[Spice-devel] [PATCH spice-server v2] test-display-base: Avoid spurious errors due to listen failures

[Frediano Ziglio]

To set up a listening socket usually you call in sequence:
- socket;
- bind;
- listen.
If you try to bind() to a port when another socket is already
listening on that port, the bind() will fail.
However, it is possible that the bind() may succeed and the listen()
will fail, as demonstrated in the following sequence:
- socket() create socket 1;
- bind() to port N on socket 1;
- socket() create socket 2;
- bind() to port N on socket 2;
- listen() on socket 1;
- listen() on socket 2 <-- failure.

When running tests (especially multiple tests running in parallel), it
may sometimes happen that there are other tests already listening on
the port that we are trying to use. In this case, we want to ignore
this error and simply try to listen on a different port. We already
attempted to handle this scenario, but we were only ignoring bind()
errors and not listen() errors. So in the scenario mentioned above,
the listen() error was causing the entire test to fail instead of
allowing us to try to listen on another port.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 server/tests/test-display-base.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

Changes since v1:
- update commit message

diff --git a/server/tests/test-display-base.c b/server/tests/test-display-base.c
index ea3a23ba..f58f76d3 100644
--- a/server/tests/test-display-base.c
+++ b/server/tests/test-display-base.c
@@ -894,10 +894,10 @@ void test_set_command_list(Test *test, Command *commands, int num_commands)
     test->num_commands = num_commands;
 }
 
-static gboolean ignore_bind_failures(const gchar *log_domain,
-                                     GLogLevelFlags log_level,
-                                     const gchar *message,
-                                     gpointer user_data)
+static gboolean ignore_in_use_failures(const gchar *log_domain,
+                                       GLogLevelFlags log_level,
+                                       const gchar *message,
+                                       gpointer user_data)
 {
     if (!g_str_equal (log_domain, G_LOG_DOMAIN)) {
         return true;
@@ -905,7 +905,8 @@ static gboolean ignore_bind_failures(const gchar *log_domain,
     if ((log_level & G_LOG_LEVEL_WARNING) == 0)  {
         return true;
     }
-    if (strstr(message, "reds_init_socket: binding socket to ") == NULL) {
+    if (strstr(message, "reds_init_socket: binding socket to ") == NULL || // bind failure
+        strstr(message, "reds_init_socket: listen: ") == NULL) { // listen failure
         g_print("XXX [%s]\n", message);
         return true;
     }
@@ -929,7 +930,7 @@ Test* test_new(SpiceCoreInterface* core)
     // some common initialization for all display tests
     port = BASE_PORT;
 
-    g_test_log_set_fatal_handler(ignore_bind_failures, NULL);
+    g_test_log_set_fatal_handler(ignore_in_use_failures, NULL);
     for (port = BASE_PORT; port < BASE_PORT + 10; port++) {
         SpiceServer* server = spice_server_new();
         spice_server_set_noauth(server);
-- 
2.17.2