php pthreads多執行緒的安裝與使用

安裝Pthreads 基本上需要重新編譯PHP，加上--enable-maintainer-zts 參數，但是用這個文檔很少；bug會很多很有很多意想不到的問題，生成環境上只能呵呵了，所以這個東西玩就算了，真正多執行緒還是用Python、C等等

一、安裝

這裡使用的是php-7.0.2

./configure \
--prefix=/usr/local/php7 \
--with-config-file-path=/etc \
--with-config-file-scan-dir=/etc/php.d \
--enable-debug \
--enable-maintainer-zts \
--enable-pcntl \
--enable-fpm \
--enable-opcache \
--enable-embed=shared \
--enable-json=shared \
--enable-phpdbg \
--with-curl=shared \
--with-mysql=/usr/local/mysql \
--with-mysqli=/usr/local/mysql/bin/mysql_config \
--with-pdo-mysql

   

pecl install pthreads

二、Thread

<?php
#1
$thread = new class extends Thread {
public function run() {
echo "Hello World {$this->getThreadId()}\n";
}
};
$thread->start() && $thread->join();
#2
class workerThread extends Thread {
public function __construct($i){
$this->i=$i;
}
public function run(){
while(true){
echo $this->i."\n";
sleep(1);
}
}
}
for($i=0;$i<50;$i++){
$workers[$i]=new workerThread($i);
$workers[$i]->start();
}
?>

   

三、 Worker 與Stackable

Stackables are tasks that aredcuted Stackby Workers reads sreads？ before, after and during their execution.

<?php
class SQLQuery extends Stackable {
public function __construct($sql) {
$this->sql = $sql;
}
public function run() {
$dbh = $this->worker->getConnection();
$row = $dbh->query($this->sql);
while($member = $row->fetch(PDO::FETCH_ASSOC)){
print_r($member);
}
}
}
class ExampleWorker extends Worker {
public static $dbh;
public function __construct($name) {
}
public function run(){
self::$dbh = new PDO(&#39;mysql:host=10.0.0.30;dbname=testdb&#39;,&#39;root&#39;,&#39;123456&#39;);
}
public function getConnection(){
return self::$dbh;
}
}
$worker = new ExampleWorker("My Worker Thread");
$sql1 = new SQLQuery(&#39;select * from test order by id desc limit 1,5&#39;);
$worker->stack($sql1);
$sql2 = new SQLQuery(&#39;select * from test order by id desc limit 5,5&#39;);
$worker->stack($sql2);
$worker->start();
$worker->shutdown();
?>

   

四、 互斥鎖

什麼情況下會用到互斥鎖？在你需要控制多個執行緒同一時刻只能有一個執行緒工作的情況下可以使用。一個簡單的計數器程序，說明有無互斥鎖情況下的不同

<?php
$counter = 0;
$handle=fopen("/tmp/counter.txt", "w");
fwrite($handle, $counter );
fclose($handle);
class CounterThread extends Thread {
public function __construct($mutex = null){
$this->mutex = $mutex;
$this->handle = fopen("/tmp/counter.txt", "w+");
}
public function __destruct(){
fclose($this->handle);
}
public function run() {
if($this->mutex)
$locked=Mutex::lock($this->mutex);
$counter = intval(fgets($this->handle));
$counter++;
rewind($this->handle);
fputs($this->handle, $counter );
printf("Thread #%lu says: %s\n", $this->getThreadId(),$counter);
if($this->mutex)
Mutex::unlock($this->mutex);
}
}
//没有互斥锁
for ($i=0;$i<50;$i++){
$threads[$i] = new CounterThread();
$threads[$i]->start();
}
//加入互斥锁
$mutex = Mutex::create(true);
for ($i=0;$i<50;$i++){
$threads[$i] = new CounterThread($mutex);
$threads[$i]->start();
}
Mutex::unlock($mutex);
for ($i=0;$i<50;$i++){
$threads[$i]->join();
}
Mutex::destroy($mutex);
?>

   

多線程與共享內存

在共享內存的例子中，沒有使用任何鎖，仍然可能正常工作，可能工作記憶體操作本身俱備鎖的功能

<?php
$tmp = tempnam(__FILE__, &#39;PHP&#39;);
$key = ftok($tmp, &#39;a&#39;);
$shmid = shm_attach($key);
$counter = 0;
shm_put_var( $shmid, 1, $counter );
class CounterThread extends Thread {
public function __construct($shmid){
$this->shmid = $shmid;
}
public function run() {
$counter = shm_get_var( $this->shmid, 1 );
$counter++;
shm_put_var( $this->shmid, 1, $counter );
printf("Thread #%lu says: %s\n", $this->getThreadId(),$counter);
}
}
for ($i=0;$i<100;$i++){
$threads[] = new CounterThread($shmid);
}
for ($i=0;$i<100;$i++){
$threads[$i]->start();
}
for ($i=0;$i<100;$i++){
$threads[$i]->join();
}
shm_remove( $shmid );
shm_detach( $shmid );
?>

