1 files changed, 44 insertions, 0 deletions
diff --git a/helgrind/tests/tc03_re_excl.c b/helgrind/tests/tc03_re_excl.c
new file mode 100644
index 0000000..4f3ce51
--- /dev/null
+++ b/helgrind/tests/tc03_re_excl.c
@@ -0,0 +1,44 @@
+
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+/* Simple test program, no race: parent only modifies x after child
+   has modified it and then joined with the parent.  Tests simple
+   thread lifetime segment handling. */
+
+/* A simple function to "use" a value, so that gcc can't
+   possibly optimise it into nothing. */
+static void use ( int x ) {
+   __asm__ __volatile__( "nop" : : "r"(x) : "cc","memory" );
+}
+
+static void* worker_thread ( void* argV )
+{
+  int* arg = (int*)argV;
+  use(arg[5]); /* read access */
+  return NULL;
+}
+
+int main ( void )
+{
+   pthread_t thread_id;
+   volatile int* x = malloc(10 * sizeof(int));
+   x[5] = 1;
+   /* x[5] is Excl(parent) */
+
+   pthread_create(&thread_id, 0, worker_thread, (void*)x);
+
+   use(x[5]); /* read access */
+
+   /* Just before the threads join, x[5] is ShR (read by both parent
+      and child) */
+   pthread_join(thread_id, 0);
+   /* x[5] is Excl(parent), because only parent and child accessed it
+      and child has merged to parent.  So now it's ok for parent to
+      access it without locking. */
+
+   x[5] = 0; /* write access */
+
+   return x[5];
+}