Adding upstream version 1:9.16.44.upstream/1%9.16.44

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 753 insertions, 0 deletions

diff --git a/lib/isc/timer.c b/lib/isc/timer.c
new file mode 100644
index 0000000..e659f58
--- /dev/null
+++ b/lib/isc/timer.c
@@ -0,0 +1,753 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#include <stdbool.h>
+
+#include <isc/app.h>
+#include <isc/condition.h>
+#include <isc/heap.h>
+#include <isc/log.h>
+#include <isc/magic.h>
+#include <isc/mem.h>
+#include <isc/once.h>
+#include <isc/platform.h>
+#include <isc/print.h>
+#include <isc/refcount.h>
+#include <isc/task.h>
+#include <isc/thread.h>
+#include <isc/time.h>
+#include <isc/timer.h>
+#include <isc/util.h>
+
+#ifdef OPENSSL_LEAKS
+#include <openssl/err.h>
+#endif /* ifdef OPENSSL_LEAKS */
+
+#ifdef ISC_TIMER_TRACE
+#define XTRACE(s)      fprintf(stderr, "%s\n", (s))
+#define XTRACEID(s, t) fprintf(stderr, "%s %p\n", (s), (t))
+#define XTRACETIME(s, d) \
+	fprintf(stderr, "%s %u.%09u\n", (s), (d).seconds, (d).nanoseconds)
+#define XTRACETIME2(s, d, n)                                      \
+	fprintf(stderr, "%s %u.%09u %u.%09u\n", (s), (d).seconds, \
+		(d).nanoseconds, (n).seconds, (n).nanoseconds)
+#define XTRACETIMER(s, t, d)                                      \
+	fprintf(stderr, "%s %p %u.%09u\n", (s), (t), (d).seconds, \
+		(d).nanoseconds)
+#else /* ifdef ISC_TIMER_TRACE */
+#define XTRACE(s)
+#define XTRACEID(s, t)
+#define XTRACETIME(s, d)
+#define XTRACETIME2(s, d, n)
+#define XTRACETIMER(s, t, d)
+#endif /* ISC_TIMER_TRACE */
+
+#define TIMER_MAGIC    ISC_MAGIC('T', 'I', 'M', 'R')
+#define VALID_TIMER(t) ISC_MAGIC_VALID(t, TIMER_MAGIC)
+
+struct isc_timer {
+	/*! Not locked. */
+	unsigned int magic;
+	isc_timermgr_t *manager;
+	isc_mutex_t lock;
+	/*! Locked by timer lock. */
+	isc_time_t idle;
+	ISC_LIST(isc_timerevent_t) active;
+	/*! Locked by manager lock. */
+	isc_timertype_t type;
+	isc_time_t expires;
+	isc_interval_t interval;
+	isc_task_t *task;
+	isc_taskaction_t action;
+	void *arg;
+	unsigned int index;
+	isc_time_t due;
+	LINK(isc_timer_t) link;
+};
+
+#define TIMER_MANAGER_MAGIC ISC_MAGIC('T', 'I', 'M', 'M')
+#define VALID_MANAGER(m)    ISC_MAGIC_VALID(m, TIMER_MANAGER_MAGIC)
+
+struct isc_timermgr {
+	/* Not locked. */
+	unsigned int magic;
+	isc_mem_t *mctx;
+	isc_mutex_t lock;
+	/* Locked by manager lock. */
+	bool done;
+	LIST(isc_timer_t) timers;
+	unsigned int nscheduled;
+	isc_time_t due;
+	isc_condition_t wakeup;
+	isc_thread_t thread;
+	isc_heap_t *heap;
+};
+
+void
+isc_timermgr_poke(isc_timermgr_t *manager0);
+
+static isc_result_t
+schedule(isc_timer_t *timer, isc_time_t *now, bool signal_ok) {
+	isc_timermgr_t *manager;
+	isc_time_t due;
+	int cmp;
+
+	/*!
+	 * Note: the caller must ensure locking.
