mjit.c: fix deadlock introduced by r65785

in mjit_pause() fired by before_fork_ruby(). When calling
RUBY_VM_CHECK_INTS() in mjit_pause()'s loop, other threads may call
start_worker() which sets `stop_worker_p = FALSE` and it could wait for
MJIT worker stop forever even while `stop_worker_p` is FALSE.

http://ci.rvm.jp/results/trunk-mjit@silicon-docker/1466333
https://gist.github.com/ko1/a57ef1a03e1c7cfd22f1495e0864b63d

http://ci.rvm.jp/results/trunk-mjit-wait@silicon-docker/1466335
https://gist.github.com/ko1/96e867e36e6b75559b3d926f8c0bdaeb

https://app.wercker.com/ruby/ruby/runs/mjit-test1/5bf1221c183106002855989c?step=5bf1225987436a0006192c31

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65790 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 1 deletions

diff --git a/mjit.c b/mjit.c
index 25b2bd9322..1578c961ae 100644
--- a/mjit.c
+++ b/mjit.c
@@ -681,10 +681,10 @@ stop_worker(void)
 {
     rb_execution_context_t *ec = GET_EC();
 
-    stop_worker_p = TRUE;
     while (!worker_stopped) {
         verbose(3, "Sending cancel signal to worker");
         CRITICAL_SECTION_START(3, "in stop_worker");
+        stop_worker_p = TRUE; /* Setting this inside loop because RUBY_VM_CHECK_INTS may make this FALSE. */
         rb_native_cond_broadcast(&mjit_worker_wakeup);
         CRITICAL_SECTION_FINISH(3, "in stop_worker");
         RUBY_VM_CHECK_INTS(ec);