[src/trunk]: src/lib/libpthread Store allocated lwpctl state in the thread ac...

[enami <enami%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ad87e8709c5a
branches:  trunk
changeset: 779018:ad87e8709c5a
user:      enami <enami%NetBSD.org@localhost>
date:      Thu Apr 26 00:21:44 2012 +0000

description:
Store allocated lwpctl state in the thread actually forked,
which is the only thread lives in the child process.

The problem originally reported here:
  https://bugs.ruby-lang.org/issues/6341

diffstat:

 lib/libpthread/pthread.c |  11 ++++-------
 1 files changed, 4 insertions(+), 7 deletions(-)

diffs (50 lines):

diff -r 7c88d8e59ced -r ad87e8709c5a lib/libpthread/pthread.c
--- a/lib/libpthread/pthread.c  Wed Apr 25 22:35:00 2012 +0000
+++ b/lib/libpthread/pthread.c  Thu Apr 26 00:21:44 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pthread.c,v 1.133 2012/03/22 20:01:18 drochner Exp $   */
+/*     $NetBSD: pthread.c,v 1.134 2012/04/26 00:21:44 enami Exp $      */
 
 /*-
  * Copyright (c) 2001, 2002, 2003, 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: pthread.c,v 1.133 2012/03/22 20:01:18 drochner Exp $");
+__RCSID("$NetBSD: pthread.c,v 1.134 2012/04/26 00:21:44 enami Exp $");
 
 #define        __EXPOSE_STACK  1
 
@@ -84,7 +84,6 @@
 
 static pthread_attr_t pthread_default_attr;
 static lwpctl_t pthread__dummy_lwpctl = { .lc_curcpu = LWPCTL_CPU_NONE };
-static pthread_t pthread__first;
 
 enum {
        DIAGASSERT_ABORT =      1<<0,
@@ -229,7 +228,6 @@
        }
 
        /* Tell libc that we're here and it should role-play accordingly. */
-       pthread__first = first;
        pthread_atfork(NULL, NULL, pthread__fork_callback);
        __isthreaded = 1;
 }
@@ -237,13 +235,12 @@
 static void
 pthread__fork_callback(void)
 {
-       struct __pthread_st *self;
+       struct __pthread_st *self = pthread__self();
 
        /* lwpctl state is not copied across fork. */
-       if (_lwp_ctl(LWPCTL_FEATURE_CURCPU, &pthread__first->pt_lwpctl)) {
+       if (_lwp_ctl(LWPCTL_FEATURE_CURCPU, &self->pt_lwpctl)) {
                err(1, "_lwp_ctl");
        }
-       self = pthread__self();
        self->pt_lid = _lwp_self();
 }