tests: adjust test-thread-pool to new aio_poll() semantics

aio_poll(ctx, true) will soon block when fd handlers have been set.
Previously aio_poll() would return early if all .io_flush() returned
false.  This means we need to check the equivalent of the .io_flush()
condition *before* calling aio_poll(ctx, true) to avoid deadlock.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

tests/test-thread-pool.c

@@ -40,19 +40,13 @@ static void done_cb(void *opaque, int ret)
     active--;
 }
 
-/* Wait until all aio and bh activity has finished */
-static void qemu_aio_wait_all(void)
-{
-    while (aio_poll(ctx, true)) {
-        /* Do nothing */
-    }
-}
-
 static void test_submit(void)
 {
     WorkerTestData data = { .n = 0 };
     thread_pool_submit(pool, worker_cb, &data);
-    qemu_aio_wait_all();
+    while (data.n == 0) {
+        aio_poll(ctx, true);
+    }
     g_assert_cmpint(data.n, ==, 1);
 }
 
@@ -65,7 +59,9 @@ static void test_submit_aio(void)
     /* The callbacks are not called until after the first wait.  */
     active = 1;
     g_assert_cmpint(data.ret, ==, -EINPROGRESS);
-    qemu_aio_wait_all();
+    while (data.ret == -EINPROGRESS) {
+        aio_poll(ctx, true);
+    }
     g_assert_cmpint(active, ==, 0);
     g_assert_cmpint(data.n, ==, 1);
     g_assert_cmpint(data.ret, ==, 0);
@@ -103,7 +99,9 @@ static void test_submit_co(void)
 
     /* qemu_aio_wait_all will execute the rest of the coroutine.  */
 
-    qemu_aio_wait_all();
+    while (data.ret == -EINPROGRESS) {
+        aio_poll(ctx, true);
+    }
 
     /* Back here after the coroutine has finished.  */
 
@@ -187,7 +185,9 @@ static void test_cancel(void)
     }
 
     /* Finish execution and execute any remaining callbacks.  */
-    qemu_aio_wait_all();
+    while (active > 0) {
+        aio_poll(ctx, true);
+    }
     g_assert_cmpint(active, ==, 0);
     for (i = 0; i < 100; i++) {
         if (data[i].n == 3) {