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Diffstat (limited to 'REORG.TODO/hurd/thread-cancel.c')
-rw-r--r-- | REORG.TODO/hurd/thread-cancel.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/REORG.TODO/hurd/thread-cancel.c b/REORG.TODO/hurd/thread-cancel.c new file mode 100644 index 0000000000..722b6adc74 --- /dev/null +++ b/REORG.TODO/hurd/thread-cancel.c @@ -0,0 +1,100 @@ +/* Thread cancellation support. + Copyright (C) 1995-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + 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 <hurd/signal.h> +#include <hurd/interrupt.h> +#include <assert.h> +#include <thread_state.h> + + +/* See hurdsig.c. */ +extern mach_port_t _hurdsig_abort_rpcs (struct hurd_sigstate *ss, + int signo, int sigthread, + struct machine_thread_all_state *, + int *state_change, + mach_port_t *reply_port, + mach_msg_type_name_t reply_port_type, + int untraced); + +error_t +hurd_thread_cancel (thread_t thread) +{ + struct hurd_sigstate *ss = _hurd_thread_sigstate (thread); + struct machine_thread_all_state state; + int state_change; + error_t err; + + if (! ss) + return EINVAL; + if (ss == _hurd_self_sigstate ()) + { + /* We are cancelling ourselves, so it is easy to succeed + quickly. Since this function is not a cancellation point, we + just leave the flag set pending the next cancellation point + (hurd_check_cancel or RPC) and return success. */ + ss->cancel = 1; + return 0; + } + + assert (! __spin_lock_locked (&ss->critical_section_lock)); + __spin_lock (&ss->critical_section_lock); + __spin_lock (&ss->lock); + err = __thread_suspend (thread); + __spin_unlock (&ss->lock); + + if (! err) + { + /* Set the flag telling the thread its operation is being cancelled. */ + ss->cancel = 1; + + /* Interrupt any interruptible RPC now in progress. */ + state.set = 0; + _hurdsig_abort_rpcs (ss, 0, 0, &state, &state_change, NULL, 0, 0); + if (state_change) + err = __thread_set_state (thread, MACHINE_THREAD_STATE_FLAVOR, + (natural_t *) &state.basic, + MACHINE_THREAD_STATE_COUNT); + + if (ss->cancel_hook) + /* The code being cancelled has a special wakeup function. + Calling this should make the thread wake up and check the + cancellation flag. */ + (*ss->cancel_hook) (); + + __thread_resume (thread); + } + + _hurd_critical_section_unlock (ss); + return err; +} + + +int +hurd_check_cancel (void) +{ + struct hurd_sigstate *ss = _hurd_self_sigstate (); + int cancel; + + __spin_lock (&ss->lock); + assert (! __spin_lock_locked (&ss->critical_section_lock)); + cancel = ss->cancel; + ss->cancel = 0; + __spin_unlock (&ss->lock); + + return cancel; +} |