convert tracker try-next test to be a simulation (and deterministic)

simulation/test_tracker.cpp

@@ -363,8 +363,17 @@ TORRENT_TEST(ipv6_support)
 	TEST_EQUAL(v6_announces, 2);
 }
 
-template <typename Announce, typename Test1, typename Test2>
+// this runs a simulation of a torrent with tracker(s), making sure the request
-void tracker_test(Announce a, Test1 test1, Test2 test2, char const* url_path = "/announce")
+// received by the tracker matches the expectation.
+// The Setup function is run first, giving the test an opportunity to add
+// trackers to the torrent. It's expected to return the number of seconds to
+// wait until test2 is called.
+// The Announce function is called on http requests. Test1 is run on the session
+// 5 seconds after startup. The tracker is running at 10.0.0.2 (or tracker.com)
+// port 8080.
+template <typename Setup, typename Announce, typename Test1, typename Test2>
+void tracker_test(Setup setup, Announce a, Test1 test1, Test2 test2
+	, char const* url_path = "/announce")
 {
 	using sim::asio::ip::address_v4;
 	sim_config network_cfg;
@@ -390,7 +399,7 @@ void tracker_test(Announce a, Test1 test1, Test2 test2, char const* url_path = "
 	p.name = "test-torrent";
 	p.save_path = ".";
 	p.info_hash.assign("abababababababababab");
-	p.trackers.push_back("http://tracker.com:8080/announce");
+	int const delay = setup(p);
 	ses->async_add_torrent(p);
 
 	// run the test 5 seconds in
@@ -405,7 +414,7 @@ void tracker_test(Announce a, Test1 test1, Test2 test2, char const* url_path = "
 	});
 
 	asio::high_resolution_timer t2(ios);
-	t2.expires_from_now(chrono::seconds(9));
+	t2.expires_from_now(chrono::seconds(5 + delay));
 	t2.async_wait([&ses,&test2](boost::system::error_code const& ec)
 	{
 		std::vector<lt::torrent_handle> torrents = ses->get_torrents();
@@ -416,7 +425,7 @@ void tracker_test(Announce a, Test1 test1, Test2 test2, char const* url_path = "
 
 	// then shut down 10 seconds in
 	asio::high_resolution_timer t3(ios);
-	t3.expires_from_now(chrono::seconds(10));
+	t3.expires_from_now(chrono::seconds(10 + delay));
 	t3.async_wait([&ses,&zombie](boost::system::error_code const& ec)
 	{
 		zombie = ses->abort();
@@ -427,6 +436,16 @@ void tracker_test(Announce a, Test1 test1, Test2 test2, char const* url_path = "
 	sim.run();
 }
 
+template <typename Announce, typename Test1, typename Test2>
+void tracker_test(Announce a, Test1 test1, Test2 test2, char const* url_path = "/announce")
+{
+	tracker_test([](lt::add_torrent_params& p) {
+		p.trackers.push_back("http://tracker.com:8080/announce");
+		return 5;
+	},
+	a, test1, test2, url_path);
+}
+
 template <typename Announce, typename Test>
 void announce_entry_test(Announce a, Test t, char const* url_path = "/announce")
 {
@@ -609,6 +628,74 @@ TORRENT_TEST(test_invalid_bencoding)
 		});
 }
 
+TORRENT_TEST(try_next)
+{
+// test that we move on to try the next tier if the first one fails
+
+	bool got_announce = false;
+	tracker_test(
+		[](lt::add_torrent_params& p)
+		{
+		// TODO: 3 use tracker_tiers here to put the trackers in different tiers
+			p.trackers.push_back("udp://failing-tracker.com/announce");
+			p.trackers.push_back("http://failing-tracker.com/announce");
+
+			// this is the working tracker
+			p.trackers.push_back("http://tracker.com:8080/announce");
+			return 60;
+		},
+		[&](std::string method, std::string req
+			, std::map<std::string, std::string>& headers)
+		{
+			got_announce = true;
+			TEST_EQUAL(method, "GET");
+
+			char response[500];
+			// respond with an empty peer list
+			int size = snprintf(response, sizeof(response), "d5:peers0:e");
+			return sim::send_response(200, "OK", size) + response;
+		}
+		, [](torrent_handle h) {}
+		, [](torrent_handle h)
+		{
+			torrent_status st = h.status();
+			TEST_EQUAL(st.current_tracker, "http://tracker.com:8080/announce");
+
+			std::vector<announce_entry> tr = h.trackers();
+
+			TEST_EQUAL(tr.size(), 3);
+
+			for (int i = 0; i < tr.size(); ++i)
+			{
+				fprintf(stderr, "tracker \"%s\"\n", tr[i].url.c_str());
+				if (tr[i].url == "http://tracker.com:8080/announce")
+				{
+					TEST_EQUAL(tr[i].fails, 0);
+					TEST_EQUAL(tr[i].verified, true);
+				}
+				else if (tr[i].url == "http://failing-tracker.com/announce")
+				{
+					TEST_CHECK(tr[i].fails >= 1);
+					TEST_EQUAL(tr[i].verified, false);
+					TEST_EQUAL(tr[i].last_error
+						, error_code(boost::asio::error::host_not_found));
+				}
+				else if (tr[i].url == "udp://failing-tracker.com/announce")
+				{
+					TEST_CHECK(tr[i].fails >= 1);
+					TEST_EQUAL(tr[i].verified, false);
+					TEST_EQUAL(tr[i].last_error
+						, error_code(boost::asio::error::host_not_found));
+				}
+				else
+				{
+					TEST_ERROR(("unexpected tracker URL: " + tr[i].url).c_str());
+				}
+			}
+		});
+	TEST_EQUAL(got_announce, true);
+}
+
 // TODO: test external IP
 // TODO: test with different queuing settings
 // TODO: test when a torrent transitions from downloading to finished and

test/test_tracker.cpp

@@ -387,121 +387,6 @@ TORRENT_TEST(udp_tracker)
 	TEST_EQUAL(num_udp_announces(), prev_udp_announces + 2);
 }
 
