Initial programs from intro chapter

intro/mem.c

@@ -0,0 +1,23 @@
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "common.h"
+
+int main(int argc, char *argv[]) {
+    if (argc != 2) { 
+	fprintf(stderr, "usage: mem <value>\n"); 
+	exit(1); 
+    } 
+    int *p; 
+    p = malloc(sizeof(int));
+    assert(p != NULL);
+    printf("(%d) addr pointed to by p: %p\n", (int) getpid(), p);
+    *p = atoi(argv[1]); // assign value to addr stored in p
+    while (1) {
+	Spin(1);
+	*p = *p + 1;
+	printf("(%d) value of p: %d\n", getpid(), *p);
+    }
+    return 0;
+}
+