(note slides are missing animated gifs and video) As PHP programmers we are used to waiting for network I/O, in general we may not even consider any other option. But why wait? Why not jump on board the Async bullet-train and experience life in the fast lane and give Go and NodeJS a run for the money. This talk will aim to make the audience aware of the benefits, opportunities, and pitfalls of asynchronous programming in PHP, and guide them through the native functionality, frameworks and PHP extensions though which it can be facilitated.

1. Exploring Async PHP
@dantleech
Symfony Live Berlin 27th
September 2019

2. MySQL

3. SLOW

4. HTTP Requests

5. SLOW

6. REDIS

7. SLOW

8. Elastic

9. SLOW

10. TL;DR;

11. SLOW
Network I/O

12. Array TCP Connect TCP Read HTTP GET (local) HTTP GET (network) HTP GET (internet)
3 432 595 1,084
9,221
94,348

13. Product Import

14. News Website

15. DEPENDENCIES
Operations with no un-resolved dependencies
can be parallezied

16. (Application)
User Widget
Menu
Nodes
RSS Feed
Category
Widget
URL 1 URL 2 URL ...

17. What can we make with
an Async PHP?

18. Concurrrent I/O
HTTP Requests
Database Queries
Child Processes

19. HTTP Server
Web Socket Servers
Long Running Processes...
Web Crawlers!
Development tools
Daemons

21. STREAMS

22. Streams
•
Abstraction layer for resources: file://, http://,
tcp://, etc
•
Can be read from and written to incrementally
•
Can be non blocking

23. 1: File get contents
<?php
echo file_get_contents('http://localhost:8080?sleep=1');

25. 2: Stream socket client
<?php
$stream = stream_socket_client('tcp://localhost:8080');
fwrite($stream, "GET /?sleep=1 HTTP/1.0rnrn");
echo stream_get_contents($stream);

27. 3: Stream set blocking
<?php
$stream = stream_socket_client('tcp://localhost:8080');
stream_set_blocking($stream, false);
echo stream_get_contents($read[0]);
die(‘Hello World’);

29. 3: Stream set blocking
<?php
$stream = stream_socket_client('tcp://localhost:8080');
stream_set_blocking($stream, false);
fwrite($stream, "GET /?sleep=1 HTTP/1.0rnrn");
$write = $except = null;
$read = [ $stream ];
stream_select($read, $write, $except, null);
echo stream_get_contents($read[0]);

31. 4: Multiple Requests<?php
$stream1 = create_non_blocking_get('tcp://localhost:8080', ‘/?sleep=1’);
$stream2 = create_non_blocking_get('tcp://localhost:8080', ‘/?sleep=1’);
$await = [ $stream1, $stream2 ];
$write = $except = null;
while ($await) {
$read = $await;
stream_select($read, $write, $except, null);
foreach ($read as $stream) {
echo stream_get_contents($stream) . PHP_EOL;
unset($await[array_search($stream, $await)]);
fclose($stream);
}
}

33. Amphp
•
Born 2013
•
Redis Client
•
MySQL Client
•
Promises
•
Coroutines
•
Event Loop

34. EVENT LOOP

37. Event Loop
<?php
$stream = create_non_blocking_get('tcp://localhost:8080', ‘/?sleep=1’);
Loop::onReadable($stream, function ($watcherId, $stream) {
echo stream_get_contents($stream);
});
Loop::run();

38. PROMISES

39. No Promise
<?php
http_request("http://example/.com/foobar", function ($response) {
echo $response->getStatusCode();
});

40. Promise
<?php
http_request("http://example/.com/foobar")->onResolve(function ($failure, $response) {
echo $response->getStatusCode();
});

41. Multiple Promise
<?php
$promise1 = http_request("http://example/.com/foobar");
$promise2 = http_request("http://example/.com/barfoo");
$results = wait ( all ($promise1, $promise2));
echo $promise1->getStatusCode();
echo $promise2->getStatusCode();

