wqueue: Reject messges if queue is considered full
The write queue was always meant to not queue more than the
max_length messages but the implementation never rejected a
message.
Begin to log and enforce the queue size limit, add a testcase
to verify the code and initialize except_cb as part of a fix
for that new test case.
Real applications might now run into the queue limit and drop
messages where they just queued them before. It is unfortunate
but I still think it is good to implement the routine as it was
intended. We need to review osmo_wqueue_enqueue once more to
see that no msgb is leaked.
Change-Id: I1e6aef30f3e73d4bcf2967bc49f0783aa65395ae
diff --git a/tests/write_queue/wqueue_test.c b/tests/write_queue/wqueue_test.c
new file mode 100644
index 0000000..827e4e8
--- /dev/null
+++ b/tests/write_queue/wqueue_test.c
@@ -0,0 +1,81 @@
+#include <osmocom/core/logging.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/write_queue.h>
+
+static const struct log_info_cat default_categories[] = {
+};
+
+static const struct log_info log_info = {
+ .cat = default_categories,
+ .num_cat = ARRAY_SIZE(default_categories),
+};
+
+static void test_wqueue_limit(void)
+{
+ struct msgb *msg;
+ struct osmo_wqueue wqueue;
+ int rc;
+
+ osmo_wqueue_init(&wqueue, 0);
+ OSMO_ASSERT(wqueue.max_length == 0);
+ OSMO_ASSERT(wqueue.current_length == 0);
+ OSMO_ASSERT(wqueue.read_cb == NULL);
+ OSMO_ASSERT(wqueue.write_cb == NULL);
+ OSMO_ASSERT(wqueue.except_cb == NULL);
+
+ /* try to add and fail */
+ msg = msgb_alloc(4096, "msg1");
+ rc = osmo_wqueue_enqueue(&wqueue, msg);
+ OSMO_ASSERT(rc < 0);
+
+ /* add one and fail on the second */
+ wqueue.max_length = 1;
+ rc = osmo_wqueue_enqueue(&wqueue, msg);
+ OSMO_ASSERT(rc == 0);
+ OSMO_ASSERT(wqueue.current_length == 1);
+ msg = msgb_alloc(4096, "msg2");
+ rc = osmo_wqueue_enqueue(&wqueue, msg);
+ OSMO_ASSERT(rc < 0);
+
+ /* add one more */
+ wqueue.max_length = 2;
+ rc = osmo_wqueue_enqueue(&wqueue, msg);
+ OSMO_ASSERT(rc == 0);
+ OSMO_ASSERT(wqueue.current_length == 2);
+
+ /* release everything */
+ osmo_wqueue_clear(&wqueue);
+ OSMO_ASSERT(wqueue.current_length == 0);
+ OSMO_ASSERT(wqueue.max_length == 2);
+
+ /* Add two, fail on the third, free it and the queue */
+ msg = msgb_alloc(4096, "msg3");
+ rc = osmo_wqueue_enqueue(&wqueue, msg);
+ OSMO_ASSERT(rc == 0);
+ OSMO_ASSERT(wqueue.current_length == 1);
+ msg = msgb_alloc(4096, "msg4");
+ rc = osmo_wqueue_enqueue(&wqueue, msg);
+ OSMO_ASSERT(rc == 0);
+ OSMO_ASSERT(wqueue.current_length == 2);
+ msg = msgb_alloc(4096, "msg5");
+ rc = osmo_wqueue_enqueue(&wqueue, msg);
+ OSMO_ASSERT(rc < 0);
+ OSMO_ASSERT(wqueue.current_length == 2);
+ msgb_free(msg);
+ osmo_wqueue_clear(&wqueue);
+}
+
+int main(int argc, char **argv)
+{
+ struct log_target *stderr_target;
+
+ log_init(&log_info, NULL);
+ stderr_target = log_target_create_stderr();
+ log_add_target(stderr_target);
+ log_set_print_filename(stderr_target, 0);
+
+ test_wqueue_limit();
+
+ printf("Done\n");
+ return 0;
+}