1 /*
2  * Window system protocol server.
3  * Use select and a single proc and single stack
4  * to avoid aggravating the X11 library, which is
5  * subtle and quick to anger.
6  */
7 
8 #include <u.h>
9 #include <sys/select.h>
10 #include <errno.h>
11 #include "x11-inc.h"
12 #include <libc.h>
13 #include <draw.h>
14 #include <memdraw.h>
15 #include <memlayer.h>
16 #include <keyboard.h>
17 #include <mouse.h>
18 #include <cursor.h>
19 #include <drawfcall.h>
20 #include "x11-memdraw.h"
21 #include "devdraw.h"
22 
23 #undef time
24 
25 #define MouseMask (\
26 	ButtonPressMask|\
27 	ButtonReleaseMask|\
28 	PointerMotionMask|\
29 	Button1MotionMask|\
30 	Button2MotionMask|\
31 	Button3MotionMask)
32 
33 #define Mask MouseMask|ExposureMask|StructureNotifyMask|KeyPressMask|EnterWindowMask|LeaveWindowMask
34 
35 typedef struct Kbdbuf Kbdbuf;
36 typedef struct Mousebuf Mousebuf;
37 typedef struct Fdbuf Fdbuf;
38 typedef struct Tagbuf Tagbuf;
39 
40 struct Kbdbuf
41 {
42 	Rune r[32];
43 	int ri;
44 	int wi;
45 	int stall;
46 };
47 
48 struct Mousebuf
49 {
50 	Mouse m[32];
51 	int resized[32];
52 	int ri;
53 	int wi;
54 	int stall;
55 };
56 
57 struct Tagbuf
58 {
59 	int t[32];
60 	int ri;
61 	int wi;
62 };
63 
64 struct Fdbuf
65 {
66 	uchar buf[2*MAXWMSG];
67 	uchar *rp;
68 	uchar *wp;
69 	uchar *ep;
70 };
71 
72 Kbdbuf kbd;
73 Mousebuf mouse;
74 Fdbuf fdin;
75 Fdbuf fdout;
76 Tagbuf kbdtags;
77 Tagbuf mousetags;
78 Tagbuf resizetags;
79 
80 void fdslide(Fdbuf*);
81 void runmsg(Wsysmsg*);
82 void replymsg(Wsysmsg*);
83 void runxevent(XEvent*);
84 void matchkbd(void);
85 void matchmouse(void);
86 void matchresized(void);
87 int fdnoblock(int);
88 
89 int chatty;
90 int drawsleep;
91 
92 void
93 usage(void)
94 {
95 	fprint(2, "usage: devdraw (don't run  directly)\n");
96 	exits("usage");
97 }
98 
99 void
100 bell(void *v, char *msg)
101 {
102 	if(strcmp(msg, "alarm") == 0)
103 		drawsleep = drawsleep ? 0 : 1000;
104 	noted(NCONT);
105 }
106 
107 void
108 main(int argc, char **argv)
109 {
110 	int n, top, firstx;
111 	fd_set rd, wr, xx;
112 	Wsysmsg m;
113 	XEvent event;
114 
115 	ARGBEGIN{
116 	case 'D':
117 		chatty++;
118 		break;
119 	default:
120 		usage();
121 	}ARGEND
122 
123 	/*
124 	 * Ignore arguments.  They're only for good ps -a listings.
125 	 */
126 	
127 	notify(bell);
128 
129 	fdin.rp = fdin.wp = fdin.buf;
130 	fdin.ep = fdin.buf+sizeof fdin.buf;
131 	
132 	fdout.rp = fdout.wp = fdout.buf;
133 	fdout.ep = fdout.buf+sizeof fdout.buf;
134 
135 	fdnoblock(0);
136 	fdnoblock(1);
137 
138 	firstx = 1;
139 	_x.fd = -1;
140 	for(;;){
141 		/* set up file descriptors */
142 		FD_ZERO(&rd);
143 		FD_ZERO(&wr);
144 		FD_ZERO(&xx);
145 		/*
146 		 * Don't read unless there's room *and* we haven't
147 		 * already filled the output buffer too much.
