From 873fa5beccbb4e95d1bbb9afb6a0eec02811f09b Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Fri, 25 Jul 2014 17:39:05 +0530 Subject: NPTL: ARC support Signed-off-by: Vineet Gupta Signed-off-by: Bernhard Reutner-Fischer --- .../sysdeps/unix/sysv/linux/arc/pthread_once.c | 100 +++++++++++++++++++++ 1 file changed, 100 insertions(+) create mode 100644 libpthread/nptl/sysdeps/unix/sysv/linux/arc/pthread_once.c (limited to 'libpthread/nptl/sysdeps/unix/sysv/linux/arc/pthread_once.c') diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/arc/pthread_once.c b/libpthread/nptl/sysdeps/unix/sysv/linux/arc/pthread_once.c new file mode 100644 index 000000000..e977a7d0c --- /dev/null +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/arc/pthread_once.c @@ -0,0 +1,100 @@ +/* Copyright (C) 2004, 2005 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#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 +attribute_protected +__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) +strong_alias (__pthread_once, __pthread_once_internal) + +#if defined(__USING_SJLJ_EXCEPTIONS__) && !defined(__PIC__) +/* When statically linked, if pthread_create is used, this file + will be brought in. The exception handling code in GCC assumes + that if pthread_create is available, so are these. */ +const void *include_pthread_getspecific attribute_hidden = pthread_getspecific; +const void *include_pthread_setspecific attribute_hidden = pthread_setspecific; +const void *include_pthread_key_create attribute_hidden = pthread_key_create; +#endif -- cgit v1.2.3