diff --git a/src/iomux_epoll.c b/src/iomux_epoll.c
index 7dfc343..586b5f0 100644
--- a/src/iomux_epoll.c
+++ b/src/iomux_epoll.c
@@ -213,6 +213,14 @@ static void iomux_epoll_delete(struct IOMux *mux)
         mux->instance = NULL;
     }
 }
+
+static const struct IOMuxOps epoll_ops = {
+    .run_impl           = iomux_epoll_run,
+    .delete_impl        = iomux_epoll_delete,
+    .register_fd_impl   = iomux_epoll_register_fd,
+    .unregister_fd_impl = iomux_epoll_unregister_fd,
+    .update_events_impl = iomux_epoll_update_events,
+};
     
 int iomux_epoll_init(struct IOMux *mux)
 {
@@ -226,12 +234,8 @@ int iomux_epoll_init(struct IOMux *mux)
         return errno;
     }
 
-    mux->instance           = mux_epoll;
-    mux->run_impl           = iomux_epoll_run;
-    mux->delete_impl        = iomux_epoll_delete;
-    mux->register_fd_impl   = iomux_epoll_register_fd;
-    mux->unregister_fd_impl = iomux_epoll_unregister_fd;
-    mux->update_events_impl = iomux_epoll_update_events;
+    mux->instance = mux_epoll;
+    mux->ops = epoll_ops;
 
     return 0;
 }
diff --git a/src/iomux_impl.c b/src/iomux_impl.c
index d4b14ed..a1e52c2 100644
--- a/src/iomux_impl.c
+++ b/src/iomux_impl.c
@@ -48,7 +48,7 @@ struct IOMux *iomux_create_ex(enum IOMUX_TYPE type, struct UCoreClock *uclock)
 
 void iomux_delete(struct IOMux *mux)
 {
-    mux->delete_impl(mux);
+    mux->ops.delete_impl(mux);
     memset(mux, 0xfa, sizeof *mux);
     free(mux);
 }
@@ -74,17 +74,18 @@ static int iomux_run_timers(struct IOMux *mux, struct timeval *timeout)
         struct timeval now;
         mux->uclock->now(mux->uclock, &now);
         future_to_interval(&first_timer, &now, timeout);
-    /*    TRACEF("now %d %d future %d %d interval %d %d\n", mux->now.tv_sec, mux->now.tv_usec,
+        /*TRACEF("now %d %d future %d %d interval %d %d\n", now.tv_sec, now.tv_usec,
                                                           first_timer.tv_sec, first_timer.tv_usec,
-                                                          timeout.tv_sec, timeout.tv_usec);
-    */  
+                                                          timeout->tv_sec, timeout->tv_usec);
+        */
+      
         assert(timeout->tv_sec >= 0);
         assert(timeout->tv_usec >= 0);
 
         return 1;
     } 
 
-    return 9;
+    return 0;
 }
 
 int iomux_run(struct IOMux *mux)
@@ -95,12 +96,13 @@ int iomux_run(struct IOMux *mux)
         struct timeval *timeoutp;
 
         if (iomux_run_timers(mux, &timeout)) {
+            TRACEF("NULL\n");
             timeoutp = &timeout;
         } else {
             timeoutp = NULL;
         }
 
-        rc = mux->run_impl(mux, timeoutp);
+        rc = mux->ops.run_impl(mux, timeoutp);
         if (rc < 0)
             return rc;
 
@@ -128,7 +130,7 @@ int iomux_register_fd(struct IOMux *mux, struct IOMuxFD *fd)
     assert(fd != NULL);
     assert(fd->callback != NULL);
     assert(fd->fd >= 0);
-    return mux->register_fd_impl(mux, fd);
+    return mux->ops.register_fd_impl(mux, fd);
 }
 
 int iomux_unregister_fd(struct IOMux *mux, struct IOMuxFD *fd)
@@ -136,7 +138,7 @@ int iomux_unregister_fd(struct IOMux *mux, struct IOMuxFD *fd)
     assert(mux != NULL);
     assert(fd != NULL);
     assert(fd->fd >= 0);
-    return mux->unregister_fd_impl(mux, fd);
+    return mux->ops.unregister_fd_impl(mux, fd);
 }
 
 int iomux_update_events(struct IOMux *mux, struct IOMuxFD *fd, unsigned int what)
@@ -148,7 +150,7 @@ int iomux_update_events(struct IOMux *mux, struct IOMuxFD *fd, unsigned int what
     assert(fd->fd >= 0);
     
     if (fd->what != what) {
-        mux->update_events_impl(mux, fd);
+        mux->ops.update_events_impl(mux, fd);
     } else {
         rc = 0;
     }
diff --git a/src/iomux_impl.h b/src/iomux_impl.h
index 6c5484a..31944cb 100644
--- a/src/iomux_impl.h
+++ b/src/iomux_impl.h
@@ -4,21 +4,7 @@
 #include "ucore/iomux.h"
 #include "ucore/timers.h"
 /** struct for IOMux implementations */
-struct IOMux {
-
-    /* TImer instance */
-    struct UCTimers timers;
-
-    /**
-     * Clock used for driving timers, and
-     * providing timeouts for the mux
-     */
-    struct UCoreClock *uclock;
-
-
-    /* Used by mux implementations to hold their own data/instance */
-    void *instance;
-
+struct IOMuxOps {
     /** Run one iteration of the mux.
      * The mux implementation must honor the timeout, if given.
      * The mux implementation must call iomux_timers_run after the
@@ -39,6 +25,26 @@ struct IOMux {
     int (*unregister_fd_impl)(struct IOMux *mux, struct IOMuxFD *fd);
     /** Update an IOMuxFD (due to its events ('what') has changed*/
     int (*update_events_impl)(struct IOMux *mux, struct IOMuxFD *fd);
+
+};
+struct IOMux {
+
+    /* TImer instance */
+    struct UCTimers timers;
+
+    /**
+     * Clock used for driving timers, and
+     * providing timeouts for the mux
+     */
+    struct UCoreClock *uclock;
+
+    struct IOMuxOps ops;
+
+
+    /* Used by mux implementations to hold their own data/instance */
+    void *instance;
+
+
 };
 
 int iomux_select_init(struct IOMux *mux);
diff --git a/src/iomux_select.c b/src/iomux_select.c
index 40156de..f680d60 100644
--- a/src/iomux_select.c
+++ b/src/iomux_select.c
@@ -199,6 +199,14 @@ static void iomux_select_delete(struct IOMux *mux)
         mux->instance = NULL;
     }
 }
+
+static const struct IOMuxOps select_ops = {
+    .run_impl           = iomux_select_run,
+    .delete_impl        = iomux_select_delete,
+    .register_fd_impl   = iomux_select_register_fd,
+    .unregister_fd_impl = iomux_select_unregister_fd,
+    .update_events_impl = iomux_select_update_events,
+};
     
 int iomux_select_init(struct IOMux *mux)
 {
@@ -208,12 +216,8 @@ int iomux_select_init(struct IOMux *mux)
 
     mux_select->max_fd = -1;
 
-    mux->instance           = mux_select;
-    mux->run_impl           = iomux_select_run;
-    mux->delete_impl        = iomux_select_delete;
-    mux->register_fd_impl   = iomux_select_register_fd;
-    mux->unregister_fd_impl = iomux_select_unregister_fd;
-    mux->update_events_impl = iomux_select_update_events;
+    mux->instance = mux_select;
+    mux->ops = select_ops;
 
     return 0;
 }