mjit: get rid of memory leak in pause+resume loop

pthread_atfork is not idempotent and repeatedly calling it
causes it to register the same hook repeatedly; leading to
unbound memory growth.

Ruby already has a (confusing-named) internal API for to call
in the forked child process: rb_thread_atfork
Call the MJIT child_after_fork hook inside that to prevent
unbound growth with the following loop:

    loop do
      RubyVM::MJIT.pause
      RubyVM::MJIT.resume
    end

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63884 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 3 deletions

diff --git a/thread_pthread.c b/thread_pthread.c
index 722ce44487..d2ce8fc50b 100644
--- a/thread_pthread.c
+++ b/thread_pthread.c
@@ -1767,14 +1767,12 @@ mjit_worker(void *arg)
 
 /* Launch MJIT thread. Returns FALSE if it fails to create thread. */
 int
-rb_thread_create_mjit_thread(void (*child_hook)(void), void (*worker_func)(void))
+rb_thread_create_mjit_thread(void (*worker_func)(void))
 {
     pthread_attr_t attr;
     pthread_t worker_pid;
     int ret = FALSE;
 
-    pthread_atfork(NULL, NULL, child_hook);
-
     if (pthread_attr_init(&attr) != 0) return ret;
 
     /* jit_worker thread is not to be joined */