本文实例讲述了PHP实现简单的协程任务调度。分享给大家供大家参考，具体如下：
<?php
class Task
{
protected $taskId;
protected $coroutine;
protected $sendValue = null;
protected $beforeFirstYield = true;
public function __construct($taskId, Generator $coroutine)
{
$this->taskId = $taskId;
$this->coroutine = $coroutine;
}
public function getTaskId()
{
return $this->taskId;
}
public function setSendValue($sendValue)
{
$this->sendValue = $sendValue;
}
public function run()
{
if ($this->beforeFirstYield) {
$this->beforeFirstYield = false;
return $this->coroutine->current();
} else {
$retval = $this->coroutine->send($this->sendValue);
$this->sendValue = null;
return $retval;
}
}
public function isFinished()
{
return !$this->coroutine->valid();
}
}
class Scheduler
{
protected $maxTaskId = 0;
protected $taskMap = []; // taskId => task
protected $taskQueue;
public function __construct()
{
$this->taskQueue = new SplQueue();
}
public function newTask(Generator $coroutine)
{
$tid = ++$this->maxTaskId;
$task = new Task($tid, $coroutine);
$this->taskMap[$tid] = $task;
$this->schedule($task);
return $tid;
}
public function schedule(Task $task)
{
$this->taskQueue->enqueue($task);
}
public function run()
{
while (!$this->taskQueue->isEmpty()) {
$task = $this->taskQueue->dequeue();
$task->run();
if ($task->isFinished()) {
unset($this->taskMap[$task->getTaskId()]);
} else {
$this->schedule($task);
}
}
}
}
function task1()
{
for ($i = 1; $i <= 10; ++$i) {
echo "This is task 1 iteration $i.\n";
sleep(1);
yield;
}
}
function task2()
{
for ($i = 1; $i <= 10; ++$i) {
echo "This is task 2 iteration $i.\n";
sleep(1);
yield;
}
}
$scheduler = new Scheduler;
$scheduler->newTask(task1());
$scheduler->newTask(task2());
$scheduler->run();
运行结果：
This is task 1 iteration 1.
This is task 1 iteration 2.
This is task 1 iteration 3.
This is task 1 iteration 4.
This is task 1 iteration 5.
This is task 1 iteration 6.
This is task 1 iteration 7.
This is task 1 iteration 8.
This is task 1 iteration 9.
This is task 1 iteration 10.
希望本文所述对大家PHP程序设计有所帮助。
