[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH 5/6] test-coroutine: add rwlock upgrade test
From: |
Paolo Bonzini |
Subject: |
[PATCH 5/6] test-coroutine: add rwlock upgrade test |
Date: |
Wed, 17 Mar 2021 13:16:40 +0100 |
Test that rwlock upgrade is fair, and readers go back to sleep if a writer
is in line.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
tests/unit/test-coroutine.c | 62 +++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)
diff --git a/tests/unit/test-coroutine.c b/tests/unit/test-coroutine.c
index e946d93a65..6e6f51d480 100644
--- a/tests/unit/test-coroutine.c
+++ b/tests/unit/test-coroutine.c
@@ -264,6 +264,67 @@ static void test_co_mutex_lockable(void)
g_assert(QEMU_MAKE_LOCKABLE(null_pointer) == NULL);
}
+static CoRwlock rwlock;
+
+/* Test that readers are properly sent back to the queue when upgrading,
+ * even if they are the sole readers. The test scenario is as follows:
+ *
+ *
+ * | c1 | c2 |
+ * |--------------+------------+
+ * | rdlock | |
+ * | yield | |
+ * | | wrlock |
+ * | | <queued> |
+ * | upgrade | |
+ * | <queued> | <dequeued> |
+ * | | unlock |
+ * | <dequeued> | |
+ * | unlock | |
+ */
+
+static void coroutine_fn rwlock_yield_upgrade(void *opaque)
+{
+ qemu_co_rwlock_rdlock(&rwlock);
+ qemu_coroutine_yield();
+
+ qemu_co_rwlock_upgrade(&rwlock);
+ qemu_co_rwlock_unlock(&rwlock);
+
+ *(bool *)opaque = true;
+}
+
+static void coroutine_fn rwlock_wrlock_yield(void *opaque)
+{
+ qemu_co_rwlock_wrlock(&rwlock);
+ qemu_coroutine_yield();
+
+ qemu_co_rwlock_unlock(&rwlock);
+ *(bool *)opaque = true;
+}
+
+static void test_co_rwlock_upgrade(void)
+{
+ bool c1_done = false;
+ bool c2_done = false;
+ Coroutine *c1, *c2;
+
+ qemu_co_rwlock_init(&rwlock);
+ c1 = qemu_coroutine_create(rwlock_yield_upgrade, &c1_done);
+ c2 = qemu_coroutine_create(rwlock_wrlock_yield, &c2_done);
+
+ qemu_coroutine_enter(c1);
+ qemu_coroutine_enter(c2);
+
+ /* c1 now should go to sleep. */
+ qemu_coroutine_enter(c1);
+ g_assert(!c1_done);
+
+ qemu_coroutine_enter(c2);
+ g_assert(c1_done);
+ g_assert(c2_done);
+}
+
/*
* Check that creation, enter, and return work
*/
@@ -501,6 +562,7 @@ int main(int argc, char **argv)
g_test_add_func("/basic/order", test_order);
g_test_add_func("/locking/co-mutex", test_co_mutex);
g_test_add_func("/locking/co-mutex/lockable", test_co_mutex_lockable);
+ g_test_add_func("/locking/co-rwlock/upgrade", test_co_rwlock_upgrade);
if (g_test_perf()) {
g_test_add_func("/perf/lifecycle", perf_lifecycle);
g_test_add_func("/perf/nesting", perf_nesting);
--
2.29.2