Add randomness to yield debug test

[urcu.git] / urcu.h

diff --git a/urcu.h b/urcu.h
index b6b5c7b039e359225d947afb91a29a2f25ba6a3c..c77b26f958e34b8521f1b8363d83b6492cb46b0f 100644 (file)
--- a/urcu.h
+++ b/urcu.h
@@ -66,6 +66,48 @@ static inline void atomic_inc(int *v)
 
 #define SIGURCU SIGUSR1
 
+#ifdef DEBUG_YIELD
+#include <sched.h>
+
+#define YIELD_READ     (1 << 0)
+#define YIELD_WRITE    (1 << 1)
+
+extern unsigned int yield_active;
+extern unsigned int __thread rand_yield;
+
+static inline void debug_yield_read(void)
+{
+       if (yield_active & YIELD_READ)
+               if (rand_r(&rand_yield) & 0x1)
+                       sched_yield();
+}
+
+static inline void debug_yield_write(void)
+{
+       if (yield_active & YIELD_WRITE)
+               if (rand_r(&rand_yield) & 0x1)
+                       sched_yield();
+}
+
+static inline void debug_yield_init(void)
+{
+       rand_yield = time(NULL) ^ pthread_self();
+}
+#else
+static inline void debug_yield_read(void)
+{
+}
+
+static inline void debug_yield_write(void)
+{
+}
+
+static inline void debug_yield_init(void)
+{
+
+}
+#endif
+
 /* Global quiescent period parity */
 extern int urcu_qparity;
 
@@ -81,23 +123,30 @@ static inline int get_urcu_qparity(void)
  */
 static inline void rcu_read_lock(int *urcu_parity)
 {
+       debug_yield_read();
        *urcu_parity = get_urcu_qparity();
+       debug_yield_read();
        urcu_active_readers[*urcu_parity]++;
+       debug_yield_read();
        /*
         * Increment active readers count before accessing the pointer.
         * See force_mb_all_threads().
         */
        barrier();
+       debug_yield_read();
 }
 
 static inline void rcu_read_unlock(int *urcu_parity)
 {
+       debug_yield_read();
        barrier();
+       debug_yield_read();
        /*
         * Finish using rcu before decrementing the pointer.
         * See force_mb_all_threads().
         */
        urcu_active_readers[*urcu_parity]--;
+       debug_yield_read();
 }
 
 extern void *urcu_publish_content(void **ptr, void *new);