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 ri;
52 	int wi;
53 	int stall;
54 	int resized;
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 
79 void fdslide(Fdbuf*);
80 void runmsg(Wsysmsg*);
81 void replymsg(Wsysmsg*);
82 void runxevent(XEvent*);
83 void matchkbd(void);
84 void matchmouse(void);
85 int fdnoblock(int);
86 
87 int chatty;
88 int drawsleep;
89 
90 void
91 usage(void)
92 {
93 	fprint(2, "usage: devdraw (don't run  directly)\n");
94 	exits("usage");
95 }
96 
97 void
98 bell(void *v, char *msg)
99 {
100 	if(strcmp(msg, "alarm") == 0)
101 		drawsleep = drawsleep ? 0 : 1000;
102 	noted(NCONT);
103 }
104 
105 void
106 main(int argc, char **argv)
107 {
108 	int n, top, firstx;
109 	fd_set rd, wr, xx;
110 	Wsysmsg m;
111 	XEvent event;
112 
113 	/*
114 	 * Move the protocol off stdin/stdout so that
115 	 * any inadvertent prints don't screw things up.
116 	 */
117 	dup(0, 3);
118 	dup(1, 4);
119 	close(0);
120 	close(1);
121 	open("/dev/null", OREAD);
122 	open("/dev/null", OWRITE);
123 
124 	fmtinstall('W', drawfcallfmt);
125 
126 	ARGBEGIN{
127 	case 'D':
128 		chatty++;
129 		break;
130 	default:
131 		usage();
132 	}ARGEND
133 
134 	/*
135 	 * Ignore arguments.  They're only for good ps -a listings.
136 	 */
137 	
138 	notify(bell);
139 
140 	fdin.rp = fdin.wp = fdin.buf;
141 	fdin.ep = fdin.buf+sizeof fdin.buf;
142 	
143 	fdout.rp = fdout.wp = fdout.buf;
144 	fdout.ep = fdout.buf+sizeof fdout.buf;
145 
146 	fdnoblock(3);
147 	fdnoblock(4);
148 
149 	firstx = 1;
150 	_x.fd = -1;
151 	for(;;){
152 		/* set up file descriptors */
153 		FD_ZERO(&rd);
154 		FD_ZERO(&wr);
155 		FD_ZERO(&xx);
156 		/*
157 		 * Don't read unless there's room *and* we haven't
158 		 * already filled the output buffer too much.
159 		 */
160 		if(fdout.wp < fdout.buf+MAXWMSG && fdin.wp < fdin.ep)
161 			FD_SET(3, &rd);
162 		if(fdout.wp > fdout.rp)
163 			FD_SET(4, &wr);
164 		FD_SET(3, &xx);
165 		FD_SET(4, &xx);
166 		top = 4;
167 		if(_x.fd >= 0){
168 			if(firstx){
169 				firstx = 0;
170 				XSelectInput(_x.display, _x.drawable, Mask);
171 			}
172 			FD_SET(_x.fd, &rd);
173 			FD_SET(_x.fd, &xx);
174 			XFlush(_x.display);
175 			if(_x.fd > top)
176 				top = _x.fd;
177 		}
178 
179 		if(chatty)
180 			fprint(2, "select %d...\n", top+1);
181 		/* wait for something to happen */
182 	    again:
183 		if(select(top+1, &rd, &wr, &xx, NULL) < 0){
184 			if(errno == EINTR)
185 				goto again;
186 			if(chatty)
187 				fprint(2, "select failure\n");
188 			exits(0);
189 		}
190 		if(chatty)
191 			fprint(2, "got select...\n");
192 
193 		{
194 			/* read what we can */
195 			n = 1;
196 			while(fdin.wp < fdin.ep && (n = read(3, fdin.wp, fdin.ep-fdin.wp)) > 0)
197 				fdin.wp += n;
198 			if(n == 0){
199 				if(chatty)
200 					fprint(2, "eof\n");
201 				exits(0);
202 			}
203 			if(n < 0 && errno != EAGAIN)
204 				sysfatal("reading wsys msg: %r");
205 
206 			/* pick off messages one by one */
207 			while((n = convM2W(fdin.rp, fdin.wp-fdin.rp, &m)) > 0){
208 				/* fprint(2, "<- %W\n", &m); */
209 				runmsg(&m);
210 				fdin.rp += n;
211 			}
212 			
213 			/* slide data to beginning of buf */
214 			fdslide(&fdin);
215 		}
216 		{
217 			/* write what we can */
218 			n = 1;
219 			while(fdout.rp < fdout.wp && (n = write(4, fdout.rp, fdout.wp-fdout.rp)) > 0)
220 				fdout.rp += n;
221 			if(n == 0)
222 				sysfatal("short write writing wsys");
223 			if(n < 0 && errno != EAGAIN)
224 				sysfatal("writing wsys msg: %r");
225 
226 			/* slide data to beginning of buf */
227 			fdslide(&fdout);
228 		}
229 		{
230 			/*
231 			 * Read an X message if we can.