42. You can yield a promise ...

43. COROUTINES

44. CO-
ROUTINE
CO-
ROUTINE
CO-
ROUTINE
CO-
ROUTINE
Event Loop (scheduler)

45. Coroutine Example
<?php
call(function () {
$response = yield http_request("http://example/.com/foobar");
echo $reponse->getStatusCode();
$body = yield $response->getBody();
echo $body;
});
call(function () {
$response = yield http_request("http://example/.com/barfoo");
});

46. LET’S
BUILD A CI
SYSTEM

47. <?php
class Runner
{
public function __construct(Workspace $workspace, array $scripts) { /** ... */ }
public function run(): int { /** ... */ }
private function runRepos(): Promise { /** ... */ }
private function runRepo($repoUrl, $scripts, int $color): Promise { /** ... */ }
private function runCommand(string $command, $cwd, int $color): Promise { /** ... */ }
private function display(ProcessInputStream $processInputStream, $color) { /** ... */ }
}

48. $runner = new Runner(
new Workspace(__DIR__ . '/../Workspace'),
[
'git@github.com:dantleech/fink' => [
'composer install --prefer-dist',
'vendor/bin/phpunit',
'vendor/bin/phpstan analyse --level=7',
],
'git@github.com:phpactor/path-finder' => [
'composer install',
'./vendor/bin/phpunit',
'vendor/bin/phpstan analyse --level=7',
]
]
);
$aggregateExitCode = $runner->run();
sprintf('Aggregate exit code: %s', $aggregateExitCode) . PHP_EOL;
exit($aggregateExitCode);

49. class Runner
{
/**
* @var array
*/
private $scripts;
/**
* @var Workspace
*/
private $workspace;
public function __construct(Workspace $workspace, array $scripts)
{
$this->scripts = $scripts;
$this->workspace = $workspace;
}
// ...

50. class Runner
{
// ...
public function run(): int
{
$this->workspace->reset();
$exitCodes = wait ( $this->runRepos());
return array_sum($exitCodes);
}

51. class Runner
{
// ...
private function runRepos(): Promise
{
$exitCodePromises = [];
$color = 31;
foreach ($this->scripts as $repoUrl => $scripts) {
$color++;
$exitCodePromises[] = $this->runRepo($repoUrl, $scripts, $color);
}
return all($exitCodePromises);
}

52. class Runner
{
// ...
private function runRepo($repoUrl, $scripts, int $color): Promise
{
return call(function () use ($repoUrl, $scripts, $color) {
$repoPath = $this->workspace->path(basename($repoUrl));
$exitCode = yield $this->runCommand(sprintf(
'git clone %s %s',
$repoUrl,
$repoPath,
), $this->workspace->path('/'), $color);
foreach ($scripts as $script) {
$exitCode += yield $this->runCommand($script, $repoPath, $color);
}
return $exitCode;
});
}

53. class Runner
{
// ...
private function runCommand(string $command, string $cwd, int $color): Promise
{
return call(function () use ($command, $cwd, $color) {
$process = new Process($command, $cwd);
$pid = yield $process->start();
$this->display($process->getStdout(), $color);
$this->display($process->getStderr(), $color);
$exitCode = yield $process->join();
return $exitCode;
});
}

54. class Runner
{
// ...
private function display(ProcessInputStream $processInputStream, $color): void
{
asyncCall(function () use ($processInputStream, $color) {
while (null !== $chunk = yield $processInputStream->read()) {
echo sprintf("033[%sm%s033[0m", $color, $chunk);
};
});
}

56. Other Frameworks

57. React PHP
•
Born 2012
•
Redis Client
•
MySQL Client
•
Promises
•
Event Emitter
•
Event Loop

59. Swoole
•
Born 2012
•
Redis Client
•
MySQL Client
•
Promises
•
Coroutines
•
Event Loop

60. PHP Extension
CLI Only

61. Can out perform Go and
NodeJS*
… at some things

63. Build cool things

64. Build an asyncrhronous
CMS in PHP

65. @dantleech
Talk to me about Phpbench and Phpactor
Works for in Berlin
Examples for this talk: https://github.com/dantleech/2019-exploring-async