1993/0528/port/devpipe.c (diff list | history)

port/devpipe.c on 1990/0227
1990/0227		#include "u.h"
1992/0321		#include "../port/lib.h"
1990/0227		#include "mem.h" #include "dat.h" #include "fns.h"
1992/0111		#include "../port/error.h"
1990/0227		#include "devtab.h"
1993/0528		#include "netif.h"
1990/0227
1990/1009		typedef struct Pipe Pipe; struct Pipe {
1991/1227		QLock;
1990/1009		Pipe *next;
1993/0528		int ref;
1992/0621		ulong path;
1993/0528		Queue *q[2]; int qref[2];
1990/1009		};
1992/0621		struct
1990/1009		{ Lock;
1992/0621		Pipe *pipe; ulong path;
1990/1009		} pipealloc;
1993/0528		enum
1990/1113		{
1993/0528		Qdir, Qdata0, Qdata1,
1990/1113		};
1990/0227
1992/0621		Dirtab pipedir[] = {
1993/0528		"data", {Qdata0}, 0, 0600, "data1", {Qdata1}, 0, 0600,
1990/1009		}; #define NPIPEDIR 4
1990/0227		void pipeinit(void) { } void pipereset(void) { } /*
1990/1009		* create a pipe, no streams are created until an open
1990/0227		*/ Chan* pipeattach(char *spec) {
1990/1009		Pipe *p;
1990/0227		Chan *c;
1990/0629
1990/0227		c = devattach('|', spec);
1993/0528		p = malloc(sizeof(Pipe)); if(p == 0) exhausted("memory");
1992/0621		p->ref = 1;
1990/1009
1993/0528		p->q[0] = qopen(64*1024, 0, 0); if(p->q[0] == 0){ free(p); exhausted("memory"); } p->q[0]->state &= ~Qmsg; p->q[1] = qopen(32*1024, 0, 0); if(p->q[1] == 0){ free(p->q[0]); free(p); exhausted("memory"); } p->q[1]->state &= ~Qmsg;
1990/1009		lock(&pipealloc);
1992/0621		p->path = ++pipealloc.path; p->next = pipealloc.pipe; pipealloc.pipe = p;
1990/1009		unlock(&pipealloc);
1993/0528		c->qid = (Qid){CHDIR|NETQID(2*p->path, Qdir), 0}; c->aux = p;
1991/1227		c->dev = 0;
1990/0227		return c; } Chan* pipeclone(Chan *c, Chan *nc) {
1990/1009		Pipe *p;
1993/0528		p = c->aux;
1990/0227		nc = devclone(c, nc);
1993/0528		qlock(p); p->ref++; qunlock(p);
1990/1009		return nc; }
1990/0227
1990/1009		int pipegen(Chan *c, Dirtab *tab, int ntab, int i, Dir *dp) { int id;
1990/0629
1993/0528		id = NETID(c->qid.path);
1990/1009		if(i > 1) id++; if(tab==0 || i>=ntab) return -1; tab += i;
1993/0528		devdir(c, (Qid){NETQID(id, tab->qid.path),0}, tab->name, tab->length, eve, tab->perm, dp);
1990/1009		return 1;
1990/0227		}
1990/1009
1990/0227		int pipewalk(Chan *c, char *name) {
1990/1009		return devwalk(c, name, pipedir, NPIPEDIR, pipegen);
1990/0227		} void pipestat(Chan *c, char *db) {
1993/0528		Pipe *p; Dir dir; p = c->aux; switch(NETTYPE(c->qid.path)){ case Qdir: devdir(c, c->qid, ".", 2*DIRLEN, eve, CHDIR|0555, &dir); break; case Qdata0: devdir(c, c->qid, "data", p->q[0]->len, eve, 0660, &dir); break; case Qdata1: devdir(c, c->qid, "data1", p->q[1]->len, eve, 0660, &dir); break; default: panic("pipestat"); } convD2M(&dir, db);
1990/0227		}
1990/1009		/* * if the stream doesn't exist, create it */
