From c82a4de14fee442f72fd49b064c330db9733594a Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sat, 27 Mar 1999 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1999-03-27

---
 carrera/clock.c  | 37 +++++++++++++++++++++++++++++--------
 carrera/fns.h    |  2 ++
 carrera/l.s      |  5 +++++
 carrera/mem.h    |  2 +-
 carrera/screen.c |  3 ---
 ip/tcp.c         |  2 +-
 mpc/fns.h        |  1 +
 pc/fns.h         |  1 +
 port/proc.c      |  1 +
 9 files changed, 41 insertions(+), 13 deletions(-)

diff --git a/carrera/clock.c b/carrera/clock.c
index 4f4def6c985ef7fa7e8557679b5f8aa09f28a91e..b671e7f2e419688acda60048020e4a3b0528ebcc 100644
--- a/carrera/clock.c
+++ b/carrera/clock.c
@@ -51,6 +51,8 @@ delay(int l)
 			;
 }
 
+ulong lastcmp;
+
 void
 clockinit(void)
 {
@@ -72,18 +74,16 @@ clockinit(void)
 
 	incr = (m->speed*1000000)/HZ;
 	fasthz = m->speed*1000000;
-	wrcompare(rdcount()+incr);
+	wrcompare(lastcmp = rdcount()+incr);
 }
 
 uvlong
 updatefastclock(ulong count)
 {
-	vlong delta;
+	ulong delta;
 
 	/* keep track of higher precision time */
 	delta = count - m->lastcyclecount;
-	if(delta < 0)
-		delta += 0x100000000LL;
 	m->lastcyclecount = count;
 	m->fastclock += delta;
 
@@ -97,7 +97,7 @@ clock(Ureg *ur)
 	ulong count;
 
 	count = rdcount();
-	wrcompare(count+incr);
+	wrcompare(lastcmp = count+incr);
 	updatefastclock(count);
 
 	m->ticks++;
@@ -136,14 +136,14 @@ clock(Ureg *ur)
 	if(up == 0 || up->state != Running)
 		return;
 
-	if(anyready())
-		sched();
-
 	/* user profiling clock */
 	if(ur->status & KUSER) {
 		(*(ulong*)(USTKTOP-BY2WD)) += TK2MS(1);
 		segclock(ur->pc);
 	}
+
+	if(anyready())
+		sched();
 }
 
 vlong
@@ -161,3 +161,24 @@ fastticks(uvlong *hz)
 
 	return (vlong)cyclecount;
 }
+
+ulong timewarp;
+
+void
+idlehands(void)
+{
+	ulong cnt, cmp, d;
+	int x;
+
+	x = splhi();
+	cnt = rdcount();
+	cmp = rdcompare();
+	cnt -= 100;		/* to cover for time from splhi to rdcount */
+	d = cmp - cnt;
+	if(d > incr+100){
+		wrcompare(lastcmp = cnt+incr);
+		timewarp++;
+//		print("%lud %lud %d %lux\n", cnt, cmp, cnt-cmp, d);
+	}
+	splx(x);
+}
diff --git a/carrera/fns.h b/carrera/fns.h
index 2efa5fa9cbe2f31bd888655c5604f6e29075e2c8..af43073d57a399c2d485449926fc3e364e80558b 100644
--- a/carrera/fns.h
+++ b/carrera/fns.h
@@ -25,6 +25,7 @@ void		gettlb(int, ulong*);
 int		gettlbp(ulong, ulong*);
 ulong		gettlbvirt(int);
 void		icflush(void *, ulong);
+void		idlehands(void);
 void		intr(Ureg*);
 void		ioinit(int);
 int		iprint(char*, ...);
@@ -48,6 +49,7 @@ Softtlb*	putstlb(ulong, ulong);
 int		puttlb(ulong, ulong, ulong);
 void		puttlbx(int, ulong, ulong, ulong, int);
 void		rdbginit(void);
+ulong		rdcompare(void);
 ulong		rdcount(void);
 ulong*		reg(Ureg*, int);
 void		restfpregs(FPsave*, ulong);
diff --git a/carrera/l.s b/carrera/l.s
index 39c583e516e59ae9a76836cda0908e2e307d7192..0e2b0e032cab64db1dde6b831b6e0d099004dce4 100644
--- a/carrera/l.s
+++ b/carrera/l.s
@@ -797,3 +797,8 @@ TEXT	rdcount(SB), $0
 TEXT	wrcompare(SB), $0
 	MOVW	R1, M(COMPARE)
 	RET
+
+TEXT	rdcompare(SB), $0
+	MOVW	M(COMPARE), R1
+	NOP
+	RET
diff --git a/carrera/mem.h b/carrera/mem.h
index c7a5e71d7c14bbaf720cdd4def865515abba2344..edf97580798d63cd7236fa6ad95e335ef97252e3 100644
--- a/carrera/mem.h
+++ b/carrera/mem.h
@@ -22,7 +22,7 @@
 /*
  * Time
  */
-#define	HZ		1000			/* clock frequency */
+#define	HZ		250			/* clock frequency */
 #define	MS2HZ		(1000/HZ)		/* millisec per clock tick */
 #define	TK2SEC(t)	((t)/HZ)		/* ticks to seconds */
 #define	TK2MS(t)	((t)*MS2HZ)		/* ticks to milliseconds */
diff --git a/carrera/screen.c b/carrera/screen.c
index a9823fb88e60a46b9ea6e73ddf664abb850aee06..58f8f5292604125fa5531ba90f5635de2f62297b 100644
--- a/carrera/screen.c
+++ b/carrera/screen.c
@@ -586,7 +586,6 @@ cursoron(int dolock)
 {
 	Dac *d;
 	Point p;
-	int s;
 
