[src/trunk]: src/lib/libpthread Rework TLS initialisation:

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

details:   https://anonhg.NetBSD.org/src/rev/c20b9e8ab37e
branches:  trunk
changeset: 763651:c20b9e8ab37e
user:      joerg <joerg%NetBSD.org@localhost>
date:      Wed Mar 30 00:03:26 2011 +0000

description:
Rework TLS initialisation:
- Update TCB for the initial thread in pthread__initthread, not
  pthread__init to get it valid as soon as possible.
- Don't overwrite the pt_tls field in pthread__initthread.
- Don't deallocate pt_tls in pthread__scrubthread. This worked more by
  chance than by design.
- Handle freeing the TLS area in pthread_create after removing the
  thread instance from the dead queue.

diffstat:

 lib/libpthread/pthread.c |  40 +++++++++++++++++++---------------------
 1 files changed, 19 insertions(+), 21 deletions(-)

diffs (96 lines):

diff -r 7cd97f410558 -r c20b9e8ab37e lib/libpthread/pthread.c
--- a/lib/libpthread/pthread.c  Tue Mar 29 23:51:32 2011 +0000
+++ b/lib/libpthread/pthread.c  Wed Mar 30 00:03:26 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pthread.c,v 1.122 2011/03/12 07:46:29 matt Exp $       */
+/*     $NetBSD: pthread.c,v 1.123 2011/03/30 00:03:26 joerg 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 1.122 2011/03/12 07:46:29 matt Exp $");
+__RCSID("$NetBSD: pthread.c,v 1.123 2011/03/30 00:03:26 joerg Exp $");
 
 #define        __EXPOSE_STACK  1
 
@@ -195,15 +195,6 @@
        pthread__initthread(first);
        pthread__scrubthread(first, NULL, 0);
 
-#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
-#ifdef __HAVE___LWP_GETTCB_FAST
-       first->pt_tls = __lwp_gettcb_fast();
-#else
-       first->pt_tls = _lwp_getprivate();
-#endif
-       first->pt_tls->tcb_pthread = first;
-#endif
-
        first->pt_lid = _lwp_self();
        PTQ_INSERT_HEAD(&pthread__allqueue, first, pt_allq);
        RB_INSERT(__pthread__alltree, &pthread__alltree, first);
@@ -294,9 +285,6 @@
 {
 
        t->pt_self = t;
-#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
-       t->pt_tls = NULL;
-#endif
        t->pt_magic = PT_MAGIC;
        t->pt_willpark = 0;
        t->pt_unpark = 0;
@@ -320,12 +308,6 @@
 pthread__scrubthread(pthread_t t, char *name, int flags)
 {
 
-#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
-       if (t->pt_tls) {
-               _rtld_tls_free(t->pt_tls);
-               t->pt_tls = NULL;
-       }
-#endif
        t->pt_state = PT_STATE_RUNNING;
        t->pt_exitval = NULL;
        t->pt_flags = flags;
@@ -389,6 +371,12 @@
                if (newthread)
                        PTQ_REMOVE(&pthread__deadqueue, newthread, pt_deadq);
                pthread_mutex_unlock(&pthread__deadqueue_lock);
+#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
+               if (newthread && newthread->pt_tls) {
+                       _rtld_tls_free(newthread->pt_tls);
+                       newthread->pt_tls = NULL;
+               }
+#endif
        }
 
        /*
@@ -410,6 +398,9 @@
 #endif
                newthread->pt_uc.uc_stack = newthread->pt_stack;
                newthread->pt_uc.uc_link = NULL;
+#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
+               newthread->pt_tls = NULL;
+#endif
 
                /* Add to list of all threads. */
                pthread_rwlock_wrlock(&pthread__alltree_lock);
@@ -1267,7 +1258,14 @@
        }
 
        *newt = t;
-#if !defined(__HAVE_TLS_VARIANT_I) && !defined(__HAVE_TLS_VARIANT_II)
+#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
+#  ifdef __HAVE___LWP_GETTCB_FAST
+       t->pt_tls = __lwp_gettcb_fast();
+#  else
+       t->pt_tls = _lwp_getprivate();
+#  endif
+       t->pt_tls->tcb_pthread = t;
+#else
        _lwp_setprivate(t);
 #endif
 }