freebsd-dev/lib/libvgl/mouse.c
Bruce Evans 0410dc5f5d Fix races in mouse signal handling almost properly using the INTOFF/INTON
method as in /bin/sh.

We still do technically undefined things in the signal handler, but it
is safe in practice to access state that is protected by INTOFF/INTON.

In a recent commit, I sprinkled VGLMouseFrozen++/-- operations in
places that need INTOFF/INTON.  This prevented clobbering of pixels
under the mouse, but left mouse signals deferred for too long.  It is
necessary to call the signal handler when the count goes to 0.  Old
versions did this in the unfreeze function, but didn't block actual
signals, so the signal handler raced itself.  The sprinkled operations
reduced the races, but when then worked to block a race they left
signals deferred for too long.

Use INTOFF/INTON to fix complete loss of mouse signals while reading
the mouse status.  Clobbering of the state was prevented by SIG_IGN'ing
mouse signals, but that has a high overhead and broke more than it
fixed by losing mouse signals completely.  sigprocmask() works to block
signals without losing them completely, but its overhead is also too
high.

libvgl's mouse signal handling is often worse than none.  Applications
can't block waiting for a mouse or keyboard or other event, but have
to busy-wait.  The SIG_IGN's lost about half of all mouse events while
busy-waiting for mouse events.
2019-03-29 15:20:48 +00:00

