From ae8adff189902c9944975aa25de781e8fd4c40be Mon Sep 17 00:00:00 2001
From: Simmo Saan <simmo.saan@gmail.com>
Date: Wed, 20 Sep 2023 15:31:04 +0300
Subject: [PATCH] Extract atomic-gcc-norace example from klib

---
 .../03-practical/46-atomic-gcc-norace.c       | 34 +++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 tests/regression/03-practical/46-atomic-gcc-norace.c

diff --git a/tests/regression/03-practical/46-atomic-gcc-norace.c b/tests/regression/03-practical/46-atomic-gcc-norace.c
new file mode 100644
index 0000000000..b5dd0f68a0
--- /dev/null
+++ b/tests/regression/03-practical/46-atomic-gcc-norace.c
@@ -0,0 +1,34 @@
+// Race-free due to GCC atomic operation.
+// Extracted from concrat/klib.
+#include <stdlib.h>
+#include <pthread.h>
+#include <goblint.h>
+extern int __VERIFIER_nondet_int();
+
+int data;
+
+void *thread(void *arg) {
+  __sync_fetch_and_add(&data, 1); // NORACE
+  return NULL;
+}
+
+int main() {
+  int threads_total = __VERIFIER_nondet_int();
+  __goblint_assume(threads_total >= 0);
+
+  pthread_t *tids = malloc(threads_total * sizeof(pthread_t));
+
+  // create threads
+  for (int i = 0; i < threads_total; i++) {
+    pthread_create(&tids[i], NULL, &thread, NULL); // may fail but doesn't matter
+  }
+
+  // join threads
+  for (int i = 0; i < threads_total; i++) {
+    pthread_join(tids[i], NULL);
+  }
+
+  free(tids);
+
+  return 0;
+}