148 		 */
149 		if(fdout.wp < fdout.buf+MAXWMSG && fdin.wp < fdin.ep)
150 			FD_SET(0, &rd);
151 		if(fdout.wp > fdout.rp)
152 			FD_SET(1, &wr);
153 		FD_SET(0, &xx);
154 		FD_SET(1, &xx);
155 		top = 1;
156 		if(_x.fd >= 0){
157 			if(firstx){
158 				firstx = 0;
159 				XSelectInput(_x.display, _x.drawable, Mask);
160 			}
161 			FD_SET(_x.fd, &rd);
162 			FD_SET(_x.fd, &xx);
163 			XFlush(_x.display);
164 			top = _x.fd;
165 		}
166 
167 		if(chatty)
168 			fprint(2, "select %d...\n", top+1);
169 		/* wait for something to happen */
170 	    again:
171 		if(select(top+1, &rd, &wr, &xx, NULL) < 0){
172 			if(errno == EINTR)
173 				goto again;
174 			if(chatty)
175 				fprint(2, "select failure\n");
176 			exits(0);
177 		}
178 		if(chatty)
179 			fprint(2, "got select...\n");
180 
181 		{
182 			/* read what we can */
183 			n = 1;
184 			while(fdin.wp < fdin.ep && (n = read(0, fdin.wp, fdin.ep-fdin.wp)) > 0)
185 				fdin.wp += n;
186 			if(n == 0){
187 				if(chatty)
188 					fprint(2, "eof\n");
189 				exits(0);
190 			}
191 			if(n < 0 && errno != EAGAIN)
192 				sysfatal("reading wsys msg: %r");
193 
194 			/* pick off messages one by one */
195 			while((n = convM2W(fdin.rp, fdin.wp-fdin.rp, &m)) > 0){
196 				runmsg(&m);
197 				fdin.rp += n;
198 			}
199 			
200 			/* slide data to beginning of buf */
201 			fdslide(&fdin);
202 		}
203 		{
204 			/* write what we can */
205 			n = 1;
206 			while(fdout.rp < fdout.wp && (n = write(1, fdout.rp, fdout.wp-fdout.rp)) > 0)
207 				fdout.rp += n;
208 			if(n == 0)
209 				sysfatal("short write writing wsys");
210 			if(n < 0 && errno != EAGAIN)
211 				sysfatal("writing wsys msg: %r");
212 
213 			/* slide data to beginning of buf */
214 			fdslide(&fdout);
215 		}
216 		{
217 			/*
218 			 * Read an X message if we can.
219 			 * (XPending actually calls select to make sure
220 			 * the display's fd is readable and then reads
221 			 * in any waiting data before declaring whether
222 			 * there are events on the queue.)
223 			 */
224 			while(XPending(_x.display)){
225 				XNextEvent(_x.display, &event);
226 				runxevent(&event);
227 			}
228 		}
229 	}
230 }
231 
232 int
233 fdnoblock(int fd)
234 {
235 	return fcntl(fd, F_SETFL, fcntl(fd, F_GETFL)|O_NONBLOCK);
236 }
237 
238 void
239 fdslide(Fdbuf *fb)
240 {
241 	int n;
242 
243 	n = fb->wp - fb->rp;
244 	if(n > 0)
245 		memmove(fb->buf, fb->rp, n);
246 	fb->rp = fb->buf;
247 	fb->wp = fb->rp+n;
248 }
249 
250 void
251 replyerror(Wsysmsg *m)
252 {
253 	char err[256];
254 	
255 	rerrstr(err, sizeof err);
256 	m->type = Rerror;
257 	m->error = err;
258 	replymsg(m);
259 }
260 
261 /* 
262  * Handle a single wsysmsg. 
263  * Might queue for later (kbd, mouse read)
264  */
265 void
266 runmsg(Wsysmsg *m)
267 {
268 	uchar buf[65536];
269 	int n;
270 	Memimage *i;
271 	
272 	switch(m->type){
273 	case Tinit:
274 		memimageinit();
275 		i = _xattach(m->label, m->winsize);
276 		_initdisplaymemimage(i);
277 		replymsg(m);
278 		break;
279 
280 	case Trdmouse:
281 		mousetags.t[mousetags.wi++] = m->tag;
282 		if(mousetags.wi == nelem(mousetags.t))
283 			mousetags.wi = 0;
284 		if(mousetags.wi == mousetags.ri)
285 			sysfatal("too many queued mouse reads");
286 		mouse.stall = 0;
287 		matchmouse();
288 		break;
289 
290 	case Trdkbd:
291 		kbdtags.t[kbdtags.wi++] = m->tag;
292 		if(kbdtags.wi == nelem(kbdtags.t))
293 			kbdtags.wi = 0;
294 		if(kbdtags.wi == kbdtags.ri)
295 			sysfatal("too many queued keyboard reads");
296 		kbd.stall = 0;
297 		matchkbd();
298 		break;
299 
300 	case Tmoveto:
301 		_xmoveto(m->mouse.xy);
302 		replymsg(m);
303 		break;
304 
305 	case Tcursor:
306 		if(m->arrowcursor)
307 			_xsetcursor(nil);
308 		else
309 			_xsetcursor(&m->cursor);
310 		replymsg(m);
311 		break;
312 			
313 	case Tbouncemouse:
314 		_xbouncemouse(&m->mouse);
315 		replymsg(m);
316 		break;
317 
318 	case Tlabel:
319 		_xsetlabel(m->label);
320 		replymsg(m);
321 		break;
322 
323 	case Trdsnarf:
324 		m->snarf = _xgetsnarf();
325 		replymsg(m);
326 		free(m->snarf);
327 		break;
328 
329 	case Twrsnarf:
330 		_xputsnarf(m->snarf);
331 		replymsg(m);
332 		break;
333 
334 	case Trddraw:
335 		n = m->count;
336 		if(n > sizeof buf)
337 			n = sizeof buf;
338 		n = _drawmsgread(buf, n);
339 		if(n < 0)
340 			replyerror(m);
341 		else{
342 			m->count = n;
343 			m->data = buf;
344 			replymsg(m);
345 		}
346 		break;
347 
348 	case Twrdraw:
349 		if(_drawmsgwrite(m->data, m->count) < 0)
350 			replyerror(m);
351 		else
352 			replymsg(m);
353 		break;
354 	
355 	case Ttop:
356 		_xtopwindow();
357 		replymsg(m);
358 		break;
359 	
360 	case Tresize:
361 		_xresizewindow(m->rect);
362 		replymsg(m);
363 		break;
364 	}
365 }
366 
367 /*
368  * Reply to m.
