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author | Zack Weinberg <zackw@panix.com> | 2017-06-08 15:39:03 -0400 |
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committer | Zack Weinberg <zackw@panix.com> | 2017-06-08 15:39:03 -0400 |
commit | 5046dbb4a7eba5eccfd258f92f4735c9ffc8d069 (patch) | |
tree | 4470480d904b65cf14ca524f96f79eca818c3eaf /REORG.TODO/nptl/cancellation.c | |
parent | 199fc19d3aaaf57944ef036e15904febe877fc93 (diff) | |
download | glibc-5046dbb4a7eba5eccfd258f92f4735c9ffc8d069.tar glibc-5046dbb4a7eba5eccfd258f92f4735c9ffc8d069.tar.gz glibc-5046dbb4a7eba5eccfd258f92f4735c9ffc8d069.tar.bz2 glibc-5046dbb4a7eba5eccfd258f92f4735c9ffc8d069.zip |
Prepare for radical source tree reorganization.zack/build-layout-experiment
All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).
Diffstat (limited to 'REORG.TODO/nptl/cancellation.c')
-rw-r--r-- | REORG.TODO/nptl/cancellation.c | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/REORG.TODO/nptl/cancellation.c b/REORG.TODO/nptl/cancellation.c new file mode 100644 index 0000000000..e3f0b619d6 --- /dev/null +++ b/REORG.TODO/nptl/cancellation.c @@ -0,0 +1,101 @@ +/* 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 <setjmp.h> +#include <stdlib.h> +#include "pthreadP.h" +#include <futex-internal.h> + + +/* 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 +__pthread_enable_asynccancel (void) +{ + 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 (__glibc_likely (curval == oldval)) + { + if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval)) + { + THREAD_SETMEM (self, result, PTHREAD_CANCELED); + __do_cancel (); + } + + break; + } + + /* Prepare the next round. */ + oldval = curval; + } + + return oldval; +} + + +void +internal_function attribute_hidden +__pthread_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 newval; + + int oldval = THREAD_GETMEM (self, cancelhandling); + + while (1) + { + newval = oldval & ~CANCELTYPE_BITMASK; + + int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval, + oldval); + if (__glibc_likely (curval == oldval)) + break; + + /* Prepare the next round. */ + oldval = curval; + } + + /* We cannot return when we are being canceled. Upon return the + thread might be things which would have to be undone. The + following loop should loop until the cancellation signal is + delivered. */ + while (__builtin_expect ((newval & (CANCELING_BITMASK | CANCELED_BITMASK)) + == CANCELING_BITMASK, 0)) + { + futex_wait_simple ((unsigned int *) &self->cancelhandling, newval, + FUTEX_PRIVATE); + newval = THREAD_GETMEM (self, cancelhandling); + } +} |