From c68d0fa2d88fc2134a38d99e7e944828384a7671 Mon Sep 17 00:00:00 2001 From: Austin Foxley Date: Sat, 17 Oct 2009 12:26:24 -0700 Subject: libpthread/nptl: core of the "Native Posix Threading Library" for uClibc targetting arm,sh,i386,mips,sparc for now Signed-off-by: Austin Foxley --- libpthread/nptl/libc-cancellation.c | 116 ++++++++++++++++++++++++++++++++++++ 1 file changed, 116 insertions(+) create mode 100644 libpthread/nptl/libc-cancellation.c (limited to 'libpthread/nptl/libc-cancellation.c') diff --git a/libpthread/nptl/libc-cancellation.c b/libpthread/nptl/libc-cancellation.c new file mode 100644 index 000000000..c9237e095 --- /dev/null +++ b/libpthread/nptl/libc-cancellation.c @@ -0,0 +1,116 @@ +/* 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 +#include "pthreadP.h" +#include "atomic.h" +#include + + +#ifndef NOT_IN_libc + +/* The next two functions are similar to pthread_setcanceltype() but + more specialized for the use in the cancelable functions like write(). + They do not need to check parameters etc. */ +int +attribute_hidden +__libc_enable_asynccancel (void) +{ + struct pthread *self = THREAD_SELF; + int oldval = THREAD_GETMEM (self, cancelhandling); + + while (1) + { + int newval = oldval | CANCELTYPE_BITMASK; + + if (__builtin_expect ((oldval & CANCELED_BITMASK) != 0, 0)) + { + /* If we are already exiting or if PTHREAD_CANCEL_DISABLED, + stop right here. */ + if ((oldval & (EXITING_BITMASK | CANCELSTATE_BITMASK)) != 0) + break; + + int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, + newval, oldval); + if (__builtin_expect (curval != oldval, 0)) + { + /* Somebody else modified the word, try again. */ + oldval = curval; + continue; + } + + THREAD_SETMEM (self, result, PTHREAD_CANCELED); + + __do_cancel (); + + /* NOTREACHED */ + } + + int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval, + oldval); + if (__builtin_expect (curval == oldval, 1)) + break; + + /* Prepare the next round. */ + oldval = curval; + } + + return oldval; +} + + +void +internal_function attribute_hidden +__libc_disable_asynccancel (int oldtype) +{ + /* If asynchronous cancellation was enabled before we do not have + anything to do. */ + if (oldtype & CANCELTYPE_BITMASK) + return; + + struct pthread *self = THREAD_SELF; + int oldval = THREAD_GETMEM (self, cancelhandling); + + while (1) + { + int newval = oldval & ~CANCELTYPE_BITMASK; + + if (newval == oldval) + break; + + int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval, + oldval); + if (__builtin_expect (curval == oldval, 1)) + break; + + /* Prepare the next round. */ + oldval = curval; + } +} + + +void +__libc_cleanup_routine (struct __pthread_cleanup_frame *f) +{ + if (f->__do_it) + f->__cancel_routine (f->__cancel_arg); +} + +#endif -- cgit v1.2.3