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

#include <u.h>
#include <libc.h>
#include <draw.h>
#include <thread.h>
#include <cursor.h>
#include <mouse.h>
#include <keyboard.h>
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
#include "dat.h"
#include "fns.h"
	/* for generating syms in mkfile only: */
	#include <bio.h>
	#include "edit.h"

void	mousethread(void*);
void	keyboardthread(void*);
void	waitthread(void*);
void	xfidallocthread(void*);
void	newwindowthread(void*);
void plumbproc(void*);

Reffont	**fontcache;
int		nfontcache;
char		wdir[512] = ".";
Reffont	*reffonts[2];
int		snarffd = -1;
int		mainpid;
int		plumbsendfd;
int		plumbeditfd;

enum{
	NSnarf = 1000	/* less than 1024, I/O buffer size */
};
Rune	snarfrune[NSnarf+1];

char		*fontnames[2] =
{
	"/lib/font/bit/lucidasans/euro.8.font",
	"/lib/font/bit/lucm/unicode.9.font"
};

Command *command;

void	acmeerrorinit(void);
void	readfile(Column*, char*);
int	shutdown(void*, char*);

void
derror(Display*, char *errorstr)
{
	error(errorstr);
}

void
threadmain(int argc, char *argv[])
{
	int i;
	char *p, *loadfile;
	char buf[256];
	Column *c;
	int ncol;
	Display *d;
	static void *arg[1];

	rfork(RFENVG|RFNAMEG);

	ncol = -1;

	loadfile = nil;
	ARGBEGIN{
	case 'a':
		globalautoindent = TRUE;
		break;
	case 'b':
		bartflag = TRUE;
		break;
	case 'c':
		p = ARGF();
		if(p == nil)
			goto Usage;
		ncol = atoi(p);
		if(ncol <= 0)
			goto Usage;
		break;
	case 'f':
		fontnames[0] = ARGF();
		if(fontnames[0] == nil)
			goto Usage;
		break;
	case 'F':
		fontnames[1] = ARGF();
		if(fontnames[1] == nil)
			goto Usage;
		break;
	case 'l':
		loadfile = ARGF();
		if(loadfile == nil)
			goto Usage;
		break;
	default:
	Usage:
		fprint(2, "usage: acme [-ab] [-c ncol] [-f font] [-F fixedfont] [-l loadfile | file...]\n");
		exits("usage");
	}ARGEND

	fontnames[0] = estrdup(fontnames[0]);
	fontnames[1] = estrdup(fontnames[1]);

	quotefmtinstall();
	cputype = getenv("cputype");
	objtype = getenv("objtype");
	home = getenv("home");
	p = getenv("tabstop");
	if(p != nil){
		maxtab = strtoul(p, nil, 0);
		free(p);
	}
	if(maxtab == 0)
		maxtab = 4; 
	if(loadfile)
		rowloadfonts(loadfile);
	putenv("font", fontnames[0]);
	snarffd = open("/dev/snarf", OREAD|OCEXEC);
	if(cputype){
		sprint(buf, "/acme/bin/%s", cputype);
		bind(buf, "/bin", MBEFORE);
	}
	bind("/acme/bin", "/bin", MBEFORE);
	getwd(wdir, sizeof wdir);

	if(geninitdraw(nil, derror, fontnames[0], "acme", nil, Refnone) < 0){
		fprint(2, "acme: can't open display: %r\n");
		exits("geninitdraw");
	}
	d = display;
	font = d->defaultfont;

	reffont.f = font;
	reffonts[0] = &reffont;
	incref(&reffont);	/* one to hold up 'font' variable */
	incref(&reffont);	/* one to hold up reffonts[0] */
	fontcache = emalloc(sizeof(Reffont*));
	nfontcache = 1;
	fontcache[0] = &reffont;

	iconinit();
	timerinit();
	rxinit();

	cwait = threadwaitchan();
	ccommand = chancreate(sizeof(Command**), 0);
	ckill = chancreate(sizeof(Rune*), 0);
	cxfidalloc = chancreate(sizeof(Xfid*), 0);
	cxfidfree = chancreate(sizeof(Xfid*), 0);
	cnewwindow = chancreate(sizeof(Channel*), 0);
	cerr = chancreate(sizeof(char*), 0);
	cedit = chancreate(sizeof(int), 0);
	cexit = chancreate(sizeof(int), 0);
	cwarn = chancreate(sizeof(void*), 1);
	if(cwait==nil || ccommand==nil || ckill==nil || cxfidalloc==nil || cxfidfree==nil || cerr==nil || cexit==nil || cwarn==nil){
		fprint(2, "acme: can't create initial channels: %r\n");
		exits("channels");
	}