   

五、 執行緒同步

有些場景我們不希望thread->start() 就開始執行程序，而是希望執行緒等待我們的指令。 thread−>wait();測作用是thread−>start()後線程並不會立即運行，只有收到thread->notify(); 發出的信號後才運行

<?php
$tmp = tempnam(__FILE__, &#39;PHP&#39;);
$key = ftok($tmp, &#39;a&#39;);
$shmid = shm_attach($key);
$counter = 0;
shm_put_var( $shmid, 1, $counter );
class CounterThread extends Thread {
public function __construct($shmid){
$this->shmid = $shmid;
}
public function run() {
$this->synchronized(function($thread){
$thread->wait();
}, $this);
$counter = shm_get_var( $this->shmid, 1 );
$counter++;
shm_put_var( $this->shmid, 1, $counter );
printf("Thread #%lu says: %s\n", $this->getThreadId(),$counter);
}
}
for ($i=0;$i<100;$i++){
$threads[] = new CounterThread($shmid);
}
for ($i=0;$i<100;$i++){
$threads[$i]->start();
}
for ($i=0;$i<100;$i++){
$threads[$i]->synchronized(function($thread){
$thread->notify();
}, $threads[$i]);
}
for ($i=0;$i<100;$i++){
$threads[$i]->join();
}
shm_remove( $shmid );
shm_detach( $shmid );
?>

   

六、線程池

一個Pool類

<?php
class Update extends Thread {
public $running = false;
public $row = array();
public function __construct($row) {
$this->row = $row;
$this->sql = null;
}
public function run() {
if(strlen($this->row[&#39;bankno&#39;]) > 100 ){
$bankno = safenet_decrypt($this->row[&#39;bankno&#39;]);
}else{
$error = sprintf("%s, %s\r\n",$this->row[&#39;id&#39;], $this->row[&#39;bankno&#39;]);
file_put_contents("bankno_error.log", $error, FILE_APPEND);
}
if( strlen($bankno) > 7 ){
$sql = sprintf("update members set bankno = &#39;%s&#39; where id = &#39;%s&#39;;", $bankno, $this->row[&#39;id&#39;]);
$this->sql = $sql;
}
printf("%s\n",$this->sql);
}
}
class Pool {
public $pool = array();
public function __construct($count) {
$this->count = $count;
}
public function push($row){
if(count($this->pool) < $this->count){
$this->pool[] = new Update($row);
return true;
}else{
return false;
}
}
public function start(){
foreach ( $this->pool as $id => $worker){
$this->pool[$id]->start();
}
}
public function join(){
foreach ( $this->pool as $id => $worker){
$this->pool[$id]->join();
}
}
public function clean(){
foreach ( $this->pool as $id => $worker){
if(! $worker->isRunning()){
unset($this->pool[$id]);
}
}
}
}
try {
$dbh = new PDO("mysql:host=" . str_replace(&#39;:&#39;, &#39;;port=&#39;, $dbhost) . ";dbname=$dbname", $dbuser, $dbpw, array(
PDO::MYSQL_ATTR_INIT_COMMAND => &#39;SET NAMES \&#39;UTF8\&#39;&#39;,
PDO::MYSQL_ATTR_COMPRESS => true
)
);
$sql = "select id,bankno from members order by id desc";
$row = $dbh->query($sql);
$pool = new Pool(5);
while($member = $row->fetch(PDO::FETCH_ASSOC))
{
while(true){
if($pool->push($member)){ //压入任务到池中
break;
}else{ //如果池已经满，就开始启动线程
$pool->start();
$pool->join();
$pool->clean();
}
}
}
$pool->start();
$pool->join();
$dbh = null;
} catch (Exception $e) {
echo &#39;[&#39; , date(&#39;H:i:s&#39;) , &#39;]&#39;, &#39;系统错误&#39;, $e->getMessage(), "\n";
}
?>

   

