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This article mainly shows you the "sample analysis of Go+Chan+Defer in the PHP collaboration process", which is easy to understand and clear. I hope it can help you solve your doubts. Let the editor lead you to study and study the "sample analysis of Go+Chan+Defer in the PHP collaboration process".

Swoole4 provides a powerful CSP programming model for the PHP language. The bottom layer provides three keywords, which can easily realize all kinds of functions.

The syntax of PHP protocol provided by Swoole4 is borrowed from Golang, and here we pay tribute to the GO development team.

PHP+Swoole and Golang can complement each other well. Golang: static language, rigorous, powerful and good performance, PHP+Swoole: dynamic language, flexible and easy to use

Keywords

Go: create a collaborator

Chan: create a channel

Defer: deferred task, executed when the collaborator exits, first in and then out

The underlying implementations of these three functions are all memory operations without any IO resource consumption. Like PHP's Array, it's very cheap. You can use it directly if necessary. This is different from socket and file operations, which require port and file descriptors from the operating system, and read and write may result in blocked IO waits.

Cooperative program concurrency

Using the go function allows a function to execute concurrently. During programming, if a piece of logic can be executed concurrently, it can be executed in a go protocol.

Sequential execution

Function test1 () {sleep (1); echo "b";} function test2 () {sleep (2); echo "c";} test1 (); test2 ()

Execution result:

Htf@LAPTOP-0K15EFQI:~$ time php b1.php bc real 0m3.080s user 0m0.016s sys 0m0.063s htf@LAPTOP-0K15EFQI:~$

In the above code, test1 and test2 are executed sequentially and take 3 seconds to complete.

Concurrent execution

Using go to create a co-program, you can make the test1 and test2 functions execute concurrently.

Swoole\ Runtime::enableCoroutine (); go (function () {sleep (1); echo "b";}); go (function () {sleep (2); echo "c";})

The function of Swoole\ Runtime::enableCoroutine () is to switch stream, sleep, pdo, mysqli, redis and other functions provided by PHP from synchronous blocking to asynchronous IO of cooperative programs.

Execution result:

Bchtf@LAPTOP-0K15EFQI:~$ time php co.php bc real 0m2.076s user 0m0.000s sys 0m0.078s htf@LAPTOP-0K15EFQI:~$

You can see that it only took 2 seconds to complete the execution here.

The time taken to execute sequentially is equal to the sum of the time spent on the execution of all tasks: T1, complete, T2, and T3.

Concurrent execution time is equal to the * value of all task execution time: max (T1, T2, T3,...)

Cooperative communication

With the go keyword, concurrent programming is much easier. At the same time, it brings a new problem. If there are two co-programs executing concurrently and the other co-program needs to rely on the execution results of these two co-programs, what if this problem is solved?

The answer is to use a Channel, which can be created by using new chan in the Swoole4 protocol. A channel can be understood as a queue with its own cooperative scheduling. It has two interfaces, push and pop:

Push: writes content to the channel. If it is full, it will enter the waiting state and resume automatically when space is available.

Pop: read the content from the channel. If it is empty, it will enter the waiting state and recover automatically when data is available.

Concurrency management can be easily achieved by using channels.

$chan = new chan (2); # Synergy 1 go (function () use ($chan) {$result = []; for ($I = 0; $I)

Pop ();} var_dump ($result);}) # go (function () use ($chan) {$cli = new Swoole\ Coroutine\ Http\ Client ('www.qq.com', 80); $cli- > set ([' timeout' = > 10]) $cli- > setHeaders (['Host' = > "www.qq.com", "User-Agent" = >' Chrome/49.0.2587.3', 'Accept' = >' text/html,application/xhtml+xml,application/xml', 'Accept-Encoding' = >' gzip',]); $ret = $cli- > get ('/') / / $cli- > body response content is too large. Here we use the Http status code to test $chan- > push (['www.qq.com' = > $cli- > statusCode]);}); # function () use ($chan) {$cli = new Swoole\ Coroutine\ Http\ Client (' www.163.com', 80); $cli- > set (['timeout' = > 10]) $cli- > setHeaders (['Host' = > "www.163.com", "User-Agent" = >' Chrome/49.0.2587.3', 'Accept' = >' text/html,application/xhtml+xml,application/xml', 'Accept-Encoding' = >' gzip',]); $ret = $cli- > get ('/') / / $cli- > body response content is too large. Use the Http status code to test $chan- > push (['www.163.com' = > $cli- > statusCode]);})

Execution result:

Htf@LAPTOP-0K15EFQI:~/swoole-src/examples/5.0$ time php co2.php array (2) {["www.qq.com"] = > int ["www.163.com"] = > int} real 0m0.268s user 0m0.016s sys 0m0.109s htf@LAPTOP-0K15EFQI:~/swoole-src/examples/5.0 $

Here, three collaborators are created using go, and Synergy 2 and 3 request the qq.com and 163.com homepages, respectively. Process 1 needs to get the result of the Http request. Chan is used here to implement concurrency management.

Coprogram 1 pop the channel twice, because the queue is empty, it will enter the waiting state

After the execution of program 2 and program 3 is completed, the data will be push, and program 1 will get the result and continue to execute downward.

Delayed task

In collaborative programming, it may be necessary to automatically perform some tasks and clean up when the collaborative program exits. Similar to PHP's register_shutdown_function, it can be implemented using defer in Swoole4.

Swoole\ Runtime::enableCoroutine (); go (function () {echo "a"; defer (function () {echo "~ a";}); echo "b"; defer (function () {echo "~ b";}); sleep (1); echo "c";})

Execution result:

Htf@LAPTOP-0K15EFQI:~/swoole-src/examples/5.0$ time php defer.php abc~b~a real 0m1.068s user 0m0.016s sys 0m0.047s htf@LAPTOP-0K15EFQI:~/swoole-src/examples/5.0$ above is all the content of the article "sample Analysis of Go+Chan+Defer in PHP collaboration". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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