Add kqueue(2) implementation to Asterisk in various places.

This will save a considerable amount of CPU on the BSDs, including Mac OS X,
as it eliminates several places in the code that we previously used a busy
loop.  Additionally, this adds a res_timing interface, using kqueue timers.

Review: https://reviewboard.asterisk.org/r/543/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@262852 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 390 insertions, 0 deletions

diff --git a/res/res_timing_kqueue.c b/res/res_timing_kqueue.c
new file mode 100644
index 000000000..99baefede
--- /dev/null
+++ b/res/res_timing_kqueue.c
@@ -0,0 +1,390 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2010, Digium, Inc.
+ *
+ * Tilghman Lesher <tlesher AT digium DOT com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*!
+ * \file
+ * \author Tilghman Lesher <tlesher AT digium DOT com>
+ *
+ * \brief kqueue timing interface
+ */
+
+/*** MODULEINFO
+	<depend>kqueue</depend>
+ ***/
+
+#include "asterisk.h"
+
+#include <sys/types.h>
+#include <sys/event.h>
+#include <sys/time.h>
+
+#include "asterisk/module.h"
+#include "asterisk/astobj2.h"
+#include "asterisk/timing.h"
+#include "asterisk/logger.h"
+#include "asterisk/utils.h"
+#include "asterisk/time.h"
+#include "asterisk/test.h"
+
+static void *timing_funcs_handle;
+
+static int kqueue_timer_open(void);
+static void kqueue_timer_close(int handle);
+static int kqueue_timer_set_rate(int handle, unsigned int rate);
+static void kqueue_timer_ack(int handle, unsigned int quantity);
+static int kqueue_timer_enable_continuous(int handle);
+static int kqueue_timer_disable_continuous(int handle);
+static enum ast_timer_event kqueue_timer_get_event(int handle);
+static unsigned int kqueue_timer_get_max_rate(int handle);
+
+static struct ast_timing_interface kqueue_timing = {
+	.name = "kqueue",
+	.priority = 150,
+	.timer_open = kqueue_timer_open,
+	.timer_close = kqueue_timer_close,
+	.timer_set_rate = kqueue_timer_set_rate,
+	.timer_ack = kqueue_timer_ack,
+	.timer_enable_continuous = kqueue_timer_enable_continuous,
+	.timer_disable_continuous = kqueue_timer_disable_continuous,
+	.timer_get_event = kqueue_timer_get_event,
+	.timer_get_max_rate = kqueue_timer_get_max_rate,
+};
+
+static struct ao2_container *kqueue_timers;
+
+struct kqueue_timer {
+	int handle;
+	uint64_t nsecs;
+	uint64_t unacked;
+	unsigned int is_continuous:1;
+};
+
+static int kqueue_timer_hash(const void *obj, const int flags)
+{
+	const struct kqueue_timer *timer = obj;
+
+	return timer->handle;
+}
+
+static int kqueue_timer_cmp(void *obj, void *args, int flags)
+{
+	struct kqueue_timer *timer1 = obj, *timer2 = args;
+	return timer1->handle == timer2->handle ? CMP_MATCH | CMP_STOP : 0;
+}
+
+static void timer_destroy(void *obj)
+{
+	struct kqueue_timer *timer = obj;
+	close(timer->handle);
+}
+
+#define lookup_timer(a)	_lookup_timer(a, __FILE__, __LINE__, __PRETTY_FUNCTION__)
+static struct kqueue_timer *_lookup_timer(int handle, const char *file, int line, const char *func)
+{
+	struct kqueue_timer *our_timer, find_helper = {
+		.handle = handle,
+	};
+
+	if (!(our_timer = ao2_find(kqueue_timers, &find_helper, OBJ_POINTER))) {
+		ast_log(__LOG_ERROR, file, line, func, "Couldn't find timer with handle %d\n", handle);
+		/* API says we set errno */
+		errno = ESRCH;
+		return NULL;
+	}
+	return our_timer;
+}
+
+static int kqueue_timer_open(void)
+{
+	struct kqueue_timer *timer;
+	int handle;
+
