[Gradle, native] Allow parallel in-process compiler execution

This commit allows parallel in-process execution of the K/N compiler
that was prohibited by 254a978a06.

Issue #KT-38991 fixed

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/GeneralNativeIT.kt

@@ -14,45 +14,10 @@ class GeneralNativeIT : BaseGradleIT() {
         get() = GradleVersionRequired.FOR_MPP_SUPPORT
 
     @Test
-    fun testParallelExecutionDetection(): Unit = with(transformProjectWithPluginsDsl("native-parallel")) {
-        val compileTasks = arrayOf(":one:compileKotlinLinux", ":two:compileKotlinLinux")
-        // Check that parallel in-process execution fails with the corresponding message.
-        build(*compileTasks) {
-            assertFailed()
-            assertContains("Parallel in-process execution of the Kotlin/Native compiler detected.")
-        }
-
-        // Parallel execution without daemon => ok.
-        build("clean", *compileTasks, "-Pkotlin.native.disableCompilerDaemon=true") {
+    fun testParallelExecutionSmoke(): Unit = with(transformProjectWithPluginsDsl("native-parallel")) {
+        // Check that the K/N compiler can be started in-process in parallel.
+        build(":one:compileKotlinLinux", ":two:compileKotlinLinux") {
             assertSuccessful()
-            assertTasksExecuted(*compileTasks)
-        }
-
-        // org.gradle.parallel must be set in the properties file (not in command line).
-        projectDir.resolve("gradle.properties").modify {
-            it.replace("org.gradle.parallel=true", "org.gradle.parallel=false")
-        }
-
-        // Sequential execution => ok.
-        build("clean", *compileTasks) {
-            assertSuccessful()
-            assertTasksExecuted(*compileTasks)
-        }
-
-        // Check for KT-37696.
-        // Add an incorrect code to trigger compilation failure.
-        projectDir.resolve("one/src/linuxMain/kotlin/main.kt").appendText("\nfun incorrect")
-        gradleBuildScript("two").appendText("""
-            
-            val compileKotlinLinux by tasks.getting
-            compileKotlinLinux.mustRunAfter(":one:compileKotlinLinux")            
-        """.trimIndent())
-
-        build("clean", *compileTasks, "--continue") {
-            assertFailed()
-            assertTasksFailed(":one:compileKotlinLinux")
-            assertTasksExecuted(":two:compileKotlinLinux")
-            assertNotContains("Parallel in-process execution of the Kotlin/Native compiler detected.")
         }
     }
 

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/compilerRunner/KotlinToolRunner.kt

@@ -90,8 +90,7 @@ internal abstract class KotlinToolRunner(
         }
     }
 
-    // TODO: Make it private again once KT-37550 is fixed.
-    protected open fun runInProcess(args: List<String>) {
+    private fun runInProcess(args: List<String>) {
         try {
             val mainClass = getIsolatedClassLoader().loadClass(mainClass)
             val entryPoint = mainClass.methods.single { it.name == daemonEntryPoint }

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/compilerRunner/nativeToolRunners.kt

@@ -83,50 +83,6 @@ internal abstract class KotlinNativeToolRunner(
     override fun transformArgs(args: List<String>) = listOf(toolName) + args
 
     final override fun getCustomJvmArgs() = project.jvmArgs
-
-    final override fun runInProcess(args: List<String>) {
-        withParallelExecutionGuard {
-            super.runInProcess(args)
-        }
-    }
-
-    // TODO: Remove once KT-37550 is fixed
-    private inline fun withParallelExecutionGuard(action: () -> Unit) {
-        try {
-            if (PropertiesProvider(project).nativeEnableParallelExecutionCheck) {
-                System.getProperties().compute(PARALLEL_EXECUTION_GUARD_PROPERTY) { _, value ->
-                    check(value == null) { PARALLEL_EXECUTION_ERROR_MESSAGE }
-                    "true"
-                }
-            }
-
-            action()
-
-        } finally {
-            if (PropertiesProvider(project).nativeEnableParallelExecutionCheck) {
-                System.clearProperty(PARALLEL_EXECUTION_GUARD_PROPERTY)
-            }
-        }
-    }
-
-    companion object {
-        private const val PARALLEL_EXECUTION_GUARD_PROPERTY = "org.jetbrains.kotlin.native.compiler.running"
-
-        private val PARALLEL_EXECUTION_ERROR_MESSAGE = """
-            Parallel in-process execution of the Kotlin/Native compiler detected.
-            
-            At this moment the parallel execution of several compiler instances in the same process is not supported.
-            To fix this, you can do one of the following things:
-            
-            - Disable in-process execution. To do this, set '${PropertiesProvider.KOTLIN_NATIVE_DISABLE_COMPILER_DAEMON}=true' project property.
-
-            - Disable parallel task execution. To do this, set 'org.gradle.parallel=false' project property.
-            
-            If you still want to run the compiler in-process in parallel, you may disable this check by setting project
-            property '${PropertiesProvider.KOTLIN_NATIVE_ENABLE_PARALLEL_EXECUTION_CHECK}=false'. Note that in this case the compiler may fail.
-            
-        """.trimIndent()
-    }
 }
 
 /** A common ancestor for all runners that run the cinterop tool. */

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinProperties.kt

@@ -170,11 +170,7 @@ internal class PropertiesProvider private constructor(private val project: Proje
      * Forces to run a compilation in a separate JVM.
      */
     val nativeDisableCompilerDaemon: Boolean?
-        get() = booleanProperty(KOTLIN_NATIVE_DISABLE_COMPILER_DAEMON)
-
-    // TODO: Remove once KT-37550 is fixed
-    val nativeEnableParallelExecutionCheck: Boolean
-        get() = booleanProperty(KOTLIN_NATIVE_ENABLE_PARALLEL_EXECUTION_CHECK) ?: true
+        get() = booleanProperty("kotlin.native.disableCompilerDaemon")
 
     /**
      * Allows a user to specify additional arguments of a JVM executing KLIB commonizer.
@@ -229,12 +225,8 @@ internal class PropertiesProvider private constructor(private val project: Proje
 
         private const val CACHED_PROVIDER_EXT_NAME = "kotlin.properties.provider"
 
-        internal const val KOTLIN_NATIVE_DISABLE_COMPILER_DAEMON = "kotlin.native.disableCompilerDaemon"
         internal const val KOTLIN_NATIVE_IGNORE_INCORRECT_DEPENDENCIES = "kotlin.native.ignoreIncorrectDependencies"
 
-        // TODO: Remove once KT-37550 is fixed
-        internal const val KOTLIN_NATIVE_ENABLE_PARALLEL_EXECUTION_CHECK = "kotlin.native.enableParallelExecutionCheck"
-
         operator fun invoke(project: Project): PropertiesProvider =
             with(project.extensions.extraProperties) {
                 if (!has(CACHED_PROVIDER_EXT_NAME)) {