TEVENT_TRACE_AFTER_LOOP_ONCE);
+
+ if (ev->nesting.level > 0) {
+ if (ev->nesting.hook_fn) {
+ int ret2;
+ ret2 = ev->nesting.hook_fn(ev,
+ ev->nesting.hook_private,
+ ev->nesting.level,
+ false,
+ (void *)&nesting_stack_ptr,
+ location);
+ if (ret2 != 0) {
+ ret = ret2;
+ goto done;
+ }
+ }
+ }
+
+done:
+ ev->nesting.level--;
+ return ret;
+}
+
+/*
+ this is a performance optimization for the samba4 nested event loop problems
+*/
+int _tevent_loop_until(struct tevent_context *ev,
+ bool (*finished)(void *private_data),
+ void *private_data,
+ const char *location)
+{
+ int ret = 0;
+ void *nesting_stack_ptr = NULL;
+
+ ev->nesting.level++;
+
+ if (ev->nesting.level > 1) {
+ if (!ev->nesting.allowed) {
+ tevent_abort_nesting(ev, location);
+ errno = ELOOP;
+ return -1;
+ }
+ }
+ if (ev->nesting.level > 0) {
+ if (ev->nesting.hook_fn) {
+ int ret2;
+ ret2 = ev->nesting.hook_fn(ev,
+ ev->nesting.hook_private,
+ ev->nesting.level,
+ true,
+ (void *)&nesting_stack_ptr,
+ location);
+ if (ret2 != 0) {
+ ret = ret2;
+ goto done;
+ }
+ }
+ }
+
+ while (!finished(private_data)) {
+ tevent_trace_point_callback(ev, TEVENT_TRACE_BEFORE_LOOP_ONCE);
+ ret = ev->ops->loop_once(ev, location);
+ tevent_trace_point_callback(ev, TEVENT_TRACE_AFTER_LOOP_ONCE);
+ if (ret != 0) {
+ break;
+ }
+ }
+
+ if (ev->nesting.level > 0) {
+ if (ev->nesting.hook_fn) {
+ int ret2;
+ ret2 = ev->nesting.hook_fn(ev,
+ ev->nesting.hook_private,
+ ev->nesting.level,
+ false,
+ (void *)&nesting_stack_ptr,
+ location);
+ if (ret2 != 0) {
+ ret = ret2;
+ goto done;
+ }
+ }
+ }
+
+done:
+ ev->nesting.level--;
+ return ret;
+}
+
+/*
+ return on failure or (with 0) if all fd events are removed
+*/
+int tevent_common_loop_wait(struct tevent_context *ev,
+ const char *location)
+{
+ /*
+ * loop as long as we have events pending
+ */
+ while (ev->fd_events ||
+ ev->timer_events ||
+ ev->immediate_events ||
+ ev->signal_events) {
+ int ret;
+ ret = _tevent_loop_once(ev, location);
+ if (ret != 0) {
+ tevent_debug(ev, TEVENT_DEBUG_FATAL,
+ "_tevent_loop_once() failed: %d - %s\n",
+ ret, strerror(errno));
+ return ret;
+ }
+ }
+
+ tevent_debug(ev, TEVENT_DEBUG_WARNING,
+ "tevent_common_loop_wait() out of events\n");
+ return 0;
}
/*
return on failure or (with 0) if all fd events are removed
*/
-int tevent_loop_wait(struct tevent_context *ev)
+int _tevent_loop_wait(struct tevent_context *ev, const char *location)
{
- return ev->ops->loop_wait(ev);
+ return ev->ops->loop_wait(ev, location);
+}
+
+
+/*
+ re-initialise a tevent context. This leaves you with the same
+ event context, but all events are wiped and the structure is
+ re-initialised. This is most useful after a fork()
+
+ zero is returned on success, non-zero on failure
+*/
+int tevent_re_initialise(struct tevent_context *ev)
+{
+ tevent_common_context_destructor(ev);
+
+ return ev->ops->context_init(ev);
}