Clean up io_input() for the "no input available" case

[empserver] / src / lib / empthread / io.c

diff --git a/src/lib/empthread/io.c b/src/lib/empthread/io.c
index 67c605206cf9592cab798a638fc88e5f59551e20..0e65c86ed972da2c0d49d72fcbd58bcc54818eb4 100644 (file)
--- a/src/lib/empthread/io.c
+++ b/src/lib/empthread/io.c
@@ -1,11 +1,11 @@
 /*
  *  Empire - A multi-player, client/server Internet based war game.
- *  Copyright (C) 1986-2010, Dave Pare, Jeff Bailey, Thomas Ruschak,
- *                           Ken Stevens, Steve McClure
+ *  Copyright (C) 1986-2011, Dave Pare, Jeff Bailey, Thomas Ruschak,
+ *                Ken Stevens, Steve McClure, Markus Armbruster
  *
- *  This program is free software; you can redistribute it and/or modify
+ *  Empire is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
+ *  the Free Software Foundation, either version 3 of the License, or
  *  (at your option) any later version.
  *
  *  This program is distributed in the hope that it will be useful,
@@ -14,8 +14,7 @@
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  *  ---
  *
@@ -28,9 +27,10 @@
  *  io.c: Arrange for input and output on a file descriptor to be queued.
  *
  *  Known contributors to this file:
- *      Doug Hay, 1998
- *      Steve McClure, 1998
- *      Ron Koenderink, 2009
+ *     Doug Hay, 1998
+ *     Steve McClure, 1998
+ *     Markus Armbruster, 2004-2012
+ *     Ron Koenderink, 2009
  */
 
 /*
@@ -108,7 +108,16 @@ io_open(int fd, int flags, int bufsize, struct timeval timeout)
 void
 io_close(struct iop *iop)
 {
-
+    char buf[IO_BUFSIZE];
+    int ret;
+
+    while (io_output(iop, 1) > 0) ;
+    shutdown(iop->fd, SHUT_WR);
+    while (empth_select(iop->fd, EMPTH_FD_READ, &iop->input_timeout) > 0) {
+       ret = read(iop->fd, buf, sizeof(buf));
+       if (ret <= 0)
+           break;
+    }
     if (iop->input)
        ioq_destroy(iop->input);
     if (iop->output)
@@ -119,9 +128,8 @@ io_close(struct iop *iop)
 
 /*
  * Return number of bytes read on success, zero on timeout, early
- * wakeup or EOF, -1 on error, with errno set appropriately.  In
- * particular, return -1 with errno set to EAGAIN or EWOULDBLOCK when
- * no data is available for non-blocking input (WAITFORINPUT false).
+ * wakeup or EOF, -1 on error.  In particular, return 0 when no data
+ * is available for non-blocking input (WAITFORINPUT false).
  * Use io_eof() to distinguish timeout and early wakeup from EOF.
  */
 int
@@ -131,16 +139,13 @@ io_input(struct iop *iop, int waitforinput)
     int cc;
     int res;
 
-    /* Not a read IOP */
-    if ((iop->flags & IO_READ) == 0) {
-       errno = EBADF;
+    if ((iop->flags & IO_READ) == 0)
        return -1;
-    }
-    /* IOP is markes as in error. */
-    if (iop->flags & IO_ERROR) {
-       errno = EBADF;
+    if (iop->flags & IO_ERROR)
        return -1;
-    }
+    if (iop->flags & IO_EOF)
+       return 0;
+
     /* Wait for the file to have input. */
     if (waitforinput) {
        res = empth_select(iop->fd, EMPTH_FD_READ, &iop->input_timeout);
@@ -154,9 +159,9 @@ io_input(struct iop *iop, int waitforinput)
     /* Do the actual read. */
     cc = read(iop->fd, buf, sizeof(buf));
     if (cc < 0) {
-       if (errno != EAGAIN && errno != EWOULDBLOCK)
-           /* Some form of file error occurred... */
-           iop->flags |= IO_ERROR;
+       if (errno == EAGAIN || errno == EWOULDBLOCK)
+           return 0;
+       iop->flags |= IO_ERROR;
        return -1;
     }
 
@@ -200,16 +205,14 @@ io_output(struct iop *iop, int wait)
     if (wait)
        ef_make_stale();
 
-    if (!ioq_qsize(iop->output))
-       return 0;
-
     if ((iop->flags & IO_WRITE) == 0)
        return -1;
 
     if (iop->flags & IO_ERROR)
        return -1;
 
-    n = ioq_makeiov(iop->output, iov, IO_BUFSIZE);
+    if (!ioq_qsize(iop->output))
+       return 0;
 
     if (wait) {
        res = empth_select(iop->fd, EMPTH_FD_WRITE, NULL);
@@ -221,6 +224,7 @@ io_output(struct iop *iop, int wait)
        }
     }
 
+    n = ioq_makeiov(iop->output, iov, IO_BUFSIZE);
     cc = writev(iop->fd, iov, n);
     if (cc < 0) {
        if (errno == EAGAIN || errno == EWOULDBLOCK)
@@ -258,7 +262,6 @@ io_output_if_queue_long(struct iop *iop, int wait)
     return io_output(iop, wait);
 }
 
-
 int
 io_peek(struct iop *iop, char *buf, int nbytes)
 {
@@ -335,6 +338,17 @@ io_eof(struct iop *iop)
     return iop->flags & IO_EOF;
 }
 
+/*
+ * Discard IOP's buffered input and set its EOF flag.
+ * No more input can be read from IOP.
+ */
+void
+io_set_eof(struct iop *iop)
+{
+    ioq_drain(iop->input);
+    iop->flags |= IO_EOF;
+}
+
 int
 io_fileno(struct iop *iop)
 {