diff --git a/OPTYap/locks_pthread.h b/OPTYap/locks_pthread.h
index e151ce732..de9579921 100755
--- a/OPTYap/locks_pthread.h
+++ b/OPTYap/locks_pthread.h
@@ -21,20 +21,19 @@
 
 #include <pthread.h>
 
-//#define DEBUG_LOCKS 1
-
-#if DEBUG_LOCKS
+#define DEBUG_PE_LOCKS 1
+//#define DEBUG_LOCKS
 #include <stdio.h>
 
 int Yap_ThreadID( void );
-extern int debug_locks;
 extern FILE *debugf;
-#endif
 
 #define INIT_LOCK(LOCK_VAR)    pthread_mutex_init(&(LOCK_VAR), NULL)
 #define DESTROY_LOCK(LOCK_VAR) pthread_mutex_destroy(&(LOCK_VAR))
 #define TRY_LOCK(LOCK_VAR)     pthread_mutex_trylock(&(LOCK_VAR))
 #if DEBUG_LOCKS
+extern int debug_locks;
+
 #define LOCK(LOCK_VAR)         (void)(fprintf(debugf,"[%d] %s:%d: LOCK(%p)\n",  Yap_ThreadID(), \
 					      __BASE_FILE__, __LINE__,&(LOCK_VAR))  && pthread_mutex_lock(&(LOCK_VAR)) )
 #define UNLOCK(LOCK_VAR)       (void)(fprintf(debugf, "[%d] %s:%d: UNLOCK(%p)\n",  Yap_ThreadID(),__BASE_FILE__, __LINE__,&(LOCK_VAR))  && pthread_mutex_unlock(&(LOCK_VAR)) )
@@ -42,6 +41,7 @@ extern FILE *debugf;
 #define LOCK(LOCK_VAR)         pthread_mutex_lock(&(LOCK_VAR))
 #define UNLOCK(LOCK_VAR)       pthread_mutex_unlock(&(LOCK_VAR))
 #endif
+
 static inline int
 xIS_LOCKED(pthread_mutex_t *LOCK_VAR) {
   if (pthread_mutex_trylock(LOCK_VAR) == 0) {
@@ -58,15 +58,39 @@ xIS_UNLOCKED(pthread_mutex_t *LOCK_VAR) {
   }
   return TRUE;
 }
+
 #define IS_LOCKED(LOCK_VAR)    xIS_LOCKED(&(LOCK_VAR))
 #define IS_UNLOCKED(LOCK_VAR)  xIS_UNLOCKED(&(LOCK_VAR))
 
+
 #define INIT_RWLOCK(X)         pthread_rwlock_init(&(X), NULL)
 #define DESTROY_RWLOCK(X)      pthread_rwlock_destroy(&(X))
+#if DEBUG_PE_LOCKS
+extern int debug_pe_locks;
+
+#define READ_LOCK(X) ((debug_pe_locks ?					\
+		      fprintf(debugf, "[%d] %s:%d: RLOCK(%p)\n",  \
+			      Yap_ThreadID(),__BASE_FILE__, __LINE__,&(X)) \
+		       : 1) && pthread_rwlock_rdlock(&(X)) )
+#define READ_UNLOCK(X) ((debug_pe_locks ?					\
+		      fprintf(debugf, "[%d] %s:%d: UNLOCK(%p)\n", \
+			      Yap_ThreadID(),__BASE_FILE__, __LINE__,&(X)) \
+			 : 1) && pthread_rwlock_unlock(&(X)) )
+#define WRITE_LOCK(X) ((debug_pe_locks ?					\
+		      fprintf(debugf, "[%d] %s:%d: RLOCK(%p)\n", \
+			      Yap_ThreadID(),__BASE_FILE__, __LINE__,&(X)) \
+			: 1) && pthread_rwlock_rdlock(&(X)) )
+#define WRITE_UNLOCK(X) ((debug_pe_locks ?					\
+		      fprintf(debugf, "[%d] %s:%d: UNLOCK(%p)\n",  \
+			      Yap_ThreadID(),__BASE_FILE__, __LINE__,&(X))\
+			  : 1) && pthread_rwlock_unlock(&(X)) )
+
+#else
 #define READ_LOCK(X)           pthread_rwlock_rdlock(&(X))
 #define READ_UNLOCK(X)         pthread_rwlock_unlock(&(X))
 #define WRITE_LOCK(X)          pthread_rwlock_wrlock(&(X))
 #define WRITE_UNLOCK(X)        pthread_rwlock_unlock(&(X))
+#endif
 
 
 #define TRUE_FUNC_WRITE_LOCK(F) WRITE_LOCK((F)->FRWLock)
@@ -78,12 +102,12 @@ xIS_UNLOCKED(pthread_mutex_t *LOCK_VAR) {
 
 #if DEBUG_LOCKS
 
-#define MUTEX_LOCK(LOCK_VAR)     (void)( debug_locks && fprintf(stderr,"[%d] %s:%d: MULOCK(%p)\n",  Yap_ThreadID(), \
-						__BASE_FILE__, __LINE__,(LOCK_VAR)) &&   \
+#define MUTEX_LOCK(LOCK_VAR)     (void)( ( debug_locks ? fprintf(stderr,"[%d] %s:%d: MULOCK(%p)\n",  Yap_ThreadID(), \
+							       __BASE_FILE__, __LINE__,(LOCK_VAR)) : 1 ) && \
 				   pthread_mutex_lock((LOCK_VAR)) )
 #define MUTEX_TRYLOCK(LOCK_VAR)  pthread_mutex_trylock((LOCK_VAR))
-#define MUTEX_UNLOCK(LOCK_VAR)  (void)( debug_locks && fprintf(stderr,"[%d] %s:%d: UNMULOCK(%p)\n",  Yap_ThreadID(), \
-						__BASE_FILE__, __LINE__,(LOCK_VAR)) &&   \
+#define MUTEX_UNLOCK(LOCK_VAR)  (void)((debug_locks? fprintf(stderr,"[%d] %s:%d: UNMULOCK(%p)\n",  Yap_ThreadID(), \
+							     __BASE_FILE__, __LINE__,(LOCK_VAR)) : 1) && \
 				  pthread_mutex_unlock((LOCK_VAR)))
 #else
 #define MUTEX_LOCK(LOCK_VAR) pthread_mutex_lock((LOCK_VAR))