Make sure process starts with no output

src/ProcessPool.php

@@ -173,6 +173,20 @@ public function startProcess(): ProcessPoolRequest
 		$proc = array_pop($this->unassignedProcs);
 		$this->runningProcs[] = $proc;
 
+		// Make sure output is cleared
+		if ($proc->hasStderrData() || $proc->hasStdoutData())
+		{
+			$stderrLines = [];
+			$stdoutLines = [];
+			while ($proc->hasStderrData())
+				$stderrLines[] = $proc->getStderrResponse();
+			while ($proc->hasStdoutData())
+				$stdoutLines[] = $proc->getStdoutResponse();
+			$proc->markAsFailed();
+			$this->releaseProcess($proc);
+			throw new ProcessPoolProcessOutputBeforeStartingException($stderrLines, $stdoutLines);
+		}
+
 		return $proc;
 	}
 

src/ProcessPoolProcessOutputBeforeStartingException.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace ssigwart\ProcessPool;
+
+/** Process pool exception that is thrown if a newly started process already has STDOUT or STDERR output */
+class ProcessPoolProcessOutputBeforeStartingException extends ProcessPoolException
+{
+	/** @var string[] STDERR lines */
+	private array $stderrLines = [];
+
+	/** @var string[] STDOUT lines */
+	private array $stdoutLines = [];
+
+	/**
+	 * Constructor
+	 *
+	 * @param string[] $stderrLines STDERR lines
+	 * @param string[] $stdoutLines STDOUT lines
+	 */
+	public function __construct(array $stderrLines, array $stdoutLines)
+	{
+		$this->stderrLines = $stderrLines;
+		$this->stdoutLines = $stdoutLines;
+	}
+
+	/**
+	 * Get STDERR lines
+	 *
+	 * @return string[] STDERR lines
+	 */
+	public function getStderrLines(): array
+	{
+		return $this->stderrLines;
+	}
+
+	/**
+	 * Get STDOUT lines
+	 *
+	 * @return string[] STDOUT lines
+	 */
+	public function getStdoutLines(): array
+	{
+		return $this->stdoutLines;
+	}
+}

tests/.phpunit.result.cache

@@ -1 +1 @@
-{"version":1,"defects":{"ProcessPoolTest::testProcessPool":3,"ProcessPoolTest::testProcessPoolErrors":3,"ProcessPoolTest::testProcessPoolWithLongMessage":4,"ProcessPoolTest::testInvalidResponse":3,"ProcessPoolTest::testProcessPoolNoRelease":3,"ProcessPoolTest::testProcessPoolWithLongResponse":4,"ProcessPoolTest::testProcessPoolEndOfFile":4,"ProcessPoolRequestTest::testProcessPoolEndOfFile":3,"ProcessPoolRequestTest::testProcessPoolInvalidMessage":3,"ProcessPoolTest::testProcessPoolWithLongStderrResponse":3,"ProcessPoolRequestTest::testProcessPoolParentClosedInput":3,"ProcessPoolRequestTest::testProcessPoolHangOnExit":4,"ProcessPoolTest::testProcessPoolExit":3,"ProcessPoolTest::testProcessPoolSlientExit":4,"ProcessPoolTest::testProcessPoolSilentExit":3,"ProcessPoolTest::testProcessPoolExitHang":3,"ProcessPoolRequestTest::testPeek":3,"ProcessPoolRequestTest::testWaitForStdoutOrStderr":4,"ProcessPoolRequestTest::testWaitForStderr":3,"ProcessPoolRequestTest::testWaitForStdout":3,"ProcessPoolTest::testProcessPoolShutDown":3,"ProcessPoolTest::testProcessPoolNoReadBeforeRelease":3,"ProcessPoolTest::testProcessPoolMarkedAsFailed":3},"times":{"ProcessPoolTest::testInvalidResponse":0.007,"ProcessPoolTest::testInvalidMaxSpares":0.003,"ProcessPoolTest::testProcessPool":0.444,"ProcessPoolTest::testProcessPoolErrors":0.107,"ProcessPoolTest::testProcessPoolNoRelease":0.098,"ProcessPoolTest::testProcessPoolWithLongMessage":0.096,"ProcessPoolTest::testProcessPoolWithLongWriteMessage":0.122,"ProcessPoolTest::testProcessPoolWithLongResponse":0.097,"ProcessPoolTest::testProcessPoolWithLongStderrResponse":0.15,"ProcessPoolTest::testProcessPoolEndOfFile":0.099,"ProcessPoolRequestTest::testProcessPoolEndOfFile":0.092,"ProcessPoolRequestTest::testProcessPoolInvalidMessage":0.209,"ProcessPoolRequestTest::testProcessPoolParentClosedInput":0.126,"ProcessPoolRequestTest::testProcessPoolHangOnExit":0.251,"ProcessPoolTest::testProcessPoolExit":0.097,"ProcessPoolTest::testProcessPoolSlientExit":0.101,"ProcessPoolTest::testProcessPoolSilentExit":0.099,"ProcessPoolTest::testProcessPoolExitHang":0.108,"ProcessPoolRequestTest::testPeek":0.113,"ProcessPoolRequestTest::testWaitForStdoutOrStderr":0.1,"ProcessPoolRequestTest::testWaitForStdout":0.113,"ProcessPoolRequestTest::testWaitForStderr":0.124,"ProcessPoolTest::testProcessPoolShutDown":0.131,"ProcessPoolTest::testProcessPoolNoReadBeforeRelease":0.101,"ProcessPoolTest::testProcessPoolNoReadBeforeRead":0.103,"ProcessPoolTest::testProcessPoolMarkedAsFailed":0.19}}
+{"version":1,"defects":{"ProcessPoolRequestTest::testWaitForStdout":3,"ProcessPoolRequestTest::testWaitForStderr":3,"ProcessPoolRequestTest::testProcessPoolInvalidMessage":3,"ProcessPoolRequestTest::testProcessPoolParentClosedInput":3,"ProcessPoolTest::testProcessPool":3,"ProcessPoolTest::testProcessPoolErrors":3,"ProcessPoolTest::testProcessPoolMarkedAsFailed":3,"ProcessPoolTest::testProcessPoolErrorBeforeResponse":3,"ProcessPoolTest::testProcessPoolNoReadBeforeRead":3,"ProcessPoolTest::testProcessPoolWithLongMessage":3,"ProcessPoolTest::testProcessPoolWithLongResponse":3,"ProcessPoolTest::testProcessPoolWithLongStderrResponse":3,"ProcessPoolTest::testProcessPoolExit":3,"ProcessPoolTest::testProcessPoolExitHang":3,"ProcessPoolTest::testProcessPoolShutDown":3},"times":{"ProcessPoolRequestTest::testWaitForStdout":0.109,"ProcessPoolRequestTest::testWaitForStderr":0.117,"ProcessPoolRequestTest::testProcessPoolInvalidMessage":0.211,"ProcessPoolRequestTest::testProcessPoolParentClosedInput":0.115,"ProcessPoolTest::testInvalidMaxSpares":0.002,"ProcessPoolTest::testProcessPool":0.454,"ProcessPoolTest::testProcessPoolErrors":0.111,"ProcessPoolTest::testProcessPoolMarkedAsFailed":0.197,"ProcessPoolTest::testProcessPoolErrorBeforeResponse":0.473,"ProcessPoolTest::testProcessPoolNoReadBeforeRead":0.101,"ProcessPoolTest::testProcessPoolWithLongMessage":0.093,"ProcessPoolTest::testProcessPoolWithLongResponse":0.092,"ProcessPoolTest::testProcessPoolWithLongStderrResponse":0.092,"ProcessPoolTest::testProcessPoolExit":0.092,"ProcessPoolTest::testProcessPoolSilentExit":0.097,"ProcessPoolTest::testProcessPoolExitHang":0.094,"ProcessPoolTest::testProcessPoolShutDown":0.119}}

