feature #37519 [Process] allow setting options esp. "create_new_conso…

…le" to detach a subprocess (andrei0x309)

This PR was merged into the 5.2-dev branch.

Discussion
----------

[Process] allow setting options esp. "create_new_console" to detach a subprocess

Process.php to include support for create_new_console (Windows ONLY)

| Q             | A
| ------------- | ---
| Branch?       | master <!-- see below -->
| Bug fix?      |  no
| New feature?  | yes <!-- please update src/**/CHANGELOG.md files -->
| Deprecations? | no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tickets       | #36583 <!-- prefix each issue number with "Fix #", no need to create an issue if none exist, explain below instead -->
| License       | MIT
| Doc PR        | symfony/symfony-docs#... <!-- required for new features -->

Based on this issue: symfony/symfony#36583
I created a quick repo [ https://github.com/andrei0x309/tets_sym_proc]( https://github.com/andrei0x309/tets_sym_proc) to illustrate
how this feature can be used, it essentially lets you run something even if your main script has terminated.

It is useful if you want to create something like
`new Process(['php', 'script_with_long_execution_time.php']);`
This was impossible to do on windows until the **create_new_console** flag was added in PHP 7.4.4.
With this feature Process can be used like this:

```
// Start a process and detach form it on Win only
$process = new Process(['php', 'worker.php']);
$process->setOptions(["create_new_console" => true]); // New method I added
$process->disableOutput();
$process->start();
Process Class behavior will never change if the user doesn't use setWinOptions()
```

Commits
-------

e9ab235b66 [Process] allow setting options esp. "create_new_console" to detach a subprocess

CHANGELOG.md

@@ -1,6 +1,13 @@
 CHANGELOG
 =========
 
+5.2.0
+-----
+
+ * added `Process::setOptions()` to set `Process` specific options
+ * added option `create_new_console` to allow a subprocess to continue
+   to run after the main script exited, both on Linux and on Windows
+
 5.1.0
 -----
 

Process.php

@@ -71,6 +71,7 @@ class Process implements \IteratorAggregate
     private $incrementalErrorOutputOffset = 0;
     private $tty = false;
     private $pty;
+    private $options = ['suppress_errors' => true, 'bypass_shell' => true];
 
     private $useFileHandles = false;
     /** @var PipesInterface */
@@ -196,7 +197,11 @@ public static function fromShellCommandline(string $command, string $cwd = null,
 
     public function __destruct()
     {
-        $this->stop(0);
+        if ($this->options['create_new_console'] ?? false) {
+            $this->processPipes->close();
+        } else {
+            $this->stop(0);
+        }
     }
 
     public function __clone()
@@ -303,10 +308,7 @@ public function start(callable $callback = null, array $env = [])
             $commandline = $this->replacePlaceholders($commandline, $env);
         }
 
-        $options = ['suppress_errors' => true];
-
         if ('\\' === \DIRECTORY_SEPARATOR) {
-            $options['bypass_shell'] = true;
             $commandline = $this->prepareWindowsCommandLine($commandline, $env);
         } elseif (!$this->useFileHandles && $this->isSigchildEnabled()) {
             // last exit code is output on the fourth pipe and caught to work around --enable-sigchild
@@ -332,7 +334,7 @@ public function start(callable $callback = null, array $env = [])
             throw new RuntimeException(sprintf('The provided cwd "%s" does not exist.', $this->cwd));
         }
 
-        $this->process = @proc_open($commandline, $descriptors, $this->processPipes->pipes, $this->cwd, $envPairs, $options);
+        $this->process = @proc_open($commandline, $descriptors, $this->processPipes->pipes, $this->cwd, $envPairs, $this->options);
 
         if (!\is_resource($this->process)) {
             throw new RuntimeException('Unable to launch a new process.');
@@ -1220,6 +1222,32 @@ public function getStartTime(): float
         return $this->starttime;
     }
 
+    /**
+     * Defines options to pass to the underlying proc_open().
+     *
+     * @see https://php.net/proc_open for the options supported by PHP.
+     *
+     * Enabling the "create_new_console" option allows a subprocess to continue
+     * to run after the main process exited, on both Windows and *nix
+     */
+    public function setOptions(array $options)
+    {
+        if ($this->isRunning()) {
+            throw new RuntimeException('Setting options while the process is running is not possible.');
+        }
+
+        $defaultOptions = $this->options;
+        $existingOptions = ['blocking_pipes', 'create_process_group', 'create_new_console'];
+
+        foreach ($options as $key => $value) {
+            if (!\in_array($key, $existingOptions)) {
+                $this->options = $defaultOptions;
+                throw new LogicException(sprintf('Invalid option "%s" passed to "%s()". Supported options are "%s".', $key, __METHOD__, implode('", "', $existingOptions)));
+            }
+            $this->options[$key] = $value;
+        }
+    }
+
     /**
      * Returns whether TTY is supported on the current operating system.
      */

Tests/CreateNewConsoleTest.php

@@ -0,0 +1,45 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Process\Tests;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Process\Process;
+
+/**
+ * @author Andrei Olteanu <[email protected]>
+ */
+class CreateNewConsoleTest extends TestCase
+{
+    public function testOptionCreateNewConsole()
+    {
+        $this->expectNotToPerformAssertions();
+        try {
+            $process = new Process(['php', __DIR__.'/ThreeSecondProcess.php']);
+            $process->setOptions(['create_new_console' => true]);
+            $process->disableOutput();
+            $process->start();
+        } catch (\Exception $e) {
+            $this->fail($e);
+        }
+    }
+
+    public function testItReturnsFastAfterStart()
+    {
+        // The started process must run in background after the main has finished but that can't be tested with PHPUnit
+        $startTime = microtime(true);
+        $process = new Process(['php', __DIR__.'/ThreeSecondProcess.php']);
+        $process->setOptions(['create_new_console' => true]);
+        $process->disableOutput();
+        $process->start();
+        $this->assertLessThan(3000, $startTime - microtime(true));
+    }
+}

Tests/ThreeSecondProcess.php

@@ -0,0 +1,14 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+echo 'Worker started';
+sleep(3);
+echo 'Worker done';