+	 */
+
+	REQUIRE(timer->type != isc_timertype_inactive);
+
+	manager = timer->manager;
+
+	/*
+	 * Compute the new due time.
+	 */
+	if (timer->type != isc_timertype_once) {
+		isc_result_t result = isc_time_add(now, &timer->interval, &due);
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+		if (timer->type == isc_timertype_limited &&
+		    isc_time_compare(&timer->expires, &due) < 0)
+		{
+			due = timer->expires;
+		}
+	} else {
+		if (isc_time_isepoch(&timer->idle)) {
+			due = timer->expires;
+		} else if (isc_time_isepoch(&timer->expires)) {
+			due = timer->idle;
+		} else if (isc_time_compare(&timer->idle, &timer->expires) < 0)
+		{
+			due = timer->idle;
+		} else {
+			due = timer->expires;
+		}
+	}
+
+	/*
+	 * Schedule the timer.
+	 */
+
+	if (timer->index > 0) {
+		/*
+		 * Already scheduled.
+		 */
+		cmp = isc_time_compare(&due, &timer->due);
+		timer->due = due;
+		switch (cmp) {
+		case -1:
+			isc_heap_increased(manager->heap, timer->index);
+			break;
+		case 1:
+			isc_heap_decreased(manager->heap, timer->index);
+			break;
+		case 0:
+			/* Nothing to do. */
+			break;
+		}
+	} else {
+		timer->due = due;
+		isc_heap_insert(manager->heap, timer);
+		manager->nscheduled++;
+	}
+
+	XTRACETIMER("schedule", timer, due);
+
+	/*
+	 * If this timer is at the head of the queue, we need to ensure
+	 * that we won't miss it if it has a more recent due time than
+	 * the current "next" timer.  We do this either by waking up the
+	 * run thread, or explicitly setting the value in the manager.
+	 */
+
+	if (timer->index == 1 && signal_ok) {
+		XTRACE("signal (schedule)");
+		SIGNAL(&manager->wakeup);
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+static void
+deschedule(isc_timer_t *timer) {
+	bool need_wakeup = false;
+	isc_timermgr_t *manager;
+
+	/*
+	 * The caller must ensure locking.
+	 */
+
+	manager = timer->manager;
+	if (timer->index > 0) {
+		if (timer->index == 1) {
+			need_wakeup = true;
+		}
+		isc_heap_delete(manager->heap, timer->index);
+		timer->index = 0;
+		INSIST(manager->nscheduled > 0);
+		manager->nscheduled--;
+		if (need_wakeup) {
+			XTRACE("signal (deschedule)");
+			SIGNAL(&manager->wakeup);
+		}
+	}
+}
+
+static void
+timerevent_unlink(isc_timer_t *timer, isc_timerevent_t *event) {
+	REQUIRE(ISC_LINK_LINKED(event, ev_timerlink));
+	ISC_LIST_UNLINK(timer->active, event, ev_timerlink);
+}
+
+static void
+timerevent_destroy(isc_event_t *event0) {
+	isc_timer_t *timer = event0->ev_destroy_arg;
+	isc_timerevent_t *event = (isc_timerevent_t *)event0;
+
+	LOCK(&timer->lock);
+	if (ISC_LINK_LINKED(event, ev_timerlink)) {
+		/* The event was unlinked via timer_purge() */
+		timerevent_unlink(timer, event);
+	}
+	UNLOCK(&timer->lock);
+
+	isc_mem_put(timer->manager->mctx, event, event0->ev_size);
+}
+
+static void
+timer_purge(isc_timer_t *timer) {
+	isc_timerevent_t *event = NULL;
+
+	while ((event = ISC_LIST_HEAD(timer->active)) != NULL) {
+		timerevent_unlink(timer, event);
+		UNLOCK(&timer->lock);
+		(void)isc_task_purgeevent(timer->task, (isc_event_t *)event);
+		LOCK(&timer->lock);
+	}
+}
+
+isc_result_t
+isc_timer_create(isc_timermgr_t *manager, isc_timertype_t type,
+		 const isc_time_t *expires, const isc_interval_t *interval,
+		 isc_task_t *task, isc_taskaction_t action, void *arg,
+		 isc_timer_t **timerp) {
+	REQUIRE(VALID_MANAGER(manager));
+	REQUIRE(task != NULL);
+	REQUIRE(action != NULL);
+
+	isc_timer_t *timer;
+	isc_result_t result;
+	isc_time_t now;
+
+	/*
+	 * Create a new 'type' timer managed by 'manager'.  The timers
+	 * parameters are specified by 'expires' and 'interval'.  Events
+	 * will be posted to 'task' and when dispatched 'action' will be
+	 * called with 'arg' as the arg value.  The new timer is returned
+	 * in 'timerp'.
