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fix wait

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This commit is contained in:
rsc 2007-03-26 14:26:32 +00:00
parent bd1b0cc17e
commit 4b241872ef
5 changed files with 97 additions and 251 deletions
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4
src/cmd/rc/fns.h
View file

@ -22,6 +22,7 @@ void Updenv(void);
void Vinit(void);
int Waitfor(int, int);
long Write(int, char*, long);
void addwaitpid(int);
int advance(void);
int back(int);
void cleanhere(char*);
@ -30,10 +31,12 @@ int compile(tree*);
char * list2str(word*);
int count(word*);
void deglob(char*);
void delwaitpid(int);
void dotrap(void);
void freenodes(void);
void freewords(word*);
void globlist(void);
int havewaitpid(int);
int idchr(int);
void inttoascii(char*, long);
void kinit(void);
@ -41,6 +44,7 @@ int mapfd(int);
int match(char*, char*, int);
int matchfn(char*, char*);
char** mkargv(word*);
void clearwaitpids(void);
void panic(char*, int);
void pathinit(void);
void poplist(void);

51
src/cmd/rc/havefork.c
View file

@ -1,3 +1,9 @@
#include <u.h>
#include <signal.h>
#if defined(PLAN9PORT) && defined(__sun__)
# define BSD_COMP /* sigh. for TIOCNOTTY */
#endif
#include <sys/ioctl.h>
#include "rc.h"
#include "getflags.h"
#include "exec.h"
@ -10,6 +16,7 @@ void
Xasync(void)
{
int null = open("/dev/null", 0);
int tty;
int pid;
char npid[10];
if(null<0){
@ -22,11 +29,39 @@ Xasync(void)
Xerror("try again");
break;
case 0:
pushredir(ROPEN, null, 0);
clearwaitpids();
/*
* I don't know what the right thing to do here is,
* so this is all experimentally determined.
* If we just dup /dev/null onto 0, then running
* ssh foo & will reopen /dev/tty, try to read a password,
* get a signal, and repeat, in a tight loop, forever.
* Arguably this is a bug in ssh (it behaves the same
* way under bash as under rc) but I'm fixing it here
* anyway. If we dissociate the process from the tty,
* then it won't be able to open /dev/tty ever again.
* The SIG_IGN on SIGTTOU makes writing the tty
* (via fd 1 or 2, for example) succeed even though
* our pgrp is not the terminal's controlling pgrp.
*/
if((tty = open("/dev/tty", OREAD)) >= 0){
/*
* Should make reads of tty fail, writes succeed.
*/
signal(SIGTTIN, SIG_IGN);
signal(SIGTTOU, SIG_IGN);
ioctl(tty, TIOCNOTTY);
close(tty);
}
if(isatty(0))
pushredir(ROPEN, null, 0);
else
close(null);
start(runq->code, runq->pc+1, runq->local);
runq->ret = 0;
break;
default:
addwaitpid(pid);
close(null);
runq->pc = runq->code[runq->pc].i;
inttoascii(npid, pid);
@ -52,12 +87,14 @@ Xpipe(void)
Xerror("try again");
break;
case 0:
clearwaitpids();
start(p->code, pc+2, runq->local);
runq->ret = 0;
close(pfd[PRD]);
pushredir(ROPEN, pfd[PWR], lfd);
break;
default:
addwaitpid(forkid);
start(p->code, p->code[pc].i, runq->local);
close(pfd[PWR]);
pushredir(ROPEN, pfd[PRD], rfd);
@ -93,11 +130,13 @@ Xbackq(void)
close(pfd[PWR]);
return;
case 0:
clearwaitpids();
close(pfd[PRD]);
start(runq->code, runq->pc+1, runq->local);
pushredir(ROPEN, pfd[PWR], 1);
return;
default:
addwaitpid(pid);
close(pfd[PWR]);
f = openfd(pfd[PRD]);
s = wd;
@ -134,7 +173,7 @@ void
Xpipefd(void)
{
struct thread *p = runq;
int pc = p->pc;
int pc = p->pc, pid;
char name[40];
int pfd[2];
int sidefd, mainfd;
@ -150,17 +189,19 @@ Xpipefd(void)
sidefd = pfd[PRD];
mainfd = pfd[PWR];
}
switch(fork()){
switch(pid = fork()){
case -1:
Xerror("try again");
break;
case 0:
clearwaitpids();
start(p->code, pc+2, runq->local);
close(mainfd);
pushredir(ROPEN, sidefd, p->code[pc].i==READ?1:0);
runq->ret = 0;
break;
default:
addwaitpid(pid);
close(sidefd);
pushredir(ROPEN, mainfd, mainfd); /* isn't this a noop? */
strcpy(name, Fdprefix);
@ -180,10 +221,12 @@ Xsubshell(void)
Xerror("try again");
break;
case 0:
clearwaitpids();
start(runq->code, runq->pc+1, runq->local);
runq->ret = 0;
break;
default:
addwaitpid(pid);
Waitfor(pid, 1);
runq->pc = runq->code[runq->pc].i;
break;
@ -201,6 +244,7 @@ execforkexec(void)
case -1:
return -1;
case 0:
clearwaitpids();
pushword("exec");
execexec();
strcpy(buf, "can't exec: ");
@ -208,5 +252,6 @@ execforkexec(void)
errstr(buf+n, ERRMAX-n);
Exit(buf);
}
addwaitpid(pid);
return pid;
}

