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-rw-r--r--ctdb/lib/tevent/tevent_timed.c355
1 files changed, 355 insertions, 0 deletions
diff --git a/ctdb/lib/tevent/tevent_timed.c b/ctdb/lib/tevent/tevent_timed.c
new file mode 100644
index 0000000000..920d39fe06
--- /dev/null
+++ b/ctdb/lib/tevent/tevent_timed.c
@@ -0,0 +1,355 @@
+/*
+ Unix SMB/CIFS implementation.
+
+ common events code for timed events
+
+ Copyright (C) Andrew Tridgell 2003-2006
+ Copyright (C) Stefan Metzmacher 2005-2009
+
+ ** 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
+ 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/time.h"
+#include "tevent.h"
+#include "tevent_internal.h"
+#include "tevent_util.h"
+
+/**
+ compare two timeval structures.
+ Return -1 if tv1 < tv2
+ Return 0 if tv1 == tv2
+ Return 1 if tv1 > tv2
+*/
+int tevent_timeval_compare(const struct timeval *tv1, const struct timeval *tv2)
+{
+ if (tv1->tv_sec > tv2->tv_sec) return 1;
+ if (tv1->tv_sec < tv2->tv_sec) return -1;
+ if (tv1->tv_usec > tv2->tv_usec) return 1;
+ if (tv1->tv_usec < tv2->tv_usec) return -1;
+ return 0;
+}
+
+/**
+ return a zero timeval
+*/
+struct timeval tevent_timeval_zero(void)
+{
+ struct timeval tv;
+ tv.tv_sec = 0;
+ tv.tv_usec = 0;
+ return tv;
+}
+
+/**
+ return a timeval for the current time
+*/
+struct timeval tevent_timeval_current(void)
+{
+ struct timeval tv;
+ gettimeofday(&tv, NULL);
+ return tv;
+}
+
+/**
+ return a timeval struct with the given elements
+*/
+struct timeval tevent_timeval_set(uint32_t secs, uint32_t usecs)
+{
+ struct timeval tv;
+ tv.tv_sec = secs;
+ tv.tv_usec = usecs;
+ return tv;
+}
+
+/**
+ return the difference between two timevals as a timeval
+ if tv1 comes after tv2, then return a zero timeval
+ (this is *tv2 - *tv1)
+*/
+struct timeval tevent_timeval_until(const struct timeval *tv1,
+ const struct timeval *tv2)
+{
+ struct timeval t;
+ if (tevent_timeval_compare(tv1, tv2) >= 0) {
+ return tevent_timeval_zero();
+ }
+ t.tv_sec = tv2->tv_sec - tv1->tv_sec;
+ if (tv1->tv_usec > tv2->tv_usec) {
+ t.tv_sec--;
+ t.tv_usec = 1000000 - (tv1->tv_usec - tv2->tv_usec);
+ } else {
+ t.tv_usec = tv2->tv_usec - tv1->tv_usec;
+ }
+ return t;
+}
+
+/**
+ return true if a timeval is zero
+*/
+bool tevent_timeval_is_zero(const struct timeval *tv)
+{
+ return tv->tv_sec == 0 && tv->tv_usec == 0;
+}
+
+struct timeval tevent_timeval_add(const struct timeval *tv, uint32_t secs,
+ uint32_t usecs)
+{
+ struct timeval tv2 = *tv;
+ tv2.tv_sec += secs;
+ tv2.tv_usec += usecs;
+ tv2.tv_sec += tv2.tv_usec / 1000000;
+ tv2.tv_usec = tv2.tv_usec % 1000000;
+
+ return tv2;
+}
+
+/**
+ return a timeval in the future with a specified offset
+*/
+struct timeval tevent_timeval_current_ofs(uint32_t secs, uint32_t usecs)
+{
+ struct timeval tv = tevent_timeval_current();
+ return tevent_timeval_add(&tv, secs, usecs);
+}
+
+/*
+ destroy a timed event
+*/
+static int tevent_common_timed_destructor(struct tevent_timer *te)
+{
+ if (te->event_ctx == NULL) {
+ return 0;
+ }
+
+ tevent_debug(te->event_ctx, TEVENT_DEBUG_TRACE,
+ "Destroying timer event %p \"%s\"\n",
+ te, te->handler_name);
+
+ if (te->event_ctx->last_zero_timer == te) {
+ te->event_ctx->last_zero_timer = DLIST_PREV(te);
+ }
+ DLIST_REMOVE(te->event_ctx->timer_events, te);
+
+ return 0;
+}
+
+static int tevent_common_timed_deny_destructor(struct tevent_timer *te)
+{
+ return -1;
+}
+
+/*
+ add a timed event
+ return NULL on failure (memory allocation error)
+*/
+static struct tevent_timer *tevent_common_add_timer_internal(
+ struct tevent_context *ev,
+ TALLOC_CTX *mem_ctx,
+ struct timeval next_event,
+ tevent_timer_handler_t handler,
+ void *private_data,
+ const char *handler_name,
+ const char *location,
+ bool optimize_zero)
+{
+ struct tevent_timer *te, *prev_te, *cur_te;
+
+ te = talloc(mem_ctx?mem_ctx:ev, struct tevent_timer);
+ if (te == NULL) return NULL;
+
+ te->event_ctx = ev;
+ te->next_event = next_event;
+ te->handler = handler;
+ te->private_data = private_data;
+ te->handler_name = handler_name;
+ te->location = location;
+ te->additional_data = NULL;
+
+ if (ev->timer_events == NULL) {
+ ev->last_zero_timer = NULL;
+ }
+
+ /* keep the list ordered */
+ prev_te = NULL;
+ if (optimize_zero && tevent_timeval_is_zero(&te->next_event)) {
+ /*
+ * Some callers use zero tevent_timer
+ * instead of tevent_immediate events.