-TORRENT_TEST(try_next)
-{
-// ========================================
-// test that we move on to try the next tier if the first one fails
-// ========================================
-
-	int http_port = start_web_server();
-	int udp_port = start_udp_tracker();
-
-	int prev_udp_announces = num_udp_announces();
-
-	settings_pack pack = settings();
-	pack.set_bool(settings_pack::announce_to_all_trackers, true);
-	pack.set_bool(settings_pack::announce_to_all_tiers, false);
-	pack.set_int(settings_pack::tracker_completion_timeout, 2);
-	pack.set_int(settings_pack::tracker_receive_timeout, 1);
-	pack.set_str(settings_pack::listen_interfaces, "0.0.0.0:39775");
-
-	boost::scoped_ptr<lt::session> s(new lt::session(pack));
-
-	error_code ec;
-	remove_all("tmp2_tracker", ec);
-	create_directory("tmp2_tracker", ec);
-	std::ofstream file(combine_path("tmp2_tracker", "temporary").c_str());
-	boost::shared_ptr<torrent_info> t = ::create_torrent(&file, "temporary", 16 * 1024, 13, false);
-	file.close();
-
-	// this should fail
-	char tracker_url[200];
-	snprintf(tracker_url, sizeof(tracker_url), "udp://www1.non-existent.com:80/announce");
-	t->add_tracker(tracker_url, 0);
-
-	// and this should fail
-	snprintf(tracker_url, sizeof(tracker_url), "http://127.0.0.2:3/announce");
-	t->add_tracker(tracker_url, 1);
-
-	// this should be announced to
-	// udp trackers are prioritized if they're on the same host as an http one
-	// so this must be before the http one on 127.0.0.1
-	snprintf(tracker_url, sizeof(tracker_url), "udp://127.0.0.1:%d/announce", udp_port);
-	t->add_tracker(tracker_url, 2);
-
-	// and this should not be announced to (since the one before it succeeded)
-	snprintf(tracker_url, sizeof(tracker_url), "http://127.0.0.1:%d/announce", http_port);
-	t->add_tracker(tracker_url, 3);
-
-	prev_udp_announces = num_udp_announces();
-
-	add_torrent_params addp;
-	addp.flags &= ~add_torrent_params::flag_paused;
-	addp.flags &= ~add_torrent_params::flag_auto_managed;
-	addp.flags |= add_torrent_params::flag_seed_mode;
-	addp.ti = t;
-	addp.save_path = "tmp2_tracker";
-	torrent_handle h = s->add_torrent(addp);
-
-	for (int i = 0; i < 50; ++i)
-	{
-		print_alerts(*s, "s");
-		if (num_udp_announces() == prev_udp_announces + 1) break;
-
-		fprintf(stderr, "UDP: %d / %d\n", int(num_udp_announces())
-			, int(prev_udp_announces) + 1);
-		test_sleep(100);
-	}
-
-	// we expect the first two trackers to have failed (because the hostname
-	// doesn't exist and the port isn't open),
-	// the second tracker to have succeeded and the third to not have been used
-	std::vector<announce_entry> tr = h.trackers();
-
-	TEST_EQUAL(tr.size(), 4);
-
-	if (tr.size() == 4)
-	{
-		// this tracker may not have failed yet, but just timed out (if the
-		// hostname lookup is slow)
-		if (tr[0].fails == 1)
-		{
-			TEST_EQUAL(tr[0].verified, false);
-			TEST_EQUAL(tr[0].last_error
-				, error_code(boost::asio::error::host_not_found));
-		}
-
-		TEST_EQUAL(tr[1].fails, 1);
-		TEST_EQUAL(tr[1].verified, false);
-		const bool tracker_error = tr[1].last_error == boost::asio::error::timed_out
-			|| tr[1].last_error == boost::system::error_condition(boost::system::errc::connection_refused)
-#ifdef TORRENT_WINDOWS
-			|| tr[1].last_error == boost::system::error_code(ERROR_CONNECTION_REFUSED, boost::system::system_category())
-#endif
-			;
-		TEST_EQUAL(tracker_error, true);
-
-		TEST_EQUAL(tr[2].fails, 0);
-		TEST_EQUAL(tr[2].verified, true);
-
-		TEST_EQUAL(tr[3].fails, 0);
-		TEST_EQUAL(tr[3].verified, false);
-	}
-	test_sleep(1000);
-
-	TEST_EQUAL(num_udp_announces(), prev_udp_announces + 1);
-
-	fprintf(stderr, "destructing session\n");
-	s.reset();
-	fprintf(stderr, "done\n");
-
-	fprintf(stderr, "stop_tracker\n");
-	stop_udp_tracker();
-	fprintf(stderr, "stop_web_server\n");
-	stop_web_server();
-	fprintf(stderr, "done\n");
-}
-
 TORRENT_TEST(http_peers)
 {
 	int http_port = start_web_server();