246
src/cmd/rc/havep9p.c
View file

@ -1,246 +0,0 @@
#include <u.h>
#include <signal.h>
#if defined(PLAN9PORT) && defined(__sun__)
# define BSD_COMP /* sigh. for TIOCNOTTY */
#endif
#include <sys/ioctl.h>
#include "rc.h"
#include "getflags.h"
#include "exec.h"
#include "io.h"
#include "fns.h"
int havefork = 1;
void
Xasync(void)
{
int null=open("/dev/null", 0);
int tty;
int pid;
char npid[10];
if(null<0){
Xerror("Can't open /dev/null\n");
return;
}
switch(pid=rfork(RFFDG|RFPROC|RFNOTEG)){
case -1:
close(null);
Xerror("try again");
break;
case 0:
/*
* I don't know what the right thing to do here is,
* so this is all experimentally determined.
* If we just dup /dev/null onto 0, then running
* ssh foo & will reopen /dev/tty, try to read a password,
* get a signal, and repeat, in a tight loop, forever.
* Arguably this is a bug in ssh (it behaves the same
* way under bash as under rc) but I'm fixing it here
* anyway. If we dissociate the process from the tty,
* then it won't be able to open /dev/tty ever again.
* The SIG_IGN on SIGTTOU makes writing the tty
* (via fd 1 or 2, for example) succeed even though
* our pgrp is not the terminal's controlling pgrp.
*/
if((tty=open("/dev/tty", OREAD)) >= 0){
/*
* Should make reads of tty fail, writes succeed.
*/
signal(SIGTTIN, SIG_IGN);
signal(SIGTTOU, SIG_IGN);
ioctl(tty, TIOCNOTTY);
close(tty);
}
if(isatty(0))
pushredir(ROPEN, null, 0);
else
close(null);
start(runq->code, runq->pc+1, runq->local);
runq->ret=0;
break;
default:
close(null);
runq->pc=runq->code[runq->pc].i;
inttoascii(npid, pid);
setvar("apid", newword(npid, (word *)0));
break;
}
}
void
Xpipe(void)
{
struct thread *p = runq;
int pc = p->pc, forkid;
int lfd = p->code[pc++].i;
int rfd = p->code[pc++].i;
int pfd[2];
if(pipe(pfd)<0){
Xerror("can't get pipe");
return;
}
switch(forkid=fork()){
case -1:
Xerror("try again");
break;
case 0:
start(p->code, pc+2, runq->local);
runq->ret=0;
close(pfd[PRD]);
pushredir(ROPEN, pfd[PWR], lfd);
break;
default:
start(p->code, p->code[pc].i, runq->local);
close(pfd[PWR]);
pushredir(ROPEN, pfd[PRD], rfd);
p->pc=p->code[pc+1].i;
p->pid=forkid;
break;
}
}
void
Xbackq(void)
{
char wd[8193];
int c;
char *s, *ewd = &wd[8192], *stop;
struct io *f;
var *ifs = vlook("ifs");
word *v, *nextv;
int pfd[2];
int pid;
stop = ifs->val?ifs->val->word:"";
if(pipe(pfd)<0){
Xerror("can't make pipe");
return;
}
switch(pid = fork()){
case -1: Xerror("try again");
close(pfd[PRD]);
close(pfd[PWR]);
return;
case 0:
close(pfd[PRD]);
start(runq->code, runq->pc+1, runq->local);
pushredir(ROPEN, pfd[PWR], 1);
return;
default:
close(pfd[PWR]);
f=openfd(pfd[PRD]);
s=wd;
v=0;
while((c=rchr(f))!=EOF){
if(strchr(stop, c) || s==ewd){
if(s!=wd){
*s='\0';
v=newword(wd, v);
s=wd;
}
}
else *s++=c;
}
if(s!=wd){
*s='\0';
v=newword(wd, v);
}
closeio(f);
Waitfor(pid, 0);
/* v points to reversed arglist -- reverse it onto argv */
while(v){
nextv=v->next;
v->next=runq->argv->words;
runq->argv->words=v;
v=nextv;
}
runq->pc=runq->code[runq->pc].i;
return;
}
}
/*
* Who should wait for the exit from the fork?
*/
void
Xpipefd(void)
{
struct thread *p=runq;
int pc=p->pc;
char name[40];
int pfd[2];
int sidefd, mainfd;
if(pipe(pfd)<0){
Xerror("can't get pipe");
return;
}
if(p->code[pc].i==READ){
sidefd=pfd[PWR];
mainfd=pfd[PRD];
}
else{
sidefd=pfd[PRD];
mainfd=pfd[PWR];
}
switch(fork()){
case -1:
Xerror("try again");
break;
case 0:
start(p->code, pc+2, runq->local);
close(mainfd);
pushredir(ROPEN, sidefd, p->code[pc].i==READ?1:0);
runq->ret=0;
break;
default:
close(sidefd);
pushredir(ROPEN, mainfd, mainfd); /* isn't this a noop? */
strcpy(name, Fdprefix);
inttoascii(name+strlen(name), mainfd);
pushword(name);
p->pc=p->code[pc+1].i;
break;
}
}
void
Xsubshell(void)
{
int pid;
switch(pid=fork()){
case -1:
Xerror("try again");
break;
case 0:
start(runq->code, runq->pc+1, runq->local);
runq->ret=0;
break;
default:
Waitfor(pid, 1);
runq->pc=runq->code[runq->pc].i;
break;
}
}
int
execforkexec(void)
{
int pid;
int n;
char buf[ERRMAX];
switch(pid = fork()){
case -1:
return -1;
case 0:
pushword("exec");
execexec();
strcpy(buf, "can't exec: ");
n = strlen(buf);
errstr(buf+n, ERRMAX-n);
Exit(buf);
}
return pid;
}