1990/0227		Chan * pipeopen(Chan *c, int omode) {
1990/1009		Pipe *p;
1990/11211		if(c->qid.path & CHDIR){
1990/1009		if(omode != OREAD)
1990/11211		error(Ebadarg);
1990/1009		c->mode = omode; c->flag |= COPEN; c->offset = 0; return c; }
1993/0528		p = c->aux;
1991/1227		qlock(p);
1993/0528		switch(NETTYPE(c->qid.path)){ case Qdata0: p->qref[0]++; break; case Qdata1: p->qref[1]++; break;
1990/1009		}
1991/1227		qunlock(p);
1990/1009
1993/0501		c->mode = omode&~OTRUNC;
1990/0227		c->flag |= COPEN; c->offset = 0; return c; } void pipecreate(Chan *c, char *name, int omode, ulong perm) {
1991/1115		USED(c, name, omode, perm);
1990/11211		error(Egreg);
1990/0227		} void piperemove(Chan *c) {
1991/1115		USED(c);
1990/11211		error(Egreg);
1990/0227		} void pipewstat(Chan *c, char *db) {
1991/1115		USED(c, db);
1990/11211		error(Eperm);
1990/0227		} void pipeclose(Chan *c) {
1992/0621		Pipe *p, *f, **l;
1990/0629
1993/0528		p = c->aux; qlock(p);
1990/0629
1990/1009		/*
1993/0528		* closing either side hangs up the stream
1990/1009		*/
1993/0528		switch(NETTYPE(c->qid.path)){ case Qdata0: p->qref[0]--; if(p->qref[0] == 0){ qclose(p->q[0]); qhangup(p->q[1]);
1991/0314		}
1993/0528		break; case Qdata1: p->qref[1]--; if(p->qref[1] == 0){ qclose(p->q[1]); qhangup(p->q[0]); } break;
1990/11211		}
1990/11161		/*
1993/0528		* if both sides are closed, they are reusable
1990/11161		*/
1993/0528		if(p->qref[0] == 0 && p->qref[1] == 0){ qreopen(p->q[0]); qreopen(p->q[1]); } /* * free the structure on last close */ p->ref--; if(p->ref == 0){ qunlock(p);
1990/11161		lock(&pipealloc);
1992/0621		l = &pipealloc.pipe; for(f = *l; f; f = f->next) { if(f == p) { *l = p->next; break; }
1992/0625		l = &f->next;
1992/0621		}
1990/11161		unlock(&pipealloc);
1993/0528		free(p->q[0]); free(p->q[1]);
1992/0621		free(p);
1990/11161		}
1993/0528		qunlock(p);
1990/0227		} long
1991/0411		piperead(Chan *c, void *va, long n, ulong offset)
1990/0227		{
1993/0528		Pipe *p;
1992/0711		USED(offset);
1992/0621
1993/0528		p = c->aux; switch(NETTYPE(c->qid.path)){ case Qdir: return devdirread(c, va, n, pipedir, NPIPEDIR, pipegen); case Qdata0: return qread(p->q[0], va, n); case Qdata1: return qread(p->q[1], va, n); default: panic("piperead"); } return -1; /* not reached */
1990/0227		}
1990/1009		/* * a write to a closed pipe causes a note to be sent to * the process. */
1990/0227		long
1991/0411		pipewrite(Chan *c, void *va, long n, ulong offset)
1990/0227		{
1993/0528		Pipe *p;
1992/0711		USED(offset);
1992/0821
1993/0528		p = c->aux;
1992/0821
1993/0528		switch(NETTYPE(c->qid.path)){ case Qdata0: return qwrite(p->q[1], va, n); case Qdata1: return qwrite(p->q[0], va, n); default: panic("piperead");
1990/0227		}
1990/0513		return n;
1990/0227		}