acme.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

			 */
			m = mousectl->Mouse;
			qlock(&row);
			t = rowwhich(&row, m.xy);
			if(t!=mousetext && mousetext!=nil && mousetext->w!=nil){
				winlock(mousetext->w, 'M');
				mousetext->eq0 = ~0;
				wincommit(mousetext->w, mousetext);
				winunlock(mousetext->w);
			}
			mousetext = t;
			if(t == nil)
				goto Continue;
			w = t->w;
			if(t==nil || m.buttons==0)
				goto Continue;
			but = 0;
			if(m.buttons == 1)
				but = 1;
			else if(m.buttons == 2)
				but = 2;
			else if(m.buttons == 4)
				but = 3;
			barttext = t;
			if(t->what==Body && ptinrect(m.xy, t->scrollr)){
				if(but){
					winlock(w, 'M');
					t->eq0 = ~0;
					textscroll(t, but);
					winunlock(w);
				}
				goto Continue;
			}
			/* scroll buttons, wheels, etc. */
			if(t->what==Body && w != nil && (m.buttons & (8|16))){
				if(m.buttons & 8)
					but = Kscrolloneup;
				else
					but = Kscrollonedown;
				winlock(w, 'M');
				t->eq0 = ~0;
				texttype(t, but);
				winunlock(w);
				goto Continue;
			}
			if(ptinrect(m.xy, t->scrollr)){
				if(but){
					if(t->what == Columntag)
						rowdragcol(&row, t->col, but);
					else if(t->what == Tag){
						coldragwin(t->col, t->w, but);
						if(t->w)
							barttext = &t->w->body;
					}
					if(t->col)
						activecol = t->col;
				}
				goto Continue;
			}
			if(m.buttons){
				if(w)
					winlock(w, 'M');
				t->eq0 = ~0;
				if(w)
					wincommit(w, t);
				else
					textcommit(t, TRUE);
				if(m.buttons & 1){
					textselect(t);
					if(w)
						winsettag(w);
					argtext = t;
					seltext = t;
					if(t->col)
						activecol = t->col;	/* button 1 only */
					if(t->w!=nil && t==&t->w->body)
						activewin = t->w;
				}else if(m.buttons & 2){
					if(textselect2(t, &q0, &q1, &argt))
						execute(t, q0, q1, FALSE, argt);
				}else if(m.buttons & 4){
					if(textselect3(t, &q0, &q1))
						look3(t, q0, q1, FALSE);
				}
				if(w)
					winunlock(w);
				goto Continue;
			}
    Continue:
			qunlock(&row);
			break;
		}
	}
}

/*
 * There is a race between process exiting and our finding out it was ever created.
 * This structure keeps a list of processes that have exited we haven't heard of.
 */
typedef struct Pid Pid;
struct Pid
{
	int	pid;
	char	msg[ERRMAX];
	Pid	*next;
};

void
waitthread(void *)
{
	Waitmsg *w;
	Command *c, *lc;
	uint pid;
	int found, ncmd;
	Rune *cmd;
	char *err;
	Text *t;
	Pid *pids, *p, *lastp;
	enum { WErr, WKill, WWait, WCmd, NWALT };
	Alt alts[NWALT+1];

	threadsetname("waitthread");
	pids = nil;
	alts[WErr].c = cerr;
	alts[WErr].v = &err;
	alts[WErr].op = CHANRCV;
	alts[WKill].c = ckill;
	alts[WKill].v = &cmd;
	alts[WKill].op = CHANRCV;
	alts[WWait].c = cwait;
	alts[WWait].v = &w;
	alts[WWait].op = CHANRCV;
	alts[WCmd].c = ccommand;
	alts[WCmd].v = &c;
	alts[WCmd].op = CHANRCV;
	alts[NWALT].op = CHANEND;

