barrier: fix race in test-code

The barrier_wait_next_twice* test-cases run:
  Parent:                             Child:
    set_alarm(10)                       sleep_for(1);
    ...                                 set_alarm(1);
    sleep_for(2)                        ...

Therefore, the parent exits after 2+ periods, the client's alarm fires
after 2+ periods. This race turns out to be lost by the child on other
machines, so avoid it by increasing the parent's sleep-interval to 4. This
way, the client has 2 periods to run the barrier test, which is far more
than enough.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/test/test-barrier.c b/src/test/test-barrier.c
index ac9dd04b99..36f27809ca 100644
--- a/src/test/test-barrier.c
+++ b/src/test/test-barrier.c
@@ -176,7 +176,7 @@ TEST_BARRIER(test_barrier_wait_next_twice,
                 set_alarm(BASE_TIME * 10);
                 assert_se(barrier_place(&b));
                 assert_se(barrier_place(&b));
-                sleep_for(BASE_TIME * 2);
+                sleep_for(BASE_TIME * 4);
         }),
         TEST_BARRIER_WAIT_SUCCESS(pid2));
 
@@ -201,7 +201,7 @@ TEST_BARRIER(test_barrier_wait_next_twice_local,
                 set_alarm(BASE_TIME * 10);
                 assert_se(barrier_place(&b));
                 assert_se(barrier_place(&b));
-                sleep_for(BASE_TIME * 2);
+                sleep_for(BASE_TIME * 4);
         }),
         TEST_BARRIER_WAIT_SUCCESS(pid2));