Re: [9fans] syscall silently kill processes

[andrey100100100@gmail.com]

В Вс, 19/06/2022 в 14:40 +0300, andrey100100100@gmail.com пишет:
> В Вс, 19/06/2022 в 10:32 +0000, adr пишет:
> > On Sun, 19 Jun 2022, andrey100100100@gmail.com wrote:
> > > No way. All processes must run simultaneously.
> > > NFN limit cannot be bypassed.
> > 
> > Yeah, that's why I said it was silly:
> > > > > The solution is obvious, cancel the process' handlers before
> > > > > it
> > > > > exits so we don't run out of space.
> > > > 
> > > > This was really silly...
> > 
> > The changes I'm testing are not for evading the limit, but for
> > making the handler managment more efficient and specially to avoid
> > the case when a process could remove another process' handler from
> > onnote[].
> 
> Ok.
> 
> 
> More complete example with thread library:
> 
> -------------------------------------------------------------
> #include <u.h>
> #include <libc.h>
> #include <thread.h>
> 
> static int
> handler_alarm(void *, char *msg)
> {
>         if(strstr(msg, "alarm")){
>                 return 1;
>         }
> 
>         return 0;
> }
> 
> static void
> proc_func(void *c)
> {
>         Channel *chan = c;
> 
>         int fd, resp_len;
>         char req[] = "request";
>         char resp[512], *r = nil;
> 
>         if(threadnotify(handler_alarm, 1) == 0){
>                 fprint(1, "handler not registred\n");
>         }
> 
>         alarm(2000);
>         if((fd = dial("udp!185.157.221.201!5678", nil, nil, nil)) >=
> 0){
>                 alarm(0);
>                 alarm(2000);
>                 if(write(fd, req, strlen(req)) == strlen(req)){
>                         alarm(0);
>                         alarm(2000);
>                         if((resp_len = read(fd, resp, sizeof(resp)))
> 0){
>                                 alarm(0);
>                                 if((r = malloc(sizeof(resp))) ==
> nil){
>                                         sysfatal("malloc error: %r");
>                                 }
>                                 memmove(r, resp, sizeof(resp));
>                         }
>                 }
>                 close(fd);
>         }
> 

+         alarm(0);

>         send(chan, r);
>         threadexits(nil);
> }
> 
> int mainstacksize = 5242880;
> 
> void
> threadmain(int argc, char *argv[])
> {
>         Channel *chan = nil;
>         char *data = nil;
>         int nproc = 0;
> 
>         ARGBEGIN{
>         case 'n':
>                 nproc = atoi(EARGF(threadexitsall(nil)));
>                 break;
>         default:
>                 threadexitsall(nil);
>         }ARGEND;
> 
>         if((chan = chancreate(sizeof(char *), 0)) == nil){
>                 sysfatal("channel error: %r");
>         }
> 
>         for(int i = 0; i < nproc; i++){
>                 proccreate(proc_func, chan, 10240);
>         }
> 
>         for(int i = 0; i < nproc; i++){
>                 if(data = recvp(chan)){
>                         free(data);
>                 }
>         }
> 
>         if(nproc)
>                 fprint(1, "EXIT with nproc: %d\n", nproc);
> 
>         threadexitsall(nil);
> }
> -------------------------------------------------------------
> 
> cpu% 6.out -n 33
> EXIT with nproc: 33
> 
> with 34:
> 
> cpu% 6.out -n 34
> handler not registred
> 
> and stalled.
> 
> 
> So it is important for me that all processes respond.
> Such use, it seems to me, simplifies the program.
> 
> 

Regards,
Andrej

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