+	 */
+	if (expires == NULL) {
+		expires = isc_time_epoch;
+	}
+	if (interval == NULL) {
+		interval = isc_interval_zero;
+	}
+	REQUIRE(type == isc_timertype_inactive ||
+		!(isc_time_isepoch(expires) && isc_interval_iszero(interval)));
+	REQUIRE(timerp != NULL && *timerp == NULL);
+	REQUIRE(type != isc_timertype_limited ||
+		!(isc_time_isepoch(expires) || isc_interval_iszero(interval)));
+
+	/*
+	 * Get current time.
+	 */
+	if (type != isc_timertype_inactive) {
+		TIME_NOW(&now);
+	} else {
+		/*
+		 * We don't have to do this, but it keeps the compiler from
+		 * complaining about "now" possibly being used without being
+		 * set, even though it will never actually happen.
+		 */
+		isc_time_settoepoch(&now);
+	}
+
+	timer = isc_mem_get(manager->mctx, sizeof(*timer));
+
+	timer->manager = manager;
+
+	if (type == isc_timertype_once && !isc_interval_iszero(interval)) {
+		result = isc_time_add(&now, interval, &timer->idle);
+		if (result != ISC_R_SUCCESS) {
+			isc_mem_put(manager->mctx, timer, sizeof(*timer));
+			return (result);
+		}
+	} else {
+		isc_time_settoepoch(&timer->idle);
+	}
+
+	timer->type = type;
+	timer->expires = *expires;
+	timer->interval = *interval;
+	timer->task = NULL;
+	isc_task_attach(task, &timer->task);
+	timer->action = action;
+	/*
+	 * Removing the const attribute from "arg" is the best of two
+	 * evils here.  If the timer->arg member is made const, then
+	 * it affects a great many recipients of the timer event
+	 * which did not pass in an "arg" that was truly const.
+	 * Changing isc_timer_create() to not have "arg" prototyped as const,
+	 * though, can cause compilers warnings for calls that *do*
+	 * have a truly const arg.  The caller will have to carefully
+	 * keep track of whether arg started as a true const.
+	 */
+	DE_CONST(arg, timer->arg);
+	timer->index = 0;
+	isc_mutex_init(&timer->lock);
+	ISC_LINK_INIT(timer, link);
+
+	ISC_LIST_INIT(timer->active);
+
+	timer->magic = TIMER_MAGIC;
+
+	LOCK(&manager->lock);
+
+	/*
+	 * Note we don't have to lock the timer like we normally would because
+	 * there are no external references to it yet.
+	 */
+
+	if (type != isc_timertype_inactive) {
+		result = schedule(timer, &now, true);
+	} else {
+		result = ISC_R_SUCCESS;
+	}
+	if (result == ISC_R_SUCCESS) {
+		*timerp = timer;
+		APPEND(manager->timers, timer, link);
+	}
+
+	UNLOCK(&manager->lock);
+
+	if (result != ISC_R_SUCCESS) {
+		timer->magic = 0;
+		isc_mutex_destroy(&timer->lock);
+		isc_task_detach(&timer->task);
+		isc_mem_put(manager->mctx, timer, sizeof(*timer));
+		return (result);
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_timer_reset(isc_timer_t *timer, isc_timertype_t type,
+		const isc_time_t *expires, const isc_interval_t *interval,
+		bool purge) {
+	isc_time_t now;
+	isc_timermgr_t *manager;
+	isc_result_t result;
+
+	/*
+	 * Change the timer's type, expires, and interval values to the given
+	 * values.  If 'purge' is true, any pending events from this timer
+	 * are purged from its task's event queue.
