1 files changed, 26 insertions, 0 deletions
diff --git a/appl/lib/lock.b b/appl/lib/lock.b
new file mode 100644
index 00000000..8b51e4f9
--- /dev/null
+++ b/appl/lib/lock.b
@@ -0,0 +1,26 @@
+implement Lock;
+
+include "sys.m";
+	sys:	Sys;
+include "lock.m";
+
+Semaphore.obtain(l: self ref Semaphore)
+{
+	l.c <-= 0;
+}
+
+Semaphore.release(l: self ref Semaphore)
+{
+	<-l.c;
+}
+
+Semaphore.new(): ref Semaphore
+{
+	l := ref Semaphore;
+	l.c = chan[1] of int;
+	return l;
+}
+
+init()
+{
+}