PHPLIB-1531: Replace FailPointObserver with different logic (#1427)

* Extract fail point management to a trait used by Context

* Ensure event listeners are still unregistered after an operation fails

This change was prompted by the addition of a finally block after executing operations. It may address a memory leak whereby listeners (and the Context they reference) would remain in PHPC's global registry until RSHUTDOWN.

---------

Co-authored-by: Jeremy Mikola <jmikola@gmail.com>

tests/UnifiedSpecTests/Context.php

@@ -38,6 +38,8 @@
  */
 final class Context
 {
+ use ManagesFailPointsTrait;
+
  private ?string $activeClient = null;
 
  private EntityMap $entityMap;

tests/UnifiedSpecTests/ManagesFailPointsTrait.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace MongoDB\Tests\UnifiedSpecTests;
+
+use MongoDB\Driver\Server;
+use MongoDB\Operation\DatabaseCommand;
+use stdClass;
+
+use function PHPUnit\Framework\assertIsString;
+use function PHPUnit\Framework\assertObjectHasAttribute;
+
+trait ManagesFailPointsTrait
+{
+ /** @var list<list{string, Server}> */
+ private array $failPointsAndServers = [];
+
+ public function configureFailPoint(stdClass $failPoint, Server $server): void
+ {
+ assertObjectHasAttribute('configureFailPoint', $failPoint);
+ assertIsString($failPoint->configureFailPoint);
+ assertObjectHasAttribute('mode', $failPoint);
+
+ $operation = new DatabaseCommand('admin', $failPoint);
+ $operation->execute($server);
+
+ if ($failPoint->mode !== 'off') {
+ $this->failPointsAndServers[] = [$failPoint->configureFailPoint, $server];
+ }
+ }
+
+ public function disableFailPoints(): void
+ {
+ foreach ($this->failPointsAndServers as [$failPoint, $server]) {
+ $operation = new DatabaseCommand('admin', ['configureFailPoint' => $failPoint, 'mode' => 'off']);
+ $operation->execute($server);
+ }
+
+ $this->failPointsAndServers = [];
+ }
+}

tests/UnifiedSpecTests/Operation.php

@@ -16,7 +16,6 @@
 use MongoDB\Model\CollectionInfo;
 use MongoDB\Model\DatabaseInfo;
 use MongoDB\Model\IndexInfo;
-use MongoDB\Operation\DatabaseCommand;
 use MongoDB\Operation\FindOneAndReplace;
 use MongoDB\Operation\FindOneAndUpdate;
 use PHPUnit\Framework\Assert;
@@ -909,16 +908,17 @@ private function executeForTestRunner()
  assertArrayHasKey('failPoint', $args);
  assertInstanceOf(Client::class, $args['client']);
  assertInstanceOf(stdClass::class, $args['failPoint']);
- $args['client']->selectDatabase('admin')->command($args['failPoint']);
+ // Configure the fail point via the Context so it can later be disabled
+ $this->context->configureFailPoint($args['failPoint'], $args['client']->getManager()->selectServer());
  break;
  case 'targetedFailPoint':
  assertArrayHasKey('session', $args);
  assertArrayHasKey('failPoint', $args);
  assertInstanceOf(Session::class, $args['session']);
  assertInstanceOf(stdClass::class, $args['failPoint']);
  assertNotNull($args['session']->getServer(), 'Session is pinned');
- $operation = new DatabaseCommand('admin', $args['failPoint']);
- $operation->execute($args['session']->getServer());
+ // Configure the fail point via the Context so it can later be disabled
+ $this->context->configureFailPoint($args['failPoint'], $args['session']->getServer());
  break;
  case 'loop':
  assertArrayHasKey('operations', $args);

tests/UnifiedSpecTests/UnifiedTestRunner.php

@@ -77,8 +77,6 @@ final class UnifiedTestRunner
  /** @var callable(EntityMap):void */
  private $entityMapObserver;
 
- private ?FailPointObserver $failPointObserver = null;
-
  private ServerParameterHelper $serverParameterHelper;
 
  public function __construct(string $internalClientUri)
@@ -150,9 +148,6 @@ private function doSetUp(): void
  * after transient error within a transaction" pinning test causes the
  * subsequent transaction test to block. */
  $this->killAllSessions();
-
- $this->failPointObserver = new FailPointObserver();
- $this->failPointObserver->start();
  }
 
  private function doTearDown(bool $hasFailed): void
@@ -163,9 +158,6 @@ private function doTearDown(bool $hasFailed): void
  $this->killAllSessions();
  }
 
- $this->failPointObserver->stop();
- $this->failPointObserver->disableFailPoints();
-
  /* Manually invoking garbage collection since each test is prone to
  * create cycles (perhaps due to EntityMap), which can leak and prevent
  * sessions from being released back into the pool. */
@@ -216,14 +208,17 @@ private function doTestCase(stdClass $test, string $schemaVersion, ?array $runOn
  $context->startEventObservers();
  $context->startEventCollectors();
 
- foreach ($test->operations as $o) {
- $operation = new Operation($o, $context);
- $operation->assert();
+ try {
+ foreach ($test->operations as $o) {
+ $operation = new Operation($o, $context);
+ $operation->assert();
+ }
+ } finally {
+ $context->stopEventObservers();
+ $context->stopEventCollectors();
+ $context->disableFailPoints();
  }
 
- $context->stopEventObservers();
- $context->stopEventCollectors();
-
  if (isset($test->expectEvents)) {
  assertIsArray($test->expectEvents);
  $context->assertExpectedEventsForClients($test->expectEvents);