create and use multiple fetch dispatches

Added API to create a set of UDP dispatches which can be shared
round-robin style when making upstream queries for authoritative
data; this should reduce lock contention in the query source
dispatch.

lib/dns/tests/dispatch_test.c

@@ -0,0 +1,160 @@
+/*
+ * Copyright (C) 2011, 2012  Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id$ */
+
+/*! \file */
+
+#include <config.h>
+
+#include <atf-c.h>
+
+#include <unistd.h>
+
+#include <isc/buffer.h>
+#include <isc/socket.h>
+#include <isc/task.h>
+#include <isc/timer.h>
+
+#include <dns/dispatch.h>
+#include <dns/name.h>
+#include <dns/view.h>
+
+#include "dnstest.h"
+
+dns_dispatchmgr_t *dispatchmgr = NULL;
+dns_dispatchset_t *dset = NULL;
+
+static isc_result_t
+make_dispatchset(unsigned int ndisps) {
+	isc_result_t result;
+	isc_sockaddr_t any;
+	unsigned int attrs;
+	dns_dispatch_t *disp = NULL;
+
+	result = dns_dispatchmgr_create(mctx, NULL, &dispatchmgr);
+	if (result != ISC_R_SUCCESS)
+		return (result);
+
+	isc_sockaddr_any(&any);
+	attrs = DNS_DISPATCHATTR_IPV4 | DNS_DISPATCHATTR_UDP;
+	result = dns_dispatch_getudp(dispatchmgr, socketmgr, taskmgr,
+				     &any, 512, 6, 1024, 17, 19, attrs,
+				     attrs, &disp);
+	if (result != ISC_R_SUCCESS)
+		return (result);
+
+	result = dns_dispatchset_create(mctx, socketmgr, taskmgr, disp,
+					&dset, ndisps);
+	dns_dispatch_detach(&disp);
+
+	return (result);
+}
+
+static void
+teardown() {
+	if (dset != NULL)
+		dns_dispatchset_destroy(&dset);
+	if (dispatchmgr != NULL)
+		dns_dispatchmgr_destroy(&dispatchmgr);
+}
+
+/*
+ * Individual unit tests
+ */
+ATF_TC(dispatchset_create);
+ATF_TC_HEAD(dispatchset_create, tc) {
+	atf_tc_set_md_var(tc, "descr", "create dispatch set");
+}
+ATF_TC_BODY(dispatchset_create, tc) {
+	isc_result_t result;
+
+	UNUSED(tc);
+
+	result = dns_test_begin(NULL, ISC_TRUE);
+	ATF_REQUIRE_EQ(result, ISC_R_SUCCESS);
+
+	result = make_dispatchset(1);
+	ATF_REQUIRE_EQ(result, ISC_R_SUCCESS);
+	teardown();
+
+	result = make_dispatchset(10);
+	ATF_REQUIRE_EQ(result, ISC_R_SUCCESS);
+	teardown();
+
+	dns_test_end();
+}
+
+
+
+ATF_TC(dispatchset_get);
+ATF_TC_HEAD(dispatchset_get, tc) {
+	atf_tc_set_md_var(tc, "descr", "test dispatch set round-robin");
+}
+ATF_TC_BODY(dispatchset_get, tc) {
+	isc_result_t result;
+	dns_dispatch_t *d1, *d2, *d3, *d4, *d5;
+
+	UNUSED(tc);
+
+	result = dns_test_begin(NULL, ISC_TRUE);
+	ATF_REQUIRE_EQ(result, ISC_R_SUCCESS);
+
+	result = make_dispatchset(1);
+	ATF_REQUIRE_EQ(result, ISC_R_SUCCESS);
+
+	d1 = dns_dispatchset_get(dset);
+	d2 = dns_dispatchset_get(dset);
+	d3 = dns_dispatchset_get(dset);
+	d4 = dns_dispatchset_get(dset);
+	d5 = dns_dispatchset_get(dset);
+
+	ATF_CHECK_EQ(d1, d2);
+	ATF_CHECK_EQ(d2, d3);
+	ATF_CHECK_EQ(d3, d4);
+	ATF_CHECK_EQ(d4, d5);
+
+	teardown();
+
+	result = make_dispatchset(4);
+	ATF_REQUIRE_EQ(result, ISC_R_SUCCESS);
+
+	d1 = dns_dispatchset_get(dset);
+	d2 = dns_dispatchset_get(dset);
+	d3 = dns_dispatchset_get(dset);
+	d4 = dns_dispatchset_get(dset);
+	d5 = dns_dispatchset_get(dset);
+
+	ATF_CHECK_EQ(d1, d5);
+	ATF_CHECK(d1 != d2);
+	ATF_CHECK(d2 != d3);
+	ATF_CHECK(d3 != d4);
+	ATF_CHECK(d4 != d5);
+
+	teardown();
+	dns_test_end();
+}
+
+
+/*
+ * Main
+ */
+ATF_TP_ADD_TCS(tp) {
+	ATF_TP_ADD_TC(tp, dispatchset_create);
+	ATF_TP_ADD_TC(tp, dispatchset_get);
+	return (atf_no_error());
+}
+