+ *
+ * As these can happen very often,
+ * we remember the last zero timer
+ * in the list.
+ */
+ prev_te = ev->last_zero_timer;
+ ev->last_zero_timer = te;
+ } else {
+ /*
+ * we traverse the list from the tail
+ * because it's much more likely that
+ * timers are added at the end of the list
+ */
+ for (cur_te = DLIST_TAIL(ev->timer_events);
+ cur_te != NULL;
+ cur_te = DLIST_PREV(cur_te))
+ {
+ int ret;
+
+ /*
+ * if the new event comes before the current
+ * we continue searching
+ */
+ ret = tevent_timeval_compare(&te->next_event,
+ &cur_te->next_event);
+ if (ret < 0) {
+ continue;
+ }
+
+ break;
+ }
+
+ prev_te = cur_te;
+ }
+
+ DLIST_ADD_AFTER(ev->timer_events, te, prev_te);
+
+ talloc_set_destructor(te, tevent_common_timed_destructor);
+
+ tevent_debug(ev, TEVENT_DEBUG_TRACE,
+ "Added timed event \"%s\": %p\n",
+ handler_name, te);
+ return te;
+}
+
+struct tevent_timer *tevent_common_add_timer(struct tevent_context *ev,
+ TALLOC_CTX *mem_ctx,
+ struct timeval next_event,
+ tevent_timer_handler_t handler,
+ void *private_data,
+ const char *handler_name,
+ const char *location)
+{
+ /*
+ * do not use optimization, there are broken Samba
+ * versions which use tevent_common_add_timer()
+ * without using tevent_common_loop_timer_delay(),
+ * it just uses DLIST_REMOVE(ev->timer_events, te)
+ * and would leave ev->last_zero_timer behind.
+ */
+ return tevent_common_add_timer_internal(ev, mem_ctx, next_event,
+ handler, private_data,
+ handler_name, location,
+ false);
+}
+
+struct tevent_timer *tevent_common_add_timer_v2(struct tevent_context *ev,
+ TALLOC_CTX *mem_ctx,
+ struct timeval next_event,
+ tevent_timer_handler_t handler,
+ void *private_data,
+ const char *handler_name,
+ const char *location)
+{
+ /*
+ * Here we turn on last_zero_timer optimization
+ */
+ return tevent_common_add_timer_internal(ev, mem_ctx, next_event,
+ handler, private_data,
+ handler_name, location,
+ true);
+}
+
+/*
+ do a single event loop using the events defined in ev
+
+ return the delay until the next timed event,
+ or zero if a timed event was triggered
+*/
+struct timeval tevent_common_loop_timer_delay(struct tevent_context *ev)
+{
+ struct timeval current_time = tevent_timeval_zero();
+ struct tevent_timer *te = ev->timer_events;
+
+ if (!te) {
+ /* have a default tick time of 30 seconds. This guarantees
+ that code that uses its own timeout checking will be
+ able to proceed eventually */
+ return tevent_timeval_set(30, 0);
+ }
+
+ /*
+ * work out the right timeout for the next timed event
+ *
+ * avoid the syscall to gettimeofday() if the timed event should
+ * be triggered directly
+ *
+ * if there's a delay till the next timed event, we're done
+ * with just returning the delay
+ */
+ if (!tevent_timeval_is_zero(&te->next_event)) {
+ struct timeval delay;
+
+ current_time = tevent_timeval_current();
+
+ delay = tevent_timeval_until(&current_time, &te->next_event);
+ if (!tevent_timeval_is_zero(&delay)) {
+ return delay;
+ }
+ }
+
+ /*
+ * ok, we have a timed event that we'll process ...
+ */
+
+ /* deny the handler to free the event */
+ talloc_set_destructor(te, tevent_common_timed_deny_destructor);
+
+ /* We need to remove the timer from the list before calling the
+ * handler because in a semi-async inner event loop called from the
+ * handler we don't want to come across this event again -- vl */
+ if (ev->last_zero_timer == te) {
+ ev->last_zero_timer = DLIST_PREV(te);
+ }
+ DLIST_REMOVE(ev->timer_events, te);
+
+ tevent_debug(te->event_ctx, TEVENT_DEBUG_TRACE,
+ "Running timer event %p \"%s\"\n",
+ te, te->handler_name);
+
+ /*
+ * If the timed event was registered for a zero current_time,
+ * then we pass a zero timeval here too! To avoid the
+ * overhead of gettimeofday() calls.
+ *
+ * otherwise we pass the current time
+ */
+ te->handler(ev, te, current_time, te->private_data);
+
+ /* The destructor isn't necessary anymore, we've already removed the
+ * event from the list. */
+ talloc_set_destructor(te, NULL);
+
+ tevent_debug(te->event_ctx, TEVENT_DEBUG_TRACE,
+ "Ending timer event %p \"%s\"\n",
+ te, te->handler_name);
+
+ talloc_free(te);
+
+ return tevent_timeval_zero();
+}
+
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