1 files changed, 463 insertions, 0 deletions
diff --git a/freebsd/sys/kern/kern_condvar.c b/freebsd/sys/kern/kern_condvar.c
new file mode 100644
index 00000000..f3be4271
--- /dev/null
+++ b/freebsd/sys/kern/kern_condvar.c
@@ -0,0 +1,463 @@
+#include <machine/rtems-bsd-kernel-space.h>
+
+/*-
+ * Copyright (c) 2000 Jake Burkholder <jake@freebsd.org>.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <rtems/bsd/local/opt_ktrace.h>
+
+#include <rtems/bsd/sys/param.h>
+#include <sys/systm.h>
+#include <rtems/bsd/sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/proc.h>
+#include <sys/kernel.h>
+#include <sys/ktr.h>
+#include <sys/condvar.h>
+#include <sys/sched.h>
+#include <sys/signalvar.h>
+#include <sys/sleepqueue.h>
+#include <sys/resourcevar.h>
+#ifdef KTRACE
+#include <sys/uio.h>
+#include <sys/ktrace.h>
+#endif
+
+/*
+ * Common sanity checks for cv_wait* functions.
+ */
+#define	CV_ASSERT(cvp, lock, td) do {					\
+	KASSERT((td) != NULL, ("%s: td NULL", __func__));		\
+	KASSERT(TD_IS_RUNNING(td), ("%s: not TDS_RUNNING", __func__));	\
+	KASSERT((cvp) != NULL, ("%s: cvp NULL", __func__));		\
+	KASSERT((lock) != NULL, ("%s: lock NULL", __func__));		\
+} while (0)
+
+/*
+ * Initialize a condition variable.  Must be called before use.
+ */
+void
+cv_init(struct cv *cvp, const char *desc)
+{
+
+	cvp->cv_description = desc;
+	cvp->cv_waiters = 0;
+}
+
+/*
+ * Destroy a condition variable.  The condition variable must be re-initialized
+ * in order to be re-used.
+ */
+void
+cv_destroy(struct cv *cvp)
+{
+#ifdef INVARIANTS
+	struct sleepqueue *sq;
+
+	sleepq_lock(cvp);
+	sq = sleepq_lookup(cvp);
+	sleepq_release(cvp);
+	KASSERT(sq == NULL, ("%s: associated sleep queue non-empty", __func__));
+#endif
+}
+
+/*
+ * Wait on a condition variable.  The current thread is placed on the condition
+ * variable's wait queue and suspended.  A cv_signal or cv_broadcast on the same
+ * condition variable will resume the thread.  The mutex is released before
+ * sleeping and will be held on return.  It is recommended that the mutex be
+ * held when cv_signal or cv_broadcast are called.
+ */
+void
+_cv_wait(struct cv *cvp, struct lock_object *lock)
+{
+	WITNESS_SAVE_DECL(lock_witness);
+	struct lock_class *class;
+	struct thread *td;
+	int lock_state;
+
+	td = curthread;
+	lock_state = 0;
+#ifdef KTRACE
+	if (KTRPOINT(td, KTR_CSW))
+		ktrcsw(1, 0, cv_wmesg(cvp));
+#endif
+	CV_ASSERT(cvp, lock, td);
+	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock,
+	    "Waiting on \"%s\"", cvp->cv_description);
+	class = LOCK_CLASS(lock);
+
+	if (cold || panicstr) {
+		/*
+		 * During autoconfiguration, just give interrupts
+		 * a chance, then just return.  Don't run any other
+		 * thread or panic below, in case this is the idle
+		 * process and already asleep.
+		 */
+		return;
+	}
+
+	sleepq_lock(cvp);
+
+	cvp->cv_waiters++;
+	if (lock == &Giant.lock_object)
+		mtx_assert(&Giant, MA_OWNED);
+	DROP_GIANT();
+
+	sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR, 0);
+	if (lock != &Giant.lock_object) {
+		if (class->lc_flags & LC_SLEEPABLE)
+			sleepq_release(cvp);
+		WITNESS_SAVE(lock, lock_witness);
+		lock_state = class->lc_unlock(lock);
+		if (class->lc_flags & LC_SLEEPABLE)
+			sleepq_lock(cvp);
+	}
+	sleepq_wait(cvp, 0);
+
+#ifdef KTRACE
+	if (KTRPOINT(td, KTR_CSW))
+		ktrcsw(0, 0, cv_wmesg(cvp));
+#endif
+	PICKUP_GIANT();
+	if (lock != &Giant.lock_object) {
+		class->lc_lock(lock, lock_state);
+		WITNESS_RESTORE(lock, lock_witness);
+	}
+}
+
+/*
+ * Wait on a condition variable.  This function differs from cv_wait by
+ * not aquiring the mutex after condition variable was signaled.
