From a4ad38f616f7ebffec86066c6b75db9c30d18882 Mon Sep 17 00:00:00 2001
From: Geoffrey Challen <challen@buffalo.edu>
Date: Wed, 30 Dec 2015 10:38:18 -0600
Subject: [PATCH] Self check added to sy1.

---
 kern/include/kern/overwrite.h | 45 +++++++++++++++++++++++++++++++++++
 kern/test/synchtest.c         | 20 ++++++++++++++++
 2 files changed, 65 insertions(+)
 create mode 100644 kern/include/kern/overwrite.h

diff --git a/kern/include/kern/overwrite.h b/kern/include/kern/overwrite.h
new file mode 100644
index 0000000..1aca330
--- /dev/null
+++ b/kern/include/kern/overwrite.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
+ *	The President and Fellows of Harvard College.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * WARNING: All the contents of this file are overwritten during automated
+ * testing. Please consider this before changing anything in this file.
+ */
+
+#ifndef _OVERWRITE_H_
+#define _OVERWRITE_H_
+
+/*
+ * You can set a custom prompt here, but the default will be used during
+ * testing.
+ */
+
+#define KERNEL_SECRET 9722720911 
+
+#endif /* _OVERWRITE_H_ */
diff --git a/kern/test/synchtest.c b/kern/test/synchtest.c
index 151971e..e586a64 100644
--- a/kern/test/synchtest.c
+++ b/kern/test/synchtest.c
@@ -37,6 +37,10 @@
 #include <thread.h>
 #include <synch.h>
 #include <test.h>
+#include <kern/overwrite.h>
+
+#define SUCCESS 0
+#define FAIL 1
 
 #define NSEMLOOPS     63
 #define NLOCKLOOPS    120
@@ -51,6 +55,9 @@ static struct lock *testlock;
 static struct cv *testcv;
 static struct semaphore *donesem;
 
+static bool semtest_status;
+static unsigned long semtest_current;
+
 static
 void
 inititems(void)
@@ -91,10 +98,16 @@ semtestthread(void *junk, unsigned long num)
 	/*
 	 * Only one of these should print at a time.
 	 */
+	random_yielder(4);
 	P(testsem);
+	semtest_current = num;
 	kprintf("Thread %2lu: ", num);
 	for (i=0; i<NSEMLOOPS; i++) {
 		kprintf("%c", (int)num+64);
+		random_yielder(4);
+		if (semtest_current != num) {
+			semtest_status = FAIL;
+		}
 	}
 	kprintf("\n");
 	V(donesem);
@@ -109,6 +122,7 @@ semtest(int nargs, char **args)
 	(void)args;
 
 	inititems();
+	semtest_status = SUCCESS;
 	kprintf("Starting semaphore test...\n");
 	kprintf("If this hangs, it's broken: ");
 	P(testsem);
@@ -132,6 +146,12 @@ semtest(int nargs, char **args)
 	V(testsem);
 	V(testsem);
 
+	if (semtest_status == SUCCESS) {
+		kprintf("SUCCESS: %llu\n", KERNEL_SECRET);
+	} else {
+		kprintf("FAIL: %llu\n", KERNEL_SECRET);
+	}
+
 	kprintf("Semaphore test done.\n");
 	return 0;
 }