338 lines
9.7 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1991-1997 Søren Schmidt
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <stdio.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/signal.h>
#include <sys/consio.h>
#include <sys/fbio.h>
#include "vgl.h"
#define X 0xff
static byte StdAndMask[MOUSE_IMG_SIZE*MOUSE_IMG_SIZE] = {
X,X,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
X,X,X,0,0,0,0,0,0,0,0,0,0,0,0,0,
X,X,X,X,0,0,0,0,0,0,0,0,0,0,0,0,
X,X,X,X,X,0,0,0,0,0,0,0,0,0,0,0,
X,X,X,X,X,X,0,0,0,0,0,0,0,0,0,0,
X,X,X,X,X,X,X,0,0,0,0,0,0,0,0,0,
X,X,X,X,X,X,X,X,0,0,0,0,0,0,0,0,
X,X,X,X,X,X,X,X,X,0,0,0,0,0,0,0,
X,X,X,X,X,X,X,0,0,0,0,0,0,0,0,0,
0,0,0,X,X,X,X,0,0,0,0,0,0,0,0,0,
0,0,0,X,X,X,X,X,0,0,0,0,0,0,0,0,
0,0,0,0,X,X,X,X,0,0,0,0,0,0,0,0,
0,0,0,0,X,X,X,X,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
};
static byte StdOrMask[MOUSE_IMG_SIZE*MOUSE_IMG_SIZE] = {
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,X,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,X,X,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,X,X,X,0,0,0,0,0,0,0,0,0,0,0,0,
0,X,X,X,X,0,0,0,0,0,0,0,0,0,0,0,
0,X,X,X,X,X,0,0,0,0,0,0,0,0,0,0,
0,X,X,X,X,X,X,0,0,0,0,0,0,0,0,0,
0,X,X,0,X,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,X,X,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,X,X,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,X,X,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,X,X,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
};
#undef X
static VGLBitmap VGLMouseStdAndMask =
VGLBITMAP_INITIALIZER(MEMBUF, MOUSE_IMG_SIZE, MOUSE_IMG_SIZE, StdAndMask);
static VGLBitmap VGLMouseStdOrMask =
VGLBITMAP_INITIALIZER(MEMBUF, MOUSE_IMG_SIZE, MOUSE_IMG_SIZE, StdOrMask);
static VGLBitmap *VGLMouseAndMask, *VGLMouseOrMask;
static byte map[MOUSE_IMG_SIZE*MOUSE_IMG_SIZE*4];
static VGLBitmap VGLMouseSave =
VGLBITMAP_INITIALIZER(MEMBUF, MOUSE_IMG_SIZE, MOUSE_IMG_SIZE, map);
static int VGLMouseVisible = 0;
static int VGLMouseShown = 0;
static int VGLMouseXpos = 0;
static int VGLMouseYpos = 0;
static int VGLMouseButtons = 0;
static volatile sig_atomic_t VGLMintpending;
static volatile sig_atomic_t VGLMsuppressint;
#define INTOFF() (VGLMsuppressint++)
#define INTON() do { \
if (--VGLMsuppressint == 0 && VGLMintpending) \
VGLMouseAction(0); \
} while (0)
void
VGLMousePointerShow()
{
byte buf[MOUSE_IMG_SIZE*MOUSE_IMG_SIZE*4];
VGLBitmap buffer =
VGLBITMAP_INITIALIZER(MEMBUF, MOUSE_IMG_SIZE, MOUSE_IMG_SIZE, buf);
byte crtcidx, crtcval, gdcidx, gdcval;
int i, pos, pos1;
if (!VGLMouseVisible) {
INTOFF();
VGLMouseVisible = 1;
crtcidx = inb(0x3c4);
crtcval = inb(0x3c5);
gdcidx = inb(0x3ce);
gdcval = inb(0x3cf);
__VGLBitmapCopy(VGLDisplay, VGLMouseXpos, VGLMouseYpos,
&VGLMouseSave, 0, 0, MOUSE_IMG_SIZE, MOUSE_IMG_SIZE);
bcopy(VGLMouseSave.Bitmap, buffer.Bitmap,
MOUSE_IMG_SIZE*MOUSE_IMG_SIZE*VGLDisplay->PixelBytes);
for (pos = 0; pos < MOUSE_IMG_SIZE*MOUSE_IMG_SIZE; pos++)
for (i = 0; i < VGLDisplay->PixelBytes; i++) {
pos1 = pos * VGLDisplay->PixelBytes + i;
buffer.Bitmap[pos1] = (buffer.Bitmap[pos1] &
~VGLMouseAndMask->Bitmap[pos]) |
VGLMouseOrMask->Bitmap[pos];
}
__VGLBitmapCopy(&buffer, 0, 0, VGLDisplay,
VGLMouseXpos, VGLMouseYpos, MOUSE_IMG_SIZE, MOUSE_IMG_SIZE);
outb(0x3c4, crtcidx);
outb(0x3c5, crtcval);
outb(0x3ce, gdcidx);
outb(0x3cf, gdcval);
INTON();
}
}
void
VGLMousePointerHide()
{
byte crtcidx, crtcval, gdcidx, gdcval;
if (VGLMouseVisible) {
INTOFF();
VGLMouseVisible = 0;
crtcidx = inb(0x3c4);
crtcval = inb(0x3c5);
gdcidx = inb(0x3ce);
gdcval = inb(0x3cf);
__VGLBitmapCopy(&VGLMouseSave, 0, 0, VGLDisplay,
VGLMouseXpos, VGLMouseYpos, MOUSE_IMG_SIZE, MOUSE_IMG_SIZE);
outb(0x3c4, crtcidx);
outb(0x3c5, crtcval);
outb(0x3ce, gdcidx);
outb(0x3cf, gdcval);
