From fb0c43f34eed8b18678c6e1f481d8564b35c99ed Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Mon, 6 Nov 2017 19:02:33 +0000 Subject: [PATCH] tests-aio-multithread: fix /aio/multi/schedule race condition test_multi_co_schedule_entry() set to_schedule[id] in the final loop iteration before terminating the coroutine. There is a race condition where the main thread attempts to enter the terminating or terminated coroutine when signalling coroutines to stop: atomic_mb_set(&now_stopping, true); for (i = 0; i < NUM_CONTEXTS; i++) { ctx_run(i, finish_cb, NULL); <--- enters dead coroutine! to_schedule[i] = NULL; } Make sure only to set to_schedule[id] if this coroutine really needs to be scheduled! Reported-by: "R.Nageswara Sastry" Signed-off-by: Stefan Hajnoczi Reviewed-by: Paolo Bonzini Message-id: 20171106190233.1175-1-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi --- tests/test-aio-multithread.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/tests/test-aio-multithread.c b/tests/test-aio-multithread.c index 549d784915..d396185972 100644 --- a/tests/test-aio-multithread.c +++ b/tests/test-aio-multithread.c @@ -144,17 +144,16 @@ static void finish_cb(void *opaque) static coroutine_fn void test_multi_co_schedule_entry(void *opaque) { g_assert(to_schedule[id] == NULL); - atomic_mb_set(&to_schedule[id], qemu_coroutine_self()); while (!atomic_mb_read(&now_stopping)) { int n; n = g_test_rand_int_range(0, NUM_CONTEXTS); schedule_next(n); - qemu_coroutine_yield(); - g_assert(to_schedule[id] == NULL); atomic_mb_set(&to_schedule[id], qemu_coroutine_self()); + qemu_coroutine_yield(); + g_assert(to_schedule[id] == NULL); } }