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-rw-r--r--nptl/pthread_setcanceltype.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/nptl/pthread_setcanceltype.c b/nptl/pthread_setcanceltype.c
new file mode 100644
index 0000000000..8f84634888
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+++ b/nptl/pthread_setcanceltype.c
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+/* Copyright (C) 2002 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 <errno.h>
+#include "pthreadP.h"
+#include <atomic.h>
+
+
+int
+pthread_setcanceltype (type, oldtype)
+ int type;
+ int *oldtype;
+{
+ volatile struct pthread *self;
+
+ if (type < PTHREAD_CANCEL_DEFERRED || type > PTHREAD_CANCEL_ASYNCHRONOUS)
+ return EINVAL;
+
+ self = THREAD_SELF;
+
+ while (1)
+ {
+ int oldval = THREAD_GETMEM (self, cancelhandling);
+ int newval = (type == PTHREAD_CANCEL_ASYNCHRONOUS
+ ? oldval | CANCELTYPE_BITMASK
+ : oldval & ~CANCELTYPE_BITMASK);
+
+ /* Store the old value. */
+ if (oldtype != NULL)
+ *oldtype = ((oldval & CANCELTYPE_BITMASK)
+ ? PTHREAD_CANCEL_ASYNCHRONOUS : PTHREAD_CANCEL_DEFERRED);
+
+ /* Avoid doing unnecessary work. The atomic operation can
+ potentially be expensive if the bug 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. */
+ if (atomic_compare_and_exchange_acq (&self->cancelhandling, newval,
+ oldval) == 0)
+ {
+ if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
+ {
+ THREAD_SETMEM (self, result, PTHREAD_CANCELED);
+ __do_cancel (CURRENT_STACK_FRAME);
+ }
+
+ break;
+ }
+ }
+
+ return 0;
+}