From 33574c17eefcf326c1cd30eb9f915ad26d3d9ef2 Mon Sep 17 00:00:00 2001 From: Samuel Thibault Date: Mon, 2 Apr 2018 01:43:22 +0200 Subject: hurd: Add hurd thread library Contributed by Agustina Arzille Amos Jeffries David Michael Marco Gerards Marcus Brinkmann Neal H. Walfield Pino Toscano Richard Braun Roland McGrath Samuel Thibault Thomas DiModica Thomas Schwinge * htl: New directory. * sysdeps/htl: New directory. * sysdeps/hurd/htl: New directory. * sysdeps/i386/htl: New directory. * sysdeps/mach/htl: New directory. * sysdeps/mach/hurd/htl: New directory. * sysdeps/mach/hurd/i386/htl: New directory. * nscd/Depend, resolv/Depend, rt/Depend: Add htl dependency. * sysdeps/mach/hurd/i386/Implies: Add mach/hurd/i386/htl imply. * sysdeps/mach/hurd/i386/libpthread.abilist: New file. --- sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c | 169 +++++++++++++++++++++++++ 1 file changed, 169 insertions(+) create mode 100644 sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c (limited to 'sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c') diff --git a/sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c b/sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c new file mode 100644 index 0000000000..41792e3711 --- /dev/null +++ b/sysdeps/mach/hurd/htl/pt-hurd-cond-timedwait.c @@ -0,0 +1,169 @@ +/* pthread_hurd_cond_timedwait_np. Hurd-specific wait on a condition. + Copyright (C) 2012-2018 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 Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If + not, see . */ + +#include +#include +#include + +#include + +extern int __pthread_hurd_cond_timedwait_internal (pthread_cond_t *cond, + pthread_mutex_t *mutex, + const struct timespec + *abstime); + +int +__pthread_hurd_cond_timedwait_np (pthread_cond_t *cond, + pthread_mutex_t *mutex, + const struct timespec *abstime) +{ + return __pthread_hurd_cond_timedwait_internal (cond, mutex, abstime); +} + +strong_alias (__pthread_hurd_cond_timedwait_np, pthread_hurd_cond_timedwait_np); + +int +__pthread_hurd_cond_timedwait_internal (pthread_cond_t *cond, + pthread_mutex_t *mutex, + const struct timespec *abstime) +{ + struct hurd_sigstate *ss = _hurd_self_sigstate (); + struct __pthread *self = _pthread_self (); + error_t err = 0; + int cancel, drain; + clockid_t clock_id = __pthread_default_condattr.__clock; + + /* This function will be called by hurd_thread_cancel while we are blocked + We wake up our thread if it's still blocking or about to block, so it will + progress and notice the cancellation flag. */ + void cancel_me (void) + { + int unblock; + + __pthread_spin_lock (&cond->__lock); + /* The thread only needs to be awaken if it's blocking or about to block. + If it was already unblocked, it's not queued any more. */ + unblock = self->prevp != NULL; + if (unblock) + __pthread_dequeue (self); + __pthread_spin_unlock (&cond->__lock); + + if (unblock) + __pthread_wakeup (self); + } + + assert (ss->intr_port == MACH_PORT_NULL); /* Sanity check for signal bugs. */ + + if (abstime != NULL && (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)) + return EINVAL; + + /* Atomically enqueue our thread on the condition variable's queue of + waiters, and mark our sigstate to indicate that `cancel_me' must be + called to wake us up. We must hold the sigstate lock while acquiring + the condition variable's lock and tweaking it, so that + hurd_thread_cancel can never suspend us and then deadlock waiting for + the condition variable's lock. */ + + __spin_lock (&ss->lock); + __pthread_spin_lock (&cond->__lock); + cancel = ss->cancel; + if (cancel) + /* We were cancelled before doing anything. Don't block at all. */ + ss->cancel = 0; + else + { + /* Put us on the queue so that pthread_cond_broadcast will know to wake + us up. */ + __pthread_enqueue (&cond->__queue, self); + if (cond->__attr) + clock_id = cond->__attr->__clock; + /* Tell hurd_thread_cancel how to unblock us. */ + ss->cancel_hook = &cancel_me; + } + __pthread_spin_unlock (&cond->__lock); + __spin_unlock (&ss->lock); + + if (cancel) + { + /* Cancelled on entry. Just leave the mutex locked. */ + mutex = NULL; + + __spin_lock (&ss->lock); + } + else + { + /* Release MUTEX before blocking. */ + __pthread_mutex_unlock (mutex); + + /* Block the thread. */ + if (abstime != NULL) + err = __pthread_timedblock (self, abstime, clock_id); + else + { + err = 0; + __pthread_block (self); + } + + /* As it was done when enqueueing, prevent hurd_thread_cancel from + suspending us while the condition lock is held. */ + __spin_lock (&ss->lock); + __pthread_spin_lock (&cond->__lock); + if (self->prevp == NULL) + /* Another thread removed us from the list of waiters, which means + a wakeup message has been sent. It was either consumed while + we were blocking, or queued after we timed out and before we + acquired the condition lock, in which case the message queue + must be drained. */ + drain = err ? 1 : 0; + else + { + /* We're still in the list of waiters. Noone attempted to wake us + up, i.e. we timed out. */ + __pthread_dequeue (self); + drain = 0; + } + __pthread_spin_unlock (&cond->__lock); + + if (drain) + __pthread_block (self); + } + + /* Clear the hook, now that we are done blocking. */ + ss->cancel_hook = NULL; + /* Check the cancellation flag; we might have unblocked due to + cancellation rather than a normal pthread_cond_signal or + pthread_cond_broadcast (or we might have just happened to get cancelled + right after waking up). */ + cancel |= ss->cancel; + ss->cancel = 0; + __spin_unlock (&ss->lock); + + if (mutex != NULL) + /* Reacquire the mutex and return. */ + __pthread_mutex_lock (mutex); + + if (cancel) + return EINTR; + else if (err) + { + assert (err == ETIMEDOUT); + return err; + } + + return 0; +} -- cgit 1.4.1