2
src/cmd/rc/mkfile
View file

@ -20,7 +20,7 @@ OFILES=\
var.$O\
y.tab.$O\
plan9ish.$O\
havep9p.$O\
havefork.$O\
HFILES=\
rc.h\

45
src/cmd/rc/plan9ish.c
View file

@ -199,7 +199,10 @@ int Waitfor(int pid, int unused0){
Waitmsg *w;
char errbuf[ERRMAX];
if(pid >= 0 && !havewaitpid(pid))
return 0;
while((w = wait()) != nil){
delwaitpid(w->pid);
if(w->pid==pid){
if(strncmp(w->msg, "signal: ", 8) == 0)
fprint(mapfd(2), "%d: %s\n", w->pid, w->msg);
@ -217,7 +220,7 @@ int Waitfor(int pid, int unused0){
free(w);
}
errstr(errbuf, sizeof errbuf);
rerrstr(errbuf, sizeof errbuf);
if(strcmp(errbuf, "interrupted")==0) return -1;
return 0;
}
@ -559,3 +562,43 @@ exitcode(char *msg)
n = 1;
return n;
}
int *waitpids;
int nwaitpids;
void
addwaitpid(int pid)
{
waitpids = realloc(waitpids, (nwaitpids+1)*sizeof waitpids[0]);
if(waitpids == 0)
panic("Can't realloc %d waitpids", nwaitpids+1);
waitpids[nwaitpids++] = pid;
}
void
delwaitpid(int pid)
{
int r, w;
for(r=w=0; r<nwaitpids; r++)
if(waitpids[r] != pid)
waitpids[w++] = waitpids[r];
nwaitpids = w;
}
void
clearwaitpids(void)
{
nwaitpids = 0;
}
int
havewaitpid(int pid)
{
int i;
for(i=0; i<nwaitpids; i++)
if(waitpids[i] == pid)
return 1;
return 0;
}