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authorSebastian Huber <sebastian.huber@embedded-brains.de>2013-10-09 22:42:09 +0200
committerSebastian Huber <sebastian.huber@embedded-brains.de>2013-10-10 09:06:58 +0200
commitbceabc95c1c85d793200446fa85f1ddc6313ea29 (patch)
tree973c8bd8deca9fd69913f2895cc91e0e6114d46c /rtemsbsd/rtems/rtems-bsd-rwlock.c
parentAdd FreeBSD sources as a submodule (diff)
downloadrtems-libbsd-bceabc95c1c85d793200446fa85f1ddc6313ea29.tar.bz2
Move files to match FreeBSD layout
Diffstat (limited to 'rtemsbsd/rtems/rtems-bsd-rwlock.c')
-rw-r--r--rtemsbsd/rtems/rtems-bsd-rwlock.c396
1 files changed, 396 insertions, 0 deletions
diff --git a/rtemsbsd/rtems/rtems-bsd-rwlock.c b/rtemsbsd/rtems/rtems-bsd-rwlock.c
new file mode 100644
index 00000000..a38a9a14
--- /dev/null
+++ b/rtemsbsd/rtems/rtems-bsd-rwlock.c
@@ -0,0 +1,396 @@
+/**
+ * @file
+ *
+ * @ingroup rtems_bsd_rtems
+ *
+ * @brief TODO.
+ */
+
+/*
+ * Copyright (c) 2011 OPTI Medical. All rights reserved.
+ *
+ * OPTI Medical
+ * 235 Hembree Park Drive
+ * Roswell, GA 30076
+ * USA
+ * <kevin.kirspel@optimedical.com>
+ *
+ * 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 <pthread.h>
+
+#include <freebsd/machine/rtems-bsd-config.h>
+
+#include <rtems/score/objectimpl.h>
+#include <rtems/posix/rwlockimpl.h>
+
+#include <sys/types.h>
+#include <freebsd/sys/param.h>
+#include <freebsd/sys/types.h>
+#include <freebsd/sys/systm.h>
+#include <freebsd/sys/lock.h>
+#include <freebsd/sys/rwlock.h>
+
+#ifndef INVARIANTS
+#define _rw_assert(rw, what, file, line)
+#endif
+
+static void assert_rw(struct lock_object *lock, int what);
+static void lock_rw(struct lock_object *lock, int how);
+#ifdef KDTRACE_HOOKS
+static int owner_rw(struct lock_object *lock, struct thread **owner);
+#endif
+static int unlock_rw(struct lock_object *lock);
+
+struct lock_class lock_class_rw = {
+ .lc_name = "rw",
+ .lc_flags = LC_SLEEPLOCK | LC_RECURSABLE | LC_UPGRADABLE,
+ .lc_assert = assert_rw,
+#ifdef DDB
+ .lc_ddb_show = db_show_rwlock,
+#endif
+ .lc_lock = lock_rw,
+ .lc_unlock = unlock_rw,
+#ifdef KDTRACE_HOOKS
+ .lc_owner = owner_rw,
+#endif
+};
+
+RTEMS_CHAIN_DEFINE_EMPTY(rtems_bsd_rwlock_chain);
+
+void
+assert_rw(struct lock_object *lock, int what)
+{
+ rw_assert((struct rwlock *)lock, what);
+}
+
+void
+lock_rw(struct lock_object *lock, int how)
+{
+ struct rwlock *rw;
+
+ rw = (struct rwlock *)lock;
+ if (how)
+ rw_wlock(rw);
+ else
+ rw_rlock(rw);
+}
+
+int
+unlock_rw(struct lock_object *lock)
+{
+ struct rwlock *rw;
+
+ rw = (struct rwlock *)lock;
+ rw_assert(rw, RA_LOCKED | LA_NOTRECURSED);
+ if (rw->rw_lock & RW_LOCK_READ) {
+ rw_runlock(rw);
+ return (0);
+ } else {
+ rw_wunlock(rw);
+ return (1);
+ }
+}
+
+#ifdef KDTRACE_HOOKS
+int
+owner_rw(struct lock_object *lock, struct thread **owner)
+{
+ struct rwlock *rw = (struct rwlock *)lock;
+ uintptr_t x = rw->rw_lock;
+
+ *owner = rw_wowner(rw);
+ return ((x & RW_LOCK_READ) != 0 ? (RW_READERS(x) != 0) :
+ (*owner != NULL));
+}
+#endif
+
+void
+rw_init_flags(struct rwlock *rw, const char *name, int opts)
+{
+ struct lock_class *class;
+ int i;
+ pthread_rwlock_t lock;
+ int iret;
+
+ if ((opts & RW_RECURSE) != 0) {
+ /* FIXME */
+ }
+
+ class = &lock_class_rw;
+
+ /* Check for double-init and zero object. */
+ KASSERT(!lock_initalized(&rw->lock_object), ("lock \"%s\" %p already initialized", name, rw->lock_object));
+
+ /* Look up lock class to find its index. */