+	if (!(timer = ao2_alloc(sizeof(*timer), timer_destroy))) {
+		ast_log(LOG_ERROR, "Could not allocate memory for kqueue_timer structure\n");
+		return -1;
+	}
+	if ((handle = kqueue()) < 0) {
+		ast_log(LOG_ERROR, "Failed to create kqueue timer: %s\n", strerror(errno));
+		ao2_ref(timer, -1);
+		return -1;
+	}
+
+	timer->handle = handle;
+	ao2_link(kqueue_timers, timer);
+	/* Get rid of the reference from the allocation */
+	ao2_ref(timer, -1);
+	return handle;
+}
+
+static void kqueue_timer_close(int handle)
+{
+	struct kqueue_timer *our_timer;
+
+	if (!(our_timer = lookup_timer(handle))) {
+		return;
+	}
+
+	ao2_unlink(kqueue_timers, our_timer);
+	ao2_ref(our_timer, -1);
+}
+
+static void kqueue_set_nsecs(struct kqueue_timer *our_timer, uint64_t nsecs)
+{
+	struct timespec nowait = { 0, 1 };
+#ifdef HAVE_KEVENT64
+	struct kevent64 kev;
+
+	EV_SET64(&kev, our_timer->handle, EVFILT_TIMER, EV_ADD | EV_ENABLE, NOTE_NSECONDS,
+		nsecs, NULL, 0, 0);
+	kevent64(our_timer->handle, &kev, 1, NULL, 0, &nowait);
+#else
+	struct kevent kev;
+
+	EV_SET(&kev, our_timer->handle, EVFILT_TIMER, EV_ADD | EV_ENABLE,
+#ifdef NOTE_NSECONDS
+		nsecs <= 0xFFffFFff ? NOTE_NSECONDS :
+#endif
+#ifdef NOTE_USECONDS
+		NOTE_USECONDS
+#else /* Milliseconds, if no constants are defined */
+		0
+#endif
+		,
+#ifdef NOTE_NSECONDS
+		nsecs <= 0xFFffFFff ? nsecs :
+#endif
+#ifdef NOTE_USECONDS
+	nsecs / 1000
+#else /* Milliseconds, if nothing else is defined */
+	nsecs / 1000000
+#endif
+	, NULL);
+	kevent(our_timer->handle, &kev, 1, NULL, 0, &nowait);
+#endif
+}
+
+static int kqueue_timer_set_rate(int handle, unsigned int rate)
+{
+	struct kqueue_timer *our_timer;
+
+	if (!(our_timer = lookup_timer(handle))) {
+		return -1;
+	}
+
+	kqueue_set_nsecs(our_timer, (our_timer->nsecs = rate ? (long) (1000000000 / rate) : 0L));
+	ao2_ref(our_timer, -1);
+
+	return 0;
+}
+
+static void kqueue_timer_ack(int handle, unsigned int quantity)
+{
+	struct kqueue_timer *our_timer;
+
+	if (!(our_timer = lookup_timer(handle))) {
+		return;
+	}
+
+	if (our_timer->unacked < quantity) {
+		ast_debug(1, "Acking more events than have expired?!!\n");
+		our_timer->unacked = 0;
+	} else {
+		our_timer->unacked -= quantity;
+	}
+}
+
+static int kqueue_timer_enable_continuous(int handle)
+{
+	struct kqueue_timer *our_timer;
+
+	if (!(our_timer = lookup_timer(handle))) {
+		return -1;
+	}
+
+	kqueue_set_nsecs(our_timer, 1);
+	our_timer->is_continuous = 1;
+	our_timer->unacked = 0;
+	ao2_ref(our_timer, -1);
+	return 0;
+}
+
+static int kqueue_timer_disable_continuous(int handle)
+{
+	struct kqueue_timer *our_timer;
+
+	if (!(our_timer = lookup_timer(handle))) {
+		return -1;
+	}
+
+	kqueue_set_nsecs(our_timer, our_timer->nsecs);
+	our_timer->is_continuous = 0;
+	our_timer->unacked = 0;
+	ao2_ref(our_timer, -1);
+	return 0;
+}
+
+static enum ast_timer_event kqueue_timer_get_event(int handle)
+{
+	enum ast_timer_event res = -1;
+	struct kqueue_timer *our_timer;
+	struct timespec sixty_seconds = { 60, 0 };
+	struct kevent kev;
+
+	if (!(our_timer = lookup_timer(handle))) {
+		return -1;
+	}
+
+	/* If we have non-ACKed events, just return immediately */
+	if (our_timer->unacked == 0) {
+		if (kevent(handle, NULL, 0, &kev, 1, &sixty_seconds) > 0) {
+			our_timer->unacked += kev.data;
+		}
+	}
+
+	if (our_timer->unacked > 0) {
+		res = our_timer->is_continuous ? AST_TIMING_EVENT_CONTINUOUS : AST_TIMING_EVENT_EXPIRED;
+	}
+
+	ao2_ref(our_timer, -1);
+	return res;
+}
+
