Initial Spring 2016 commit.

userland/testbin/forkbomb/Makefile

@@ -0,0 +1,11 @@
+# Makefile for forkbomb
+
+TOP=../../..
+.include "$(TOP)/mk/os161.config.mk"
+
+PROG=forkbomb
+SRCS=forkbomb.c
+BINDIR=/testbin
+
+.include "$(TOP)/mk/os161.prog.mk"
+

userland/testbin/forkbomb/forkbomb.c

@@ -0,0 +1,76 @@
+/*
+ * 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.
+ */
+
+/*
+ * forkbomb - apply malthus to an operating system ;-)
+ *
+ * DO NOT RUN THIS ON A REAL SYSTEM - IT WILL GRIND TO A HALT AND
+ * PEOPLE WILL COME AFTER YOU WIELDING BASEBALL BATS OR THE AD
+ * BOARD(*). WE WARNED YOU.
+ *
+ * We don't expect your system to withstand this without grinding to
+ * a halt, but once your basic system calls are complete it shouldn't
+ * crash. Likewise for after your virtual memory system is complete.
+ *
+ * (...at least in an ideal world. However, it can be difficult to
+ * handle all the loose ends involved. Heroic measures are not
+ * expected. If in doubt, talk to the course staff.)
+ *
+ *
+ * (*) The Administrative Board of Harvard College handles formal
+ * disciplinary action.
+ */
+
+#include <unistd.h>
+#include <err.h>
+
+static volatile int pid;
+
+int
+main(void)
+{
+	int i;
+
+	while (1) {
+		fork();
+
+		pid = getpid();
+
+		/* Make sure each fork has its own address space. */
+		for (i=0; i<300; i++) {
+			volatile int seenpid;
+			seenpid = pid;
+			if (seenpid != getpid()) {
+				errx(1, "pid mismatch (%d, should be %d) "
+				     "- your vm is broken!",
+				     seenpid, getpid());
+			}
+		}
+	}
+}