Sympa::Process.3Sympa - Man Page

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.

Info

2021-04-27 sympa 6.2.62