tests/TestAuxFiles/PhpUnitTestProcess.php

@@ -63,6 +63,13 @@ public function handleRequest(string $data)
 		// Check if we should output request count
 		else if ($data === 'req-count')
 			print $this->numRequests;
+		// Check if we should test error with late STDOUT
+		else if ($data === 'error-late-stdout')
+		{
+			fwrite(STDERR, 'Error, then sleep.');
+			usleep(20000);
+			print 'Done sleep';
+		}
 		else
 		{
 			// Output MD5 of data

tests/TestCases/ProcessPoolTest.php

@@ -7,6 +7,7 @@
 use ssigwart\ProcessPool\ProcessPool;
 use ssigwart\ProcessPool\ProcessPoolException;
 use ssigwart\ProcessPool\ProcessPoolPoolExhaustedException;
+use ssigwart\ProcessPool\ProcessPoolProcessOutputBeforeStartingException;
 
 /**
  * Process pool test
@@ -172,6 +173,50 @@ public function testProcessPoolMarkedAsFailed(): void
 		$pool->releaseProcess($req);
 	}
 
+	/**
+	 * Test process pool error before response
+	 */
+	public function testProcessPoolErrorBeforeResponse(): void
+	{
+		$poolSize = 1;
+		$pool = new ProcessPool($poolSize, $poolSize, 'php processes/phpUnitProcesses.php', realpath(__DIR__ . DIRECTORY_SEPARATOR . '..'));
+
+		$req = $pool->startProcess();
+		$req->sendRequest('req-count');
+		self::assertEquals('1', $req->getStdoutResponse(), 'MD5 incorrect.');
+		$pool->releaseProcess($req);
+
+		$req = $pool->startProcess();
+		$req->sendRequest('req-count');
+		self::assertEquals('2', $req->getStdoutResponse(), 'MD5 incorrect.');
+		$pool->releaseProcess($req);
+
+		$req = $pool->startProcess();
+		$req->sendRequest('error-late-stdout');
+		usleep(5000);
+		self::assertEquals('Error, then sleep.', $req->getStderrResponse(), 'MD5 incorrect.');
+		self::assertEquals(false, $req->hasStdoutData(), 'No STDOUT expected.');
+		$pool->releaseProcess($req);
+		usleep(250000);
+
+		try {
+			$req = $pool->startProcess();
+			self::fail('Expected ProcessPoolProcessOutputBeforeStartingException.');
+		} catch (ProcessPoolProcessOutputBeforeStartingException $e) {
+			self::assertEquals([], $e->getStderrLines());
+			self::assertEquals(['Done sleep'], $e->getStdoutLines());
+		}
+		$req = $pool->startProcess();
+		$req->sendRequest('req-count');
+		self::assertEquals('1', $req->getStdoutResponse(), 'MD5 incorrect.');
+		$pool->releaseProcess($req);
+
+		$req = $pool->startProcess();
+		$req->sendRequest('req-count');
+		self::assertEquals('2', $req->getStdoutResponse(), 'MD5 incorrect.');
+		$pool->releaseProcess($req);
+	}
+
 	/**
 	 * Test pool release before read
 	 */