diff options
Diffstat (limited to 'REORG.TODO/nptl/pthread_setcancelstate.c')
-rw-r--r-- | REORG.TODO/nptl/pthread_setcancelstate.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/REORG.TODO/nptl/pthread_setcancelstate.c b/REORG.TODO/nptl/pthread_setcancelstate.c new file mode 100644 index 0000000000..8a1cb9ac3f --- /dev/null +++ b/REORG.TODO/nptl/pthread_setcancelstate.c @@ -0,0 +1,71 @@ +/* Copyright (C) 2002-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@redhat.com>, 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, see + <http://www.gnu.org/licenses/>. */ + +#include <errno.h> +#include "pthreadP.h" +#include <atomic.h> + + +int +__pthread_setcancelstate (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 (__glibc_likely (curval == oldval)) + { + 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) +hidden_def (__pthread_setcancelstate) |