2 * Empire - A multi-player, client/server Internet based war game.
3 * Copyright (C) 1986-2008, Dave Pare, Jeff Bailey, Thomas Ruschak,
4 * Ken Stevens, Steve McClure
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * See files README, COPYING and CREDITS in the root of the source
23 * tree for related information and legal notices. It is expected
24 * that future projects/authors will amend these files as needed.
28 * io.c: Arrange for input and output on a file descriptor to be queued.
30 * Known contributors to this file:
36 * Arrange for input and output on a file descriptor
37 * to be queued. Provide main loop -- a mechanism for
38 * blocking across all registered file descriptors, and
39 * reading or writing when appropriate.
47 #include <sys/socket.h>
48 #include <sys/types.h>
52 #include "empthread.h"
60 struct ioqueue *input;
61 struct ioqueue *output;
72 io_open(int fd, int flags, int bufsize)
76 flags = flags & (IO_READ | IO_WRITE | IO_NBLOCK | IO_NEWSOCK);
77 if ((flags & (IO_READ | IO_WRITE)) == 0)
79 iop = malloc(sizeof(struct iop));
86 iop->bufsize = bufsize;
87 if ((flags & IO_READ) && (flags & IO_NEWSOCK) == 0)
88 iop->input = ioq_create(bufsize);
89 if ((flags & IO_WRITE) && (flags & IO_NEWSOCK) == 0)
90 iop->output = ioq_create(bufsize);
91 if (flags & IO_NBLOCK)
92 io_noblocking(iop, 1); /* FIXME check success */
98 io_close(struct iop *iop)
102 ioq_destroy(iop->input);
103 if (iop->output != 0)
104 ioq_destroy(iop->output);
105 (void)close(iop->fd);
110 io_input(struct iop *iop, int waitforinput)
112 char buf[IO_BUFSIZE];
116 if ((iop->flags & IO_READ) == 0)
118 /* IOP is markes as in error. */
119 if (iop->flags & IO_ERROR)
121 /* Wait for the file to have input. */
123 empth_select(iop->fd, EMPTH_FD_READ);
125 /* Do the actual read. */
126 cc = read(iop->fd, buf, sizeof(buf));
128 /* would block, so nothing to read. */
129 if (errno == EAGAIN || errno == EWOULDBLOCK)
132 /* Some form of file error occurred... */
133 iop->flags |= IO_ERROR;
139 iop->flags |= IO_EOF;
143 /* Append the input to the IOQ. */
144 ioq_append(iop->input, buf, cc);
149 io_inputwaiting(struct iop *iop)
151 return ioq_qsize(iop->input);
155 io_outputwaiting(struct iop *iop)
157 return ioq_qsize(iop->output);
161 io_output(struct iop *iop, int waitforoutput)
163 struct iovec iov[16];
168 /* If there is no output waiting. */
169 if (!io_outputwaiting(iop))
172 /* If the iop is not write enabled. */
173 if ((iop->flags & IO_WRITE) == 0)
176 /* If the io is marked as in error... */
177 if (iop->flags & IO_ERROR)
180 /* make the iov point to the data in the queue. */
181 /* I.E., each of the elements in the queue. */
182 /* returns the number of elements in the iov. */
183 n = ioq_makeiov(iop->output, iov, IO_BUFSIZE);
189 /* wait for the file to be output ready. */
190 if (waitforoutput != IO_NOWAIT) {
191 /* This waits for the file to be ready for writing, */
192 /* and lets other threads run. */
193 empth_select(iop->fd, EMPTH_FD_WRITE);
196 /* Do the actual write. */
197 cc = writev(iop->fd, iov, n);
199 /* if it failed.... */
201 /* Hmm, it would block. file is opened noblock, soooooo.. */
202 if (errno == EAGAIN || errno == EWOULDBLOCK) {
203 /* If there are remaining bytes, set the IO as remaining.. */
204 remain = ioq_qsize(iop->output);
207 iop->flags |= IO_ERROR;
211 /* If no bytes were written, something happened.. Like an EOF. */
213 iop->flags |= IO_EOF;
217 /* Remove the number of written bytes from the queue. */
218 ioq_dequeue(iop->output, cc);
224 io_peek(struct iop *iop, char *buf, int nbytes)
226 if ((iop->flags & IO_READ) == 0)
228 return ioq_peek(iop->input, buf, nbytes);
232 io_read(struct iop *iop, char *buf, int nbytes)
236 if ((iop->flags & IO_READ) == 0)
238 cc = ioq_peek(iop->input, buf, nbytes);
240 ioq_dequeue(iop->input, cc);
245 io_write(struct iop *iop, char *buf, int nbytes, int doWait)
249 if ((iop->flags & IO_WRITE) == 0)
251 ioq_append(iop->output, buf, nbytes);
252 len = ioq_qsize(iop->output);
253 if (len > iop->bufsize) {
257 /* only try a write every BUFSIZE characters */
258 if (((len - nbytes) % iop->bufsize) < (len % iop->bufsize))
259 io_output(iop, IO_NOWAIT);
266 io_output_all(struct iop *iop)
271 * Mustn't block a player thread while update is pending, or else
272 * a malicous player could delay the update indefinitely
274 while ((n = io_output(iop, IO_NOWAIT)) > 0 && !play_wrlock_wanted)
275 empth_select(iop->fd, EMPTH_FD_WRITE);
281 io_gets(struct iop *iop, char *buf, int nbytes)
283 if ((iop->flags & IO_READ) == 0)
285 return ioq_gets(iop->input, buf, nbytes);
289 io_puts(struct iop *iop, char *buf)
291 if ((iop->flags & IO_WRITE) == 0)
293 return ioq_puts(iop->output, buf);
297 io_shutdown(struct iop *iop, int flags)
299 flags &= (IO_READ | IO_WRITE);
300 if ((iop->flags & flags) != flags)
302 if (flags & IO_READ) {
303 shutdown(iop->fd, 0);
304 ioq_drain(iop->input);
306 if (flags & IO_WRITE) {
307 shutdown(iop->fd, 1);
308 ioq_drain(iop->output);
314 io_noblocking(struct iop *iop, int value)
318 flags = fcntl(iop->fd, F_GETFL, 0);
322 flags &= ~O_NONBLOCK;
325 if (fcntl(iop->fd, F_SETFL, flags) < 0)
328 iop->flags &= ~IO_NBLOCK;
330 iop->flags |= IO_NBLOCK;
335 io_error(struct iop *iop)
337 return iop->flags & IO_ERROR;
341 io_eof(struct iop *iop)
343 return iop->flags & IO_EOF;
347 io_fileno(struct iop *iop)