a

win32-386/tas.c

@@ -0,0 +1,22 @@
+// could also use windozy InterlockedCompareExchange(p, 1, 0), but why
+int
+tas(long *p)
+{	
+	int v;
+	
+	_asm {
+		mov	eax, p
+		mov	ebx, 1
+		xchg	ebx, [eax]
+		mov	v, ebx
+	}
+
+	switch(v) {
+	case 0:
+	case 1:
+		return v;
+	default:
+		print("canlock: corrupted 0x%lux\n", v);
+		return 1;
+	}
+}