| Message ID | 20210317121641.215714-6-pbonzini@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | coroutine rwlock downgrade fix, minor VDI changes | expand |
On Wednesday, 2021-03-17 at 13:16:40 +01, Paolo Bonzini wrote: > 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> Reviewed-by: David Edmondson <david.edmondson@oracle.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 dme.
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);
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(+)