+ int (*wait)(int timeout, void *pollclosure);
+ void *(*open)(int fd, void *closure, void *pollclosure);
+ int (*on_readable)(void *hndl, void (*cb)(void *closure));
+ int (*on_writable)(void *hndl, void (*cb)(void *closure));
+ void (*on_hangup)(void *hndl, void (*cb)(void *closure));
+ void (*close)(void *hndl);