diff --git a/include/ucore/wqueue.h b/include/ucore/wqueue.h
index 879434f..7e32511 100644
--- a/include/ucore/wqueue.h
+++ b/include/ucore/wqueue.h
@@ -8,7 +8,7 @@ enum UC_WQ_RESULT {
     /** INdicates the MBuf was fully processed and can be freed*/
     UC_WQ_DONE = 1,
     /** Indicates the MBuf was not fully processed, and will not be freed */
-    UC_WQ_UC_PARTIAL = 0,
+    UC_WQ_PARTIAL = 0,
     /** Indicats an error and further processing of the wqueue should not be done*/
     UC_WQ_ABORT = -1
 };
@@ -38,7 +38,7 @@ enum UC_WQ_RESULT {
  *          for this event.
  * 
  */
-typedef UC_WQ_RESULT (*wqueue_write_cb)(struct IOMux *mux, struct IOMuxFD *fd, struct MBuf *mbuf);
+typedef enum UC_WQ_RESULT (*wqueue_write_cb)(struct IOMux *mux, struct IOMuxFD *fd, struct MBuf *mbuf);
 
 /**
  * Callback when read events are indicated.
@@ -49,7 +49,7 @@ typedef UC_WQ_RESULT (*wqueue_write_cb)(struct IOMux *mux, struct IOMuxFD *fd, s
  * @param mux associated IOMux
  * @param the fd of the current wqueue
  */
-typedef UC_WQ_RESULT (*wqueue_read_cb)(struct IOMux *mux, struct IOMuxFD *fd);
+typedef enum UC_WQ_RESULT (*wqueue_read_cb)(struct IOMux *mux, struct IOMuxFD *fd);
 
 /** Represents a queue of data to write.
  */
diff --git a/test/console_print.c b/test/console_print.c
index dd3f580..a22d562 100644
--- a/test/console_print.c
+++ b/test/console_print.c
@@ -6,6 +6,7 @@
 #include <ucore/utils.h>
 #include <ucore/iomux.h>
 #include <ucore/wqueue.h>
+#include <ucore/fd_utils.h>
 
 
 int stdout_read(struct IOMux *mux, struct IOMuxFD *fd)
@@ -14,20 +15,26 @@ int stdout_read(struct IOMux *mux, struct IOMuxFD *fd)
 }
 void stdin_read_cb(struct IOMux *mux, struct IOMuxFD *fd, unsigned int event)
 {
-    struct MBuf *mbuf = uc_mbuf_new(512);
+    struct MBuf *mbuf = uc_mbuf_new(65);
     uint8_t *buf = uc_mbuf_head(mbuf);
+    struct UCWQueue *wqueue = fd->cookie_ptr;
 
-    ssize_t len = read(fd->fd, buf, sizeof buf);
+    ssize_t len = read(fd->fd, buf, 65);
     
     printf("Read %d bytes\n", len);
     if (len <= 0) {
         uc_mbuf_free(mbuf);
+        iomux_unregister_fd(mux, fd);
+        uc_wqueue_clear(wqueue);
+        iomux_unregister_fd(mux, &wqueue->fd);
+
         return;
     }
     uc_mbuf_put(mbuf, len);
     
-    struct UCWQueue *wqueue = fd->cookie_ptr;
     uc_wqueue_enqueue(wqueue, mbuf);
+    struct MBuf *mbuf2 = uc_mbuf_copy_data(mbuf);
+    uc_wqueue_enqueue(wqueue, mbuf2);
 }
 
 struct IOMuxFD stdin_fd = {
@@ -48,28 +55,32 @@ int stdout_write(struct IOMux *mux, struct IOMuxFD *fd, struct MBuf *mbuf)
     wlen = write(fd->fd, data, len);
 
     if (wlen < 0) {
-        perror("write");
-        return -1;
+        if (errno != EWOULDBLOCK) {
+            perror("write");
+        }
+        return UC_WQ_ABORT;
     }
 
     if (wlen == len) {
-        return 1;
+        return UC_WQ_DONE;
     }
 
-    return 0;
+    return UC_WQ_PARTIAL;
 }
 
 struct UCWQueue stdout_queue;
 
 int main(int argc, char *argv[])
 {
-    struct IOMux *mux = iomux_create(IOMUX_TYPE_DEFAULT);
+    //struct IOMux *mux = iomux_create(IOMUX_TYPE_SELECT);
+    struct IOMux *mux = iomux_create(IOMUX_TYPE_EPOLL);
     uc_wqueue_init(&stdout_queue, mux);
     stdin_fd.cookie_ptr = &stdout_queue;
     stdout_queue.fd.fd = 1;
-    stdout_queue.fd.what = MUX_EV_READ;
     stdout_queue.write_cb = stdout_write;
-    stdout_queue.read_cb = stdout_read;
+//    stdout_queue.read_cb = stdout_read; //we should not get read events here.
+
+    uc_set_nonblocking(1); 
 
     iomux_register_fd(mux, &stdin_fd);
     iomux_register_fd(mux, &stdout_queue.fd);