+static unsigned int kqueue_timer_get_max_rate(int handle)
+{
+	/* Actually, the max rate is 2^64-1 seconds, but that's not representable in a 32-bit integer. */
+	return UINT_MAX;
+}
+
+#ifdef TEST_FRAMEWORK
+AST_TEST_DEFINE(test_kqueue_timing)
+{
+	int res = AST_TEST_PASS, handle, i;
+	uint64_t diff;
+	struct pollfd pfd = { 0, POLLIN, 0 };
+	struct kqueue_timer *kt;
+	struct timeval start;
+
+	switch (cmd) {
+	case TEST_INIT:
+		info->name = "test_kqueue_timing";
+		info->category = "res/res_timing_kqueue";
+		info->summary = "Test KQueue timing interface";
+		info->description = "Verify that the KQueue timing interface correctly generates timing events";
+		return AST_TEST_NOT_RUN;
+	case TEST_EXECUTE:
+		break;
+	}
+
+	if (!(handle = kqueue_timer_open())) {
+		ast_test_status_update(test, "Cannot open timer!\n");
+		return AST_TEST_FAIL;
+	}
+
+	do {
+		pfd.fd = handle;
+		if (kqueue_timer_set_rate(handle, 1000)) {
+			ast_test_status_update(test, "Cannot set timer rate to 1000/s\n");
+			res = AST_TEST_FAIL;
+			break;
+		}
+		if (ast_poll(&pfd, 1, 1000) < 1) {
+			ast_test_status_update(test, "Polling on a kqueue doesn't work\n");
+			res = AST_TEST_FAIL;
+			break;
+		}
+		if (pfd.revents != POLLIN) {
+			ast_test_status_update(test, "poll() should have returned POLLIN, but instead returned %hd\n", pfd.revents);
+			res = AST_TEST_FAIL;
+			break;
+		}
+		if (!(kt = lookup_timer(handle))) {
+			ast_test_status_update(test, "Could not find timer structure in container?!!\n");
+			res = AST_TEST_FAIL;
+			break;
+		}
+		if (kqueue_timer_get_event(handle) <= 0) {
+			ast_test_status_update(test, "No events generated after a poll returned successfully?!!\n");
+			res = AST_TEST_FAIL;
+			break;
+		}
+		if (kt->unacked == 0) {
+			ast_test_status_update(test, "Unacked events is 0, but there should be at least 1.\n");
+			res = AST_TEST_FAIL;
+			break;
+		}
+		kqueue_timer_enable_continuous(handle);
+		start = ast_tvnow();
+		for (i = 0; i < 100; i++) {
+			if (ast_poll(&pfd, 1, 1000) < 1) {
+				ast_test_status_update(test, "Polling on a kqueue doesn't work\n");
+				res = AST_TEST_FAIL;
+				break;
+			}
+			if (kqueue_timer_get_event(handle) <= 0) {
+				ast_test_status_update(test, "No events generated in continuous mode after 1 microsecond?!!\n");
+				res = AST_TEST_FAIL;
+				break;
+			}
+		}
+		diff = ast_tvdiff_us(ast_tvnow(), start);
+		ast_test_status_update(test, "diff is %llu\n", diff);
+		/*
+		if (abs(diff - kt->unacked) == 0) {
+			ast_test_status_update(test, "Unacked events should be around 1000, not %llu\n", kt->unacked);
+			res = AST_TEST_FAIL;
+		}
+		*/
+	} while (0);
+	kqueue_timer_close(handle);
+	return res;
+}
+#endif
+
+static int load_module(void)
+{
+	if (!(kqueue_timers = ao2_container_alloc(563, kqueue_timer_hash, kqueue_timer_cmp))) {
+		return AST_MODULE_LOAD_DECLINE;
+	}
+
+	if (!(timing_funcs_handle = ast_register_timing_interface(&kqueue_timing))) {
+		ao2_ref(kqueue_timers, -1);
+		return AST_MODULE_LOAD_DECLINE;
+	}
+
+	AST_TEST_REGISTER(test_kqueue_timing);
+	return AST_MODULE_LOAD_SUCCESS;
+}
+
+static int unload_module(void)
+{
+	int res;
+
+	AST_TEST_UNREGISTER(test_kqueue_timing);
+	if (!(res = ast_unregister_timing_interface(timing_funcs_handle))) {
+		ao2_ref(kqueue_timers, -1);
+		kqueue_timers = NULL;
+	}
+
+	return res;
+}
+
+AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "KQueue Timing Interface",
+		.load = load_module,
+		.unload = unload_module,
+		.load_pri = 10,
+		);