	mousectl = initmouse(nil, screen);
	if(mousectl == nil){
		fprint(2, "acme: can't initialize mouse: %r\n");
		exits("mouse");
	}
	mouse = mousectl;
	keyboardctl = initkeyboard(nil);
	if(keyboardctl == nil){
		fprint(2, "acme: can't initialize keyboard: %r\n");
		exits("keyboard");
	}
	mainpid = getpid();
	plumbeditfd = plumbopen("edit", OREAD|OCEXEC);
	if(plumbeditfd >= 0){
		cplumb = chancreate(sizeof(Plumbmsg*), 0);
		proccreate(plumbproc, nil, STACK);
	}
	plumbsendfd = plumbopen("send", OWRITE|OCEXEC);

	fsysinit();

	#define	WPERCOL	8
	disk = diskinit();
	if(!loadfile || !rowload(&row, loadfile, TRUE)){
		rowinit(&row, screen->clipr);
		if(ncol < 0){
			if(argc == 0)
				ncol = 2;
			else{
				ncol = (argc+(WPERCOL-1))/WPERCOL;
				if(ncol < 2)
					ncol = 2;
			}
		}
		if(ncol == 0)
			ncol = 2;
		for(i=0; i<ncol; i++){
			c = rowadd(&row, nil, -1);
			if(c==nil && i==0)
				error("initializing columns");
		}
		c = row.col[row.ncol-1];
		if(argc == 0)
			readfile(c, wdir);
		else
			for(i=0; i<argc; i++){
				p = utfrrune(argv[i], '/');
				if((p!=nil && strcmp(p, "/guide")==0) || i/WPERCOL>=row.ncol)
					readfile(c, argv[i]);
				else
					readfile(row.col[i/WPERCOL], argv[i]);
			}
	}
	flushimage(display, 1);

	acmeerrorinit();
	threadcreate(keyboardthread, nil, STACK);
	threadcreate(mousethread, nil, STACK);
	threadcreate(waitthread, nil, STACK);
	threadcreate(xfidallocthread, nil, STACK);
	threadcreate(newwindowthread, nil, STACK);

	threadnotify(shutdown, 1);
	recvul(cexit);
	killprocs();
	threadexitsall(nil);
}

void
readfile(Column *c, char *s)
{
	Window *w;
	Rune rb[256];
	int nb, nr;
	Runestr rs;

	w = coladd(c, nil, nil, -1);
	cvttorunes(s, strlen(s), rb, &nb, &nr, nil);
	rs = cleanrname((Runestr){rb, nr});
	winsetname(w, rs.r, rs.nr);
	textload(&w->body, 0, s, 1);
	w->body.file->mod = FALSE;
	w->dirty = FALSE;
	winsettag(w);
	textscrdraw(&w->body);
	textsetselect(&w->tag, w->tag.file->nc, w->tag.file->nc);
}

char *oknotes[] ={
	"delete",
	"hangup",
	"kill",
	"exit",
	nil
};

int	dumping;

int
shutdown(void*, char *msg)
{
	int i;

	killprocs();
	if(!dumping && strcmp(msg, "kill")!=0 && strcmp(msg, "exit")!=0 && getpid()==mainpid){
		dumping = TRUE;
		rowdump(&row, nil);
	}
	for(i=0; oknotes[i]; i++)
		if(strncmp(oknotes[i], msg, strlen(oknotes[i])) == 0)
			threadexitsall(msg);
	print("acme: %s\n", msg);
	abort();
	return 0;
}

void
killprocs(void)
{
	Command *c;

	fsysclose();
//	if(display)
//		flushimage(display, 1);

	for(c=command; c; c=c->next)
		postnote(PNGROUP, c->pid, "hangup");
	remove(acmeerrorfile);
}

static int errorfd;

void
acmeerrorproc(void *)
{
	char *buf;
	int n;

	threadsetname("acmeerrorproc");
	buf = emalloc(8192+1);
	while((n=read(errorfd, buf, 8192)) >= 0){
		buf[n] = '\0';
		sendp(cerr, estrdup(buf));
	}
}

void
acmeerrorinit(void)
{
	int fd, pfd[2];
	char buf[64];

