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76 lines
2.5 KiB
C
76 lines
2.5 KiB
C
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/* Copyright (C) 2002 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <errno.h>
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#include <stdlib.h>
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#include "atomic.h"
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#include "pthreadP.h"
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int
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pthread_tryjoin_np (threadid, thread_return)
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pthread_t threadid;
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void **thread_return;
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{
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struct pthread *self;
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struct pthread *pd = (struct pthread *) threadid;
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/* Make sure the descriptor is valid. */
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if (DEBUGGING_P && __find_in_stack_list (pd) == NULL)
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/* Not a valid thread handle. */
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return ESRCH;
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/* Is the thread joinable?. */
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if (IS_DETACHED (pd))
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/* We cannot wait for the thread. */
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return EINVAL;
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self = THREAD_SELF;
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if (pd == self || self->joinid == pd)
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/* This is a deadlock situation. The threads are waiting for each
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other to finish. Note that this is a "may" error. To be 100%
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sure we catch this error we would have to lock the data
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structures but it is not necessary. In the unlikely case that
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two threads are really caught in this situation they will
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deadlock. It is the programmer's problem to figure this
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out. */
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return EDEADLK;
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/* Return right away if the thread hasn't terminated yet. */
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if (pd->tid != 0)
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return EBUSY;
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/* Wait for the thread to finish. If it is already locked something
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is wrong. There can only be one waiter. */
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if (atomic_compare_and_exchange_acq (&pd->joinid, self, NULL) != 0)
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/* There is already somebody waiting for the thread. */
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return EINVAL;
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/* Store the return value if the caller is interested. */
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if (thread_return != NULL)
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*thread_return = pd->result;
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/* Free the TCB. */
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__free_tcb (pd);
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return 0;
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}
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