ref: 39c3fd117ab4988c041800490b23c2aedb1858d3
dir: /sys/src/cmd/upas/q/runq.c/
#include "common.h"
#include <ctype.h>
void doalldirs(void);
void dodir(char*);
void dofile(Dir*);
void rundir(char*);
char* file(char*, char);
void warning(char*, void*);
void error(char*, void*);
int returnmail(char**, char*, char*);
void logit(char*, char*, char**);
void doload(int);
#define HUNK 32
char *cmd;
char *root;
int debug;
int giveup = 2*24*60*60;
int load;
int limit;
/* the current directory */
Dir *dirbuf;
long ndirbuf = 0;
int nfiles;
char *curdir;
char *runqlog = "runq";
int *pidlist;
char **badsys; /* array of recalcitrant systems */
int nbad;
int npid = 50;
int sflag; /* single thread per directory */
int aflag; /* all directories */
int Eflag; /* ignore E.xxxxxx dates */
int Rflag; /* no giving up, ever */
void
usage(void)
{
fprint(2, "usage: runq [-adsE] [-q dir] [-l load] [-t time] [-r nfiles] [-n nprocs] q-root cmd\n");
exits("");
}
void
main(int argc, char **argv)
{
char *qdir, *x;
qdir = 0;
ARGBEGIN{
case 'l':
x = ARGF();
if(x == 0)
usage();
load = atoi(x);
if(load < 0)
load = 0;
break;
case 'E':
Eflag++;
break;
case 'R': /* no giving up -- just leave stuff in the queue */
Rflag++;
break;
case 'a':
aflag++;
break;
case 'd':
debug++;
break;
case 'r':
limit = atoi(ARGF());
break;
case 's':
sflag++;
break;
case 't':
giveup = 60*60*atoi(ARGF());
break;
case 'q':
qdir = ARGF();
if(qdir == 0)
usage();
break;
case 'n':
npid = atoi(ARGF());
if(npid == 0)
usage();
break;
}ARGEND;
if(argc != 2)
usage();
pidlist = malloc(npid*sizeof(*pidlist));
if(pidlist == 0)
error("can't malloc", 0);
if(aflag == 0 && qdir == 0) {
qdir = getuser();
if(qdir == 0)
error("unknown user", 0);
}
root = argv[0];
cmd = argv[1];
if(chdir(root) < 0)
error("can't cd to %s", root);
doload(1);
if(aflag)
doalldirs();
else
dodir(qdir);
doload(0);
exits(0);
}
int
emptydir(char *name)
{
int fd;
long n;
char buf[2048];
fd = open(name, OREAD);
if(fd < 0)
return 1;
n = read(fd, buf, sizeof(buf));
close(fd);
if(n <= 0) {
if(debug)
fprint(2, "removing directory %s\n", name);
syslog(0, runqlog, "rmdir %s", name);
remove(name);
return 1;
}
return 0;
}
int
forkltd(void)
{
int i;
int pid;
for(i = 0; i < npid; i++){
if(pidlist[i] <= 0)
break;
}
while(i >= npid){
pid = waitpid();
if(pid < 0){
syslog(0, runqlog, "forkltd confused");
exits(0);
}
for(i = 0; i < npid; i++)
if(pidlist[i] == pid)
break;
}
pidlist[i] = fork();
return pidlist[i];
}
/*
* run all user directories, must be bootes (or root on unix) to do this
*/
void
doalldirs(void)
{
Dir *db;
int fd;
long i, n;
fd = open(".", OREAD);
if(fd == -1){
warning("reading %s", root);
return;
}
n = dirreadall(fd, &db);
if(n > 0){
for(i=0; i<n; i++){
if(db[i].qid.type & QTDIR){
if(emptydir(db[i].name))
continue;
switch(forkltd()){
case -1:
syslog(0, runqlog, "out of procs");
doload(0);
exits(0);
case 0:
if(sysdetach() < 0)
error("%r", 0);
dodir(db[i].name);
exits(0);
default:
break;
}
}
}
free(db);
}
close(fd);
}
/*
* cd to a user directory and run it
*/
void
dodir(char *name)
{
curdir = name;
if(chdir(name) < 0){
warning("cd to %s", name);
return;
}
if(debug)
fprint(2, "running %s\n", name);
rundir(name);
chdir("..");
}
/*
* run the current directory
*/
void
rundir(char *name)
{
int fd;
long i;
if(aflag && sflag)
fd = sysopenlocked(".", OREAD);
else
fd = open(".", OREAD);
if(fd == -1){
warning("reading %s", name);
return;
}
nfiles = dirreadall(fd, &dirbuf);
if(nfiles > 0){
for(i=0; i<nfiles; i++){
if(dirbuf[i].name[0]!='C' || dirbuf[i].name[1]!='.')