+	 */
+
+	REQUIRE(VALID_TIMER(timer));
+	manager = timer->manager;
+	REQUIRE(VALID_MANAGER(manager));
+
+	if (expires == NULL) {
+		expires = isc_time_epoch;
+	}
+	if (interval == NULL) {
+		interval = isc_interval_zero;
+	}
+	REQUIRE(type == isc_timertype_inactive ||
+		!(isc_time_isepoch(expires) && isc_interval_iszero(interval)));
+	REQUIRE(type != isc_timertype_limited ||
+		!(isc_time_isepoch(expires) || isc_interval_iszero(interval)));
+
+	/*
+	 * Get current time.
+	 */
+	if (type != isc_timertype_inactive) {
+		TIME_NOW(&now);
+	} else {
+		/*
+		 * We don't have to do this, but it keeps the compiler from
+		 * complaining about "now" possibly being used without being
+		 * set, even though it will never actually happen.
+		 */
+		isc_time_settoepoch(&now);
+	}
+
+	LOCK(&manager->lock);
+	LOCK(&timer->lock);
+
+	if (purge) {
+		timer_purge(timer);
+	}
+	timer->type = type;
+	timer->expires = *expires;
+	timer->interval = *interval;
+	if (type == isc_timertype_once && !isc_interval_iszero(interval)) {
+		result = isc_time_add(&now, interval, &timer->idle);
+	} else {
+		isc_time_settoepoch(&timer->idle);
+		result = ISC_R_SUCCESS;
+	}
+
+	if (result == ISC_R_SUCCESS) {
+		if (type == isc_timertype_inactive) {
+			deschedule(timer);
+			result = ISC_R_SUCCESS;
+		} else {
+			result = schedule(timer, &now, true);
+		}
+	}
+
+	UNLOCK(&timer->lock);
+	UNLOCK(&manager->lock);
+
+	return (result);
+}
+
+isc_timertype_t
+isc_timer_gettype(isc_timer_t *timer) {
+	isc_timertype_t t;
+
+	REQUIRE(VALID_TIMER(timer));
+
+	LOCK(&timer->lock);
+	t = timer->type;
+	UNLOCK(&timer->lock);
+
+	return (t);
+}
+
+isc_result_t
+isc_timer_touch(isc_timer_t *timer) {
+	isc_result_t result;
+	isc_time_t now;
+
+	/*
+	 * Set the last-touched time of 'timer' to the current time.
+	 */
+
+	REQUIRE(VALID_TIMER(timer));
+
+	LOCK(&timer->lock);
+
+	/*
+	 * We'd like to
+	 *
+	 *	REQUIRE(timer->type == isc_timertype_once);
+	 *
+	 * but we cannot without locking the manager lock too, which we
+	 * don't want to do.
