如何在php中跨线程共享全局变量?
在多线程中,全局变量或资源在线程之间共享。 我正在c中使用pthread库如何在php中跨线程共享全局变量?,php,multithreading,pthreads,Php,Multithreading,Pthreads,在多线程中,全局变量或资源在线程之间共享。 我正在c中使用pthread库 #include <stdio.h> #include <pthread.h> #include <unistd.h> void *worker(void *); int ctr = 0; pthread_mutex_t lock; int main(int argc, char *argv[]) { pthread_t t[2]; int i = 0; //~ pth
#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
void *worker(void *);
int ctr = 0;
pthread_mutex_t lock;
int main(int argc, char *argv[])
{
pthread_t t[2];
int i = 0;
//~ pthread_mutex_init(&lock, NULL);
while(i < 2)
{
pthread_create(&t[i], NULL, &worker, NULL);
i++;
}
pthread_join(t[0], NULL);
pthread_join(t[1], NULL);
//~ pthread_mutex_destroy(&lock);
//~ pthread_join(t[1], NULL);
return 0;
}
void *worker(void *arg)
{
//~ pthread_mutex_lock(&lock);
//~ int ctr = 0;
ctr += 1;
printf("job %d started\n", ctr);
sleep(1);
//~ ctr += 1;
printf("job %d finished\n", ctr);
//~ pthread_mutex_unlock(&lock);
}
在该代码中,变量ctr
在线程之间共享,因此其他线程对该变量所做的更改对另一个线程可见(除非调用了一些互斥体
)
我曾在php中尝试过,但没有成功(使用PHPPThreads
)。
这是我的php代码:
global $ctr;
Class WorkerThread extends Worker
{
private $thread_id;
//~ public static $ctr = 0;
private $mutext;
public function WorkerThread($mutex = NULL)
{
//~ $this->ctr = $ctr;
$this->mutex = $mutex;
$this->start();
}
public function run()
{
//~ Mutex::lock($this->mutex);
$new_line = php_sapi_name() == "cli" ? PHP_EOL : "<br>";
//~ global $ctr;
$ctr = 0;
$ctr += 1;
echo "Thread " . $ctr . " started" . " [ " . $this->getThreadId() . " ]" . $new_line;
sleep(1);
echo "Thread " . $ctr . " Finished" . " [ " . $this->getThreadId() . " ]" . $new_line;
//~ var_dump($this);
//~ Mutex::unlock($this->mutex);
}
}
//~ $mutex = Mutex::create();
$i = 0;
$worker = array();
while($i < 2)
{
$worker[$i] = new WorkerThread();
//~ $worker[$i]->start();
$i++;
}
foreach(range(0, 1) as $t)
$worker[$t]->join();
//~ Mutex::destroy($mutex);
变量ctr
(全局)没有像上面的c代码那样由线程更新吗
在php中如何实现这一点(跨线程共享资源)?通常,线程与启动它们的进程在相同的地址空间中执行 因此,在C中,新线程能够直接访问主程序堆栈上的变量 在PHP中创建新线程时,它有一个单独的堆,必须在单独的地址空间中执行 这意味着默认情况下,您不能在线程之间共享全局状态 这是PHP的正常线程模型-不共享任何内容 pthreads所做的是引入能够在许多上下文中操作的对象,并且能够在这些上下文之间共享数据 等效的PHP代码可能类似于:
<?php
class Atomic extends Threaded {
public function __construct($value = 0) {
$this->value = $value;
}
public function inc() {
return $this->value++;
}
/* ... */
private $value;
}
class Test extends Thread {
public function __construct(Atomic $atomic) {
$this->atomic = $atomic;
}
public function run() {
$this->atomic->inc();
}
private $atomic;
}
$atomic = new Atomic();
$threads = [];
for ($thread = 0; $thread < 2; $thread++) {
$threads[$thread] = new Test($atomic);
$threads[$thread]->start();
}
foreach ($threads as $thread)
$thread->join();
var_dump($atomic);
?>
最后,给事物命名的一课
您似乎觉得Posix线程(标准,pthread)和pthreads(PHP扩展)之间有一些相似之处,这是可以原谅的
pthreads
,PHP扩展恰好使用Posix线程,但它没有实现任何类似Posix线程的功能
名称pthreads
应表示PHP线程。。。给事物命名很难
Thread 1 started [ -1257948352 ]
Thread 1 started [ -1267893440 ]
Thread 1 Finished [ -1257948352 ]
Thread 1 Finished [ -1267893440 ]
<?php
class Atomic extends Threaded {
public function __construct($value = 0) {
$this->value = $value;
}
public function inc() {
return $this->value++;
}
/* ... */
private $value;
}
class Test extends Thread {
public function __construct(Atomic $atomic) {
$this->atomic = $atomic;
}
public function run() {
$this->atomic->inc();
}
private $atomic;
}
$atomic = new Atomic();
$threads = [];
for ($thread = 0; $thread < 2; $thread++) {
$threads[$thread] = new Test($atomic);
$threads[$thread]->start();
}
foreach ($threads as $thread)
$thread->join();
var_dump($atomic);
?>
public function run() {
$this->atomic->synchronized(function($atomic){
/* exclusive */
$atomic->inc();
}, $this->atomic);
}