1 files changed, 130 insertions, 0 deletions
diff --git a/lib/libthr/thread/thr_spinlock.c b/lib/libthr/thread/thr_spinlock.c
new file mode 100644
index 0000000..c0e57b0
--- /dev/null
+++ b/lib/libthr/thread/thr_spinlock.c
@@ -0,0 +1,130 @@
+/*
+ * Copyright (c) 1997 John Birrell <jb@cimlogic.com.au>.
+ * 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.
+ * 3. Neither the name of the author nor the names of any co-contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL 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.
+ *
+ * $FreeBSD$
+ *
+ */
+
+#include <sys/types.h>
+#include <pthread.h>
+#include <libc_private.h>
+#include <spinlock.h>
+
+#include "thr_private.h"
+
+#define	MAX_SPINLOCKS	72
+
+/*
+ * These data structures are used to trace all spinlocks
+ * in libc.
+ */
+struct spinlock_extra {
+	spinlock_t	*owner;
+	struct umutex	lock;
+};
+
+static struct umutex		spinlock_static_lock = DEFAULT_UMUTEX;
+static struct spinlock_extra	extra[MAX_SPINLOCKS];
+static int			spinlock_count;
+static int			initialized;
+
+static void	init_spinlock(spinlock_t *lck);
+
+/*
+ * These are for compatability only.  Spinlocks of this type
+ * are deprecated.
+ */
+
+void
+_spinunlock(spinlock_t *lck)
+{
+	struct spinlock_extra	*extra;
+
+	extra = (struct spinlock_extra *)lck->fname;
+	THR_UMUTEX_UNLOCK(_get_curthread(), &extra->lock);
+}
+
+void
+_spinlock(spinlock_t *lck)
+{
+	struct spinlock_extra *extra;
+
+	if (!__isthreaded)
+		PANIC("Spinlock called when not threaded.");
+	if (!initialized)
+		PANIC("Spinlocks not initialized.");
+	if (lck->fname == NULL)
+		init_spinlock(lck);
+	extra = (struct spinlock_extra *)lck->fname;
+	THR_UMUTEX_LOCK(_get_curthread(), &extra->lock);
+}
+
+void
+_spinlock_debug(spinlock_t *lck, char *fname __unused, int lineno __unused)
+{
+	_spinlock(lck);
+}
+
+static void
+init_spinlock(spinlock_t *lck)
+{
+	struct pthread *curthread = _get_curthread();
+
+	THR_UMUTEX_LOCK(curthread, &spinlock_static_lock);
+	if ((lck->fname == NULL) && (spinlock_count < MAX_SPINLOCKS)) {
+		lck->fname = (char *)&extra[spinlock_count];
+		_thr_umutex_init(&extra[spinlock_count].lock);
+		extra[spinlock_count].owner = lck;
+		spinlock_count++;
+	}
+	THR_UMUTEX_UNLOCK(curthread, &spinlock_static_lock);
+	if (lck->fname == NULL)
+		PANIC("Warning: exceeded max spinlocks");
+}
+
+void
+_thr_spinlock_init(void)
+{
+	int i;
+
+	_thr_umutex_init(&spinlock_static_lock);
+	if (initialized != 0) {
+		/*
+		 * called after fork() to reset state of libc spin locks,
+		 * it is not quite right since libc may be in inconsistent
+		 * state, resetting the locks to allow current thread to be
+		 * able to hold them may not help things too much, but
+		 * anyway, we do our best.
+		 * it is better to do pthread_atfork in libc.
+		 */
+		for (i = 0; i < spinlock_count; i++)
+			_thr_umutex_init(&extra[i].lock);
+	} else {
+		initialized = 1;
+	}
+}