/*
* Empire - A multi-player, client/server Internet based war game.
- * Copyright (C) 1986-2008, Dave Pare, Jeff Bailey, Thomas Ruschak,
- * Ken Stevens, Steve McClure
+ * Copyright (C) 1986-2021, 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,
* 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/>.
*
* ---
*
* ---
*
* 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
+ * Doug Hay, 1998
+ * Steve McClure, 1998
+ * Markus Armbruster, 2004-2012
+ * Ron Koenderink, 2009
*/
/*
#include <unistd.h>
#include "empio.h"
#include "empthread.h"
+#include "file.h"
#include "ioqueue.h"
#include "misc.h"
-#include "queue.h"
-#include "server.h"
struct iop {
int fd;
struct ioqueue *output;
int flags;
int bufsize;
+ int last_out;
};
+static struct timeval *io_timeout(struct timeval *, time_t);
+
void
io_init(void)
{
struct iop *
io_open(int fd, int flags, int bufsize)
{
+ int fdfl;
struct iop *iop;
- flags = flags & (IO_READ | IO_WRITE | IO_NBLOCK | IO_NEWSOCK);
+ flags = flags & (IO_READ | IO_WRITE);
if ((flags & (IO_READ | IO_WRITE)) == 0)
return NULL;
+
+ fdfl = fcntl(fd, F_GETFL, 0);
+ if (fdfl < 0)
+ return NULL;
+ fdfl |= O_NONBLOCK;
+ if (fcntl(fd, F_SETFL, fdfl) < 0)
+ return NULL;
+
iop = malloc(sizeof(struct iop));
if (!iop)
return NULL;
iop->fd = fd;
- iop->input = 0;
- iop->output = 0;
- iop->flags = 0;
+ iop->input = NULL;
+ iop->output = NULL;
+ iop->flags = flags;
+ iop->last_out = 0;
iop->bufsize = bufsize;
- if ((flags & IO_READ) && (flags & IO_NEWSOCK) == 0)
+ if (flags & IO_READ)
iop->input = ioq_create(bufsize);
- if ((flags & IO_WRITE) && (flags & IO_NEWSOCK) == 0)
+ if (flags & IO_WRITE)
iop->output = ioq_create(bufsize);
- if (flags & IO_NBLOCK)
- io_noblocking(iop, 1); /* FIXME check success */
- iop->flags = flags;
return iop;
}
+/*
+ * Close @iop.
+ * Flush output and wait for the client to close the connection.
+ * Wait at most until @deadline. (time_t)-1 means wait as long as it
+ * takes (no timeout).
+ * Both the flush and the wait can be separately cut short by
+ * empth_wakeup(). This is almost certainly not what you want. If
+ * you need early wakeup, better fix this function not to go to sleep
+ * after wakeup during flush.
+ */
void
-io_close(struct iop *iop)
+io_close(struct iop *iop, time_t deadline)
{
-
- if (iop->input != 0)
+ struct timeval timeout;
+ char buf[IO_BUFSIZE];
+ int ret;
+
+ while (io_output(iop, deadline) > 0) ;
+ shutdown(iop->fd, SHUT_WR);
+ while (empth_select(iop->fd, EMPTH_FD_READ,
+ io_timeout(&timeout, deadline)) > 0) {
+ ret = read(iop->fd, buf, sizeof(buf));
+ if (ret <= 0)
+ break;
+ }
+ if (iop->input)
ioq_destroy(iop->input);
- if (iop->output != 0)
+ if (iop->output)
ioq_destroy(iop->output);
(void)close(iop->fd);
free(iop);
}
+static struct timeval *
+io_timeout(struct timeval *timeout, time_t deadline)
+{
+ struct timeval now;
+
+ if (deadline == (time_t)-1)
+ return NULL; /* no deadline */
+
+ gettimeofday(&now, NULL);
+ if (now.tv_sec >= deadline) {
+ /* deadline reached already */
+ timeout->tv_sec = 0;
+ timeout->tv_usec = 0;
+ } else {
+ /* deadline in future */
+ timeout->tv_sec = deadline - now.tv_sec - 1;
+ timeout->tv_usec = 999999 - now.tv_usec;
+ /* yes, this is 1usec early; sue me */
+ }
+
+ return timeout;
+}
+
+/*
+ * Read input from @iop and enqueue it.
+ * 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 input can be cut short by empth_wakeup().
+ * Return number of bytes read on success, -1 on error.
+ * In particular, return zero on timeout, early wakeup or EOF. Use
+ * io_eof() to distinguish timeout and early wakeup from EOF.
+ */
int
-io_input(struct iop *iop, int waitforinput)
+io_input(struct iop *iop, time_t deadline)
{
+ struct timeval timeout;
char buf[IO_BUFSIZE];
int cc;
+ int res;
- /* Not a read IOP */
if ((iop->flags & IO_READ) == 0)
return -1;
- /* IOP is markes as in error. */
if (iop->flags & IO_ERROR)
return -1;
- /* Wait for the file to have input. */
- if (waitforinput) {
- empth_select(iop->fd, EMPTH_FD_READ);
+ if (iop->flags & IO_EOF)
+ return 0;
+
+ if (deadline) {
+ res = empth_select(iop->fd, EMPTH_FD_READ,
+ io_timeout(&timeout, deadline));
+ if (res < 0) {
+ iop->flags |= IO_ERROR;
+ return -1;
+ } else if (res == 0)
+ return 0;
}
- /* Do the actual read. */
+
cc = read(iop->fd, buf, sizeof(buf));
if (cc < 0) {
- /* would block, so nothing to read. */
if (errno == EAGAIN || errno == EWOULDBLOCK)
return 0;
-
- /* Some form of file error occurred... */
iop->flags |= IO_ERROR;
return -1;
}
-
- /* We eof'd */
if (cc == 0) {
iop->flags |= IO_EOF;
return 0;
}
- /* Append the input to the IOQ. */
ioq_append(iop->input, buf, cc);
return cc;
}
return ioq_qsize(iop->output);
}
+/*
+ * Write output queued in @iop.
