test-aio-multithread: simplify test_multi_co_schedule
Instead of using qatomic_mb_{read,set} mindlessly, just use a per-coroutine
flag that requires no synchronization.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/tests/unit/test-aio-multithread.c b/tests/unit/test-aio-multithread.c
index 3c61526..80c5d4e 100644
--- a/tests/unit/test-aio-multithread.c
+++ b/tests/unit/test-aio-multithread.c
@@ -107,8 +107,7 @@
/* aio_co_schedule test. */
static Coroutine *to_schedule[NUM_CONTEXTS];
-
-static bool now_stopping;
+static bool stop[NUM_CONTEXTS];
static int count_retry;
static int count_here;
@@ -136,6 +135,7 @@
static void finish_cb(void *opaque)
{
+ stop[id] = true;
schedule_next(id);
}
@@ -143,13 +143,19 @@
{
g_assert(to_schedule[id] == NULL);
- while (!qatomic_mb_read(&now_stopping)) {
+ /*
+ * The next iteration will set to_schedule[id] again, but once finish_cb
+ * is scheduled there is no guarantee that it will actually be woken up,
+ * so at that point it must not go to sleep.
+ */
+ while (!stop[id]) {
int n;
n = g_test_rand_int_range(0, NUM_CONTEXTS);
schedule_next(n);
qatomic_mb_set(&to_schedule[id], qemu_coroutine_self());
+ /* finish_cb can run here. */
qemu_coroutine_yield();
g_assert(to_schedule[id] == NULL);
}
@@ -161,7 +167,6 @@
int i;
count_here = count_other = count_retry = 0;
- now_stopping = false;
create_aio_contexts();
for (i = 0; i < NUM_CONTEXTS; i++) {
@@ -171,10 +176,10 @@
g_usleep(seconds * 1000000);
- qatomic_mb_set(&now_stopping, true);
+ /* Guarantee that each AioContext is woken up from its last wait. */
for (i = 0; i < NUM_CONTEXTS; i++) {
ctx_run(i, finish_cb, NULL);
- to_schedule[i] = NULL;
+ g_assert(to_schedule[i] == NULL);
}
join_aio_contexts();
@@ -199,6 +204,7 @@
static uint32_t running;
static uint32_t counter;
static CoMutex comutex;
+static bool now_stopping;
static void coroutine_fn test_multi_co_mutex_entry(void *opaque)
{
