Thread pools and asynchronous programming practices in PHP

In recent years, PHP developers have developed many concurrent programming technologies, among which thread pools and asynchronous programming are the most widely used. This article will introduce the basic concepts of thread pools and asynchronous programming and their practical application in PHP.

1. The concept of thread pool

Thread pool is a common technology in the field of concurrent programming. It is a thread collection composed of a group of threads. This group of threads has been created when the program is initialized and is waiting to process tasks. Using thread pools can optimize system performance and reduce resource consumption.

The main idea of ​​the thread pool is to submit tasks to the thread pool, and the thread pool will uniformly manage the execution of the tasks and reuse the created threads to reduce the overhead caused by thread creation and destruction.

The implementation process of the thread pool includes a series of operations such as the creation of threads, the enqueuing of tasks to be processed, the threads in the thread pool executing tasks, and the threads that have completed the tasks return to the thread pool. In the thread pool, in order to avoid interference between threads, shared variables need to be synchronized and mutually exclusive.

2. The concept of asynchronous programming

Asynchronous programming is an event-driven programming method. It can process other tasks or perform other operations during the waiting time of task execution, making it easy to implement non-stop programming. Blocking IO operations. PHP provides many asynchronous programming technologies, such as swoole, ReactPHP, Amp, etc.

Example:

function handle($socket)
{

echo "New Connection

";
}

$socket = stream_socket_server("tcp://0.0.0.0:8001", $errno, $errstr);

stream_set_blocking($socket, 0);

$event = $loop->addReadStream($socket, function($socket) {

$client = stream_socket_accept($socket);
handle($client);

});

$loop->run();

above In the example, the stream_set_blocking function sets the $socket socket to non-blocking mode, which means that the socket will not be blocked all the time, but only wakes up the process listening to the socket when data arrives. On the other hand, in the event loop The addReadStream() method listens to the readable event of the socket, and when the event occurs, execute the handle() function.

3. Practical application in PHP

Thread pool technology in PHP This can be achieved using the multi-thread extension pthreads. The multi-thread extension phtreds can support the creation and destruction of threads, as well as synchronization and mutual exclusion operations between threads. At the same time, developers can use thread pool technology to optimize program performance and reduce resource consumption.

Asynchronous programming technology in PHP is also very powerful. Currently, the more popular implementation methods are swoole and ReactPHP. These technologies can provide non-blocking IO operations and can directly solve the problem of PHP blocking IO in terms of run time.

4. Summary

Thread pool and asynchronous programming are two different concurrent programming technologies. They both help to improve the running efficiency and performance of the program. The thread pool is used to manage multiple threads and implement Reuse of tasks reduces the overhead of thread creation and destruction. Asynchronous programming is used to convert the execution flow of the program into an event-driven process to achieve efficient non-blocking IO operations.

In the practice of PHP developers, threads Pool and asynchronous programming technology have also been widely used to improve program performance and operating efficiency.

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