 	p = mousexy();
 
@@ -594,7 +593,6 @@ cursoron(int dolock)
 
 	if(dolock)
 		lock(&cursor);
-	s = splhi();
 
 	p.x += 296;		/* adjusted by experiment */
 	p.y += 9;		/* adjusted by experiment */
@@ -605,7 +603,6 @@ cursoron(int dolock)
 	d->cr2 = p.y&0xFF;
 	d->cr2 = (p.y>>8)&0xF;
 
-	splx(s);
 	if(dolock)
 		unlock(&cursor);
 	return 0;
diff --git a/ip/tcp.c b/ip/tcp.c
index 2c119c44559c685d200b359d4ab558dab5c540b9..e939913a2d74aa51d14003b2935d954e750fa774 100644
--- a/ip/tcp.c
+++ b/ip/tcp.c
@@ -454,7 +454,7 @@ static void
 tcpcreate(Conv *c)
 {
 	c->rq = qopen(QMAX, 0, tcpacktimer, c);
-	c->wq = qopen(QMAX, 0, 0, 0);
+	c->wq = qopen(2*QMAX, 0, 0, 0);
 }
 
 void
diff --git a/mpc/fns.h b/mpc/fns.h
index 2ae180049ad5441ca7f0e58a96bfe4e2020665aa..ae6fc1c7fd84109ebf99b4c8d72573fd37e1e1c9 100644
--- a/mpc/fns.h
+++ b/mpc/fns.h
@@ -41,6 +41,7 @@ ulong	gettbu(void);
 void	gotopc(ulong);
 void	icflush(void*, ulong);
 void	idle(void);
+#define	idlehands()			/* nothing to do in the runproc */
 int	iprint(char*, ...);
 void	intr(Ureg*);
 void	intrenable(int, void (*)(Ureg*, void*), void*, int);
diff --git a/pc/fns.h b/pc/fns.h
index 095eaafd9db9bb4bbd5045f9e3998ecc13ca993d..6bc6b480c32aa1933bf04dd16167cf71b30c4163 100644
--- a/pc/fns.h
+++ b/pc/fns.h
@@ -40,6 +40,7 @@ uvlong	i8253read(uvlong*);
 void	i8259init(void);
 int	i8259enable(Vctl*);
 void	idle(void);
+#define	idlehands()			/* nothing to do in the runproc */
 int	inb(int);
 void	insb(int, void*, int);
 ushort	ins(int);
diff --git a/port/proc.c b/port/proc.c
index ea26f0afdbbaf68a9012ce91826cbf5547fd4635..c7ee02c77919f6230ef8d88251b0fc947aabcd70 100644
--- a/port/proc.c
+++ b/port/proc.c
@@ -200,6 +200,7 @@ loop:
 	 */
 	spllo();
 	for(;;){
+		idlehands();
 		if((++(m->fairness) & 3) == 0){
 			/*
 			 *  once in a while, run process that's been waiting longest