INTON();
}
}
void
VGLMouseMode(int mode)
{
if (mode == VGL_MOUSESHOW) {
if (VGLMouseShown == VGL_MOUSEHIDE) {
VGLMousePointerShow();
VGLMouseShown = VGL_MOUSESHOW;
}
}
else {
if (VGLMouseShown == VGL_MOUSESHOW) {
VGLMousePointerHide();
VGLMouseShown = VGL_MOUSEHIDE;
}
}
}
void
VGLMouseAction(int dummy)
{
struct mouse_info mouseinfo;
if (VGLMsuppressint) {
VGLMintpending = 1;
return;
}
again:
INTOFF();
VGLMintpending = 0;
mouseinfo.operation = MOUSE_GETINFO;
ioctl(0, CONS_MOUSECTL, &mouseinfo);
if (VGLMouseShown == VGL_MOUSESHOW)
VGLMousePointerHide();
VGLMouseXpos = mouseinfo.u.data.x;
VGLMouseYpos = mouseinfo.u.data.y;
VGLMouseButtons = mouseinfo.u.data.buttons;
if (VGLMouseShown == VGL_MOUSESHOW)
VGLMousePointerShow();
/*
* Loop to handle any new (suppressed) signals. This is INTON() without
* recursion. !SA_RESTART prevents recursion in signal handling. So the
* maximum recursion is 2 levels.
*/
VGLMsuppressint = 0;
if (VGLMintpending)
goto again;
}
void
VGLMouseSetImage(VGLBitmap *AndMask, VGLBitmap *OrMask)
{
if (VGLMouseShown == VGL_MOUSESHOW)
VGLMousePointerHide();
VGLMouseAndMask = AndMask;
VGLMouseOrMask = OrMask;
if (VGLMouseShown == VGL_MOUSESHOW)
VGLMousePointerShow();
}
void
VGLMouseSetStdImage()
{
if (VGLMouseShown == VGL_MOUSESHOW)
VGLMousePointerHide();
VGLMouseAndMask = &VGLMouseStdAndMask;
VGLMouseOrMask = &VGLMouseStdOrMask;
if (VGLMouseShown == VGL_MOUSESHOW)
VGLMousePointerShow();
}
int
VGLMouseInit(int mode)
{
struct mouse_info mouseinfo;
int error, i, mask;
switch (VGLModeInfo.vi_mem_model) {
case V_INFO_MM_PACKED:
case V_INFO_MM_PLANAR:
mask = 0x0f;
break;
case V_INFO_MM_VGAX:
mask = 0x3f;
break;
default:
mask = 0xff;
break;
}
for (i = 0; i < 256; i++)
VGLMouseStdOrMask.Bitmap[i] &= mask;
VGLMouseSetStdImage();
mouseinfo.operation = MOUSE_MODE;
mouseinfo.u.mode.signal = SIGUSR2;
if ((error = ioctl(0, CONS_MOUSECTL, &mouseinfo)))
return error;
signal(SIGUSR2, VGLMouseAction);
mouseinfo.operation = MOUSE_GETINFO;
ioctl(0, CONS_MOUSECTL, &mouseinfo);
VGLMouseXpos = mouseinfo.u.data.x;
VGLMouseYpos = mouseinfo.u.data.y;
VGLMouseButtons = mouseinfo.u.data.buttons;
VGLMouseMode(mode);
return 0;
}
int
VGLMouseStatus(int *x, int *y, char *buttons)
{
INTOFF();
*x = VGLMouseXpos;
*y = VGLMouseYpos;
*buttons = VGLMouseButtons;
INTON();
return VGLMouseShown;
}
int
VGLMouseFreeze(int x, int y, int width, int hight, u_long color)
{
int i, xstride, ystride;
INTOFF();
if (width > 1 || hight > 1 || (color & 0xc0000000) == 0) { /* bitmap */
if (VGLMouseShown == 1) {
int overlap;
if (x > VGLMouseXpos)
overlap = (VGLMouseXpos + MOUSE_IMG_SIZE) - x;
else
overlap = (x + width) - VGLMouseXpos;
if (overlap > 0) {
if (y > VGLMouseYpos)
overlap = (VGLMouseYpos + MOUSE_IMG_SIZE) - y;
else
overlap = (y + hight) - VGLMouseYpos;
if (overlap > 0)
VGLMousePointerHide();
}
}
}
else { /* bit */
if (VGLMouseShown &&
x >= VGLMouseXpos && x < VGLMouseXpos + MOUSE_IMG_SIZE &&
y >= VGLMouseYpos && y < VGLMouseYpos + MOUSE_IMG_SIZE) {
xstride = VGLDisplay->PixelBytes;
ystride = MOUSE_IMG_SIZE * xstride;
if (color & 0x40000000) { /* Get */
color = 0;
for (i = xstride - 1; i >= 0; i--)
color = (color << 8) |
VGLMouseSave.Bitmap[(y-VGLMouseYpos)*ystride+
(x-VGLMouseXpos)*xstride+i];
return 0x40000000 | (color & 0xffffff);
} else { /* Set */
color &= 0xffffff; /* discard flag and other garbage */
for (i = 0; i < xstride; i++, color >>= 8)
VGLMouseSave.Bitmap[(y-VGLMouseYpos)*ystride+
(x-VGLMouseXpos)*xstride+i] = color;
if (VGLMouseAndMask->Bitmap
[(y-VGLMouseYpos)*MOUSE_IMG_SIZE+(x-VGLMouseXpos)]) {
return 1;
}
}
}
}
return 0;
}
void
VGLMouseUnFreeze()
{
if (VGLMouseShown == VGL_MOUSESHOW && !VGLMouseVisible && !VGLMintpending)
VGLMousePointerShow();
while (VGLMsuppressint)
INTON();
}