Chapter 1. ZendX_Console_Process_Unix
<sect1>
<title>ZendX_Console_Process_Unix</title>
<sect2>
<title>Introduction</title>
<para>
<classname>ZendX_Console_Process_Unix</classname> allows developers to spawn
an object as a new process, and so do multiple tasks in parallel on
console environments. Through its specific nature, it is only
working on *nix based systems like Linux, Solaris, Mac/OSx and such.
Additionally, the <code>shmop_*</code>, <code>pcntl_*</code> and
<code>posix_*</code> modules are required for this component to
run. If one of the requirements is not met, it will throw an
exception after instantiating the component.
</para>
</sect2>
<sect2>
<title>Basic usage of ZendX_Console_Process_Unix</title>
<para>
<classname>ZendX_Console_Process_Unix</classname> is an abstract class, which
requires the user to extend it. It has a single abstract method
called <methodname>_run()</methodname> which has to be implemented to create a
working process. It also comes with multiple methods for checking
the alive status and share variables between the parent and the
child process.
</para>
<para>
The <methodname>_run()</methodname> method and every method which is called
by it is executed by the child process. Every other method which is
called directly by the parent is executed by the parent process.
</para>
<para>
<methodname>setVariable()</methodname> and <methodname>getVariable()</methodname> can be
used from both the parent- and the child process to share variables.
To observe the alive status, the child process should call
<methodname>_setAlive()</methodname> in a frequent interval, so that the parent
process can check the last alive time via <methodname>getLastAlive()</methodname>.
To get the PID of the child process, the parent can call
<methodname>getPid()</methodname>.
</para>
<example>
<title>Basic example for processing</title>
<para>
This example illustrates a basic child process
</para>
<programlisting>
class MyProcess extends ZendX_Console_Process_Unix
{
protected function _run()
{
for ($i = 0; $i < 10; $i++) {
// Doing something really important which can't wait: sleeping
sleep(1);
}
}
}
// This part should last about 10 seconds, not 20.
$process1 = new MyProcess();
$process1->start();
$process2 = new MyProcess();
$process2->start();
while ($process1->isRunning() || $process2->isRunning()) {
sleep(1);
}
echo 'All processes completed';
</programlisting>
<para>
In this example a process is forked twice and executed. As every
process runs 10 seconds, the parent process will be finished after
10 seconds (and not 20).
</para>
</example>
</sect2>
</sect1>