The Perl Toolchain Summit needs more sponsors. If your company depends on Perl, please support this very important event.

Pcore::Core::Exception

Pharaoh::Core::Sig - signals management for Pharaoh::Core.

This package is part of Pharaoh::Core.

EXPORTS

CORE::GLOBAL::exit

Common exit() family functions behaviour:

  • threads->exit() and CORE::exit() is unhandled in threads and perform exit according to threads->set_thread_exit_only;

  • CORE::exit() is unhandled;

SIGNALS

SIGDIE

Standart $SIG{__DIE__} exceptions handler. Use following code to redefined callback:

    local $SIG{__DIE__};        # Redefine handler locally, no callback defined, $SIG{__DIE__} will be ignored
    local $SIG{__DIE__} = sub { # Ditto with callback defined
            ...do something...
        };
  • $SIG{__DIE__} called from eval block produce ERROR log with stack trace and returns;

  • $SIG{__DIE__} called from NOT eval block produce FATAL log with stack trace and exit from process / thread;

  • __ALRM__ exception from eval ignored;

  • __ALRM__ exception from NOT eval block produce FATAL exception;

  • __EXIT__ exception is ignored totally and can be processed in your code. See CORE::GLOBAL::exit for example;

  • Calling die() in $SIG{__DIE__} will overwrite $@ and exit $SIG{__DIE__} immidiately;

  • Overriding die will only catch actual calls to die, not run-time errors;

SIGWARN

Standart $SIG{__WARN__} handler. Produce standart log event on WARN level with stack backtace. To avoid call use following in your code:

    local $SIG{__WARN__} = sub { };    # Redefine callback locally
    local $SIG{__WARN__} = undef;      # Restore standart behaviour in current block

SIGALRM

Standart $SIG{ALRM} handler. Produce __ALRM__ exception. To redefine callback use following in your code:

    local $SIG{ALRM} = sub { };    # Redefine callback locally

or use this alarm - safe code:

    my $orig_alarm = 0;
    eval{
        $orig_alarm = alarm 5;    # Store previous alarm() timer internally
        ...some code here...
    };
    alarm $orig_alarm;            # Restore previous timer

    if($@ =~ /^__ALRM__/){
        ...do something on alarm...
    }

NOTES

  • If $SIG{ALRM} not defined - process will killed on alarm. SIG{__DIE__} don't handle alarm exception;

  • Alarm - safe code must restore previous alarm timer at the end of execution. We can't control bad written code in other modules, so be ready that you alarm timers will not work if you use not alarm - safe modules;

  • alarm() works on MSWin and in threads as expected;

  • You must remove alarm timer immidiately after end of eval block (not in block), because if evaluated code will die - eval block will be broken and your alarm will not be removed;

  • alarm() call on MSWin didn't return amount of time remaining for previous timer. So chained timers on MSWin NOT WORKED.