<?php
/**
* PHP_Fork class usage examples
* ==================================================================================
* NOTE: In real world you surely want to keep each class into
* a separate file, then include() it into your application.
* For this examples is more useful to keep all_code_into_one_file,
* so that each example shows a unique feature of the PHP_Fork framework.
* ==================================================================================
* exec_methods.php
*
* This example shows a workaround to execute methods into the child process.
* Always remember that this is an emulation, and the variable spaces are
* separated between separate processes!
* There're two kinds of methods: PHP_FORK_VOID_METHOD and PHP_FORK_RETURN_METHOD
* the first returns nothing, the second can return any serializable value
*
* ATTENTION: this feature of PHP_Fork is highly experimental;
* all things are OK until we run such an example, that does nothing and simply
* sleep() all time waiting for a call. Some experiement with real applications
* seems to show that firing the child process with a signal (that is part of the
* workaround...) causes the process to stop execution, and then to repeat ALL the
* run() method after signal caught... This is not an acceptable behaviour and
* should be tested better.
*
* ==================================================================================
*
* Copyright (c) 2003-2002 by Luca Mariano (luca.mariano@email.it)
* http://www.lucamariano.it
*
* This program is free software. You can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License.
*/
// Import of base class
require_once ("../Fork.php");
// number of executeThreads we want
define ("NUM_THREAD", 2);
// this is needed as PHP 4.3 in order to use pcntl_signal()
declare (ticks = 1);
/**
* Classes definition. In real world you surely want to keep each class into
* a separate file, then include() it into your application.
* For this examples is more useful to keep all_code_into_one_file
*
* executeThread class inherit from PHP_Fork and must redefine the run() method
* all the code contained into the run() method will be executed only by the child
* process; all other methods that you define will be accessible both to the parent
* and to the child (and will be executed into the relative process)
*/
class executeThread extends PHP_Fork {
function executeThread($name)
{
$this->PHP_Fork($name);
$GLOBALS["counter"] = 0;
}
function run()
{
while (true) {
$GLOBALS["counter"]++;
sleep(1);
}
}
/**
* A simple method that can be called from the parent process;
* There are 2 types of methods, according to the return value
*
* PHP_FORK_VOID_METHOD is a method that return no value; a SINGLE array of parameters (or a single parameter) is expected to be passed
* PHP_FORK_RETURN_METHOD is a method that return an array to the calling process
*
* if nothing is specified, PHP_FORK_VOID_METHOD behaviour is the default
*/
function setCounter($val)
{
if ($this->_isChild) {
// do all your stuff here
// remember that only GLOBAL variables can be accessed with this trick, so
// if we need to change the value of the variable $counter from the parent into the
// child (like this code does...) we can't use a class variable ($this->counter),
// neither a local variable...
/**
* * START OF METHOD IMPLEMENTATION *
*/
$GLOBALS["counter"] = $val[0];
/**
* * END OF METHOD IMPLEMENTATION *
*/
}
/**
* Never change this line, it requires no adjustments...
*/
else return $this->register_callback_func(func_get_args(), __FUNCTION__);
}
function getCounter($params)
{
if ($this->_isChild) {
return $GLOBALS["counter"];
} else return $this->register_callback_func(func_get_args(), __FUNCTION__);
}
}
/**
* Functions used by the console
*/
function _getInputCLI()
{
$opt = _read();
$opt = strtoupper (trim($opt));
return $opt;
}
function _read()
{
$fp = fopen("php://stdin", "r");
$input = fgets($fp, 255);
fclose($fp);
return $input;
}
/**
* Main program. Bring up two instances of the executeThread class that
* runs concurrently. It's a multi-thread app with a few lines of code!!!
* executeThread does nothing interesting, it simply has a counter and increment
* this counter each second... (see class definition at top of this file)
*/
for ($i = 0;$i < NUM_THREAD;$i++) {
$executeThread[$i] = &new executeThread ("executeThread-" . $i);
$executeThread[$i]->start();
echo "Started " . $executeThread[$i]->getName() . " with PID " . $executeThread[$i]->getPid() . "...\n";
}
print "This is the main process.\nPress [X] to terminate, [S] to reset all counters, [G] to get the actual value of counters.\n";
/**
* Console simple listener
*/
while (true) {
echo ">";
$opt = _getInputCLI();
echo "\n";
switch ($opt) {
case "X":
// stops all threads
for ($i = 0;$i < NUM_THREAD;$i++) {
$executeThread[$i]->stop();
echo "Stopped " . $executeThread[$i]->getName() . "\n";
}
exit;
break;
case "S":
// setCounter is a PHP_FORK_VOID_METHOD
// it only need a paramenter (an array containing data that must be passed to child)
for ($i = 0;$i < NUM_THREAD;$i++) {
$executeThread[$i]->setCounter(0);
}
break;
case "G":
// getCounter is a method that reads the value of the thread counter
// so getCounter is a RETURN_METHOD and MUST be called with 2 parameters;
// the first is an array of data that must be passed to the method, the second is
// the constant (RETURN_METHOD)
for ($i = 0;$i < NUM_THREAD;$i++) {
echo $executeThread[$i]->getName() . " returns " . $executeThread[$i]->getCounter('', PHP_FORK_RETURN_METHOD) . "\n";
}
break;
}
}
?>
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