xenocara/xserver/hw/xfree86/os-support/shared/sigio.c
2006-11-26 18:13:41 +00:00

286 lines
7.4 KiB
C

/* sigio.c -- Support for SIGIO handler installation and removal
* Created: Thu Jun 3 15:39:18 1999 by faith@precisioninsight.com
*
* Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Authors: Rickard E. (Rik) Faith <faith@valinux.com>
*/
/*
* Copyright (c) 2002 by The XFree86 Project, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Except as contained in this notice, the name of the copyright holder(s)
* and author(s) shall not be used in advertising or otherwise to promote
* the sale, use or other dealings in this Software without prior written
* authorization from the copyright holder(s) and author(s).
*/
#ifdef HAVE_XORG_CONFIG_H
#include <xorg-config.h>
#endif
# include <X11/X.h>
# include "xf86.h"
# include "xf86Priv.h"
# include "xf86_OSlib.h"
# include "inputstr.h"
/*
* Linux libc5 defines FASYNC, but not O_ASYNC. Don't know if it is
* functional or not.
*/
#if defined(FASYNC) && !defined(O_ASYNC)
# define O_ASYNC FASYNC
#endif
#ifdef MAX_DEVICES
/* MAX_DEVICES represents the maximimum number of input devices usable
* at the same time plus one entry for DRM support.
*/
# define MAX_FUNCS (MAX_DEVICES + 1)
#else
# define MAX_FUNCS 16
#endif
typedef struct _xf86SigIOFunc {
void (*f) (int, void *);
int fd;
void *closure;
} Xf86SigIOFunc;
static Xf86SigIOFunc xf86SigIOFuncs[MAX_FUNCS];
static int xf86SigIOMax;
static int xf86SigIOMaxFd;
static fd_set xf86SigIOMask;
/*
* SIGIO gives no way of discovering which fd signalled, select
* to discover
*/
static void
xf86SIGIO (int sig)
{
int i;
fd_set ready;
struct timeval to;
int r;
ready = xf86SigIOMask;
to.tv_sec = 0;
to.tv_usec = 0;
SYSCALL (r = select (xf86SigIOMaxFd, &ready, 0, 0, &to));
for (i = 0; r > 0 && i < xf86SigIOMax; i++)
if (xf86SigIOFuncs[i].f && FD_ISSET (xf86SigIOFuncs[i].fd, &ready))
{
(*xf86SigIOFuncs[i].f)(xf86SigIOFuncs[i].fd,
xf86SigIOFuncs[i].closure);
r--;
}
if (r > 0) {
xf86Msg(X_ERROR, "SIGIO %d descriptors not handled\n", r);
}
}
static int
xf86IsPipe (int fd)
{
struct stat buf;
if (fstat (fd, &buf) < 0)
return 0;
return S_ISFIFO(buf.st_mode);
}
_X_EXPORT int
xf86InstallSIGIOHandler(int fd, void (*f)(int, void *), void *closure)
{
struct sigaction sa;
struct sigaction osa;
int i;
int blocked;
for (i = 0; i < MAX_FUNCS; i++)
{
if (!xf86SigIOFuncs[i].f)
{
if (xf86IsPipe (fd))
return 0;
blocked = xf86BlockSIGIO();
if (fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_ASYNC) == -1) {
xf86Msg(X_WARNING, "fcntl(%d, O_ASYNC): %s\n",
fd, strerror(errno));
xf86UnblockSIGIO(blocked);
return 0;
}
if (fcntl(fd, F_SETOWN, getpid()) == -1) {
xf86Msg(X_WARNING, "fcntl(%d, F_SETOWN): %s\n",
fd, strerror(errno));
xf86UnblockSIGIO(blocked);
return 0;
}
sigemptyset(&sa.sa_mask);
sigaddset(&sa.sa_mask, SIGIO);
sa.sa_flags = 0;
sa.sa_handler = xf86SIGIO;
sigaction(SIGIO, &sa, &osa);
xf86SigIOFuncs[i].fd = fd;
xf86SigIOFuncs[i].closure = closure;
xf86SigIOFuncs[i].f = f;
if (i >= xf86SigIOMax)
xf86SigIOMax = i+1;
if (fd >= xf86SigIOMaxFd)
xf86SigIOMaxFd = fd + 1;
FD_SET (fd, &xf86SigIOMask);
xf86UnblockSIGIO(blocked);
return 1;
}
/* Allow overwriting of the closure and callback */
else if (xf86SigIOFuncs[i].fd == fd)
{
xf86SigIOFuncs[i].closure = closure;
xf86SigIOFuncs[i].f = f;
return 1;
}
}
return 0;
}
_X_EXPORT int
xf86RemoveSIGIOHandler(int fd)
{
struct sigaction sa;
struct sigaction osa;
int i;
int max;
int maxfd;
int ret;
max = 0;
maxfd = -1;
ret = 0;
for (i = 0; i < MAX_FUNCS; i++)
{
if (xf86SigIOFuncs[i].f)
{
if (xf86SigIOFuncs[i].fd == fd)
{
xf86SigIOFuncs[i].f = 0;
xf86SigIOFuncs[i].fd = 0;
xf86SigIOFuncs[i].closure = 0;
FD_CLR (fd, &xf86SigIOMask);
ret = 1;
}
else
{
max = i + 1;
if (xf86SigIOFuncs[i].fd >= maxfd)
maxfd = xf86SigIOFuncs[i].fd + 1;
}
}
}
if (ret)
{
fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_ASYNC);
xf86SigIOMax = max;
xf86SigIOMaxFd = maxfd;
if (!max)
{
sigemptyset(&sa.sa_mask);
sigaddset(&sa.sa_mask, SIGIO);
sa.sa_flags = 0;
sa.sa_handler = SIG_DFL;
sigaction(SIGIO, &sa, &osa);
}
}
return ret;
}
_X_EXPORT int
xf86BlockSIGIO (void)
{
sigset_t set, old;
int ret;
sigemptyset (&set);
sigaddset (&set, SIGIO);
sigprocmask (SIG_BLOCK, &set, &old);
ret = sigismember (&old, SIGIO);
#ifdef DEBUG
ErrorF("%i = xf86BlockSIGIO()\n",ret);
#endif
return ret;
}
_X_EXPORT void
xf86UnblockSIGIO (int wasset)
{
sigset_t set;
#ifdef DEBUG
ErrorF("xf86UnblockSIGIO(%i)\n",wasset);
#endif
if (!wasset)
{
sigemptyset (&set);
sigaddset (&set, SIGIO);
sigprocmask (SIG_UNBLOCK, &set, NULL);
}
}
void
xf86AssertBlockedSIGIO (char *where)
{
sigset_t set, old;
sigemptyset (&set);
sigprocmask (SIG_BLOCK, &set, &old);
if (!sigismember (&old, SIGIO))
xf86Msg (X_ERROR, "SIGIO not blocked at %s\n", where);
}
/* XXX This is a quick hack for the benefit of xf86SetSilkenMouse() */
int
xf86SIGIOSupported (void)
{
return 1;
}