continue;
dofile(&dirbuf[i]);
}
free(dirbuf);
}
if(aflag && sflag)
sysunlockfile(fd);
else
close(fd);
}
/*
* free files matching name in the current directory
*/
void
remmatch(char *name)
{
long i;
syslog(0, runqlog, "removing %s/%s", curdir, name);
for(i=0; i<nfiles; i++){
if(strcmp(&dirbuf[i].name[1], &name[1]) == 0)
remove(dirbuf[i].name);
}
/* error file (may have) appeared after we read the directory */
/* stomp on data file in case of phase error */
remove(file(name, 'D'));
remove(file(name, 'E'));
}
/*
* like trylock, but we've already got the lock on fd,
* and don't want an L. lock file.
*/
static Mlock *
keeplockalive(char *path, int fd)
{
char buf[1];
Mlock *l;
l = malloc(sizeof(Mlock));
if(l == 0)
return 0;
l->fd = fd;
snprint(l->name, sizeof l->name, "%s", path);
/* fork process to keep lock alive until sysunlock(l) */
switch(l->pid = rfork(RFPROC)){
default:
break;
case 0:
fd = l->fd;
for(;;){
sleep(1000*60);
if(pread(fd, buf, 1, 0) < 0)
break;
}
_exits(0);
}
return l;
}
/*
* try a message
*/
void
dofile(Dir *dp)
{
Dir *d;
int dfd, ac, dtime, efd, pid, i, etime;
char *buf, *cp, **av;
Waitmsg *wm;
Biobuf *b;
Mlock *l = nil;
if(debug)
fprint(2, "dofile %s\n", dp->name);
/*
* if no data file or empty control or data file, just clean up
* the empty control file must be 15 minutes old, to minimize the
* chance of a race.
*/
d = dirstat(file(dp->name, 'D'));
if(d == nil){
syslog(0, runqlog, "no data file for %s", dp->name);
remmatch(dp->name);
return;
}
if(dp->length == 0){
if(time(0)-dp->mtime > 15*60){
syslog(0, runqlog, "empty ctl file for %s", dp->name);
remmatch(dp->name);
}
return;
}
dtime = d->mtime;
free(d);
/*
* retry times depend on the age of the errors file
*/
if(!Eflag && (d = dirstat(file(dp->name, 'E'))) != nil){
etime = d->mtime;
free(d);
if(etime - dtime < 60*60){
/* up to the first hour, try every 15 minutes */
if(time(0) - etime < 15*60)
return;
} else {
/* after the first hour, try once an hour */
if(time(0) - etime < 60*60)
return;
}
}
/*
* open control and data
*/
b = sysopen(file(dp->name, 'C'), "rl", 0660);
if(b == 0) {
if(debug)
fprint(2, "can't open %s: %r\n", file(dp->name, 'C'));
return;
}
dfd = open(file(dp->name, 'D'), OREAD);
if(dfd < 0){
if(debug)
fprint(2, "can't open %s: %r\n", file(dp->name, 'D'));
Bterm(b);
sysunlockfile(Bfildes(b));
return;
}
/*
* make arg list
* - read args into (malloc'd) buffer
* - malloc a vector and copy pointers to args into it
*/
buf = malloc(dp->length+1);
if(buf == 0){
warning("buffer allocation", 0);
Bterm(b);
sysunlockfile(Bfildes(b));
close(dfd);
return;
}
if(Bread(b, buf, dp->length) != dp->length){
warning("reading control file %s\n", dp->name);
Bterm(b);
sysunlockfile(Bfildes(b));
close(dfd);
free(buf);
return;
}
buf[dp->length] = 0;
av = malloc(2*sizeof(char*));
if(av == 0){
warning("argv allocation", 0);
close(dfd);
free(buf);
Bterm(b);