369  */
370 void
371 replymsg(Wsysmsg *m)
372 {
373 	int n;
374 
375 	/* T -> R msg */
376 	if(m->type%2 == 0)
377 		m->type++;
378 		
379 	/* copy to output buffer */
380 	n = sizeW2M(m);
381 	if(fdout.wp+n > fdout.ep)
382 		sysfatal("out of space for reply message");
383 	convW2M(m, fdout.wp, n);
384 	fdout.wp += n;
385 }
386 
387 /*
388  * Match queued kbd reads with queued kbd characters.
389  */
390 void
391 matchkbd(void)
392 {
393 	Wsysmsg m;
394 	
395 	if(kbd.stall)
396 		return;
397 	while(kbd.ri != kbd.wi && kbdtags.ri != kbdtags.wi){
398 		m.type = Rrdkbd;
399 		m.tag = kbdtags.t[kbdtags.ri++];
400 		if(kbdtags.ri == nelem(kbdtags.t))
401 			kbdtags.ri = 0;
402 		m.rune = kbd.r[kbd.ri++];
403 		if(kbd.ri == nelem(kbd.r))
404 			kbd.ri = 0;
405 		replymsg(&m);
406 	}
407 }
408 
409 /*
410  * Match queued mouse reads with queued mouse events.
411  */
412 void
413 matchmouse(void)
414 {
415 	Wsysmsg m;
416 	
417 	if(mouse.stall)
418 		return;
419 	while(mouse.ri != mouse.wi && mousetags.ri != mousetags.wi){
420 		m.type = Rrdmouse;
421 		m.tag = mousetags.t[mousetags.ri++];
422 		if(mousetags.ri == nelem(mousetags.t))
423 			mousetags.ri = 0;
424 		m.mouse = mouse.m[mouse.ri];
425 		m.resized = mouse.resized[mouse.ri];
426 		mouse.ri++;
427 		if(mouse.ri == nelem(mouse.m))
428 			mouse.ri = 0;
429 		replymsg(&m);
430 	}
431 }
432 
433 /*
434  * Handle an incoming X event.
435  */
436 void
437 runxevent(XEvent *xev)
438 {
439 	int c;
440 	static Mouse m;
441 
442 	switch(xev->type){
443 	case Expose:
444 		_xexpose(xev);
445 		break;
446 	
447 	case DestroyNotify:
448 		if(_xdestroy(xev))
449 			exits(0);
450 		break;
451 
452 	case ConfigureNotify:
453 		if(_xconfigure(xev)){
454 			mouse.resized[mouse.wi] = 1;
455 			_xreplacescreenimage();
456 			goto addmouse;
457 		}
458 		break;
459 
460 	case ButtonPress:
461 	case ButtonRelease:
462 	case MotionNotify:
463 		if(mouse.stall)
464 			return;
465 		if(_xtoplan9mouse(xev, &m) < 0)
466 			return;
467 		mouse.resized[mouse.wi] = 0;
468 	addmouse:
469 		mouse.m[mouse.wi] = m;
470 		mouse.wi++;
471 		if(mouse.wi == nelem(mouse.m))
472 			mouse.wi = 0;
473 		if(mouse.wi == mouse.ri)
474 			mouse.stall = 1;
475 		matchmouse();
476 		break;
477 	
478 	case KeyPress:
479 		if(kbd.stall)
480 			return;
481 		if((c = _xtoplan9kbd(xev)) < 0)
482 			return;
483 		kbd.r[kbd.wi++] = c;
484 		if(kbd.wi == nelem(kbd.r))
485 			kbd.wi = 0;
486 		if(kbd.ri == kbd.wi)
487 			kbd.stall = 1;
488 		matchkbd();
489 		break;
490 	
491 	case SelectionRequest:
492 		_xselect(xev);
493 		break;
494 	}
495 }
496