Add deadline support to io_output(), io_output_if_queue_long()

Replace parameter wait by deadline.  Non-zero wait argument becomes
(time_t)-1 argument, zero wait argument becomes zero deadline
argument.  No functional change, yet.

include/empio.h

@@ -47,8 +47,8 @@ extern void io_close(struct iop *, time_t);
 extern int io_input(struct iop *, time_t);
 extern int io_inputwaiting(struct iop *);
 extern int io_outputwaiting(struct iop *);
-extern int io_output(struct iop *, int);
-extern int io_output_if_queue_long(struct iop *, int);
+extern int io_output(struct iop *, time_t);
+extern int io_output_if_queue_long(struct iop *, time_t);
 extern int io_peek(struct iop *, char *, int);
 extern int io_read(struct iop *, char *, int);
 extern int io_write(struct iop *, char *, int);

src/lib/empthread/io.c

@@ -112,7 +112,7 @@ io_close(struct iop *iop, time_t deadline)
     char buf[IO_BUFSIZE];
     int ret;
 
-    while (io_output(iop, 1) > 0) ;
+    while (io_output(iop, (time_t)-1) > 0) ;
     shutdown(iop->fd, SHUT_WR);
     while (empth_select(iop->fd, EMPTH_FD_READ,
 			io_timeout(&timeout, deadline)) > 0) {
@@ -216,19 +216,24 @@ io_outputwaiting(struct iop *iop)
 
 /*
  * Write output queued in IOP.
- * If WAIT, writing may put the thread to sleep.
+ * Wait at most until DEADLINE for input to arrive.  (time_t)-1 means
+ * wait as long as it takes (no timeout).
+ * Does not yield the processor when DEADLINE is zero.
+ * A wait for output can be cut short by empth_wakeup().
  * Return number of bytes written on success, -1 on error.
  * In particular, return zero when nothing was written because the
- * queue was empty, or because the write slept and got woken up (only
- * if WAIT), or because the write refused to sleep (only if !WAIT).
+ * queue is empty, and on timeout or early wakeup.  Use
+ * io_outputwaiting() to distinguish timeout and early wakeup from
+ * empty queue.
  */
 int
-io_output(struct iop *iop, int wait)
+io_output(struct iop *iop, time_t deadline)
 {
+    struct timeval timeout;
     struct iovec iov[16];
     int n, res, cc;
 
-    if (wait)
+    if (deadline)
 	ef_make_stale();
 
     if ((iop->flags & IO_WRITE) == 0)
@@ -240,8 +245,9 @@ io_output(struct iop *iop, int wait)
     if (!ioq_qsize(iop->output))
 	return 0;
 
-    if (wait) {
-	res = empth_select(iop->fd, EMPTH_FD_WRITE, NULL);
+    if (deadline) {
+	res = empth_select(iop->fd, EMPTH_FD_WRITE,
+			   io_timeout(&timeout, deadline));
 	if (res == 0)
 	    return 0;
 	if (res < 0) {
@@ -267,25 +273,27 @@ io_output(struct iop *iop, int wait)
 /*
  * Write output queued in IOP if enough have been enqueued.
  * Write if at least one buffer has been filled since the last write.
- * If WAIT, writing may put the thread to sleep.
+ * Wait at most until DEADLINE for output to be accepted.  (time_t)-1
+ * means wait as long as it takes (no timeout).
+ * Does not yield the processor when DEADLINE is zero.
+ * A wait for output can be cut short by empth_wakeup().
  * Return number of bytes written on success, -1 on error.
  * In particular, return zero when nothing was written because the
- * queue was not long, or the write slept and got woken up (only if
- * WAIT), or the write refused to sleep (only if !WAIT).
+ * queue isn't long, and on timeout or early wakeup.
  */
 int
-io_output_if_queue_long(struct iop *iop, int wait)
+io_output_if_queue_long(struct iop *iop, time_t deadline)
 {
     int len = ioq_qsize(iop->output);
 
     if (CANT_HAPPEN(iop->last_out > len))
 	iop->last_out = 0;
     if (len - iop->last_out < iop->bufsize) {
-	if (wait)
+	if (deadline)
 	    ef_make_stale();
 	return 0;
     }
-    return io_output(iop, wait);
+    return io_output(iop, deadline);
 }
 
 int

src/lib/player/login.c

@@ -87,7 +87,7 @@ player_login(void *ud)
     pr_id(player, C_INIT, "Empire server ready\n");
 
     for (;;) {
-	io_output(player->iop, 1);
+	io_output(player->iop, (time_t)-1);
 	if (io_gets(player->iop, buf, sizeof(buf)) < 0) {
 	    res = io_input(player->iop, player->curup + minutes(max_idle));
 	    if (res <= 0) {

src/lib/player/recvclient.c

@@ -61,6 +61,7 @@ int
 recvclient(char *cmd, int size)
 {
     int count, res;
+    time_t deadline;
 
     count = -1;
     while (!player->aborted) {
@@ -80,8 +81,9 @@ recvclient(char *cmd, int size)
 	 * Flush all queued output before potentially sleeping in
 	 * io_input(), to make sure player sees the prompt.
 	 */
-	while (io_output(player->iop,
-			 player->may_sleep >= PLAYER_SLEEP_ON_INPUT) > 0)
+	deadline = (time_t)(player->may_sleep >= PLAYER_SLEEP_ON_INPUT
+			    ? -1 : 0);
+	while (io_output(player->iop, deadline) > 0)
 	    ;
 
 	/*

src/lib/subs/pr.c

@@ -30,7 +30,7 @@
  *     Dave Pare, 1986, 1989
  *     Steve McClure, 1998-2000
  *     Ron Koenderink, 2005
- *     Markus Armbruster, 2005-2011
+ *     Markus Armbruster, 2005-2012
  */
 
 /*
@@ -223,6 +223,7 @@ pr_player(struct player *pl, int id, char *buf)
     char *p;
     char *bp;
     int len;
+    time_t deadline;
 
     journal_output(pl, id, buf);
 
@@ -247,8 +248,9 @@ pr_player(struct player *pl, int id, char *buf)
     }
 
     if (player == pl) {
-	while (io_output_if_queue_long(pl->iop,
-			pl->may_sleep == PLAYER_SLEEP_FREELY) > 0)
+	deadline = (time_t)(pl->may_sleep == PLAYER_SLEEP_FREELY
+			    ? -1 : 0);
+	while (io_output_if_queue_long(pl->iop, deadline) > 0)
 	    ;
     }
 }
@@ -266,6 +268,7 @@ upr_player(struct player *pl, int id, char *buf)
     int standout = 0;
     char printbuf[2];
     char ch;
+    time_t deadline;
 
     journal_output(pl, id, buf);
 
@@ -305,8 +308,9 @@ upr_player(struct player *pl, int id, char *buf)
     }
 
     if (player == pl) {
-	while (io_output_if_queue_long(pl->iop,
-			pl->may_sleep == PLAYER_SLEEP_FREELY) > 0)
+	deadline = (time_t)(pl->may_sleep == PLAYER_SLEEP_FREELY
+			    ? -1 : 0);
+	while (io_output_if_queue_long(pl->iop, deadline) > 0)
 	    ;
     }
 }