From 5e65915c6c4197b1b7a874ae8ace23127148cc92 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Wed, 13 Sep 1995 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1995-09-13

---
 port/devcons.c | 48 ++++++++++++++++++++++++++++++++++++++----------
 port/proc.c    |  5 -----
 2 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/port/devcons.c b/port/devcons.c
index 902b0a1fb155a914fdf5e377e86c64a5f7776502..d5d90561f85d6d3acc690df59c95421817b23c37 100644
--- a/port/devcons.c
+++ b/port/devcons.c
@@ -30,7 +30,7 @@ static struct
 char	sysname[NAMELEN];
 
 static ulong randomread(uchar*, ulong);
-static void randomreset(void);
+static void randominit(void);
 
 void
 printinit(void)
@@ -410,12 +410,12 @@ readstr(ulong off, char *buf, ulong n, char *str)
 void
 consreset(void)
 {
-	randomreset();
 }
 
 void
 consinit(void)
 {
+	randominit();
 }
 
 Chan*
@@ -891,7 +891,8 @@ setterm(char *f)
 static struct
 {
 	QLock;
-	Rendez	r;
+	Rendez	producer;
+	Rendez	consumer;
 	uchar	buf[4096];
 	uchar	*ep;
 	uchar	*rp;
@@ -903,11 +904,34 @@ static struct
 
 ulong randomcount;
 
+static int
+rbnotfull(void*)
+{
+	int i;
+
+	i = rb.rp - rb.wp;
+	return i != 1 && i != (1 - sizeof(rb.buf));
+}
+
+void
+genrandom(void*)
+{
+	up->basepri = PriNormal;
+	up->priority = up->basepri;
+
+	for(;;){
+		if(!rbnotfull(0))
+			sleep(&rb.producer, rbnotfull, 0);
+		randomcount++;
+	}
+}
+
 void
-randomreset(void)
+randominit(void)
 {
 	rb.ep = rb.buf + sizeof(rb.buf);
 	rb.rp = rb.wp = rb.buf;
+	kproc("genrandom", genrandom, 0);
 }
 
 /*
@@ -916,14 +940,16 @@ randomreset(void)
 void
 randomclock(void)
 {
-	int i;
 	uchar *p;
 
-	i = rb.rp - rb.wp;
-	if(i == 1 || i == (1 - sizeof(rb.buf)))
+	if(randomcount == 0)
+		return;
+
+	if(!rbnotfull(0))
 		return;
 
 	rb.bits = (rb.bits<<2) ^ randomcount;
+	randomcount = 0;
 	rb.next += 2;
 	if(rb.next != 8)
 		return;
@@ -936,11 +962,11 @@ randomclock(void)
 	rb.wp = p;
 
 	if(rb.wakeme)
-		wakeup(&rb.r);
+		wakeup(&rb.consumer);
 }
 
 static int
-notempty(void*)
+rbnotempty(void*)
 {
 	return rb.wp != rb.rp;
 }
@@ -964,7 +990,7 @@ randomread(uchar *p, ulong n)
 		i = rb.wp - rb.rp;
 		if(i == 0){
 			rb.wakeme = 1;
-			sleep(&rb.r, notempty, 0);
+			sleep(&rb.consumer, rbnotempty, 0);
 			rb.wakeme = 0;
 			continue;
 		}
@@ -981,5 +1007,7 @@ randomread(uchar *p, ulong n)
 	qunlock(&rb);
 	poperror();
 
+	wakeup(&rb.producer);
+
 	return n;
 }
diff --git a/port/proc.c b/port/proc.c
index e0c8d2f09745b8eb92381619be14c88225b32f8f..d387e1aaa1bda50e6f597d705a9d34226635afc9 100644
--- a/port/proc.c
+++ b/port/proc.c
@@ -47,8 +47,6 @@ char *statename[] =
 	"Rendez",
 };
 
-ulong randomcount;
-
 /*
  * Always splhi()'ed.
  */
@@ -186,9 +184,6 @@ loop:
 	 */
 	spllo();
 	for(;;){
-		if(m->machno == 0)
-			randomcount++;
-
 		/*
 		 *  Once a second we look for a long waiting process
 		 *  in the lowest priority queue to make sure nothing