+ for (i = 0; i < LOCK_CLASS_MAX; i++)
+ {
+ if (lock_classes[i] == class)
+ {
+ rw->lock_object.lo_flags = i << LO_CLASSSHIFT;
+ break;
+ }
+ }
+ KASSERT(i < LOCK_CLASS_MAX, ("unknown lock class %p", class));
+
+ iret = pthread_rwlock_init( &lock, NULL );
+ BSD_ASSERT( iret == 0 );
+
+ rw->lock_object.lo_name = name;
+ rw->lock_object.lo_flags |= LO_INITIALIZED;
+ rw->lock_object.lo_id = lock;
+
+ rtems_chain_append(&rtems_bsd_rwlock_chain, &rw->lock_object.lo_node);
+}
+
+void
+rw_destroy(struct rwlock *rw)
+{
+ int iret;
+ pthread_rwlock_destroy( rw->lock_object.lo_id );
+ BSD_ASSERT( iret == 0 );
+ rtems_chain_extract( &rw->lock_object.lo_node );
+ rw->lock_object.lo_id = 0;
+ rw->lock_object.lo_flags &= ~LO_INITIALIZED;
+}
+
+void
+rw_sysinit(void *arg)
+{
+ struct rw_args *args = arg;
+
+ rw_init(args->ra_rw, args->ra_desc);
+}
+
+void
+rw_sysinit_flags(void *arg)
+{
+ struct rw_args_flags *args = arg;
+
+ rw_init_flags(args->ra_rw, args->ra_desc, args->ra_flags);
+}
+
+/* XXX add pthread_rwlock_is_wlocked_np( id, &wlocked )
+ * XXX returns 0 or -1 w/error
+ * XXX wlocked = 1 if write locked
+ * XXX
+/* XXX add pthread_rwlock_is_rlocked_np( id, &wlocked )
+ * XXX similar behavior
+ * XXX probably want to add "unlocked" state to RTEMS SuperCore rwlock
+ * XXX
+ * XXX Rationale: This violates the API layering BADLY!!!!!
+ * XXX Consider: Adding pthread_np.h to hold np methods like FreeBSD
+ * XXX This would avoid polluting pthread.h
+ */
+int
+rw_wowned(struct rwlock *rw)
+{
+ int is_locked_for_write = 0;
+ Objects_Locations location;
+ POSIX_RWLock_Control *the_rwlock;
+
+ the_rwlock = _POSIX_RWLock_Get(&rw->lock_object.lo_id, &location);
+ switch ( location ) {
+
+ case OBJECTS_LOCAL:
+ if (the_rwlock->RWLock.current_state == CORE_RWLOCK_LOCKED_FOR_WRITING)
+ is_locked_for_write = 1;
+ _Thread_Enable_dispatch();
+ return is_locked_for_write;
+
+#if defined(RTEMS_MULTIPROCESSING)
+ case OBJECTS_REMOTE:
+#endif
+ case OBJECTS_ERROR:
+ break;
+ }
+ _Thread_Enable_dispatch();
+
+ BSD_PANIC("unexpected semaphore location or attributes");
+}
+
+void
+_rw_wlock(struct rwlock *rw, const char *file, int line)
+{
+ int iret;
+
+ pthread_rwlock_wrlock( &rw->lock_object.lo_id );
+ BSD_ASSERT( iret == 0 );
+
+ return 0;
+}
+
+int
+_rw_try_wlock(struct rwlock *rw, const char *file, int line)
+{
+ int iret;
+
+ iret = pthread_rwlock_trywrlock( &rw->lock_object.lo_id );
+ if (iret == 0) {
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+void
+_rw_wunlock(struct rwlock *rw, const char *file, int line)
+{
+ int iret;
+
+ iret = pthread_rwlock_unlock( &rw->lock_object.lo_id );
+ BSD_ASSERT( iret == 0 );
+}
+
+void
+_rw_rlock(struct rwlock *rw, const char *file, int line)
+{
+ int iret;
+
+ iret = pthread_rwlock_rdlock( &rw->lock_object.lo_id );
+ BSD_ASSERT( iret == 0 );
+}
+
+int
+_rw_try_rlock(struct rwlock *rw, const char *file, int line)
+{
+ int iret;
+
+ iret = pthread_rwlock_tryrdlock( &rw->lock_object.lo_id );
+ if (iret == 0) {
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+void
+_rw_runlock(struct rwlock *rw, const char *file, int line)
+{
+ int iret;
+
+ iret = pthread_rwlock_unlock( &rw->lock_object.lo_id );
+ BSD_ASSERT( iret == 0 );
+}
+
+/*
+ * Attempt to do a non-blocking upgrade from a read lock to a write
+ * lock. This will only succeed if this thread holds a single read
+ * lock. Returns true if the upgrade succeeded and false otherwise.
