《PHP學(xué)習(xí)：php多線程實(shí)現(xiàn)方法及用法實(shí)例詳解》要點(diǎn)：
本文介紹了PHP學(xué)習(xí)：php多線程實(shí)現(xiàn)方法及用法實(shí)例詳解，希望對您有用。如果有疑問，可以聯(lián)系我們。
PHP實(shí)戰(zhàn)下面我們來介紹具體php多線程實(shí)現(xiàn)程序代碼,有需要了解的同學(xué)可參考.
當(dāng)有人想要實(shí)現(xiàn)并發(fā)功能時,他們通常會想到用fork或者spawn threads,但是當(dāng)他們發(fā)現(xiàn)php不支持多線程的時候,大概會轉(zhuǎn)換思路去用一些不夠好的語言,比如perl.
其實(shí)的是大多數(shù)情況下,你大可不必使用fork 或者線程,并且你會得到比用fork 或thread 更好的性能.
假設(shè)你要建立一個服務(wù)來檢查正在運(yùn)行的n臺服務(wù)器,以確定他們還在正常運(yùn)轉(zhuǎn).你可能會寫下面這樣的代碼：
代碼如下?
PHP實(shí)戰(zhàn)
<?php
$hosts = array("host1.sample.com", "host2.sample.com", "host3.sample.com");
$timeout = 15;
$status = array();
foreach ($hosts as $host) {
$errno = 0;
$errstr = "";
$s = fsockopen($host, 80, $errno, $errstr, $timeout);
if ($s) {
$status[$host] = "Connectedn";
fwrite($s, "HEAD / HTTP/1.0rnHost: $hostrnrn");
do {
$data = fread($s, 8192);
if (strlen($data) == 0) {
break;
}
$status[$host] .= $data;
} while (true);
fclose($s);
} else {
$status[$host] = "Connection failed: $errno $errstrn";
}
}
print_r($status);
?>
PHP實(shí)戰(zhàn)它運(yùn)行的很好,但是在fsockopen()分析完hostname并且建立一個成功的連接(或者延時$timeout秒)之前,擴(kuò)充這段代碼來管理大量服務(wù)器將耗費(fèi)很長時間.
因此我們必須放棄這段代碼；我們可以建立異步連接-不需要等待fsockopen返回連接狀態(tài).PHP仍然需要解析hostname(所以直接使用ip更加明智),不過將在打開一個連接之后立刻返回,繼而我們就可以連接下一臺服務(wù)器.
有兩種辦法可以實(shí)現(xiàn)：PHP5中可以使用新增的stream_socket_client()函數(shù)直接替換掉fsocketopen().PHP5之前的版本,你需要自己動手,用sockets擴(kuò)展解決問題.
下面是PHP5中的解決辦法：
代碼如下
PHP實(shí)戰(zhàn)
<?php
$hosts = array("host1.sample.com", "host2.sample.com", "host3.sample.com");
$timeout = 15;
$status = array();
$sockets = array();
/* Initiate connections to all the hosts simultaneously */
foreach ($hosts as $id => $host) {
$s = stream_socket_client("
$
$host:80", $errno, $errstr, $timeout,
STREAM_CLIENT_ASYNC_CONNECT|STREAM_CLIENT_CONNECT);
if ($s) {
$sockets[$id] = $s;
$status[$id] = "in progress";
} else {
$status[$id] = "failed, $errno $errstr";
}
}
/* Now, wait for the results to come back in */
while (count($sockets)) {
$read = $write = $sockets;
/* This is the magic function - explained below */
$n = stream_select($read, $write, $e = null, $timeout);
if ($n > 0) {
/* readable sockets either have data for us, or are failed
* connection attempts */
foreach ($read as $r) {
$id = array_search($r, $sockets);
$data = fread($r, 8192);
if (strlen($data) == 0) {
if ($status[$id] == "in progress") {
$status[$id] = "failed to connect";
}
fclose($r);
unset($sockets[$id]);
} else {
$status[$id] .= $data;
}
}
/* writeable sockets can accept an HTTP request */
foreach ($write as $w) {
$id = array_search($w, $sockets);
fwrite($w, "HEAD / HTTP/1.0rnHost: "
. $hosts[$id] . "rnrn");
$status[$id] = "waiting for response";
}
} else {
/* timed out waiting; assume that all hosts associated
* with $sockets are faulty */
foreach ($sockets as $id => $s) {
$status[$id] = "timed out " . $status[$id];
}
break;
}
}
foreach ($hosts as $id => $host) {
echo "Host: $hostn";
echo "Status: " . $status[$id] . "nn";
}
?>
PHP實(shí)戰(zhàn)我們用stream_select()等待sockets打開的連接事件.stream_select()調(diào)用系統(tǒng)的select(2)函數(shù)來工作：前面三個參數(shù)是你要使用的streams的數(shù)組；你可以對其讀取,寫入和獲取異常(分別針對三個參數(shù)).stream_select()可以通過設(shè)置$timeout(秒)參數(shù)來等待事件發(fā)生-事件發(fā)生時,相應(yīng)的sockets數(shù)據(jù)將寫入你傳入的參數(shù).
