Scheduler - configurable maximum number of processes (threads to use)

ondrejmirtes · ondrejmirtes · commit 71bda0984b2e · 2020-02-16T14:11:08.000+01:00
diff --git a/conf/config.neon b/conf/config.neon
@@ -41,6 +41,7 @@ parameters:
 	parallel:
 		jobSize: 20
 		processTimeout: 60.0
+		maximumNumberOfProcesses: 32
 	polluteScopeWithLoopInitialAssignments: true
 	polluteScopeWithAlwaysIterableForeach: true
 	polluteCatchScopeWithTryAssignments: false
@@ -150,7 +151,8 @@ parametersSchema:
 	reportStaticMethodSignatures: bool()
 	parallel: structure([
 		jobSize: int(),
-		processTimeout: float()
+		processTimeout: float(),
+		maximumNumberOfProcesses: int()
 	])
 	polluteScopeWithLoopInitialAssignments: bool()
 	polluteScopeWithAlwaysIterableForeach: bool()
@@ -385,6 +387,7 @@ services:
 		class: PHPStan\Parallel\Scheduler
 		arguments:
 			jobSize: %parallel.jobSize%
+			maximumNumberOfProcesses: %parallel.maximumNumberOfProcesses%
 
 	-
 		class: PHPStan\Parser\CachedParser
diff --git a/src/Parallel/Scheduler.php b/src/Parallel/Scheduler.php
@@ -8,9 +8,16 @@ class Scheduler
 	/** @var int */
 	private $jobSize;
 
-	public function __construct(int $jobSize)
+	/** @var int */
+	private $maximumNumberOfProcesses;
+
+	public function __construct(
+		int $jobSize,
+		int $maximumNumberOfProcesses
+	)
 	{
 		$this->jobSize = $jobSize;
+		$this->maximumNumberOfProcesses = $maximumNumberOfProcesses;
 	}
 
 	/**
@@ -26,7 +33,7 @@ public function scheduleWork(
 		$jobs = array_chunk($files, $this->jobSize);
 		$numberOfProcesses = min(count($jobs), $cpuCores);
 
-		return new Schedule($numberOfProcesses, $jobs);
+		return new Schedule(min($numberOfProcesses, $this->maximumNumberOfProcesses), $jobs);
 	}
 
 }
diff --git a/tests/PHPStan/Parallel/SchedulerTest.php b/tests/PHPStan/Parallel/SchedulerTest.php
@@ -12,19 +12,30 @@ public function dataSchedule(): array
 		return [
 			[
 				1,
+				16,
 				50,
 				115,
 				1,
 				[50, 50, 15],
 			],
 			[
+				16,
 				16,
 				30,
 				124,
 				5,
 				[30, 30, 30, 30, 4],
 			],
 			[
+				16,
+				3,
+				30,
+				124,
+				3,
+				[30, 30, 30, 30, 4],
+			],
+			[
+				16,
 				16,
 				10,
 				298,
@@ -37,21 +48,23 @@ public function dataSchedule(): array
 	/**
 	 * @dataProvider dataSchedule
 	 * @param int $cpuCores
+	 * @param int $maximumNumberOfProcesses
 	 * @param int $jobSize
 	 * @param int $numberOfFiles
 	 * @param int $expectedNumberOfProcesses
 	 * @param array<int> $expectedJobSizes
 	 */
 	public function testSchedule(
 		int $cpuCores,
+		int $maximumNumberOfProcesses,
 		int $jobSize,
 		int $numberOfFiles,
 		int $expectedNumberOfProcesses,
 		array $expectedJobSizes
 	): void
 	{
 		$files = array_fill(0, $numberOfFiles, 'file.php');
-		$scheduler = new Scheduler($jobSize);
+		$scheduler = new Scheduler($jobSize, $maximumNumberOfProcesses);
 		$schedule = $scheduler->scheduleWork($cpuCores, $files);
 
 		$this->assertSame($expectedNumberOfProcesses, $schedule->getNumberOfProcesses());

Original file line number	Diff line number	Diff line change
`@@ -8,9 +8,16 @@ class Scheduler`
`8`	`8`	`/** @var int */`
`9`	`9`	`private $jobSize;`
`10`	`10`
`11`		`- public function __construct(int $jobSize)`
	`11`	`+ /** @var int */`
	`12`	`+ private $maximumNumberOfProcesses;`
	`13`	`+`
	`14`	`+ public function __construct(`
	`15`	`+ int $jobSize,`
	`16`	`+ int $maximumNumberOfProcesses`
	`17`	`+ )`
`12`	`18`	`{`
`13`	`19`	`$this->jobSize = $jobSize;`
	`20`	`+ $this->maximumNumberOfProcesses = $maximumNumberOfProcesses;`
`14`	`21`	`}`
`15`	`22`
`16`	`23`	`/**`
`@@ -26,7 +33,7 @@ public function scheduleWork(`
`26`	`33`	`$jobs = array_chunk($files, $this->jobSize);`
`27`	`34`	`$numberOfProcesses = min(count($jobs), $cpuCores);`
`28`	`35`
`29`		`- return new Schedule($numberOfProcesses, $jobs);`
	`36`	`+ return new Schedule(min($numberOfProcesses, $this->maximumNumberOfProcesses), $jobs);`
`30`	`37`	`}`
`31`	`38`
`32`	`39`	`}`