+ */
+void
+_cv_wait_unlock(struct cv *cvp, struct lock_object *lock)
+{
+	struct lock_class *class;
+	struct thread *td;
+
+	td = curthread;
+#ifdef KTRACE
+	if (KTRPOINT(td, KTR_CSW))
+		ktrcsw(1, 0, cv_wmesg(cvp));
+#endif
+	CV_ASSERT(cvp, lock, td);
+	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock,
+	    "Waiting on \"%s\"", cvp->cv_description);
+	KASSERT(lock != &Giant.lock_object,
+	    ("cv_wait_unlock cannot be used with Giant"));
+	class = LOCK_CLASS(lock);
+
+	if (cold || panicstr) {
+		/*
+		 * During autoconfiguration, just give interrupts
+		 * a chance, then just return.  Don't run any other
+		 * thread or panic below, in case this is the idle
+		 * process and already asleep.
+		 */
+		class->lc_unlock(lock);
+		return;
+	}
+
+	sleepq_lock(cvp);
+
+	cvp->cv_waiters++;
+	DROP_GIANT();
+
+	sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR, 0);
+	if (class->lc_flags & LC_SLEEPABLE)
+		sleepq_release(cvp);
+	class->lc_unlock(lock);
+	if (class->lc_flags & LC_SLEEPABLE)
+		sleepq_lock(cvp);
+	sleepq_wait(cvp, 0);
+
+#ifdef KTRACE
+	if (KTRPOINT(td, KTR_CSW))
+		ktrcsw(0, 0, cv_wmesg(cvp));
+#endif
+	PICKUP_GIANT();
+}
+
+/*
+ * Wait on a condition variable, allowing interruption by signals.  Return 0 if
+ * the thread was resumed with cv_signal or cv_broadcast, EINTR or ERESTART if
+ * a signal was caught.  If ERESTART is returned the system call should be
+ * restarted if possible.
+ */
+int
+_cv_wait_sig(struct cv *cvp, struct lock_object *lock)
+{
+#ifndef __rtems__
+	WITNESS_SAVE_DECL(lock_witness);
+	struct lock_class *class;
+	struct thread *td;
+	int lock_state, rval;
+
+	td = curthread;
+	lock_state = 0;
+#ifdef KTRACE
+	if (KTRPOINT(td, KTR_CSW))
+		ktrcsw(1, 0, cv_wmesg(cvp));
+#endif
+	CV_ASSERT(cvp, lock, td);
+	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock,
+	    "Waiting on \"%s\"", cvp->cv_description);
+	class = LOCK_CLASS(lock);
+
+	if (cold || panicstr) {
+		/*
+		 * After a panic, or during autoconfiguration, just give
+		 * interrupts a chance, then just return; don't run any other
+		 * procs or panic below, in case this is the idle process and
+		 * already asleep.
+		 */
+		return (0);
+	}
+
+	sleepq_lock(cvp);
+
+	cvp->cv_waiters++;
+	if (lock == &Giant.lock_object)
+		mtx_assert(&Giant, MA_OWNED);
+	DROP_GIANT();
+
+	sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR |
+	    SLEEPQ_INTERRUPTIBLE, 0);
+	if (lock != &Giant.lock_object) {
+		if (class->lc_flags & LC_SLEEPABLE)
+			sleepq_release(cvp);
+		WITNESS_SAVE(lock, lock_witness);
+		lock_state = class->lc_unlock(lock);
+		if (class->lc_flags & LC_SLEEPABLE)
+			sleepq_lock(cvp);
+	}
+	rval = sleepq_wait_sig(cvp, 0);
+
+#ifdef KTRACE
+	if (KTRPOINT(td, KTR_CSW))
+		ktrcsw(0, 0, cv_wmesg(cvp));
+#endif
+	PICKUP_GIANT();
+	if (lock != &Giant.lock_object) {
+		class->lc_lock(lock, lock_state);
+		WITNESS_RESTORE(lock, lock_witness);
+	}
+
+	return (rval);
+#else /* __rtems__ */
+	_cv_wait(cvp, lock);
+
+	return (0);
+#endif /* __rtems__ */
+}
+
+/*
+ * Wait on a condition variable for at most timo/hz seconds.  Returns 0 if the
+ * process was resumed by cv_signal or cv_broadcast, EWOULDBLOCK if the timeout
+ * expires.
+ */
+int
+_cv_timedwait(struct cv *cvp, struct lock_object *lock, int timo)
+{
+	WITNESS_SAVE_DECL(lock_witness);
+	struct lock_class *class;
+	struct thread *td;
+	int lock_state, rval;
+
+	td = curthread;
+	lock_state = 0;
+#ifdef KTRACE
+	if (KTRPOINT(td, KTR_CSW))
+		ktrcsw(1, 0, cv_wmesg(cvp));
+#endif
+	CV_ASSERT(cvp, lock, td);
+	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock,
+	    "Waiting on \"%s\"", cvp->cv_description);
+	class = LOCK_CLASS(lock);
+
+	if (cold || panicstr) {
+		/*
+		 * After a panic, or during autoconfiguration, just give
+		 * interrupts a chance, then just return; don't run any other
+		 * thread or panic below, in case this is the idle process and
+		 * already asleep.