232 			 * (XPending actually calls select to make sure
233 			 * the display's fd is readable and then reads
234 			 * in any waiting data before declaring whether
235 			 * there are events on the queue.)
236 			 */
237 			while(XPending(_x.display)){
238 				XNextEvent(_x.display, &event);
239 				runxevent(&event);
240 			}
241 		}
242 	}
243 }
244 
245 int
246 fdnoblock(int fd)
247 {
248 	return fcntl(fd, F_SETFL, fcntl(fd, F_GETFL)|O_NONBLOCK);
249 }
250 
251 void
252 fdslide(Fdbuf *fb)
253 {
254 	int n;
255 
256 	n = fb->wp - fb->rp;
257 	if(n > 0)
258 		memmove(fb->buf, fb->rp, n);
259 	fb->rp = fb->buf;
260 	fb->wp = fb->rp+n;
261 }
262 
263 void
264 replyerror(Wsysmsg *m)
265 {
266 	char err[256];
267 	
268 	rerrstr(err, sizeof err);
269 	m->type = Rerror;
270 	m->error = err;
271 	replymsg(m);
272 }
273 
274 /* 
275  * Handle a single wsysmsg. 
276  * Might queue for later (kbd, mouse read)
277  */
278 void
279 runmsg(Wsysmsg *m)
280 {
281 	uchar buf[65536];
282 	int n;
283 	Memimage *i;
284 	
285 	switch(m->type){
286 	case Tinit:
287 		memimageinit();
288 		i = _xattach(m->label, m->winsize);
289 		_initdisplaymemimage(i);
290 		replymsg(m);
291 		break;
292 
293 	case Trdmouse:
294 		mousetags.t[mousetags.wi++] = m->tag;
295 		if(mousetags.wi == nelem(mousetags.t))
296 			mousetags.wi = 0;
297 		if(mousetags.wi == mousetags.ri)
298 			sysfatal("too many queued mouse reads");
299 		/* fprint(2, "mouse unstall\n"); */
300 		mouse.stall = 0;
301 		matchmouse();
302 		break;
303 
304 	case Trdkbd:
305 		kbdtags.t[kbdtags.wi++] = m->tag;
306 		if(kbdtags.wi == nelem(kbdtags.t))
307 			kbdtags.wi = 0;
308 		if(kbdtags.wi == kbdtags.ri)
309 			sysfatal("too many queued keyboard reads");
310 		kbd.stall = 0;
311 		matchkbd();
312 		break;
313 
314 	case Tmoveto:
315 		_xmoveto(m->mouse.xy);
316 		replymsg(m);
317 		break;
318 
319 	case Tcursor:
320 		if(m->arrowcursor)
321 			_xsetcursor(nil);
322 		else
323 			_xsetcursor(&m->cursor);
324 		replymsg(m);
325 		break;
326 			
327 	case Tbouncemouse:
328 		_xbouncemouse(&m->mouse);
329 		replymsg(m);
330 		break;
331 
332 	case Tlabel:
333 		_xsetlabel(m->label);
334 		replymsg(m);
335 		break;
336 
337 	case Trdsnarf:
338 		m->snarf = _xgetsnarf();
339 		replymsg(m);
340 		free(m->snarf);
341 		break;
342 
343 	case Twrsnarf:
344 		_xputsnarf(m->snarf);
345 		replymsg(m);
346 		break;
347 
348 	case Trddraw:
349 		n = m->count;
350 		if(n > sizeof buf)
351 			n = sizeof buf;
352 		n = _drawmsgread(buf, n);
353 		if(n < 0)
354 			replyerror(m);
355 		else{
356 			m->count = n;
357 			m->data = buf;
358 			replymsg(m);
359 		}
360 		break;
361 
362 	case Twrdraw:
363 		if(_drawmsgwrite(m->data, m->count) < 0)
364 			replyerror(m);
365 		else
366 			replymsg(m);
367 		break;
368 	
369 	case Ttop:
370 		_xtopwindow();
371 		replymsg(m);
372 		break;
373 	
374 	case Tresize:
375 		_xresizewindow(m->rect);
376 		replymsg(m);
377 		break;
378 	}
379 }
380 
381 /*
382  * Reply to m.
