1 files changed, 65 insertions, 0 deletions
diff --git a/lib/libc/gen/insque.c b/lib/libc/gen/insque.c
new file mode 100644
index 000000000000..6c0908c06364
--- /dev/null
+++ b/lib/libc/gen/insque.c
@@ -0,0 +1,65 @@
+/*
+ *  Copyright (c) 1993 John Brezak
+ *  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. The name of the author may be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `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 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.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char rcsid[] = "$Id: insque.c,v 1.1 1993/08/25 09:39:09 alm Exp $";
+#endif /* LIBC_SCCS and not lint */
+
+struct qelem {
+        struct qelem *q_forw;
+        struct qelem *q_back;
+	char *q_data;
+};
+
+/*
+ * Link p before s.
+ */
+#define reque(p, s) (p)->q_forw = (s), (s)->q_back = (p)
+
+/*
+ * Insert entry in circular queue after pred.
+ */
+struct qelem *
+insque(entry, pred)
+	struct qelem *entry, *pred;
+{
+	reque(entry, pred->q_forw);
+	reque(pred, entry);
+	return (entry);
+}
+
+/*
+ * Remove entry from circular queue.
+ */
+struct qelem *
+remque(entry)
+	struct qelem *entry;
+{
+	reque(entry->q_back, entry->q_forw);
+	return (entry);
+}