+ */
+int
+_rw_try_upgrade(struct rwlock *rw, const char *file, int line)
+{
+ return 0; /* XXX */
+}
+
+/*
+ * Downgrade a write lock into a single read lock.
+ */
+void
+_rw_downgrade(struct rwlock *rw, const char *file, int line)
+{
+ /* XXX */
+}
+
+#ifdef INVARIANT_SUPPORT
+#ifndef INVARIANTS
+#undef _rw_assert
+#endif
+
+/*
+ * In the non-WITNESS case, rw_assert() can only detect that at least
+ * *some* thread owns an rlock, but it cannot guarantee that *this*
+ * thread owns an rlock.
+ */
+void
+_rw_assert(struct rwlock *rw, int what, const char *file, int line)
+{
+
+ if (panicstr != NULL)
+ return;
+ switch (what) {
+ case RA_LOCKED:
+ case RA_LOCKED | RA_RECURSED:
+ case RA_LOCKED | RA_NOTRECURSED:
+ case RA_RLOCKED:
+#ifdef WITNESS
+ witness_assert(&rw->lock_object, what, file, line);
+#else
+ /*
+ * If some other thread has a write lock or we have one
+ * and are asserting a read lock, fail. Also, if no one
+ * has a lock at all, fail.
+ */
+ if (rw->rw_lock == RW_UNLOCKED ||
+ (!(rw->rw_lock & RW_LOCK_READ) && (what == RA_RLOCKED ||
+ rw_wowner(rw) != curthread)))
+ panic("Lock %s not %slocked @ %s:%d\n",
+ rw->lock_object.lo_name, (what == RA_RLOCKED) ?
+ "read " : "", file, line);
+
+ if (!(rw->rw_lock & RW_LOCK_READ)) {
+ if (rw_recursed(rw)) {
+ if (what & RA_NOTRECURSED)
+ panic("Lock %s recursed @ %s:%d\n",
+ rw->lock_object.lo_name, file,
+ line);
+ } else if (what & RA_RECURSED)
+ panic("Lock %s not recursed @ %s:%d\n",
+ rw->lock_object.lo_name, file, line);
+ }
+#endif
+ break;
+ case RA_WLOCKED:
+ case RA_WLOCKED | RA_RECURSED:
+ case RA_WLOCKED | RA_NOTRECURSED:
+ if (rw_wowner(rw) != curthread)
+ panic("Lock %s not exclusively locked @ %s:%d\n",
+ rw->lock_object.lo_name, file, line);
+ if (rw_recursed(rw)) {
+ if (what & RA_NOTRECURSED)
+ panic("Lock %s recursed @ %s:%d\n",
+ rw->lock_object.lo_name, file, line);
+ } else if (what & RA_RECURSED)
+ panic("Lock %s not recursed @ %s:%d\n",
+ rw->lock_object.lo_name, file, line);
+ break;
+ case RA_UNLOCKED:
+#ifdef WITNESS
+ witness_assert(&rw->lock_object, what, file, line);
+#else
+ /*
+ * If we hold a write lock fail. We can't reliably check
+ * to see if we hold a read lock or not.
+ */
+ if (rw_wowner(rw) == curthread)
+ panic("Lock %s exclusively locked @ %s:%d\n",
+ rw->lock_object.lo_name, file, line);
+#endif
+ break;
+ default:
+ panic("Unknown rw lock assertion: %d @ %s:%d", what, file,
+ line);
+ }
+}
+#endif /* INVARIANT_SUPPORT */