動態隊列線程池

上面的例子是當線程池滿後執行。

<?php
class Update extends Thread {
public $running = false;
public $row = array();
public function __construct($row) {
$this->row = $row;
$this->sql = null;
//print_r($this->row);
}
public function run() {
if(strlen($this->row[&#39;bankno&#39;]) > 100 ){
$bankno = safenet_decrypt($this->row[&#39;bankno&#39;]);
}else{
$error = sprintf("%s, %s\r\n",$this->row[&#39;id&#39;], $this->row[&#39;bankno&#39;]);
file_put_contents("bankno_error.log", $error, FILE_APPEND);
}
if( strlen($bankno) > 7 ){
$sql = sprintf("update members set bankno = &#39;%s&#39; where id = &#39;%s&#39;;", $bankno, $this->row[&#39;id&#39;]);
$this->sql = $sql;
}
printf("%s\n",$this->sql);
}
}
try {
$dbh = new PDO("mysql:host=" . str_replace(&#39;:&#39;, &#39;;port=&#39;, $dbhost) . ";dbname=$dbname", $dbuser, $dbpw, array(
PDO::MYSQL_ATTR_INIT_COMMAND => &#39;SET NAMES \&#39;UTF8\&#39;&#39;,
PDO::MYSQL_ATTR_COMPRESS => true
)
);
$sql = "select id,bankno from members order by id desc limit 50";
$row = $dbh->query($sql);
$pool = array();
while($member = $row->fetch(PDO::FETCH_ASSOC))
{
$id = $member[&#39;id&#39;];
while (true){
if(count($pool) < 5){
$pool[$id] = new Update($member);
$pool[$id]->start();
break;
}else{
foreach ( $pool as $name => $worker){
if(! $worker->isRunning()){
unset($pool[$name]);
}
}
}
}
}
$dbh = null;
} catch (Exception $e) {
echo &#39;【&#39; , date(&#39;H:i:s&#39;) , &#39;】&#39;, &#39;【系统错误】&#39;, $e->getMessage(), "\n";
}
?>

   

pthreads Pool類

<?php
class WebWorker extends Worker {
public function __construct(SafeLog $logger) {
$this->logger = $logger;
}
protected $loger;
}
class WebWork extends Stackable {
public function isComplete() {
return $this->complete;
}
public function run() {
$this->worker
->logger
->log("%s executing in Thread #%lu",
__CLASS__, $this->worker->getThreadId());
$this->complete = true;
}
protected $complete;
}
class SafeLog extends Stackable {
protected function log($message, $args = []) {
$args = func_get_args();
if (($message = array_shift($args))) {
echo vsprintf(
"{$message}\n", $args);
}
}
}
$pool = new Pool(8, \WebWorker::class, [new SafeLog()]);
$pool->submit($w=new WebWork());
$pool->submit(new WebWork());
$pool->submit(new WebWork());
$pool->submit(new WebWork());
$pool->submit(new WebWork());
$pool->submit(new WebWork());
$pool->submit(new WebWork());
$pool->submit(new WebWork());
$pool->submit(new WebWork());
$pool->submit(new WebWork());
$pool->submit(new WebWork());
$pool->submit(new WebWork());
$pool->submit(new WebWork());
$pool->submit(new WebWork());
$pool->shutdown();
$pool->collect(function($work){
return $work->isComplete();
});
var_dump($pool);

   

七、多取文件安全讀寫程式取得的佔用空間編號入的程序

LOCK_UN 釋放鎖定（無論共享或獨佔）

LOCK_NB 如果不希望flock() 在鎖定時堵塞

<?php
$fp = fopen("/tmp/lock.txt", "r+");
if (flock($fp, LOCK_EX)) { // 进行排它型锁定
ftruncate($fp, 0); // truncate file
fwrite($fp, "Write something here\n");
fflush($fp); // flush output before releasing the lock
flock($fp, LOCK_UN); // 释放锁定
} else {
echo "Couldn&#39;t get the lock!";
}
fclose($fp);
$fp = fopen(&#39;/tmp/lock.txt&#39;, &#39;r+&#39;);
if(!flock($fp, LOCK_EX | LOCK_NB)) {
echo &#39;Unable to obtain lock&#39;;
exit(-1);
}
fclose($fp);
?>

   

、多肉與資料連接時需要注意使用資料連接器一點，需要靜態聲明public static $dbh;並且透過單例模式存取資料庫連接。

進一步改進上面程序，我們使用單例模式$this->worker->getInstance(); 全局僅做一次數據庫連接，線程使用共享的數據庫連接

<?php
class Work extends Stackable {
public function __construct() {
}
public function run() {
$dbh = $this->worker->getConnection();
$sql = "select id,name from members order by id desc limit ";
$row = $dbh->query($sql);
while($member = $row->fetch(PDO::FETCH_ASSOC)){
print_r($member);
}
}
}
class ExampleWorker extends Worker {
public static $dbh;
public function __construct($name) {
}
/*
* The run method should just prepare the environment for the work that is coming ...
*/
public function run(){
self::$dbh = new PDO(&#39;mysql:host=...;dbname=example&#39;,&#39;www&#39;,&#39;&#39;);
}
public function getConnection(){
return self::$dbh;
}
}
$worker = new ExampleWorker("My Worker Thread");
$work=new Work();
$worker->stack($work);
$worker->start();
$worker->shutdown();
?>

   

多線程中操作資料庫總結

總的來說pthreads 仍然處在發展中，仍有一些不足的地方，我們也可以看到pthreads的git在不斷改進這個項目

數據庫持久鏈接很重要，否則每個線程都會開啟一次數據庫連接，然後關閉，會導致很多連結逾時。多執行緒的安裝與使用相關文章請關注PHP中文網！