	command = nil;
	for(;;){
		switch(alt(alts)){
		case WErr:
			qlock(&row);
			warning(nil, "%s", err);
			free(err);
			flushimage(display, 1);
			qunlock(&row);
			break;
		case WKill:
			found = FALSE;
			ncmd = runestrlen(cmd);
			for(c=command; c; c=c->next){
				/* -1 for blank */
				if(runeeq(c->name, c->nname-1, cmd, ncmd) == TRUE){
					if(postnote(PNGROUP, c->pid, "kill") < 0)
						warning(nil, "kill %S: %r\n", cmd);
					found = TRUE;
				}
			}
			if(!found)
				warning(nil, "Kill: no process %S\n", cmd);
			free(cmd);
			break;
		case WWait:
			pid = w->pid;
			lc = nil;
			for(c=command; c; c=c->next){
				if(c->pid == pid){
					if(lc)
						lc->next = c->next;
					else
						command = c->next;
					break;
				}
				lc = c;
			}
			qlock(&row);
			t = &row.tag;
			textcommit(t, TRUE);
			if(c == nil){
				/* helper processes use this exit status */
				if(strncmp(w->msg, "libthread", 9) != 0){
					p = emalloc(sizeof(Pid));
					p->pid = pid;
					strncpy(p->msg, w->msg, sizeof(p->msg));
					p->next = pids;
					pids = p;
				}
			}else{
				if(search(t, c->name, c->nname)){
					textdelete(t, t->q0, t->q1, TRUE);
					textsetselect(t, 0, 0);
				}
				if(w->msg[0])
					warning(c->md, "%s\n", w->msg);
				flushimage(display, 1);
			}
			qunlock(&row);
			free(w);
    Freecmd:
			if(c){
				if(c->iseditcmd)
					sendul(cedit, 0);
				free(c->text);
				free(c->name);
				fsysdelid(c->md);
				free(c);
			}
			break;
		case WCmd:
			/* has this command already exited? */
			lastp = nil;
			for(p=pids; p!=nil; p=p->next){
				if(p->pid == c->pid){
					if(p->msg[0])
						warning(c->md, "%s\n", p->msg);
					if(lastp == nil)
						pids = p->next;
					else
						lastp->next = p->next;
					free(p);
					goto Freecmd;
				}
				lastp = p;
			}
			c->next = command;
			command = c;
			qlock(&row);
			t = &row.tag;
			textcommit(t, TRUE);
			textinsert(t, 0, c->name, c->nname, TRUE);
			textsetselect(t, 0, 0);
			flushimage(display, 1);
			qunlock(&row);
			break;
		}
	}
}

void
xfidallocthread(void*)
{
	Xfid *xfree, *x;
	enum { Alloc, Free, N };
	static Alt alts[N+1];

	threadsetname("xfidallocthread");
	alts[Alloc].c = cxfidalloc;
	alts[Alloc].v = nil;
	alts[Alloc].op = CHANRCV;
	alts[Free].c = cxfidfree;
	alts[Free].v = &x;
	alts[Free].op = CHANRCV;
	alts[N].op = CHANEND;

	xfree = nil;
	for(;;){
		switch(alt(alts)){
		case Alloc:
			x = xfree;
			if(x)
				xfree = x->next;
			else{
				x = emalloc(sizeof(Xfid));
				x->c = chancreate(sizeof(void(*)(Xfid*)), 0);
				x->arg = x;
				threadcreate(xfidctl, x->arg, STACK);
			}
			sendp(cxfidalloc, x);
			break;
		case Free:
			x->next = xfree;
			xfree = x;
			break;
		}
	}
}

/* this thread, in the main proc, allows fsysproc to get a window made without doing graphics */
void
newwindowthread(void*)
{
	Window *w;

	threadsetname("newwindowthread");

	for(;;){
		/* only fsysproc is talking to us, so synchronization is trivial */
		recvp(cnewwindow);
		w = makenewwindow(nil);
		winsettag(w);
		sendp(cnewwindow, w);
	}
}

Reffont*
rfget(int fix, int save, int setfont, char *name)
{
	Reffont *r;
	Font *f;
	int i;

	r = nil;
	if(name == nil){
		name = fontnames[fix];
		r = reffonts[fix];
	}
	if(r == nil){
		for(i=0; i<nfontcache; i++)
			if(strcmp(name, fontcache[i]->f->name) == 0){
				r = fontcache[i];
				goto Found;
			}
		f = openfont(display, name);
		if(f == nil){
			warning(nil, "can't open font file %s: %r\n", name);
			return nil;
		}
		r = emalloc(sizeof(Reffont));
		r->f = f;
		fontcache = erealloc(fontcache, (nfontcache+1)*sizeof(Reffont*));
		fontcache[nfontcache++] = r;
	}
    Found:
	if(save){
		incref(r);
		if(reffonts[fix])
			rfclose(reffonts[fix]);
		reffonts[fix] = r;
		if(name != fontnames[fix]){
			free(fontnames[fix]);
			fontnames[fix] = estrdup(name);
		}
	}
	if(setfont){
		reffont.f = r->f;
		incref(r);
		rfclose(reffonts[0]);
		font = r->f;
		reffonts[0] = r;
		incref(r);
		iconinit();
	}
	incref(r);
	return r;
}

void
rfclose(Reffont *r)
{
	int i;

	if(decref(r) == 0){
		for(i=0; i<nfontcache; i++)
			if(r == fontcache[i])
				break;
		if(i >= nfontcache)
			warning(nil, "internal error: can't find font in cache\n");
		else{
			nfontcache--;
			memmove(fontcache+i, fontcache+i+1, (nfontcache-i)*sizeof(Reffont*));
		}
		freefont(r->f);
		free(r);
	}
}