383  */
384 void
385 replymsg(Wsysmsg *m)
386 {
387 	int n;
388 
389 	/* T -> R msg */
390 	if(m->type%2 == 0)
391 		m->type++;
392 		
393 	/* fprint(2, "-> %W\n", m); */
394 	/* copy to output buffer */
395 	n = sizeW2M(m);
396 	if(fdout.wp+n > fdout.ep)
397 		sysfatal("out of space for reply message");
398 	convW2M(m, fdout.wp, n);
399 	fdout.wp += n;
400 }
401 
402 /*
403  * Match queued kbd reads with queued kbd characters.
404  */
405 void
406 matchkbd(void)
407 {
408 	Wsysmsg m;
409 	
410 	if(kbd.stall)
411 		return;
412 	while(kbd.ri != kbd.wi && kbdtags.ri != kbdtags.wi){
413 		m.type = Rrdkbd;
414 		m.tag = kbdtags.t[kbdtags.ri++];
415 		if(kbdtags.ri == nelem(kbdtags.t))
416 			kbdtags.ri = 0;
417 		m.rune = kbd.r[kbd.ri++];
418 		if(kbd.ri == nelem(kbd.r))
419 			kbd.ri = 0;
420 		replymsg(&m);
421 	}
422 }
423 
424 /*
425  * Match queued mouse reads with queued mouse events.
426  */
427 void
428 matchmouse(void)
429 {
430 	Wsysmsg m;
431 	
432 	while(mouse.ri != mouse.wi && mousetags.ri != mousetags.wi){
433 		m.type = Rrdmouse;
434 		m.tag = mousetags.t[mousetags.ri++];
435 		if(mousetags.ri == nelem(mousetags.t))
436 			mousetags.ri = 0;
437 		m.mouse = mouse.m[mouse.ri];
438 		m.resized = mouse.resized;
439 		/*
440 		if(m.resized)
441 			fprint(2, "sending resize\n");
442 		*/
443 		mouse.resized = 0;
444 		mouse.ri++;
445 		if(mouse.ri == nelem(mouse.m))
446 			mouse.ri = 0;
447 		replymsg(&m);
448 	}
449 }
450 
451 /*
452  * Handle an incoming X event.
453  */
454 void
455 runxevent(XEvent *xev)
456 {
457 	int c;
458 	static Mouse m;
459 
460 	switch(xev->type){
461 	case Expose:
462 		_xexpose(xev);
463 		break;
464 	
465 	case DestroyNotify:
466 		if(_xdestroy(xev))
467 			exits(0);
468 		break;
469 
470 	case ConfigureNotify:
471 		if(_xconfigure(xev)){
472 			mouse.resized = 1;
473 			_xreplacescreenimage();
474 			goto addmouse;
475 		}
476 		break;
477 
478 	case ButtonPress:
479 	case ButtonRelease:
480 	case MotionNotify:
481 		if(mouse.stall)
482 			return;
483 		if(_xtoplan9mouse(xev, &m) < 0)
484 			return;
485 	addmouse:
486 		mouse.m[mouse.wi] = m;
487 		mouse.wi++;
488 		if(mouse.wi == nelem(mouse.m))
489 			mouse.wi = 0;
490 		if(mouse.wi == mouse.ri){
491 			mouse.stall = 1;
492 			mouse.ri = 0;
493 			mouse.wi = 1;
494 			mouse.m[0] = m;
495 			/* fprint(2, "mouse stall\n"); */
496 		}
497 		matchmouse();
498 		break;
499 	
500 	case KeyPress:
501 		if(kbd.stall)
502 			return;
503 		if((c = _xtoplan9kbd(xev)) < 0)
504 			return;
505 		kbd.r[kbd.wi++] = c;
506 		if(kbd.wi == nelem(kbd.r))
507 			kbd.wi = 0;
508 		if(kbd.ri == kbd.wi)
509 			kbd.stall = 1;
510 		matchkbd();
511 		break;
512 	
513 	case SelectionRequest:
514 		_xselect(xev);
515 		break;
516 	}
517 }
518