From patchwork Mon Dec 8 17:51:46 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Torvald Riegel X-Patchwork-Id: 4110 Received: (qmail 10601 invoked by alias); 8 Dec 2014 17:51:57 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 10590 invoked by uid 89); 8 Dec 2014 17:51:57 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.0 required=5.0 tests=AWL, BAYES_00, SPF_HELO_PASS, SPF_PASS, T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Subject: [PATCH] Remove custom pthread_once implementation on s390. From: Torvald Riegel To: Martin Schwidefsky , Andreas Krebbel Cc: GLIBC Devel Date: Mon, 08 Dec 2014 18:51:46 +0100 Message-ID: <1418061106.25868.99.camel@triegel.csb> Mime-Version: 1.0 This patch removes the custom implementation of pthread_once on s390. I have not tested this, but the generic implementation in nptl/pthread_once.c works well on several architectures. The custom implementation is a C implementation of essentially the same algorithm the generic implementation uses (but with fixes) -- the only difference is that inline asm is used for the atomic ops instead of using the atomic.h atomic ops. OK to commit? commit ebab418a50900f5ce1d995bbb99f5ee6987457a8 Author: Torvald Riegel Date: Mon Dec 8 18:32:14 2014 +0100 Remove custom pthread_once implementation on s390. diff --git a/sysdeps/unix/sysv/linux/s390/pthread_once.c b/sysdeps/unix/sysv/linux/s390/pthread_once.c deleted file mode 100644 index ce02206..0000000 --- a/sysdeps/unix/sysv/linux/s390/pthread_once.c +++ /dev/null @@ -1,110 +0,0 @@ -/* Copyright (C) 2003-2014 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Martin Schwidefsky , 2003. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - . */ - -#include "pthreadP.h" -#include - - -unsigned long int __fork_generation attribute_hidden; - - -static void -clear_once_control (void *arg) -{ - pthread_once_t *once_control = (pthread_once_t *) arg; - - *once_control = 0; - lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE); -} - - -int -__pthread_once (once_control, init_routine) - pthread_once_t *once_control; - void (*init_routine) (void); -{ - while (1) - { - int oldval; - int newval; - - /* Pseudo code: - oldval = *once_control; - if ((oldval & 2) == 0) - { - newval = (oldval & 3) | __fork_generation | 1; - *once_control = newval; - } - Do this atomically. */ - __asm __volatile (" l %1,%0\n" - "0: lhi %2,2\n" - " tml %1,2\n" - " jnz 1f\n" - " nr %2,%1\n" - " ahi %2,1\n" - " o %2,%3\n" - " cs %1,%2,%0\n" - " jl 0b\n" - "1:" - : "=Q" (*once_control), "=&d" (oldval), "=&d" (newval) - : "m" (__fork_generation), "m" (*once_control) - : "cc" ); - /* Check if the initialized has already been done. */ - if ((oldval & 2) != 0) - break; - /* Check if another thread already runs the initializer. */ - if ((oldval & 1) != 0) - { - /* Check whether the initializer execution was interrupted - by a fork. */ - if (((oldval ^ newval) & -4) == 0) - { - /* Same generation, some other thread was faster. Wait. */ - lll_futex_wait (once_control, newval, LLL_PRIVATE); - continue; - } - } - - /* This thread is the first here. Do the initialization. - Register a cleanup handler so that in case the thread gets - interrupted the initialization can be restarted. */ - pthread_cleanup_push (clear_once_control, once_control); - - init_routine (); - - pthread_cleanup_pop (0); - - - /* Add one to *once_control. */ - __asm __volatile (" l %1,%0\n" - "0: lr %2,%1\n" - " ahi %2,1\n" - " cs %1,%2,%0\n" - " jl 0b\n" - : "=Q" (*once_control), "=&d" (oldval), "=&d" (newval) - : "m" (*once_control) : "cc" ); - - /* Wake up all other threads. */ - lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE); - break; - } - - return 0; -} -weak_alias (__pthread_once, pthread_once) -hidden_def (__pthread_once)