From: Eric Wong <normalperson@...>
Date: 2012-01-05T07:00:13+09:00
Subject: [ruby-core:41905] Re: [ruby-trunk - Feature #5543] rb_thread_blocking_region() API is poorly designed

Mike Dalessio <mike.dalessio@gmail.com> wrote:
> It appears that the current implementation (1.9.3) of
> rb_thread_blocking_region_begin() and _end() does in fact support this
> calling style, but they are not global symbols, and so I cannot call
> them from my C extension.

rb_thread_call_with_gvl() is globally-visible (but not in headers)
for 1.9.3: https://bugs.ruby-lang.org/issues/4328

Perhaps you can use that?