sysunlockfile(Bfildes(b));
return;
}
for(ac = 1, cp = buf; *cp; ac++){
while(isspace(*cp))
*cp++ = 0;
if(*cp == 0)
break;
av = realloc(av, (ac+2)*sizeof(char*));
if(av == 0){
warning("argv allocation", 0);
close(dfd);
free(buf);
Bterm(b);
sysunlockfile(Bfildes(b));
return;
}
av[ac] = cp;
while(*cp && !isspace(*cp)){
if(*cp++ == '"'){
while(*cp && *cp != '"')
cp++;
if(*cp)
cp++;
}
}
}
av[0] = cmd;
av[ac] = 0;
if(!Eflag &&time(0) - dtime > giveup){
if(returnmail(av, dp->name, "Giveup") != 0)
logit("returnmail failed", dp->name, av);
remmatch(dp->name);
goto done;
}
for(i = 0; i < nbad; i++){
if(strcmp(av[3], badsys[i]) == 0)
goto done;
}
/*
* Ken's fs, for example, gives us 5 minutes of inactivity before
* the lock goes stale, so we have to keep reading it.
*/
l = keeplockalive(file(dp->name, 'C'), Bfildes(b));
/*
* transfer
*/
pid = fork();
switch(pid){
case -1:
sysunlock(l);
sysunlockfile(Bfildes(b));
syslog(0, runqlog, "out of procs");
exits(0);
case 0:
if(debug) {
fprint(2, "Starting %s", cmd);
for(ac = 0; av[ac]; ac++)
fprint(2, " %s", av[ac]);
fprint(2, "\n");
}
logit("execing", dp->name, av);
close(0);
dup(dfd, 0);
close(dfd);
close(2);
efd = open(file(dp->name, 'E'), OWRITE);
if(efd < 0){
if(debug) syslog(0, "runq", "open %s as %s: %r", file(dp->name,'E'), getuser());
efd = create(file(dp->name, 'E'), OWRITE, 0666);
if(efd < 0){
if(debug) syslog(0, "runq", "create %s as %s: %r", file(dp->name, 'E'), getuser());
exits("could not open error file - Retry");
}
}
seek(efd, 0, 2);
exec(cmd, av);
error("can't exec %s", cmd);
break;
default:
for(;;){
wm = wait();
if(wm == nil)
error("wait failed: %r", "");
if(wm->pid == pid)
break;
free(wm);
}
if(debug)
fprint(2, "wm->pid %d wm->msg == %s\n", wm->pid, wm->msg);
if(wm->msg[0]){
if(debug)
fprint(2, "[%d] wm->msg == %s\n", getpid(), wm->msg);
if(!Rflag && strstr(wm->msg, "Retry")==0){
/* return the message and remove it */
if(returnmail(av, dp->name, wm->msg) != 0)
logit("returnmail failed", dp->name, av);
remmatch(dp->name);
} else {
/* add sys to bad list and try again later */
nbad++;
badsys = realloc(badsys, nbad*sizeof(char*));
badsys[nbad-1] = strdup(av[3]);
}
} else {
/* it worked remove the message */
remmatch(dp->name);
}
free(wm);
}
done:
if (l)
sysunlock(l);
Bterm(b);
sysunlockfile(Bfildes(b));
free(buf);
free(av);
close(dfd);
}
/*
* return a name starting with the given character
*/
char*
file(char *name, char type)
{
static char nname[Elemlen+1];
strncpy(nname, name, Elemlen);
nname[Elemlen] = 0;
nname[0] = type;
return nname;
}
/*
* send back the mail with an error message
*
* return 0 if successful
*/
int
returnmail(char **av, char *name, char *msg)
{
char buf[256], attachment[Pathlen], *sender;
int i, fd, pfd[2];
long n;
Waitmsg *wm;
String *s;
if(av[1] == 0 || av[2] == 0){
logit("runq - dumping bad file", name, av);
return 0;
}
s = unescapespecial(s_copy(av[2]));