+		 */
+		return 0;
+	}
+
+	sleepq_lock(cvp);
+
+	cvp->cv_waiters++;
+	if (lock == &Giant.lock_object)
+		mtx_assert(&Giant, MA_OWNED);
+	DROP_GIANT();
+
+	sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR, 0);
+	sleepq_set_timeout(cvp, timo);
+	if (lock != &Giant.lock_object) {
+		if (class->lc_flags & LC_SLEEPABLE)
+			sleepq_release(cvp);
+		WITNESS_SAVE(lock, lock_witness);
+		lock_state = class->lc_unlock(lock);
+		if (class->lc_flags & LC_SLEEPABLE)
+			sleepq_lock(cvp);
+	}
+	rval = sleepq_timedwait(cvp, 0);
+
+#ifdef KTRACE
+	if (KTRPOINT(td, KTR_CSW))
+		ktrcsw(0, 0, cv_wmesg(cvp));
+#endif
+	PICKUP_GIANT();
+	if (lock != &Giant.lock_object) {
+		class->lc_lock(lock, lock_state);
+		WITNESS_RESTORE(lock, lock_witness);
+	}
+
+	return (rval);
+}
+
+#ifndef __rtems__
+/*
+ * Wait on a condition variable for at most timo/hz seconds, allowing
+ * interruption by signals.  Returns 0 if the thread was resumed by cv_signal
+ * or cv_broadcast, EWOULDBLOCK if the timeout expires, and EINTR or ERESTART if
+ * a signal was caught.
+ */
+int
+_cv_timedwait_sig(struct cv *cvp, struct lock_object *lock, int timo)
+{
+	WITNESS_SAVE_DECL(lock_witness);
+	struct lock_class *class;
+	struct thread *td;
+	int lock_state, rval;
+
+	td = curthread;
+	lock_state = 0;
+#ifdef KTRACE
+	if (KTRPOINT(td, KTR_CSW))
+		ktrcsw(1, 0, cv_wmesg(cvp));
+#endif
+	CV_ASSERT(cvp, lock, td);
+	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock,
+	    "Waiting on \"%s\"", cvp->cv_description);
+	class = LOCK_CLASS(lock);
+
+	if (cold || panicstr) {
+		/*
+		 * After a panic, or during autoconfiguration, just give
+		 * interrupts a chance, then just return; don't run any other
+		 * thread or panic below, in case this is the idle process and
+		 * already asleep.
+		 */
+		return 0;
+	}
+
+	sleepq_lock(cvp);
+
+	cvp->cv_waiters++;
+	if (lock == &Giant.lock_object)
+		mtx_assert(&Giant, MA_OWNED);
+	DROP_GIANT();
+
+	sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR |
+	    SLEEPQ_INTERRUPTIBLE, 0);
+	sleepq_set_timeout(cvp, timo);
+	if (lock != &Giant.lock_object) {
+		if (class->lc_flags & LC_SLEEPABLE)
+			sleepq_release(cvp);
+		WITNESS_SAVE(lock, lock_witness);
+		lock_state = class->lc_unlock(lock);
+		if (class->lc_flags & LC_SLEEPABLE)
+			sleepq_lock(cvp);
+	}
+	rval = sleepq_timedwait_sig(cvp, 0);
+
+#ifdef KTRACE
+	if (KTRPOINT(td, KTR_CSW))
+		ktrcsw(0, 0, cv_wmesg(cvp));
+#endif
+	PICKUP_GIANT();
+	if (lock != &Giant.lock_object) {
+		class->lc_lock(lock, lock_state);
+		WITNESS_RESTORE(lock, lock_witness);
+	}
+
+	return (rval);
+}
+#endif /* __rtems__ */
+
+/*
+ * Signal a condition variable, wakes up one waiting thread.  Will also wakeup
+ * the swapper if the process is not in memory, so that it can bring the
+ * sleeping process in.  Note that this may also result in additional threads
+ * being made runnable.  Should be called with the same mutex as was passed to
+ * cv_wait held.
+ */
+void
+cv_signal(struct cv *cvp)
+{
+	int wakeup_swapper;
+
+	wakeup_swapper = 0;
+	sleepq_lock(cvp);
+	if (cvp->cv_waiters > 0) {
+		cvp->cv_waiters--;
+		wakeup_swapper = sleepq_signal(cvp, SLEEPQ_CONDVAR, 0, 0);
+	}
+	sleepq_release(cvp);
+	if (wakeup_swapper)
+		kick_proc0();
+}
+
+/*
+ * Broadcast a signal to a condition variable.  Wakes up all waiting threads.
+ * Should be called with the same mutex as was passed to cv_wait held.
+ */
+void
+cv_broadcastpri(struct cv *cvp, int pri)
+{
+	int wakeup_swapper;
+
+	/*
+	 * XXX sleepq_broadcast pri argument changed from -1 meaning
+	 * no pri to 0 meaning no pri.
+	 */
+	wakeup_swapper = 0;
+	if (pri == -1)
+		pri = 0;
+	sleepq_lock(cvp);
+	if (cvp->cv_waiters > 0) {
+		cvp->cv_waiters = 0;
+		wakeup_swapper = sleepq_broadcast(cvp, SLEEPQ_CONDVAR, pri, 0);
+	}
+	sleepq_release(cvp);
+	if (wakeup_swapper)
+		kick_proc0();
+}