From 878a6eb61c7a055c45aa1b79347929b827d9c250 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Fri, 5 Aug 1994 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1994-08-05

---
 port/proc.c    |  9 ++++++++-
 port/taslock.c | 11 +++++++++--
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/port/proc.c b/port/proc.c
index eea6b08f78b43aedb9f19a9105520e29fca8ce1b..2007eaab5f707aacb61821d517f71c503e87f1af 100644
--- a/port/proc.c
+++ b/port/proc.c
@@ -351,7 +351,7 @@ tfn(void *arg)
 void
 tsleep(Rendez *r, int (*fn)(void*), void *arg, int ms)
 {
-	ulong when;
+	ulong when, i;
 	Proc *f, **l;
 
 	when = MS2TK(ms)+MACHP(0)->ticks;
@@ -359,6 +359,7 @@ tsleep(Rendez *r, int (*fn)(void*), void *arg, int ms)
 	lock(&talarm);
 	/* take out of list if checkalarm didn't */
 	if(up->trend) {
+i = 0;
 		l = &talarm.list;
 		for(f = *l; f; f = f->tlink) {
 			if(f == up) {
@@ -366,6 +367,12 @@ tsleep(Rendez *r, int (*fn)(void*), void *arg, int ms)
 				break;
 			}
 			l = &f->tlink;
+if(i++ > 20) {
+	print("tlarm loop: %lux\n", talarm.list);
+	for(i = 20, f = talarm.list; f && i--; f = f->tlink)
+		print("%lux ", f);
+		for(;;);
+}
 		}
 	}
 	/* insert in increasing time order */
diff --git a/port/taslock.c b/port/taslock.c
index 0e1bd45d6d83eb749e8f3f975e403f603323e2ef..5cb45191e1d1305e15ef20e3f25637d739d97e70 100644
--- a/port/taslock.c
+++ b/port/taslock.c
@@ -8,12 +8,19 @@
 void
 lock(Lock *l)
 {
+	int loop;
+
 	if(tas(&l->key) == 0)
 		return;
 
+	loop = 50000000;
 	for(;;){
-		while(l->key)
-			;
+		while(l->key) {
+			if(loop-- <= 0) {
+				dumpstack();
+				panic("lock loop: lock %lux\n", l);
+			}
+		}
 		if(tas(&l->key) == 0)
 			return;
 	}