+struct test_array {
+ int a;
+};
+
+static volatile int test_go, test_stop;
+
+static unsigned long wdelay;
+
+static struct test_array *test_rcu_pointer;
+
+static unsigned long duration;
+
+/* read-side C.S. duration, in loops */
+static unsigned long rduration;
+
+static inline void loop_sleep(unsigned long l)
+{
+ while(l-- != 0)
+ cpu_relax();
+}
+
+static int verbose_mode;
+
+#define printf_verbose(fmt, args...) \
+ do { \
+ if (verbose_mode) \
+ printf(fmt, args); \
+ } while (0)
+
+/*
+ * returns 0 if test should end.
+ */
+static int test_duration_write(void)
+{
+ return !test_stop;
+}
+
+static int test_duration_read(void)
+{
+ return !test_stop;
+}
+
+static unsigned long long __thread nr_writes;
+static unsigned long long __thread nr_reads;
+
+static unsigned int nr_readers;
+static unsigned int nr_writers;
+
+pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+void rcu_copy_mutex_lock(void)
+{
+ int ret;
+ ret = pthread_mutex_lock(&rcu_copy_mutex);
+ if (ret) {
+ perror("Error in pthread mutex lock");
+ exit(-1);
+ }
+}
+
+void rcu_copy_mutex_unlock(void)
+{
+ int ret;
+
+ ret = pthread_mutex_unlock(&rcu_copy_mutex);
+ if (ret) {
+ perror("Error in pthread mutex unlock");
+ exit(-1);
+ }
+}
+
+/*
+ * malloc/free are reusing memory areas too quickly, which does not let us
+ * test races appropriately. Use a large circular array for allocations.
+ * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail.
+ */
+#define ARRAY_SIZE (1048576 * nr_writers)
+#define ARRAY_POISON 0xDEADBEEF
+static int array_index;
+static struct test_array *test_array;
+
+static struct test_array *test_array_alloc(void)
+{
+ struct test_array *ret;
+ int index;
+
+ rcu_copy_mutex_lock();
+ index = array_index % ARRAY_SIZE;
+ assert(test_array[index].a == ARRAY_POISON ||
+ test_array[index].a == 0);
+ ret = &test_array[index];
+ array_index++;
+ if (array_index == ARRAY_SIZE)
+ array_index = 0;
+ rcu_copy_mutex_unlock();
+ return ret;
+}
+
+static void test_array_free(struct test_array *ptr)
+{
+ if (!ptr)
+ return;
+ rcu_copy_mutex_lock();
+ ptr->a = ARRAY_POISON;
+ rcu_copy_mutex_unlock();
+}
+
+void *thr_reader(void *_count)
+{
+ unsigned long long *count = _count;
+ struct test_array *local_ptr;
+
+ printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
+ "reader", pthread_self(), (unsigned long)gettid());
+
+ rcu_register_thread();
+
+ while (!test_go)
+ {
+ }
+ smp_mb();
+
+ for (;;) {
+ rcu_read_lock();
+ local_ptr = rcu_dereference(test_rcu_pointer);
+ debug_yield_read();
+ if (local_ptr)
+ assert(local_ptr->a == 8);
+ if (unlikely(rduration))
+ loop_sleep(rduration);
+ rcu_read_unlock();
+ nr_reads++;
+ if (unlikely(!test_duration_read()))
+ break;
+ }
+
+ rcu_unregister_thread();
+
+ *count = nr_reads;
+ printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
+ "reader", pthread_self(), (unsigned long)gettid());
+ return ((void*)1);
+
+}
+
+void *thr_writer(void *_count)
+{
+ unsigned long long *count = _count;
+ struct test_array *new, *old;
+
+ printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
+ "writer", pthread_self(), (unsigned long)gettid());
+
+ while (!test_go)
+ {
+ }
+ smp_mb();