NAME

Sympa::Process - Process of Sympa

SYNOPSIS

use Sympa::Process;
my $process = Sympa::Process->instance;
$process->init(pidname => 'sympa');

$process->daemonize;

$process->fork;

DESCRIPTION

Sympa::Process implements the class to handle process itself of Sympa software.

Signal handling

Once Sympa::Process is loaded, SIGCHLD signals are captured, and only defunct child processes invoked by fork() method are reaped.

Methods

• instance ( )

  Constructor. Creates a singleton instance of Sympa::Process object.

  Returns:

  A new Sympa::Process instance, or undef for failure.

• init ( key => value, … )

  Instance method. TBD.

• daemonize ( )

  Instance method. Daemonizes process itself. Process is given new process group, detached from TTY and given new process ID.

  Parameters:

  None.

  Returns:

  None.

• fork ( [ $tag ] )

  Instance method. Forks process. Note that this method should be used instead of fork() in Perl core.

  Parameter:

  • $tag

    A string to determine new child process. By default the name of calling process.

  Returns:

  See “fork” in perlfunc.

• reap_child ( [ blocking => 1 ] )

  DEPRECATED.

• wait_child ( )

  Instance method. Waits for any child process.

  Parameters:

  None.

  Returns:

  0. Returns -1 on failure.

• sync_child ( [ hash => \%hash ], [ file => 1 ] )

  Updates process information in external data.

  Parameters:

  • hash => \%hash

    Syncs PIDs in local map %hash

  • file => 1

    Syncs child PIDs in PID file. If dead PID is found, notification will be sent to super-listmaster.

  Returns:

  None.

• remove_pid ([ pid => $pid ], [ final => 1 ] )

  Instance method. Removes process ID from PID file. Then if the file is empty, it will be removed.

• write_pid ( [ initial => 1 ], [ pid => $pid ] )

  Instance method. Writes or adds process ID to PID file.

  Parameters:

  • initial => 1

    Initializes PID file. If the file remains, notification will be sent to super-listmaster.

  • pid => $pid

    Process ID to be written. By default PID of current process.

• direct_stderr_to_file ( )

  Instance method. TBD.

Attributes

Sympa::Process instance may have following attributes:

• {children}

  Hashref with child PIDs forked by fork() method as keys.

• {detached}

  True value is set if daemonize() method was called and the process has been detached from TTY.

• {generation}

  Generation of process. If fork() method succeeds, it will be increased by child process.

Utility functions

• eval_in_time ( $subref, $timeout )

  Evaluate subroutine $subref in $timeout seconds.

  TBD.

• register_handler ( )

  Registers SIGCHLD handler. This function is usually called automatically during initialization.

HISTORY

Sympa::Tools::Daemon appeared on Sympa 6.2a.41.

Renamed Sympa::Process appeared on Sympa 6.2.12 and began to provide OO interface.

Sympa 6.2.13 introduced daemonize() method and {detached} attribute.

As of Sympa 6.2.14, SIGCHLD signal was captured and child processes were reaped immediately. reap_child() method (formerly reaper()) was deprecated.