+ * 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 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 waitforoutput)
+io_output(struct iop *iop, time_t deadline)
{
+ struct timeval timeout;
struct iovec iov[16];
- int cc;
- int n;
- int remain;
+ int n, res, cc;
- /* If there is no output waiting. */
- if (!io_outputwaiting(iop))
- return 0;
+ if (deadline)
+ ef_make_stale();
- /* If the iop is not write enabled. */
if ((iop->flags & IO_WRITE) == 0)
return -1;
- /* If the io is marked as in error... */
if (iop->flags & IO_ERROR)
return -1;
- /* make the iov point to the data in the queue. */
- /* I.E., each of the elements in the queue. */
- /* returns the number of elements in the iov. */
- n = ioq_makeiov(iop->output, iov, IO_BUFSIZE);
-
- if (n <= 0) {
+ if (!ioq_qsize(iop->output))
return 0;
- }
- /* wait for the file to be output ready. */
- if (waitforoutput != IO_NOWAIT) {
- /* This waits for the file to be ready for writing, */
- /* and lets other threads run. */
- empth_select(iop->fd, EMPTH_FD_WRITE);
+ if (deadline) {
+ res = empth_select(iop->fd, EMPTH_FD_WRITE,
+ io_timeout(&timeout, deadline));
+ if (res == 0)
+ return 0;
+ if (res < 0) {
+ iop->flags |= IO_ERROR;
+ return -1;
+ }
}
- /* Do the actual write. */
+ n = ioq_makeiov(iop->output, iov, IO_BUFSIZE);
cc = writev(iop->fd, iov, n);
-
- /* if it failed.... */
if (cc < 0) {
- /* Hmm, it would block. file is opened noblock, soooooo.. */
- if (errno == EAGAIN || errno == EWOULDBLOCK) {
- /* If there are remaining bytes, set the IO as remaining.. */
- remain = ioq_qsize(iop->output);
- return remain;
- }
+ if (errno == EAGAIN || errno == EWOULDBLOCK)
+ return 0;
iop->flags |= IO_ERROR;
return -1;
}
- /* If no bytes were written, something happened.. Like an EOF. */
- if (cc == 0) {
- iop->flags |= IO_EOF;
- return 0;
- }
-
- /* Remove the number of written bytes from the queue. */
ioq_dequeue(iop->output, cc);
-
+ iop->last_out = ioq_qsize(iop->output);
return cc;
}
+/*
+ * Write output queued in @iop if enough have been enqueued.
+ * Write if at least one buffer has been filled since the last write.
+ * 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 isn't long, and on timeout or early wakeup.
+ */
+int
+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 (deadline)
+ ef_make_stale();
+ return 0;
+ }
+ return io_output(iop, deadline);
+}
+
int
io_peek(struct iop *iop, char *buf, int nbytes)
{
}
int
-io_write(struct iop *iop, char *buf, int nbytes, int doWait)
+io_write(struct iop *iop, char *buf, int nbytes)
{
- int len;
-
if ((iop->flags & IO_WRITE) == 0)
return -1;
ioq_append(iop->output, buf, nbytes);
- len = ioq_qsize(iop->output);
- if (len > iop->bufsize) {
- if (doWait) {
- io_output_all(iop);
- } else {
- /* only try a write every BUFSIZE characters */
- if (((len - nbytes) % iop->bufsize) < (len % iop->bufsize))
- io_output(iop, IO_NOWAIT);
- }
- }
return nbytes;
}
-int
-io_output_all(struct iop *iop)
-{
- int n;
-
- /*
- * Mustn't block a player thread while update is pending, or else
- * a malicous player could delay the update indefinitely
- */
- while ((n = io_output(iop, IO_NOWAIT)) > 0 && !play_wrlock_wanted)
- empth_select(iop->fd, EMPTH_FD_WRITE);
-
- return n;
-}
-
int
io_gets(struct iop *iop, char *buf, int nbytes)
{
return ioq_puts(iop->output, buf);
}
-int
-io_shutdown(struct iop *iop, int flags)
-{
- flags &= (IO_READ | IO_WRITE);
- if ((iop->flags & flags) != flags)
- return -1;
- if (flags & IO_READ) {
- shutdown(iop->fd, 0);
- ioq_drain(iop->input);
- }
- if (flags & IO_WRITE) {
- shutdown(iop->fd, 1);
- ioq_drain(iop->output);
- }
- return 0;
-}
-
-int
-io_noblocking(struct iop *iop, int value)
-{
- int flags;
-
- flags = fcntl(iop->fd, F_GETFL, 0);
- if (flags < 0)
- return -1;
- if (value == 0)
- flags &= ~O_NONBLOCK;
- else
- flags |= O_NONBLOCK;
- if (fcntl(iop->fd, F_SETFL, flags) < 0)
- return -1;
- if (value == 0)
- iop->flags &= ~IO_NBLOCK;
- else
- iop->flags |= IO_NBLOCK;
- return 0;
-}
-
int
io_error(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)
{