	if(pipe(pfd) < 0)
		error("can't create pipe");
	sprint(acmeerrorfile, "/srv/acme.%s.%d", getuser(), mainpid);
	fd = create(acmeerrorfile, OWRITE, 0666);
	if(fd < 0){
		remove(acmeerrorfile);
  		fd = create(acmeerrorfile, OWRITE, 0666);
		if(fd < 0)
			error("can't create acmeerror file");
	}
	sprint(buf, "%d", pfd[0]);
	write(fd, buf, strlen(buf));
	close(fd);
	/* reopen pfd[1] close on exec */
	sprint(buf, "/fd/%d", pfd[1]);
	errorfd = open(buf, OREAD|OCEXEC);
	if(errorfd < 0)
		error("can't re-open acmeerror file");
	close(pfd[1]);
	close(pfd[0]);
	proccreate(acmeerrorproc, nil, STACK);
}

void
plumbproc(void *)
{
	Plumbmsg *m;

	threadsetname("plumbproc");
	for(;;){
		m = plumbrecv(plumbeditfd);
		if(m == nil)
			threadexits(nil);
		sendp(cplumb, m);
	}
}

void
keyboardthread(void *)
{
	Rune r;
	Timer *timer;
	Text *t;
	enum { KTimer, KKey, NKALT };
	static Alt alts[NKALT+1];

	alts[KTimer].c = nil;
	alts[KTimer].v = nil;
	alts[KTimer].op = CHANNOP;
	alts[KKey].c = keyboardctl->c;
	alts[KKey].v = &r;
	alts[KKey].op = CHANRCV;
	alts[NKALT].op = CHANEND;

	timer = nil;
	typetext = nil;
	threadsetname("keyboardthread");
	for(;;){
		switch(alt(alts)){
		case KTimer:
			timerstop(timer);
			t = typetext;
			if(t!=nil && t->what==Tag){
				winlock(t->w, 'K');
				wincommit(t->w, t);
				winunlock(t->w);
				flushimage(display, 1);
			}
			alts[KTimer].c = nil;
			alts[KTimer].op = CHANNOP;
			break;
		case KKey:
		casekeyboard:
			typetext = rowtype(&row, r, mouse->xy);
			t = typetext;
			if(t!=nil && t->col!=nil && !(r==Kdown || r==Kleft || r==Kright))	/* scrolling doesn't change activecol */
				activecol = t->col;
			if(t!=nil && t->w!=nil)
				t->w->body.file->curtext = &t->w->body;
			if(timer != nil)
				timercancel(timer);
			if(t!=nil && t->what==Tag) {
				timer = timerstart(500);
				alts[KTimer].c = timer->c;
				alts[KTimer].op = CHANRCV;
			}else{
				timer = nil;
				alts[KTimer].c = nil;
				alts[KTimer].op = CHANNOP;
			}
			if(nbrecv(keyboardctl->c, &r) > 0)
				goto casekeyboard;
			flushimage(display, 1);
			break;
		}
	}
}

void
mousethread(void *)
{
	Text *t, *argt;
	int but;
	uint q0, q1;
	Window *w;
	Plumbmsg *pm;
	Mouse m;
	char *act;
	enum { MResize, MMouse, MPlumb, MWarnings, NMALT };
	static Alt alts[NMALT+1];

	threadsetname("mousethread");
	alts[MResize].c = mousectl->resizec;
	alts[MResize].v = nil;
	alts[MResize].op = CHANRCV;
	alts[MMouse].c = mousectl->c;
	alts[MMouse].v = &mousectl->Mouse;
	alts[MMouse].op = CHANRCV;
	alts[MPlumb].c = cplumb;
	alts[MPlumb].v = &pm;
	alts[MPlumb].op = CHANRCV;
	alts[MWarnings].c = cwarn;
	alts[MWarnings].v = nil;
	alts[MWarnings].op = CHANRCV;
	if(cplumb == nil)
		alts[MPlumb].op = CHANNOP;
	alts[NMALT].op = CHANEND;
	
	for(;;){
		qlock(&row);
		flushwarnings();
		qunlock(&row);
		flushimage(display, 1);
		switch(alt(alts)){
		case MResize:
			if(getwindow(display, Refnone) < 0)
				error("attach to window");
			scrlresize();
			rowresize(&row, screen->clipr);
			break;
		case MPlumb:
			if(strcmp(pm->type, "text") == 0){
				act = plumblookup(pm->attr, "action");
				if(act==nil || strcmp(act, "showfile")==0)
					plumblook(pm);
				else if(strcmp(act, "showdata")==0)
					plumbshow(pm);
			}
			plumbfree(pm);
			break;
		case MWarnings:
			break;
		case MMouse:
			/*
			 * Make a copy so decisions are consistent; mousectl changes
			 * underfoot.  Can't just receive into m because this introduces
			 * another race; see /sys/src/libdraw/mouse.c.