Decouple the signalling into a struct IOMuxSignaller

include/ucore/iomux_waker.h

@@ -10,6 +10,11 @@ extern "C" {
 struct IOMuxWaker;
 typedef void (*uc_waker_cb)(struct IOMuxWaker *wk);
 
+/** Usef for signalling an IOMux */
+struct IOMuxSignaller {
+    int fd;
+};
+
 /** These are primitives to wake up an IOMux.
  * An IOMux event loop can be woken up from e.g. an unix signal handler
  * or another thread. The IOMuxWaker itself is not thread safe, it's members
@@ -22,11 +27,11 @@ typedef void (*uc_waker_cb)(struct IOMuxWaker *wk);
  */
 struct IOMuxWaker {
     //private fields
-    int fds[2];
     struct IOMuxFD read_fd;
     uc_waker_cb wake_cb;
 
     //public fields
+    struct IOMuxSignaller signaller;
     struct IOMux *mux;
     void *cookie;
 };
@@ -47,6 +52,8 @@ int uc_iomux_waker_init(struct IOMux *mux, struct IOMuxWaker *wk, uc_waker_cb cb
  *  Care must be taken so the IOMuxWaker is destroyed
  *  without race conditions with a thread that wants to _signal the
  *  waker.
+ *  The embedded IOMuxSignaller of the IOMuxWaker can be used
+ *  by someone else in the uc_iomux_waker_signal() function
  * 
  * @param wk
  * @return 0 on success, errno on failure (Things are seriously
@@ -63,7 +70,7 @@ int uc_iomux_waker_destroy(struct IOMuxWaker *wk);
  * @return 0 on success, errno on failure (Things are seriously
  *         wrong if this fails)
  */
-int uc_iomux_waker_signal(struct IOMuxWaker *wk);
+int uc_iomux_waker_signal(struct IOMuxSignaller *signaller);
 
 #ifdef __cplusplus
 }