Merge change 1867 into donut

#ifndef __FDEVENT_H

#define __FDEVENT_H

#include <stdint.h>  /* for int64_t */

/* events that may be observed */

#define FDE_READ              0x0001

#define FDE_WRITE             0x0002

#define FDE_ERROR             0x0004

#define FDE_TIMEOUT           0x0008

/* features that may be set (via the events set/add/del interface) */

#define FDE_DONT_CLOSE        0x0080

typedef void (*fd_func)(int fd, unsigned events, void *userdata);

/* Allocate and initialize a new fdevent object

 * Note: use FD_TIMER as 'fd' to create a fd-less object

 * (used to implement timers).

*/

fdevent *fdevent_create(int fd, fd_func func, void *arg);

void fdevent_add(fdevent *fde, unsigned events);

void fdevent_del(fdevent *fde, unsigned events);

void fdevent_set_timeout(fdevent *fde, int64_t  timeout_ms);

/* loop forever, handling events.

*/

void fdevent_loop();

reversed.

--- CONNECT(version, maxdata, "system-identity-string") ----------------

The CONNECT message establishes the presence of a remote system.

not change on later READY messages sent to the same stream.

--- WRITE(0, remote-id, "data") ----------------------------------------

The WRITE message sends data to the recipient's stream identified by

#define A_WRTE 0x45545257

--- implementation details ---------------------------------------------

The core of the bridge program will use three threads.  One thread