diff options
Diffstat (limited to 'nptl/sysdeps/pthread')
| -rw-r--r-- | nptl/sysdeps/pthread/Makefile | 3 | ||||
| -rw-r--r-- | nptl/sysdeps/pthread/librt-cancellation.c | 122 |
2 files changed, 124 insertions, 1 deletions
diff --git a/nptl/sysdeps/pthread/Makefile b/nptl/sysdeps/pthread/Makefile index 1d248bf720..58cfbb38ef 100644 --- a/nptl/sysdeps/pthread/Makefile +++ b/nptl/sysdeps/pthread/Makefile @@ -26,8 +26,9 @@ libpthread-sysdep_routines += errno-loc endif ifeq ($(subdir),rt) -librt-sysdep_routines += timer_routines +librt-sysdep_routines += timer_routines librt-cancellation CPPFLAGS-timer_routines.c = -I../nptl +CFLAGS-librt-cancellation.c += -fexceptions -fasynchronous-unwind-tables ifeq (yes,$(build-shared)) $(objpfx)tst-timer: $(objpfx)librt.so $(shared-thread-library) diff --git a/nptl/sysdeps/pthread/librt-cancellation.c b/nptl/sysdeps/pthread/librt-cancellation.c new file mode 100644 index 0000000000..5f530ed712 --- /dev/null +++ b/nptl/sysdeps/pthread/librt-cancellation.c @@ -0,0 +1,122 @@ +/* Copyright (C) 2002, 2003 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <setjmp.h> +#include <signal.h> +#include <stdlib.h> +#include "pthreadP.h" +#include "atomic.h" + + +#ifdef IS_IN_librt + +/* 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 +__librt_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 stop right here. */ + if ((oldval & EXITING_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 +__librt_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; + } +} + + +/* XXX Hack ahead. In librt we currently do not have access to a + function equivalent to __pthread_unwind. Therefore we just raise a + signal. */ +void +attribute_hidden +__pthread_unwind (__pthread_unwind_buf_t *buf) +{ + INTERNAL_SYSCALL_DECL (err); + while (1) + INTERNAL_SYSCALL (tkill, err, 2, THREAD_GETMEM (THREAD_SELF, tid), + SIGCANCEL); +} + + +#endif |