From 36875b06e0ed7f137190b9228bef553adfc338ba Mon Sep 17 00:00:00 2001 From: Torvald Riegel Date: Wed, 8 May 2013 16:35:10 +0200 Subject: Fixed and unified pthread_once. [BZ #15215] This unifies various pthread_once architecture-specific implementations which were using the same algorithm with slightly different implementations. It also adds missing memory barriers that are required for correctness. --- .../unix/sysv/linux/aarch64/nptl/pthread_once.c | 90 --------------------- sysdeps/unix/sysv/linux/arm/nptl/pthread_once.c | 89 -------------------- sysdeps/unix/sysv/linux/ia64/nptl/pthread_once.c | 93 --------------------- sysdeps/unix/sysv/linux/m68k/nptl/pthread_once.c | 90 --------------------- sysdeps/unix/sysv/linux/mips/nptl/pthread_once.c | 93 --------------------- sysdeps/unix/sysv/linux/tile/nptl/pthread_once.c | 94 ---------------------- 6 files changed, 549 deletions(-) delete mode 100644 sysdeps/unix/sysv/linux/aarch64/nptl/pthread_once.c delete mode 100644 sysdeps/unix/sysv/linux/arm/nptl/pthread_once.c delete mode 100644 sysdeps/unix/sysv/linux/ia64/nptl/pthread_once.c delete mode 100644 sysdeps/unix/sysv/linux/m68k/nptl/pthread_once.c delete mode 100644 sysdeps/unix/sysv/linux/mips/nptl/pthread_once.c delete mode 100644 sysdeps/unix/sysv/linux/tile/nptl/pthread_once.c (limited to 'sysdeps/unix/sysv') diff --git a/sysdeps/unix/sysv/linux/aarch64/nptl/pthread_once.c b/sysdeps/unix/sysv/linux/aarch64/nptl/pthread_once.c deleted file mode 100644 index d1b28ff51f..0000000000 --- a/sysdeps/unix/sysv/linux/aarch64/nptl/pthread_once.c +++ /dev/null @@ -1,90 +0,0 @@ -/* Copyright (C) 2004-2014 Free Software Foundation, Inc. - - This file is part of the GNU C Library. - - 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 (pthread_once_t *once_control, void (*init_routine) (void)) -{ - for (;;) - { - int oldval; - int newval; - - /* Pseudo code: - newval = __fork_generation | 1; - oldval = *once_control; - if ((oldval & 2) == 0) - *once_control = newval; - Do this atomically. - */ - do - { - newval = __fork_generation | 1; - oldval = *once_control; - if (oldval & 2) - break; - } while (atomic_compare_and_exchange_val_acq (once_control, newval, oldval) != oldval); - - /* Check if the initializer has already been done. */ - if ((oldval & 2) != 0) - return 0; - - /* Check if another thread already runs the initializer. */ - if ((oldval & 1) == 0) - break; - - /* Check whether the initializer execution was interrupted by a fork. */ - if (oldval != newval) - break; - - /* Same generation, some other thread was faster. Wait. */ - lll_futex_wait (once_control, oldval, LLL_PRIVATE); - } - - /* 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); - - /* Say that the initialisation is done. */ - *once_control = __fork_generation | 2; - - /* Wake up all other threads. */ - lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE); - - return 0; -} -weak_alias (__pthread_once, pthread_once) -hidden_def (__pthread_once) diff --git a/sysdeps/unix/sysv/linux/arm/nptl/pthread_once.c b/sysdeps/unix/sysv/linux/arm/nptl/pthread_once.c deleted file mode 100644 index a063149925..0000000000 --- a/sysdeps/unix/sysv/linux/arm/nptl/pthread_once.c +++ /dev/null @@ -1,89 +0,0 @@ -/* Copyright (C) 2004-2014 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - 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 (pthread_once_t *once_control, void (*init_routine) (void)) -{ - for (;;) - { - int oldval; - int newval; - - /* Pseudo code: - newval = __fork_generation | 1; - oldval = *once_control; - if ((oldval & 2) == 0) - *once_control = newval; - Do this atomically. - */ - do - { - newval = __fork_generation | 1; - oldval = *once_control; - if (oldval & 2) - break; - } while (atomic_compare_and_exchange_val_acq (once_control, newval, oldval) != oldval); - - /* Check if the initializer has already been done. */ - if ((oldval & 2) != 0) - return 0; - - /* Check if another thread already runs the initializer. */ - if ((oldval & 1) == 0) - break; - - /* Check whether the initializer execution was interrupted by a fork. */ - if (oldval != newval) - break; - - /* Same generation, some other thread was faster. Wait. */ - lll_futex_wait (once_control, oldval, LLL_PRIVATE); - } - - /* 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); - - /* Say that the initialisation is done. */ - *once_control = __fork_generation | 2; - - /* Wake up all other threads. */ - lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE); - - return 0; -} -weak_alias (__pthread_once, pthread_once) -hidden_def (__pthread_once) diff --git a/sysdeps/unix/sysv/linux/ia64/nptl/pthread_once.c b/sysdeps/unix/sysv/linux/ia64/nptl/pthread_once.c deleted file mode 100644 index a231e55879..0000000000 --- a/sysdeps/unix/sysv/linux/ia64/nptl/pthread_once.c +++ /dev/null @@ -1,93 +0,0 @@ -/* Copyright (C) 2003-2014 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Jakub Jelinek , 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, val, newval; - - val = *once_control; - do - { - /* Check if the initialized has already been done. */ - if ((val & 2) != 0) - return 0; - - oldval = val; - newval = (oldval & 3) | __fork_generation | 1; - val = atomic_compare_and_exchange_val_acq (once_control, newval, - oldval); - } - while (__builtin_expect (val != oldval, 0)); - - /* 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. */ - atomic_increment (once_control); - - /* 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) diff --git a/sysdeps/unix/sysv/linux/m68k/nptl/pthread_once.c b/sysdeps/unix/sysv/linux/m68k/nptl/pthread_once.c deleted file mode 100644 index 01542e9c74..0000000000 --- a/sysdeps/unix/sysv/linux/m68k/nptl/pthread_once.c +++ /dev/null @@ -1,90 +0,0 @@ -/* Copyright (C) 2010-2014 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Maxim Kuvyrkov , 2010. - - 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 (pthread_once_t *once_control, void (*init_routine) (void)) -{ - for (;;) - { - int oldval; - int newval; - - /* Pseudo code: - newval = __fork_generation | 1; - oldval = *once_control; - if ((oldval & 2) == 0) - *once_control = newval; - Do this atomically. - */ - do - { - newval = __fork_generation | 1; - oldval = *once_control; - if (oldval & 2) - break; - } while (atomic_compare_and_exchange_val_acq (once_control, newval, oldval) != oldval); - - /* Check if the initializer has already been done. */ - if ((oldval & 2) != 0) - return 0; - - /* Check if another thread already runs the initializer. */ - if ((oldval & 1) == 0) - break; - - /* Check whether the initializer execution was interrupted by a fork. */ - if (oldval != newval) - break; - - /* Same generation, some other thread was faster. Wait. */ - lll_futex_wait (once_control, oldval, LLL_PRIVATE); - } - - /* 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); - - /* Say that the initialisation is done. */ - *once_control = __fork_generation | 2; - - /* Wake up all other threads. */ - lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE); - - return 0; -} -weak_alias (__pthread_once, pthread_once) -hidden_def (__pthread_once) diff --git a/sysdeps/unix/sysv/linux/mips/nptl/pthread_once.c b/sysdeps/unix/sysv/linux/mips/nptl/pthread_once.c deleted file mode 100644 index 3e3430dbc6..0000000000 --- a/sysdeps/unix/sysv/linux/mips/nptl/pthread_once.c +++ /dev/null @@ -1,93 +0,0 @@ -/* Copyright (C) 2003-2014 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Jakub Jelinek , 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, val, newval; - - val = *once_control; - do - { - /* Check if the initialized has already been done. */ - if ((val & 2) != 0) - return 0; - - oldval = val; - newval = (oldval & 3) | __fork_generation | 1; - val = atomic_compare_and_exchange_val_acq (once_control, newval, - oldval); - } - while (__builtin_expect (val != oldval, 0)); - - /* 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. */ - atomic_increment (once_control); - - /* 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) diff --git a/sysdeps/unix/sysv/linux/tile/nptl/pthread_once.c b/sysdeps/unix/sysv/linux/tile/nptl/pthread_once.c deleted file mode 100644 index 1b38999870..0000000000 --- a/sysdeps/unix/sysv/linux/tile/nptl/pthread_once.c +++ /dev/null @@ -1,94 +0,0 @@ -/* Copyright (C) 2011-2014 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Chris Metcalf , 2011. - Based on work contributed by Jakub Jelinek , 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 -#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, val, newval; - - val = *once_control; - do - { - /* Check if the initialized has already been done. */ - if ((val & 2) != 0) - return 0; - - oldval = val; - newval = (oldval & 3) | __fork_generation | 1; - val = atomic_compare_and_exchange_val_acq (once_control, newval, - oldval); - } - while (__builtin_expect (val != oldval, 0)); - - /* 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. */ - atomic_increment (once_control); - - /* 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) -- cgit 1.4.1