Fix OOME: Metaspace (#2678)

* Fix OOME: Metaspace

* Add stress test

* Run sample analysis from `Dispatchers.Default`

3 files changed, 49 insertions, 4 deletions

diff --git a/integration-tests/gradle/src/integrationTest/kotlin/org/jetbrains/dokka/it/gradle/SequentialTasksExecutionStressTest.kt b/integration-tests/gradle/src/integrationTest/kotlin/org/jetbrains/dokka/it/gradle/SequentialTasksExecutionStressTest.kt
new file mode 100644
index 00000000..32ed27f4
--- /dev/null
+++ b/integration-tests/gradle/src/integrationTest/kotlin/org/jetbrains/dokka/it/gradle/SequentialTasksExecutionStressTest.kt
@@ -0,0 +1,45 @@
+package org.jetbrains.dokka.it.gradle
+
+import org.gradle.testkit.runner.TaskOutcome
+import org.junit.runners.Parameterized.Parameters
+import java.io.File
+import kotlin.test.*
+
+/**
+ *  Creates 100 tasks for the test project and runs them sequentially under low memory settings.
+ *
+ *  If the test passes, it's likely there are no noticeable memory leaks.
+ *  If it fails, it's likely that memory is leaking somewhere.
+ */
+class SequentialTasksExecutionStressTest(override val versions: BuildVersions) : AbstractGradleIntegrationTest() {
+
+    companion object {
+        @get:JvmStatic
+        @get:Parameters(name = "{0}")
+        val versions =  listOf(TestedVersions.LATEST)
+    }
+
+    @BeforeTest
+    fun prepareProjectFiles() {
+        val templateProjectDir = File("projects", "it-sequential-tasks-execution-stress")
+
+        templateProjectDir.listFiles().orEmpty()
+            .filter { it.isFile }
+            .forEach { topLevelFile -> topLevelFile.copyTo(File(projectDir, topLevelFile.name)) }
+
+        File(templateProjectDir, "src").copyRecursively(File(projectDir, "src"))
+    }
+
+    @Test
+    fun execute() {
+        val result = createGradleRunner(
+            "runTasks",
+            "--info",
+            "--stacktrace",
+            "-Ptask_number=100",
+            jvmArgs = listOf("-Xmx1G", "-XX:MaxMetaspaceSize=350m")
+        ).buildRelaxed()
+
+        assertEquals(TaskOutcome.SUCCESS, assertNotNull(result.task(":runTasks")).outcome)
+    }
+}
diff --git a/integration-tests/gradle/src/integrationTest/kotlin/org/jetbrains/dokka/it/gradle/TestedVersions.kt b/integration-tests/gradle/src/integrationTest/kotlin/org/jetbrains/dokka/it/gradle/TestedVersions.kt
index b6f2abd3..2b8e5b3c 100644
--- a/integration-tests/gradle/src/integrationTest/kotlin/org/jetbrains/dokka/it/gradle/TestedVersions.kt
+++ b/integration-tests/gradle/src/integrationTest/kotlin/org/jetbrains/dokka/it/gradle/TestedVersions.kt
@@ -2,6 +2,7 @@ package org.jetbrains.dokka.it.gradle
 
 internal object TestedVersions {
 
+    val LATEST = BuildVersions("7.4.2", "1.7.20")
     val BASE =
         BuildVersions.permutations(
             gradleVersions = listOf("7.4.2", "6.9"),
diff --git a/integration-tests/gradle/src/main/kotlin/org/jetbrains/dokka/it/gradle/AbstractGradleIntegrationTest.kt b/integration-tests/gradle/src/main/kotlin/org/jetbrains/dokka/it/gradle/AbstractGradleIntegrationTest.kt
index 9998f3fd..84efac93 100644
--- a/integration-tests/gradle/src/main/kotlin/org/jetbrains/dokka/it/gradle/AbstractGradleIntegrationTest.kt
+++ b/integration-tests/gradle/src/main/kotlin/org/jetbrains/dokka/it/gradle/AbstractGradleIntegrationTest.kt
@@ -6,8 +6,6 @@ import org.gradle.testkit.runner.internal.DefaultGradleRunner
 import org.gradle.tooling.GradleConnectionException
 import org.gradle.util.GradleVersion
 import org.jetbrains.dokka.it.AbstractIntegrationTest
-import org.junit.Assume
-import org.junit.Assume.assumeFalse
 import org.junit.AssumptionViolatedException
 import org.junit.runner.RunWith
 import org.junit.runners.Parameterized
@@ -29,7 +27,8 @@ abstract class AbstractGradleIntegrationTest : AbstractIntegrationTest() {
     }
 
     fun createGradleRunner(
-        vararg arguments: String
+        vararg arguments: String,
+        jvmArgs: List<String> = listOf("-Xmx4G", "-XX:MaxMetaspaceSize=2G")
     ): GradleRunner {
         return GradleRunner.create()
             .withProjectDir(projectDir)
@@ -46,7 +45,7 @@ abstract class AbstractGradleIntegrationTest : AbstractIntegrationTest() {
                     * arguments
                 )
             ).run { this as DefaultGradleRunner }
-            .withJvmArguments("-Xmx4G", "-XX:MaxMetaspaceSize=2G")
+            .withJvmArguments(jvmArgs)
     }
 
     fun GradleRunner.buildRelaxed(): BuildResult {