@samitouri / QOSamiQemu / commits / d5444408c7

tests/qtest/vhost-user-test: Use g_timeout_add() to schedule connect

In vhost-user-test, we currently create a new g_thread to run the connect_thread() function. This function sleeps for 1 second, and then calls test_server_create_chr() to create and configure a chardev: chr = qemu_chr_new(server->chr_name, chr_path, server->context); g_assert(chr); qemu_chr_fe_init(&server->chr, chr, &error_abort); qemu_chr_fe_set_handlers(&server->chr, chr_can_read, chr_read, chr_event, NULL, server, server->context, true); This has a race condition, because when we set the 'reconnect-ms=1000' option on the chardev the socket chardev's implementation handles the connect asynchronously, via a background thread and a callback invoked in the main-loop thread. This means that that callback and the test_server_create_chr() call to qemu_chr_fe_set_handlers() can both enter the char-socket code simultaneously. The result is random assertion failures and memory leaks reported by the clang address-sanitizer. Fix this by using g_timeout_source_new() to set up a GSource that will run test_server_connect() on the main-loop thread. This ensures it can't execute in parallel with the callback that the socket chardev sets up. This is similar to how we already handle the reconnect_cb() in test_reconnect(). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Fabiano Rosas <farosas@suse.de> Signed-off-by: Fabiano Rosas <farosas@suse.de>

Peter Maydell committed Mar 6, 2026 at 17:01 UTC d5444408c7ef4cc17aa02879713a6de828b94967

1 file changed +27 -9

tests/qtest/vhost-user-test.c

+27 -9

@@ -930,26 +930,42 @@ reconnect_cb(gpointer user_data)

930 return FALSE;

931 }

932

933 -static gpointer

934 -connect_thread(gpointer data)

933 +static gboolean connect_cb(gpointer user_data)

934 {

936 - TestServer *s = data;

935 + TestServer *s = user_data;

936

938 - /* wait for qemu to start before first try, to avoid extra warnings */

939 - g_usleep(G_USEC_PER_SEC);

937 test_server_connect(s);

938

942 - return NULL;

939 + /* We only need to be called once */

940 + return G_SOURCE_REMOVE;

941 +}

942 +

943 +/* Initial delay before connect, in milliseconds (1 second) */

944 +#define INITIAL_CONNECT_DELAY_MS (1 * 1000)

945 +

946 +static void test_schedule_connect(TestServer *s)

947 +{

948 + /*

949 + * Wait for a bit for QEMU to start before we first try to connect,

950 + * to avoid extra warnings. We must run the "connect" on the

951 + * main-loop thread so it doesn't race with a callback that

952 + * the socket-chardev sets up on the main-loop.

953 + */

954 + GSource *src = g_timeout_source_new(INITIAL_CONNECT_DELAY_MS);

955 + g_source_set_callback(src, connect_cb, s, NULL);

956 + g_source_attach(src, s->context);

957 + g_source_unref(src);

958 }

959

960 static void *vhost_user_test_setup_reconnect(GString *cmd_line, void *arg)

961 {

962 TestServer *s = test_server_new("reconnect", arg);

963

949 - g_thread_unref(g_thread_new("connect", connect_thread, s));

964 append_mem_opts(s, cmd_line, 256, TEST_MEMFD_AUTO);

965 s->vu_ops->append_opts(s, cmd_line, ",server=on");

966

967 + test_schedule_connect(s);

968 +

969 g_test_queue_destroy(vhost_user_test_cleanup, s);

970

971 return s;

@@ -983,10 +999,11 @@ static void *vhost_user_test_setup_connect_fail(GString *cmd_line, void *arg)

999

1000 s->test_fail = true;

1001

986 - g_thread_unref(g_thread_new("connect", connect_thread, s));

1002 append_mem_opts(s, cmd_line, 256, TEST_MEMFD_AUTO);

1003 s->vu_ops->append_opts(s, cmd_line, ",server=on");

1004

1005 + test_schedule_connect(s);

1006 +

1007 g_test_queue_destroy(vhost_user_test_cleanup, s);

1008

1009 return s;

@@ -998,10 +1015,11 @@ static void *vhost_user_test_setup_flags_mismatch(GString *cmd_line, void *arg)

1015

1016 s->test_flags = TEST_FLAGS_DISCONNECT;

1017

1001 - g_thread_unref(g_thread_new("connect", connect_thread, s));

1018 append_mem_opts(s, cmd_line, 256, TEST_MEMFD_AUTO);

1019 s->vu_ops->append_opts(s, cmd_line, ",server=on");

1020

1021 + test_schedule_connect(s);

1022 +

1023 g_test_queue_destroy(vhost_user_test_cleanup, s);

1024

1025 return s;