xenocara/xserver/hw/xfree86/os-support/shared/sigio.c
2019-12-12 06:05:17 +00:00

302 lines
8.7 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 <xserver_poll.h>
#include "xf86.h"
#include "xf86Priv.h"
#include "xf86_OSlib.h"
#include "inputstr.h"
#ifdef HAVE_STROPTS_H
#include <stropts.h>
#endif
#ifdef MAXDEVICES
/* MAXDEVICES represents the maximimum number of input devices usable
* at the same time plus one entry for DRM support.
*/
#define MAX_FUNCS (MAXDEVICES + 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 struct pollfd *xf86SigIOFds;
static int xf86SigIONum;
static Bool
xf86SigIOAdd(int fd)
{
struct pollfd *n;
n = realloc(xf86SigIOFds, (xf86SigIONum + 1) * sizeof (struct pollfd));
if (!n)
return FALSE;
n[xf86SigIONum].fd = fd;
n[xf86SigIONum].events = POLLIN;
xf86SigIONum++;
xf86SigIOFds = n;
return TRUE;
}
static void
xf86SigIORemove(int fd)
{
int i;
for (i = 0; i < xf86SigIONum; i++)
if (xf86SigIOFds[i].fd == fd) {
memmove(&xf86SigIOFds[i], &xf86SigIOFds[i+1], (xf86SigIONum - i - 1) * sizeof (struct pollfd));
xf86SigIONum--;
break;
}
}
/*
* SIGIO gives no way of discovering which fd signalled, select
* to discover
*/
static void
xf86SIGIO(int sig)
{
int i, f;
int save_errno = errno; /* do not clobber the global errno */
int r;
inSignalContext = TRUE;
SYSCALL(r = xserver_poll(xf86SigIOFds, xf86SigIONum, 0));
for (f = 0; r > 0 && f < xf86SigIONum; f++) {
if (xf86SigIOFds[f].revents & POLLIN) {
for (i = 0; i < xf86SigIOMax; i++)
if (xf86SigIOFuncs[i].f && xf86SigIOFuncs[i].fd == xf86SigIOFds[f].fd)
(*xf86SigIOFuncs[i].f) (xf86SigIOFuncs[i].fd,
xf86SigIOFuncs[i].closure);
r--;
}
}
if (r > 0) {
xf86Msg(X_ERROR, "SIGIO %d descriptors not handled\n", r);
}
/* restore global errno */
errno = save_errno;
inSignalContext = FALSE;
}
static int
xf86IsPipe(int fd)
{
struct stat buf;
if (fstat(fd, &buf) < 0)
return 0;
return S_ISFIFO(buf.st_mode);
}
static void
block_sigio(void)
{
sigset_t set;
sigemptyset(&set);
sigaddset(&set, SIGIO);
xthread_sigmask(SIG_BLOCK, &set, NULL);
}
static void
release_sigio(void)
{
sigset_t set;
sigemptyset(&set);
sigaddset(&set, SIGIO);
xthread_sigmask(SIG_UNBLOCK, &set, NULL);
}
int
xf86InstallSIGIOHandler(int fd, void (*f) (int, void *), void *closure)
{
struct sigaction sa;
struct sigaction osa;
int i;
int installed = FALSE;
if (!xf86Info.useSIGIO)
return 0;
for (i = 0; i < MAX_FUNCS; i++) {
if (!xf86SigIOFuncs[i].f) {
if (xf86IsPipe(fd))
return 0;
block_sigio();
#ifdef O_ASYNC
if (fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_ASYNC) == -1) {
xf86Msg(X_WARNING, "fcntl(%d, O_ASYNC): %s\n",
fd, strerror(errno));
}
else {
if (fcntl(fd, F_SETOWN, getpid()) == -1) {
xf86Msg(X_WARNING, "fcntl(%d, F_SETOWN): %s\n",
fd, strerror(errno));
}
else {
installed = TRUE;
}
}
#endif
#if defined(I_SETSIG) && defined(HAVE_ISASTREAM)
/* System V Streams - used on Solaris for input devices */
if (!installed && isastream(fd)) {
if (ioctl(fd, I_SETSIG, S_INPUT | S_ERROR | S_HANGUP) == -1) {
xf86Msg(X_WARNING, "fcntl(%d, I_SETSIG): %s\n",
fd, strerror(errno));
}
else {
installed = TRUE;
}
}
#endif
if (!installed) {
release_sigio();
return 0;
}
sigemptyset(&sa.sa_mask);
sigaddset(&sa.sa_mask, SIGIO);
sa.sa_flags = SA_RESTART;
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;
xf86SigIOAdd(fd);
release_sigio();
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;
}
int
xf86RemoveSIGIOHandler(int fd)
{
struct sigaction sa;
struct sigaction osa;
int i;
int max;
int ret;
if (!xf86Info.useSIGIO)
return 0;
max = 0;
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;
xf86SigIORemove(fd);
ret = 1;
}
else {
max = i + 1;
}
}
}
if (ret) {
#ifdef O_ASYNC
fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_ASYNC);
#endif
#if defined(I_SETSIG) && defined(HAVE_ISASTREAM)
if (isastream(fd)) {
if (ioctl(fd, I_SETSIG, 0) == -1) {
xf86Msg(X_WARNING, "fcntl(%d, I_SETSIG, 0): %s\n",
fd, strerror(errno));
}
}
#endif
xf86SigIOMax = max;
if (!max) {
sigemptyset(&sa.sa_mask);
sigaddset(&sa.sa_mask, SIGIO);
sa.sa_flags = 0;
sa.sa_handler = SIG_IGN;
sigaction(SIGIO, &sa, &osa);
}
}
return ret;
}