下面是PHP4.1.0之后版本的實(shí)現(xiàn),如果你已經(jīng)在編譯PHP時包含了sockets(ext/sockets)支持,你可以使用根上面類似的代碼,只是需要將上面的streams/filesystem函數(shù)的功能用ext/sockets函數(shù)實(shí)現(xiàn).主要的不同在于我們用下面的函數(shù)代替stream_socket_client()來建立連接：
代碼如下?
PHP實(shí)戰(zhàn)
<?php
// This value is correct for Linux, other systems have other values
define('EINPROGRESS', 115);
function non_blocking_connect($host, $port, &$errno, &$errstr, $timeout) {
$ip = gethostbyname($host);
$s = socket_create(AF_INET, SOCK_STREAM, 0);
if (socket_set_nonblock($s)) {
$r = @socket_connect($s, $ip, $port);
if ($r || socket_last_error() == EINPROGRESS) {
$errno = EINPROGRESS;
return $s;
}
}
$errno = socket_last_error($s);
$errstr = socket_strerror($errno);
socket_close($s);
return false;
}
?>
PHP實(shí)戰(zhàn)現(xiàn)在用socket_select()替換掉stream_select(),用socket_read()替換掉fread(),用socket_write()替換掉fwrite(),用socket_close()替換掉fclose()就可以執(zhí)行腳本了!
PHP5的先進(jìn)之處在于,你可以用stream_select()處理幾乎所有的stream-例如你可以通過include STDIN用它接收鍵盤輸入并保存進(jìn)數(shù)組,你還可以接收通過proc_open()打開的管道中的數(shù)據(jù).
下面來分享一個PHP多線程類
代碼如下
PHP實(shí)戰(zhàn)
* @title: PHP多線程類(Thread)
* @version: 1.0
*
* PHP多線程應(yīng)用示例：
* require_once 'thread.class.php';
* $thread = new thread();
* $thread->addthread('action_log','a');
* $thread->addthread('action_log','b');
* $thread->addthread('action_log','c');
* $thread->runthread();
*
* function action_log($info) {
* $log = 'log/' . microtime() . '.log';
* $txt = $info . "rnrn" . 'Set in ' . Date('h:i:s', time()) . (double)microtime() . "rn";
* $fp = fopen($log, 'w');
* fwrite($fp, $txt);
* fclose($fp);
* }
*/
class thread {
var $hooks = array();
var $args = array();
function thread() {
}
function addthread($func)
{
$args = array_slice(func_get_args(), 1);
$this->hooks[] = $func;
$this->args[] = $args;
return true;
}
function runthread()
{
if(isset($_GET['flag']))
{
$flag = intval($_GET['flag']);
}
if($flag || $flag === 0)
{
call_user_func_array($this->hooks[$flag], $this->args[$flag]);
}
else
{
for($i = 0, $size = count($this->hooks); $i < $size; $i++)
{
$fp=fsockopen($_SERVER['HTTP_HOST'],$_SERVER['SERVER_PORT']);
if($fp)
{
$out = "GET {$_SERVER['PHP_SELF']}?flag=$i HTTP/1.1rn";
$out .= "Host: {$_SERVER['HTTP_HOST']}rn";
$out .= "Connection: Closernrn";
fputs($fp,$out);
fclose($fp);
}
}
}
}
}
PHP實(shí)戰(zhàn)希望本文所述對大家的PHP程序設(shè)計(jì)有所贊助.
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