From 0b3366f6a93ac0f7e2028745ea557c0acd8722c6 Mon Sep 17 00:00:00 2001 From: "\"Steven J. Hill\"" Date: Sat, 7 May 2005 02:04:55 +0000 Subject: Import in NPTL code from glibc. For further information please consult the 'README.NPTL' file. --- libpthread/nptl/pthread_setcancelstate.c | 73 ++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 libpthread/nptl/pthread_setcancelstate.c (limited to 'libpthread/nptl/pthread_setcancelstate.c') diff --git a/libpthread/nptl/pthread_setcancelstate.c b/libpthread/nptl/pthread_setcancelstate.c new file mode 100644 index 000000000..a452c2ec4 --- /dev/null +++ b/libpthread/nptl/pthread_setcancelstate.c @@ -0,0 +1,73 @@ +/* Copyright (C) 2002, 2003 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper , 2002. + + 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 +#include "pthreadP.h" +#include + + +int +__pthread_setcancelstate (state, oldstate) + int state; + int *oldstate; +{ + volatile struct pthread *self; + + if (state < PTHREAD_CANCEL_ENABLE || state > PTHREAD_CANCEL_DISABLE) + return EINVAL; + + self = THREAD_SELF; + + int oldval = THREAD_GETMEM (self, cancelhandling); + while (1) + { + int newval = (state == PTHREAD_CANCEL_DISABLE + ? oldval | CANCELSTATE_BITMASK + : oldval & ~CANCELSTATE_BITMASK); + + /* Store the old value. */ + if (oldstate != NULL) + *oldstate = ((oldval & CANCELSTATE_BITMASK) + ? PTHREAD_CANCEL_DISABLE : PTHREAD_CANCEL_ENABLE); + + /* Avoid doing unnecessary work. The atomic operation can + potentially be expensive if the memory has to be locked and + remote cache lines have to be invalidated. */ + if (oldval == newval) + break; + + /* Update the cancel handling word. This has to be done + atomically since other bits could be modified as well. */ + int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval, + oldval); + if (__builtin_expect (curval == oldval, 1)) + { + if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval)) + __do_cancel (); + + break; + } + + /* Prepare for the next round. */ + oldval = curval; + } + + return 0; +} +strong_alias (__pthread_setcancelstate, pthread_setcancelstate) -- cgit v1.2.3