1 files changed, 111 insertions, 0 deletions
diff --git a/lib/libdtrace/common/dt_list.c b/lib/libdtrace/common/dt_list.c
new file mode 100644
index 000000000000..32279e9bd274
--- /dev/null
+++ b/lib/libdtrace/common/dt_list.c
@@ -0,0 +1,111 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License").  You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+/*
+ * Simple doubly-linked list implementation.  This implementation assumes that
+ * each list element contains an embedded dt_list_t (previous and next
+ * pointers), which is typically the first member of the element struct.
+ * An additional dt_list_t is used to store the head (dl_next) and tail
+ * (dl_prev) pointers.  The current head and tail list elements have their
+ * previous and next pointers set to NULL, respectively.
+ */
+
+#include <unistd.h>
+#include <assert.h>
+#include <dt_list.h>
+
+void
+dt_list_append(dt_list_t *dlp, void *new)
+{
+	dt_list_t *p = dlp->dl_prev;	/* p = tail list element */
+	dt_list_t *q = new;		/* q = new list element */
+
+	dlp->dl_prev = q;
+	q->dl_prev = p;
+	q->dl_next = NULL;
+
+	if (p != NULL) {
+		assert(p->dl_next == NULL);
+		p->dl_next = q;
+	} else {
+		assert(dlp->dl_next == NULL);
+		dlp->dl_next = q;
+	}
+}
+
+void
+dt_list_prepend(dt_list_t *dlp, void *new)
+{
+	dt_list_t *p = new;		/* p = new list element */
+	dt_list_t *q = dlp->dl_next;	/* q = head list element */
+
+	dlp->dl_next = p;
+	p->dl_prev = NULL;
+	p->dl_next = q;
+
+	if (q != NULL) {
+		assert(q->dl_prev == NULL);
+		q->dl_prev = p;
+	} else {
+		assert(dlp->dl_prev == NULL);
+		dlp->dl_prev = p;
+	}
+}
+
+void
+dt_list_insert(dt_list_t *dlp, void *after_me, void *new)
+{
+	dt_list_t *p = after_me;
+	dt_list_t *q = new;
+
+	if (p == NULL || p->dl_next == NULL) {
+		dt_list_append(dlp, new);
+		return;
+	}
+
+	q->dl_next = p->dl_next;
+	q->dl_prev = p;
+	p->dl_next = q;
+	q->dl_next->dl_prev = q;
+}
+
+void
+dt_list_delete(dt_list_t *dlp, void *existing)
+{
+	dt_list_t *p = existing;
+
+	if (p->dl_prev != NULL)
+		p->dl_prev->dl_next = p->dl_next;
+	else
+		dlp->dl_next = p->dl_next;
+
+	if (p->dl_next != NULL)
+		p->dl_next->dl_prev = p->dl_prev;
+	else
+		dlp->dl_prev = p->dl_prev;
+}