2d3d740b6f
2000-07-25 Mark Kettenis <kettenis@gnu.org> * hurd/thread-cancel.c (hurd_thread_cancel): When cancelling the calling thread, set the cancellation flag and return success instead of EINTR.
102 lines
3.0 KiB
C
102 lines
3.0 KiB
C
/* Thread cancellation support.
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Copyright (C) 1995, 1996, 1997, 2000 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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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 Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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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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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <hurd/signal.h>
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#include <hurd/interrupt.h>
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#include <assert.h>
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#include <thread_state.h>
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/* See hurdsig.c. */
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extern mach_port_t _hurdsig_abort_rpcs (struct hurd_sigstate *ss,
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int signo, int sigthread,
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struct machine_thread_all_state *,
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int *state_change,
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mach_port_t *reply_port,
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mach_msg_type_name_t reply_port_type,
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int untraced);
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error_t
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hurd_thread_cancel (thread_t thread)
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{
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struct hurd_sigstate *ss = _hurd_thread_sigstate (thread);
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struct machine_thread_all_state state;
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int state_change;
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error_t err;
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if (! ss)
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return EINVAL;
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if (ss == _hurd_self_sigstate ())
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{
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/* We are cancelling ourselves, so it is easy to succeed
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quickly. Since this function is not a cancellation point, we
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just leave the flag set pending the next cancellation point
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(hurd_check_cancel or RPC) and return success. */
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ss->cancel = 1;
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return 0;
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}
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assert (! __spin_lock_locked (&ss->critical_section_lock));
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__spin_lock (&ss->critical_section_lock);
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__spin_lock (&ss->lock);
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err = __thread_suspend (thread);
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__spin_unlock (&ss->lock);
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if (! err)
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{
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/* Set the flag telling the thread its operation is being cancelled. */
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ss->cancel = 1;
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/* Interrupt any interruptible RPC now in progress. */
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state.set = 0;
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_hurdsig_abort_rpcs (ss, 0, 0, &state, &state_change, NULL, 0, 0);
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if (state_change)
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err = __thread_set_state (thread, MACHINE_THREAD_STATE_FLAVOR,
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(natural_t *) &state.basic,
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MACHINE_THREAD_STATE_COUNT);
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if (ss->cancel_hook)
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/* The code being cancelled has a special wakeup function.
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Calling this should make the thread wake up and check the
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cancellation flag. */
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(*ss->cancel_hook) ();
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__thread_resume (thread);
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}
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_hurd_critical_section_unlock (ss);
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return err;
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}
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int
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hurd_check_cancel (void)
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{
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struct hurd_sigstate *ss = _hurd_self_sigstate ();
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int cancel;
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__spin_lock (&ss->lock);
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assert (! __spin_lock_locked (&ss->critical_section_lock));
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cancel = ss->cancel;
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ss->cancel = 0;
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__spin_unlock (&ss->lock);
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return cancel;
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}
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