Cursor boxcursor = {
	{-7, -7},
	{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
	 0xFF, 0xFF, 0xF8, 0x1F, 0xF8, 0x1F, 0xF8, 0x1F,
	 0xF8, 0x1F, 0xF8, 0x1F, 0xF8, 0x1F, 0xFF, 0xFF,
	 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
	{0x00, 0x00, 0x7F, 0xFE, 0x7F, 0xFE, 0x7F, 0xFE,
	 0x70, 0x0E, 0x70, 0x0E, 0x70, 0x0E, 0x70, 0x0E,
	 0x70, 0x0E, 0x70, 0x0E, 0x70, 0x0E, 0x70, 0x0E,
	 0x7F, 0xFE, 0x7F, 0xFE, 0x7F, 0xFE, 0x00, 0x00}
};

void
iconinit(void)
{
	Rectangle r;
	Image *tmp;

	/* Blue */
	tagcols[BACK] = allocimagemix(display, DPalebluegreen, DWhite);
	tagcols[HIGH] = allocimage(display, Rect(0,0,1,1), screen->chan, 1, DPalegreygreen);
	tagcols[BORD] = allocimage(display, Rect(0,0,1,1), screen->chan, 1, DPurpleblue);
	tagcols[TEXT] = display->black;
	tagcols[HTEXT] = display->black;

	/* Yellow */
	textcols[BACK] = allocimagemix(display, DPaleyellow, DWhite);
	textcols[HIGH] = allocimage(display, Rect(0,0,1,1), screen->chan, 1, DDarkyellow);
	textcols[BORD] = allocimage(display, Rect(0,0,1,1), screen->chan, 1, DYellowgreen);
	textcols[TEXT] = display->black;
	textcols[HTEXT] = display->black;

	if(button){
		freeimage(button);
		freeimage(modbutton);
		freeimage(colbutton);
	}

	r = Rect(0, 0, Scrollwid+2, font->height+1);
	button = allocimage(display, r, screen->chan, 0, DNofill);
	draw(button, r, tagcols[BACK], nil, r.min);
	r.max.x -= 2;
	border(button, r, 2, tagcols[BORD], ZP);

	r = button->r;
	modbutton = allocimage(display, r, screen->chan, 0, DNofill);
	draw(modbutton, r, tagcols[BACK], nil, r.min);
	r.max.x -= 2;
	border(modbutton, r, 2, tagcols[BORD], ZP);
	r = insetrect(r, 2);
	tmp = allocimage(display, Rect(0,0,1,1), screen->chan, 1, DMedblue);
	draw(modbutton, r, tmp, nil, ZP);
	freeimage(tmp);

	r = button->r;
	colbutton = allocimage(display, r, screen->chan, 0, DPurpleblue);

	but2col = allocimage(display, r, screen->chan, 1, 0xAA0000FF);
	but3col = allocimage(display, r, screen->chan, 1, 0x006600FF);
}

/*
 * /dev/snarf updates when the file is closed, so we must open our own
 * fd here rather than use snarffd
 */

/* rio truncates larges snarf buffers, so this avoids using the
 * service if the string is huge */

#define MAXSNARF 100*1024

void
putsnarf(void)
{
	int fd, i, n;

	if(snarffd<0 || snarfbuf.nc==0)
		return;
	if(snarfbuf.nc > MAXSNARF)
		return;
	fd = open("/dev/snarf", OWRITE);
	if(fd < 0)
		return;
	for(i=0; i<snarfbuf.nc; i+=n){
		n = snarfbuf.nc-i;
		if(n >= NSnarf)
			n = NSnarf;
		bufread(&snarfbuf, i, snarfrune, n);
		if(fprint(fd, "%.*S", n, snarfrune) < 0)
			break;
	}
	close(fd);
}

void
getsnarf()
{
	int nulls;

	if(snarfbuf.nc > MAXSNARF)
		return;
	if(snarffd < 0)
		return;
	seek(snarffd, 0, 0);
	bufreset(&snarfbuf);
	bufload(&snarfbuf, 0, snarffd, &nulls);
}