[src/trunk]: src/lib/libpthread Lock/unlock/reinit pthread__deadqueue_lock ov...

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

details:   https://anonhg.NetBSD.org/src/rev/86637e0aed83
branches:  trunk
changeset: 932767:86637e0aed83
user:      joerg <joerg%NetBSD.org@localhost>
date:      Fri May 15 14:30:23 2020 +0000

description:
Lock/unlock/reinit pthread__deadqueue_lock over fork.

diffstat:

 lib/libpthread/pthread.c |  45 +++++++++++++++++++++++++++++----------------
 1 files changed, 29 insertions(+), 16 deletions(-)

diffs (83 lines):

diff -r 0439da8750fd -r 86637e0aed83 lib/libpthread/pthread.c
--- a/lib/libpthread/pthread.c  Fri May 15 14:29:53 2020 +0000
+++ b/lib/libpthread/pthread.c  Fri May 15 14:30:23 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pthread.c,v 1.168 2020/04/14 23:35:07 joerg Exp $      */
+/*     $NetBSD: pthread.c,v 1.169 2020/05/15 14:30:23 joerg Exp $      */
 
 /*-
  * Copyright (c) 2001, 2002, 2003, 2006, 2007, 2008, 2020
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: pthread.c,v 1.168 2020/04/14 23:35:07 joerg Exp $");
+__RCSID("$NetBSD: pthread.c,v 1.169 2020/05/15 14:30:23 joerg Exp $");
 
 #define        __EXPOSE_STACK  1
 
@@ -82,7 +82,6 @@
 static void    pthread__initthread(pthread_t);
 static void    pthread__scrubthread(pthread_t, char *, int);
 static void    pthread__initmain(pthread_t *);
-static void    pthread__fork_callback(void);
 static void    pthread__reap(pthread_t);
 
 void   pthread__init(void);
@@ -155,6 +154,32 @@
        char            pad[64];
 } hashlocks[NHASHLOCK] __aligned(64);
 
+static void
+pthread__prefork(void)
+{
+       pthread_mutex_lock(&pthread__deadqueue_lock);
+}
+
+static void
+pthread__fork_parent(void)
+{
+       pthread_mutex_unlock(&pthread__deadqueue_lock);
+}
+
+static void
+pthread__fork_child(void)
+{
+       struct __pthread_st *self = pthread__self();
+
+       pthread_mutex_init(&pthread__deadqueue_lock, NULL);
+
+       /* lwpctl state is not copied across fork. */
+       if (_lwp_ctl(LWPCTL_FEATURE_CURCPU, &self->pt_lwpctl)) {
+               err(EXIT_FAILURE, "_lwp_ctl");
+       }
+       self->pt_lid = _lwp_self();
+}
+
 /*
  * This needs to be started by the library loading code, before main()
  * gets to run, for various things that use the state of the initial thread
@@ -256,22 +281,10 @@
        }
 
        /* Tell libc that we're here and it should role-play accordingly. */
-       pthread_atfork(NULL, NULL, pthread__fork_callback);
+       pthread_atfork(pthread__prefork, pthread__fork_parent, pthread__fork_child);
        __isthreaded = 1;
 }
 
-static void
-pthread__fork_callback(void)
-{
-       struct __pthread_st *self = pthread__self();
-
-       /* lwpctl state is not copied across fork. */
-       if (_lwp_ctl(LWPCTL_FEATURE_CURCPU, &self->pt_lwpctl)) {
-               err(EXIT_FAILURE, "_lwp_ctl");
-       }
-       self->pt_lid = _lwp_self();
-}
-
 /* General-purpose thread data structure sanitization. */
 /* ARGSUSED */
 static void