test: rmwprog: support command-line argument

This test can easily be extended to allow more than 2 atomic increments
per thread. For instance, it's interesting to see the model-checker
behavior for 4 increments per thread. Now, you can do this with a simple
numeric command-line argument that gets passed to the user program.

Example - run rmwprog with 4 increments per thread, viewing the
execution traces verbosely:

  ./run.sh test/rmwprog.o -v -- 4

diff --git a/test/rmwprog.c b/test/rmwprog.c
index feac7766c9f68154e169c143d0903cbf18b44141..57ab54462bab9b03b48a87cf86578d06c8c5e070 100644 (file)
--- a/test/rmwprog.c
+++ b/test/rmwprog.c
@@ -1,3 +1,4 @@
+#include <stdlib.h>
 #include <stdio.h>
 #include <threads.h>
 #include <stdatomic.h>
@@ -5,17 +6,22 @@
 #include "librace.h"
 
 atomic_int x;
+static int N = 2;
 
 static void a(void *obj)
 {
-       atomic_fetch_add_explicit(&x, 1, memory_order_relaxed);
-       atomic_fetch_add_explicit(&x, 1, memory_order_relaxed);
+       int i;
+       for (i = 0; i < N; i++)
+               atomic_fetch_add_explicit(&x, 1, memory_order_relaxed);
 }
 
 int user_main(int argc, char **argv)
 {
        thrd_t t1, t2;
 
+       if (argc > 1)
+               N = atoi(argv[1]);
+
        atomic_init(&x, 0);
        thrd_create(&t1, (thrd_start_t)&a, NULL);
        thrd_create(&t2, (thrd_start_t)&a, NULL);