Re^3: Cannot catch ALRM signal for timeout

ikegami, what do you mean by "move the eof into the eval"? I try this:

        sub process_scheme{
          my ($output_file) = @_;
          open (OUTPUT_FILE, ">", $output_file) || die "cannot open lo
+g file";
          my $scheme_pid = open (WORKER, "worker_program < $input |") 
               || die "cannot pipe worker";
          my $str;
          while (1) {
              eval{
                  local $SIG{ALRM} = sub { die "alarm\n" }; # NB: \n r
+equired
                  alarm 1;
                  if (eof(WORKER)){    
                      close WORKER;
                      close OUTPUT;
                      return 1;
                  }

                  $str = <WORKER>;
                  alarm 0; # if this line is removed, the signal is ca
+ught, but outside of eval, so it halts the script
              };
              if ($@) {
                  close OUTPUT_FILE;
                  close WORKER;
                  return 0;
              }

              # process the line
              #  some code ...
              # print the line to log
              print OUTPUT_FILE $str;
          }
      }
[download]

but it still does not work :( Thank you for your hint, tho

Comment on Re^3: Cannot catch ALRM signal for timeout Download Code

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Re^4: Cannot catch ALRM signal for timeout by ikegami (Patriarch) on Dec 08, 2009 at 21:24 UTC
but it still does not work What doesn't work? The timeout works fine. I changed `my $scheme_pid = open (WORKER, "worker_program < $input \|")` [download] to `my $scheme_pid = open (WORKER, "-\|", $^X, '-e', '$\|=1; for (1..100) { +print "%d\n", $_*$t; sleep(2) }')` [download] and the timeout triggered. The log file contained only "0". You'll need to fix the `return 1`, though. That will only return out of the `eval`, not out of the sub.	[reply] [d/l] [select]
Re^5: Cannot catch ALRM signal for timeout by Magice (Novice) on Dec 08, 2009 at 22:28 UTC
It still stuck, not alarmed for some reasons. My code right now has become: sub process_scheme{ my ($output_file) = @_; open (OUTPUT_FILE, ">", $output_file) \|\| die "cannot open log file +"; my $scheme_pid = open (SCHEME, "./t.pl \| ") \|\| die "cannot pipe sc +heme"; my $str = ""; MAIN: while (1) { eval{ local $SIG{ALRM} = sub { die "alarm\n" }; # NB: \n require +d alarm 5;#$allow_time; if (eof(SCHEME)){ close OUTPUT_FILE; close SCHEME; last MAIN; } $str = <SCHEME>; alarm 0; }; if ($@) { close OUTPUT_FILE; kill $scheme_pid; close SCHEME; return -$current_player; } # process the line print OUTPUT_FILE $str; } return 1; } [download] where the t.pl is `while(1){};` [download] The script gets stuck, waiting forever, not stopping/returning anything	[reply] [d/l] [select]
Re^6: Cannot catch ALRM signal for timeout by almut (Canon) on Dec 08, 2009 at 23:35 UTC
`kill $scheme_pid;` You probably meant something like `kill INT => $scheme_pid;` [download] As you have it, `kill` would try to send the signal number `$scheme_pid` to no processes — so nothing happens, effectively... As a result, your code hangs in the implicit `wait` behind `close SCHEME`, because the child process is still alive.	[reply] [d/l] [select]
Re^6: Cannot catch ALRM signal for timeout by ikegami (Patriarch) on Dec 08, 2009 at 22:45 UTC
what makes you think it's stuck? Are you sure it's really stuck and that you're not suffering from buffering? Add `OUTPUT_FILE->autoflush(1);` [download] after the `open`. You'll need `use IO::Handle qw( );` [download] at the top.	[reply] [d/l] [select]