diff options
Diffstat (limited to 'tests')
| -rw-r--r-- | tests/unit/test-coroutine.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/tests/unit/test-coroutine.c b/tests/unit/test-coroutine.c index e946d93a65..aa77a3bcb3 100644 --- a/tests/unit/test-coroutine.c +++ b/tests/unit/test-coroutine.c @@ -264,6 +264,165 @@ 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); +} + +static void coroutine_fn rwlock_rdlock_yield(void *opaque) +{ + qemu_co_rwlock_rdlock(&rwlock); + qemu_coroutine_yield(); + + qemu_co_rwlock_unlock(&rwlock); + qemu_coroutine_yield(); + + *(bool *)opaque = true; +} + +static void coroutine_fn rwlock_wrlock_downgrade(void *opaque) +{ + qemu_co_rwlock_wrlock(&rwlock); + + qemu_co_rwlock_downgrade(&rwlock); + qemu_co_rwlock_unlock(&rwlock); + *(bool *)opaque = true; +} + +static void coroutine_fn rwlock_rdlock(void *opaque) +{ + qemu_co_rwlock_rdlock(&rwlock); + + qemu_co_rwlock_unlock(&rwlock); + *(bool *)opaque = true; +} + +static void coroutine_fn rwlock_wrlock(void *opaque) +{ + qemu_co_rwlock_wrlock(&rwlock); + + qemu_co_rwlock_unlock(&rwlock); + *(bool *)opaque = true; +} + +/* + * Check that downgrading a reader-writer lock does not cause a hang. + * + * Four coroutines are used to produce a situation where there are + * both reader and writer hopefuls waiting to acquire an rwlock that + * is held by a reader. + * + * The correct sequence of operations we aim to provoke can be + * represented as: + * + * | c1 | c2 | c3 | c4 | + * |--------+------------+------------+------------| + * | rdlock | | | | + * | yield | | | | + * | | wrlock | | | + * | | <queued> | | | + * | | | rdlock | | + * | | | <queued> | | + * | | | | wrlock | + * | | | | <queued> | + * | unlock | | | | + * | yield | | | | + * | | <dequeued> | | | + * | | downgrade | | | + * | | | <dequeued> | | + * | | | unlock | | + * | | ... | | | + * | | unlock | | | + * | | | | <dequeued> | + * | | | | unlock | + */ +static void test_co_rwlock_downgrade(void) +{ + bool c1_done = false; + bool c2_done = false; + bool c3_done = false; + bool c4_done = false; + Coroutine *c1, *c2, *c3, *c4; + + qemu_co_rwlock_init(&rwlock); + + c1 = qemu_coroutine_create(rwlock_rdlock_yield, &c1_done); + c2 = qemu_coroutine_create(rwlock_wrlock_downgrade, &c2_done); + c3 = qemu_coroutine_create(rwlock_rdlock, &c3_done); + c4 = qemu_coroutine_create(rwlock_wrlock, &c4_done); + + qemu_coroutine_enter(c1); + qemu_coroutine_enter(c2); + qemu_coroutine_enter(c3); + qemu_coroutine_enter(c4); + + qemu_coroutine_enter(c1); + + g_assert(c2_done); + g_assert(c3_done); + g_assert(c4_done); + + qemu_coroutine_enter(c1); + + g_assert(c1_done); +} + /* * Check that creation, enter, and return work */ @@ -501,6 +660,8 @@ 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); + g_test_add_func("/locking/co-rwlock/downgrade", test_co_rwlock_downgrade); if (g_test_perf()) { g_test_add_func("/perf/lifecycle", perf_lifecycle); g_test_add_func("/perf/nesting", perf_nesting); |