thread_pthread.c: reinitialize ubf_list at fork

It's possible for the ubf_list_head to be populated with dead
threads at fork or the ubf_list_lock to be held, so reinitialize
both at startup.

And while we're at it, use a static initializer at startup
to save a library call and kill some ifdef.

[ruby-core:88578] [Bug #15013]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64485 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 0 deletions

diff --git a/thread.c b/thread.c
index c756b53bea..51710d24a7 100644
--- a/thread.c
+++ b/thread.c
@@ -4396,6 +4396,7 @@ rb_thread_atfork_internal(rb_thread_t *th, void (*atfork)(rb_thread_t *, const r
     vm->main_thread = th;
 
     gvl_atfork(th->vm);
+    ubf_list_atfork();
 
     list_for_each(&vm->living_threads, i, vmlt_node) {
 	atfork(i, th);