mjit.c: keep mutex unlocked on destroy

`mjit_finish` may destroy mutex even while it's still locked by
`worker` by race condition. That would result in the following error:
[BUG] pthread_mutex_destroy: Device or resource busy (EBUSY)

Actually I couldn't get a core dump for it and reproduce it multiple
times. So I'm not sure this fixes the issue which I faced or not.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62714 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 2 deletions

diff --git a/mjit.c b/mjit.c
index 0cd2839d80..ecd3ee6c0a 100644
--- a/mjit.c
+++ b/mjit.c
@@ -926,9 +926,8 @@ worker(void)
         }
     }
 
-    CRITICAL_SECTION_START(3, "in the end of worker to update worker_finished");
+    /* To keep mutex unlocked when it is destroyed by mjit_finish, don't wrap CRITICAL_SECTION here. */
     worker_finished = TRUE;
-    CRITICAL_SECTION_FINISH(3, "in the end of worker to update worker_finished");
 }
 
 /* MJIT info related to an existing continutaion.  */