thread_sync.c (rb_mutex_t): eliminate fork_gen

The true bug fork_gen was hiding was rb_mutex_abandon_locking_mutex
failing to unconditionally clear the waitq of mutexes it was
waiting on.  So we fix rb_mutex_abandon_locking_mutex, instead,
and eliminate rb_mutex_cleanup_keeping_mutexes.

This commit was tested heavily on a single-core Pentium-M which
was my most reliable reproducer of the "crash.rb" script from
[Bug #15383]

[Bug #14578] [Bug #15383]

Note: [Bug #15430] turned out to be an entirely different
problem: RLIMIT_NPROC limit was hit on the CI VMs.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66489 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 0 insertions, 1 deletions

diff --git a/thread.c b/thread.c
index faecec7a04..58e7651446 100644
--- a/thread.c
+++ b/thread.c
@@ -4449,7 +4449,6 @@ rb_thread_atfork(void)
     rb_thread_t *th = GET_THREAD();
     rb_thread_atfork_internal(th, terminate_atfork_i);
     th->join_list = NULL;
-    rb_mutex_cleanup_keeping_mutexes(th);
     rb_fiber_atfork(th);
 
     /* We don't want reproduce CVE-2003-0900. */