With more workers blockingly waiting on udp sockets, we need to keep track of all sockets to shut them down on exit

2 files changed, 98 insertions, 0 deletions

diff --git a/tests/integration/test_shutdown.py b/tests/integration/test_shutdown.py
new file mode 100644
index 0000000..063d779
--- /dev/null
+++ b/tests/integration/test_shutdown.py
@@ -0,0 +1,58 @@
+"""That every thread the tracker starts also ends when it is asked to stop.
+
+The rest of the suite stops a tracker too, so a thread left behind already
+shows up in teardown as the complaint that the tracker had to be killed.
+These ask for the arrangements that park a thread in a blocking read in the
+first place, and they time the exit, because a reader woken only by its own
+receive timeout passes a correctness check while taking a second over it.
+"""
+
+import time
+import unittest
+
+from harness import Tracker, TrackerTestCase
+
+# Generous enough for a platform where shutting the socket down does not wake
+# the reader and the receive timeout has to expire, tight enough that a reader
+# which is never woken at all fails instead of hanging the suite
+PATIENCE = 3.0
+
+
+def time_the_exit(extra_config):
+    tracker = Tracker(extra_config)
+    try:
+        # Serve one request of each kind first, so the threads that are about
+        # to be joined have actually run
+        tracker.announce(b"shutdown-probe\0\0\0\0\0\0")
+        sock, connection_id = tracker.udp_connect()
+        tracker.udp_announce(sock, connection_id, b"shutdown-probe\0\0\0\0\0\0")
+        sock.close()
+        started = time.time()
+        complaints = tracker.stop()
+        return time.time() - started, complaints
+    finally:
+        tracker._cleanup()
+
+
+class UdpWorkers(TrackerTestCase):
+    config = "listen.udp.workers 8\n"
+
+    def test_announce_reaches_one_of_eight_workers(self):
+        """Keeps the workers from being merely started and never used."""
+        sock, connection_id = self.tracker.udp_connect()
+        answer = self.tracker.udp_announce(sock, connection_id, self.hash_for("eight-workers"))
+        sock.close()
+        self.assertEqual(answer["seeders"], 1)
+
+
+class ShutdownEndsEveryThread(unittest.TestCase):
+    def test_eight_udp_workers_are_joined(self):
+        took, complaints = time_the_exit("listen.udp.workers 8\n")
+        self.assertEqual(complaints, [], "the tracker reported:\n" + "\n".join(complaints))
+        self.assertLess(took, PATIENCE, "stopping eight udp workers took %.1f s" % took)
+
+    def test_udp_in_the_event_loop_still_stops(self):
+        """Worker count zero leaves no thread to join, which must also work."""
+        took, complaints = time_the_exit("listen.udp.workers 0\n")
+        self.assertEqual(complaints, [], "the tracker reported:\n" + "\n".join(complaints))
+        self.assertLess(took, PATIENCE, "stopping without workers took %.1f s" % took)
diff --git a/tests/t_socket.c b/tests/t_socket.c
index 8eef7fd..ede8ae0 100644
--- a/tests/t_socket.c
+++ b/tests/t_socket.c
@@ -10,6 +10,7 @@
 #include <poll.h>
 #include <string.h>
 #include <sys/socket.h>
+#include <time.h>
 #include <unistd.h>
 
 /* Opentracker */
@@ -144,6 +145,44 @@ static void case_udp_roundtrip(void) {
   close(s);
 }
 
+/* udp_workers_deinit relies on a worker parked in a read coming back. The
+   receive timeout is what guarantees that; shutting the socket down is what
+   makes it prompt where the platform allows it. Neither is uniform across the
+   systems opentracker runs on, so both are checked rather than assumed. */
+static void case_blocking_read_comes_back(void) {
+  char     buf[32], ip[16], own_ip[16];
+  uint16_t port = 0, own_port = 0;
+  time_t   started;
+  int      s;
+
+  test_case("a receive timeout does not delay a datagram that is already there");
+  s = socket_udp_bind(ip_loopback, 0, SOCKET_EXCLUSIVE);
+  CHECK(s != -1);
+  CHECK_INT(socket_set_blocking(s, 1), 0);
+  CHECK_INT(socket_set_timeout(s, 1), 0);
+  bound_address(s, own_ip, &own_port);
+  CHECK_INT(socket_send(s, "opentracker", 11, own_ip, own_port), 11);
+  CHECK_INT(socket_recv(s, buf, sizeof(buf), ip, &port), 11);
+
+  test_case("and ends a read that would otherwise never return");
+  started = time(NULL);
+  CHECK_INT(socket_recv(s, buf, sizeof(buf), ip, &port), -1);
+  CHECK(errno == EAGAIN || errno == EWOULDBLOCK);
+  CHECK(time(NULL) - started <= 3);
+  close(s);
+
+  test_case("shutting the socket down ends one too");
+  s = socket_udp_bind(ip_loopback, 0, SOCKET_EXCLUSIVE);
+  CHECK(s != -1);
+  CHECK_INT(socket_set_blocking(s, 1), 0);
+  CHECK_INT(socket_set_timeout(s, 1), 0);
+  shutdown(s, SHUT_RD);
+  started = time(NULL);
+  CHECK(socket_recv(s, buf, sizeof(buf), ip, &port) <= 0);
+  CHECK(time(NULL) - started <= 3);
+  close(s);
+}
+
 /* An IPv4 peer must arrive in the v4 mapped form opentracker stores, however
    the kernel chose to report it. Linux fills a v4 mapped sockaddr_in6 here
    and the BSDs fill a plain sockaddr_in, so this is the case that tells the
@@ -293,6 +332,7 @@ void test_socket(void) {
   case_sharing_is_opt_in();
 #endif
   case_udp_roundtrip();
+  case_blocking_read_comes_back();
   case_udp_v4mapped();
   case_tcp_roundtrip();
   case_connect_refused();