From: Gregory Minshall <minshall@ucbvax.Berkeley.EDU>
Date: Sun, 11 Oct 1987 04:39:07 +0000 (-0800)
Subject: date and time created 87/10/10 12:39:07 by minshall
X-Git-Tag: BSD-4_3_Net_1-Snapshot-Development~3508
X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/commitdiff_plain/097761fdc3e801c2297941d40fc5fb83029667b2

date and time created 87/10/10 12:39:07 by minshall

SCCS-vsn: usr.bin/telnet/ring.h 1.1
---

diff --git a/usr/src/usr.bin/telnet/ring.h b/usr/src/usr.bin/telnet/ring.h
new file mode 100644
index 0000000000..fc8c9a0ef6
--- /dev/null
+++ b/usr/src/usr.bin/telnet/ring.h
@@ -0,0 +1,52 @@
+/*
+ * This defines a structure for a receive or send ring buffer.
+ *
+ * The circular buffer actually has three parts:
+ *(((
+ *	full, sent, not acked:	[ack, send)
+ *	full, not sent:		[send, add)
+ *	empty:			[add, ack)
+ *]]]
+ *
+ * Any given byte will go through "empty" -> "send" -> "ack" -> "empty"
+ * as data is moved through it.  The transition from "ack" to "empty"
+ * may occur instantaneously (as in the case of sending data up to another
+ * process).
+ */
+typedef struct {
+    char	*ack,		/* where you can't add at */
+    		*send,		/* where data comes out of */
+    		*add,		/* where data comes in to */
+		*bottom,	/* lowest address in buffer */
+		*top;		/* highest address+1 in buffer */
+    int		size;		/* size in bytes of buffer */
+    u_long	acktime,	/* the relations between these clocks */
+		sendtime,	/* help us keep straight full, empty, etc. */
+		addtime;
+} Ring;
+
+/* Here are some functions and macros to deal with the ring buffer */
+
+
+#if	defined(LINT_ARGS)
+
+/* Data movement routines */
+extern void
+	ring_add_data(Ring *ring, char *buffer, int count),
+	ring_send_data(Ring *ring, char *buffer, int count);
+
+/* Buffer state transition routines */
+extern void
+	ring_added(Ring *ring, int count),
+	ring_sent(Ring *ring, int count),
+	ring_acked(Ring *ring, int count);
+
+/* Buffer state query routines */
+extern int
+	ring_empty_count(Ring *ring),
+	ring_empty_consecutive(Ring *ring),
+	ring_unsent_count(Ring *ring),
+	ring_unsent_consecutive(Ring *ring),
+	ring_unacked_count(Ring *ring);
+
+#endif	/* defined(LINT_ARGS) */