+	 */
+
+	TIME_NOW(&now);
+	result = isc_time_add(&now, &timer->interval, &timer->idle);
+
+	UNLOCK(&timer->lock);
+
+	return (result);
+}
+
+void
+isc_timer_destroy(isc_timer_t **timerp) {
+	isc_timer_t *timer = NULL;
+	isc_timermgr_t *manager = NULL;
+
+	REQUIRE(timerp != NULL && VALID_TIMER(*timerp));
+
+	timer = *timerp;
+	*timerp = NULL;
+
+	manager = timer->manager;
+
+	LOCK(&manager->lock);
+
+	LOCK(&timer->lock);
+	timer_purge(timer);
+	deschedule(timer);
+	UNLOCK(&timer->lock);
+
+	UNLINK(manager->timers, timer, link);
+
+	UNLOCK(&manager->lock);
+
+	isc_task_detach(&timer->task);
+	isc_mutex_destroy(&timer->lock);
+	timer->magic = 0;
+	isc_mem_put(manager->mctx, timer, sizeof(*timer));
+}
+
+static void
+timer_post_event(isc_timermgr_t *manager, isc_timer_t *timer,
+		 isc_eventtype_t type) {
+	isc_timerevent_t *event;
+	XTRACEID("posting", timer);
+
+	event = (isc_timerevent_t *)isc_event_allocate(
+		manager->mctx, timer, type, timer->action, timer->arg,
+		sizeof(*event));
+
+	ISC_LINK_INIT(event, ev_timerlink);
+	((isc_event_t *)event)->ev_destroy = timerevent_destroy;
+	((isc_event_t *)event)->ev_destroy_arg = timer;
+
+	event->due = timer->due;
+
+	LOCK(&timer->lock);
+	ISC_LIST_APPEND(timer->active, event, ev_timerlink);
+	UNLOCK(&timer->lock);
+
+	isc_task_send(timer->task, ISC_EVENT_PTR(&event));
+}
+
+static void
+dispatch(isc_timermgr_t *manager, isc_time_t *now) {
+	bool done = false, post_event, need_schedule;
+	isc_eventtype_t type = 0;
+	isc_timer_t *timer;
+	isc_result_t result;
+	bool idle;
+
+	/*!
+	 * The caller must be holding the manager lock.
+	 */
+
+	while (manager->nscheduled > 0 && !done) {
+		timer = isc_heap_element(manager->heap, 1);
+		INSIST(timer != NULL && timer->type != isc_timertype_inactive);
+		if (isc_time_compare(now, &timer->due) >= 0) {
+			if (timer->type == isc_timertype_ticker) {
+				type = ISC_TIMEREVENT_TICK;
+				post_event = true;
+				need_schedule = true;
+			} else if (timer->type == isc_timertype_limited) {
+				int cmp;
+				cmp = isc_time_compare(now, &timer->expires);
+				if (cmp >= 0) {
+					type = ISC_TIMEREVENT_LIFE;
+					post_event = true;
+					need_schedule = false;
+				} else {
+					type = ISC_TIMEREVENT_TICK;
+					post_event = true;
+					need_schedule = true;
+				}
+			} else if (!isc_time_isepoch(&timer->expires) &&
+				   isc_time_compare(now, &timer->expires) >= 0)
+			{
+				type = ISC_TIMEREVENT_LIFE;
+				post_event = true;
+				need_schedule = false;
+			} else {
+				idle = false;
+
+				LOCK(&timer->lock);
+				if (!isc_time_isepoch(&timer->idle) &&
+				    isc_time_compare(now, &timer->idle) >= 0)
+				{
+					idle = true;
+				}
+				UNLOCK(&timer->lock);
+				if (idle) {
+					type = ISC_TIMEREVENT_IDLE;
+					post_event = true;
+					need_schedule = false;
+				} else {
+					/*
+					 * Idle timer has been touched;
+					 * reschedule.