sender = s_to_c(s);
if(!returnable(sender) || strcmp(sender, "postmaster") == 0) {
logit("runq - dumping p to p mail", name, av);
return 0;
}
if(pipe(pfd) < 0){
logit("runq - pipe failed", name, av);
return -1;
}
switch(rfork(RFFDG|RFPROC|RFENVG)){
case -1:
logit("runq - fork failed", name, av);
return -1;
case 0:
logit("returning", name, av);
close(pfd[1]);
close(0);
dup(pfd[0], 0);
close(pfd[0]);
putenv("upasname", "/dev/null");
snprint(buf, sizeof(buf), "%s/marshal", UPASBIN);
snprint(attachment, sizeof(attachment), "%s", file(name, 'D'));
execl(buf, "send", "-A", attachment, "-s", "permanent failure", sender, nil);
error("can't exec", 0);
break;
default:
break;
}
close(pfd[0]);
fprint(pfd[1], "\n"); /* get out of headers */
if(av[1]){
fprint(pfd[1], "Your request ``%.20s ", av[1]);
for(n = 3; av[n]; n++)
fprint(pfd[1], "%s ", av[n]);
}
fprint(pfd[1], "'' failed (code %s).\nThe symptom was:\n\n", msg);
fd = open(file(name, 'E'), OREAD);
if(fd >= 0){
for(;;){
n = read(fd, buf, sizeof(buf));
if(n <= 0)
break;
if(write(pfd[1], buf, n) != n){
close(fd);
goto out;
}
}
close(fd);
}
close(pfd[1]);
out:
wm = wait();
if(wm == nil){
syslog(0, "runq", "wait: %r");
logit("wait failed", name, av);
return -1;
}
i = 0;
if(wm->msg[0]){
i = -1;
syslog(0, "runq", "returnmail child: %s", wm->msg);
logit("returnmail child failed", name, av);
}
free(wm);
return i;
}
/*
* print a warning and continue
*/
void
warning(char *f, void *a)
{
char err[ERRMAX];
char buf[256];
rerrstr(err, sizeof(err));
snprint(buf, sizeof(buf), f, a);
fprint(2, "runq: %s: %s\n", buf, err);
}
/*
* print an error and die
*/
void
error(char *f, void *a)
{
char err[ERRMAX];
char buf[256];
rerrstr(err, sizeof(err));
snprint(buf, sizeof(buf), f, a);
fprint(2, "runq: %s: %s\n", buf, err);
exits(buf);
}
void
logit(char *msg, char *file, char **av)
{
int n, m;
char buf[256];
n = snprint(buf, sizeof(buf), "%s/%s: %s", curdir, file, msg);
for(; *av; av++){
m = strlen(*av);
if(n + m + 4 > sizeof(buf))
break;
sprint(buf + n, " '%s'", *av);
n += m + 3;
}
syslog(0, runqlog, "%s", buf);
}
char *loadfile = ".runqload";
/*
* load balancing
*/
void
doload(int start)
{
int fd;
char buf[32];
int i, n;
Mlock *l;
Dir *d;
if(load <= 0)
return;
if(chdir(root) < 0){
load = 0;
return;
}
l = syslock(loadfile);
fd = open(loadfile, ORDWR);
if(fd < 0){
fd = create(loadfile, 0666, ORDWR);
if(fd < 0){
load = 0;
sysunlock(l);
return;
}
}
/* get current load */
i = 0;
n = read(fd, buf, sizeof(buf)-1);
if(n >= 0){
buf[n] = 0;
i = atoi(buf);
}
if(i < 0)
i = 0;
/* ignore load if file hasn't been changed in 30 minutes */
d = dirfstat(fd);
if(d != nil){
if(d->mtime + 30*60 < time(0))
i = 0;
free(d);
}
/* if load already too high, give up */
if(start && i >= load){
sysunlock(l);
exits(0);
}
/* increment/decrement load */
if(start)
i++;
else
i--;
seek(fd, 0, 0);
fprint(fd, "%d\n", i);
sysunlock(l);
close(fd);
}