+					 */
+					XTRACEID("idle reschedule", timer);
+					post_event = false;
+					need_schedule = true;
+				}
+			}
+
+			if (post_event) {
+				timer_post_event(manager, timer, type);
+			}
+
+			timer->index = 0;
+			isc_heap_delete(manager->heap, 1);
+			manager->nscheduled--;
+
+			if (need_schedule) {
+				result = schedule(timer, now, false);
+				if (result != ISC_R_SUCCESS) {
+					UNEXPECTED_ERROR(__FILE__, __LINE__,
+							 "%s: %u",
+							 "couldn't schedule "
+							 "timer",
+							 result);
+				}
+			}
+		} else {
+			manager->due = timer->due;
+			done = true;
+		}
+	}
+}
+
+static isc_threadresult_t
+#ifdef _WIN32 /* XXXDCL */
+	WINAPI
+#endif /* ifdef _WIN32 */
+	run(void *uap) {
+	isc_timermgr_t *manager = uap;
+	isc_time_t now;
+	isc_result_t result;
+
+	LOCK(&manager->lock);
+	while (!manager->done) {
+		TIME_NOW(&now);
+
+		XTRACETIME("running", now);
+
+		dispatch(manager, &now);
+
+		if (manager->nscheduled > 0) {
+			XTRACETIME2("waituntil", manager->due, now);
+			result = WAITUNTIL(&manager->wakeup, &manager->lock,
+					   &manager->due);
+			INSIST(result == ISC_R_SUCCESS ||
+			       result == ISC_R_TIMEDOUT);
+		} else {
+			XTRACETIME("wait", now);
+			WAIT(&manager->wakeup, &manager->lock);
+		}
+		XTRACE("wakeup");
+	}
+	UNLOCK(&manager->lock);
+
+#ifdef OPENSSL_LEAKS
+	ERR_remove_state(0);
+#endif /* ifdef OPENSSL_LEAKS */
+
+	return ((isc_threadresult_t)0);
+}
+
+static bool
+sooner(void *v1, void *v2) {
+	isc_timer_t *t1, *t2;
+
+	t1 = v1;
+	t2 = v2;
+	REQUIRE(VALID_TIMER(t1));
+	REQUIRE(VALID_TIMER(t2));
+
+	if (isc_time_compare(&t1->due, &t2->due) < 0) {
+		return (true);
+	}
+	return (false);
+}
+
+static void
+set_index(void *what, unsigned int index) {
+	isc_timer_t *timer;
+
+	REQUIRE(VALID_TIMER(what));
+	timer = what;
+
+	timer->index = index;
+}
+
+isc_result_t
+isc_timermgr_create(isc_mem_t *mctx, isc_timermgr_t **managerp) {
+	isc_timermgr_t *manager;
+
+	/*
+	 * Create a timer manager.
+	 */
+
+	REQUIRE(managerp != NULL && *managerp == NULL);
+
+	manager = isc_mem_get(mctx, sizeof(*manager));
+
+	manager->magic = TIMER_MANAGER_MAGIC;
+	manager->mctx = NULL;
+	manager->done = false;
+	INIT_LIST(manager->timers);
+	manager->nscheduled = 0;
+	isc_time_settoepoch(&manager->due);
+	manager->heap = NULL;
+	isc_heap_create(mctx, sooner, set_index, 0, &manager->heap);
+	isc_mutex_init(&manager->lock);
+	isc_mem_attach(mctx, &manager->mctx);
+	isc_condition_init(&manager->wakeup);
+	isc_thread_create(run, manager, &manager->thread);
+	isc_thread_setname(manager->thread, "isc-timer");
+
+	*managerp = manager;
+
+	return (ISC_R_SUCCESS);
+}
+
+void
+isc_timermgr_poke(isc_timermgr_t *manager) {
+	REQUIRE(VALID_MANAGER(manager));
+
+	SIGNAL(&manager->wakeup);
+}
+
+void
+isc_timermgr_destroy(isc_timermgr_t **managerp) {
+	isc_timermgr_t *manager;
+
+	/*
+	 * Destroy a timer manager.
+	 */
+
+	REQUIRE(managerp != NULL);
+	manager = *managerp;
+	REQUIRE(VALID_MANAGER(manager));
+
+	LOCK(&manager->lock);
+
+	REQUIRE(EMPTY(manager->timers));
+	manager->done = true;
+
+	XTRACE("signal (destroy)");
+	SIGNAL(&manager->wakeup);
+
+	UNLOCK(&manager->lock);
+
+	/*
+	 * Wait for thread to exit.
+	 */
+	isc_thread_join(manager->thread, NULL);
+
+	/*
+	 * Clean up.
+	 */
+	(void)isc_condition_destroy(&manager->wakeup);
+	isc_mutex_destroy(&manager->lock);
+	isc_heap_destroy(&manager->heap);
+	manager->magic = 0;
+	isc_mem_putanddetach(&manager->mctx, manager, sizeof(*manager));
+
+	*managerp = NULL;
+}