another attempt to fix parallel compilation - enabling keepalive in compiler use sites, but in jps taking parallel compilation option into account, so it should be now not set in tests

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/Properties.kt

@@ -17,3 +17,11 @@
 package org.jetbrains.kotlin.cli.common
 
 public val KOTLIN_COMPILER_ENVIRONMENT_KEEPALIVE_PROPERTY = "kotlin.environment.keepalive"
+
+
+fun String?.toBooleanLenient(): Boolean? = when (this?.toLowerCase()) {
+    null -> false
+    in listOf("", "yes", "true", "on", "y") -> true
+    in listOf("no", "false", "off", "n") -> false
+    else -> null
+}

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/KotlinCoreEnvironment.kt

@@ -60,6 +60,7 @@ import org.jetbrains.kotlin.cli.common.messages.CompilerMessageLocation
 import org.jetbrains.kotlin.cli.common.messages.CompilerMessageSeverity
 import org.jetbrains.kotlin.cli.common.messages.CompilerMessageSeverity.ERROR
 import org.jetbrains.kotlin.cli.common.messages.CompilerMessageSeverity.WARNING
+import org.jetbrains.kotlin.cli.common.toBooleanLenient
 import org.jetbrains.kotlin.cli.jvm.config.JVMConfigurationKeys
 import org.jetbrains.kotlin.cli.jvm.config.JavaSourceRoot
 import org.jetbrains.kotlin.cli.jvm.config.JvmClasspathRoot
@@ -258,7 +259,7 @@ public class KotlinCoreEnvironment private constructor(
             val appEnv = getOrCreateApplicationEnvironmentForProduction(configuration, configFilePaths)
             // Disposing of the environment is unsafe in production then parallel builds are enabled, but turning it off universally
             // breaks a lot of tests, therefore it is disabled for production and enabled for tests
-            if (System.getProperty(KOTLIN_COMPILER_ENVIRONMENT_KEEPALIVE_PROPERTY) == null) {
+            if (!(System.getProperty(KOTLIN_COMPILER_ENVIRONMENT_KEEPALIVE_PROPERTY).toBooleanLenient() ?: false)) {
                 // JPS may run many instances of the compiler in parallel (there's an option for compiling independent modules in parallel in IntelliJ)
                 // All projects share the same ApplicationEnvironment, and when the last project is disposed, the ApplicationEnvironment is disposed as well
                 Disposer.register(parentDisposable, object : Disposable {

compiler/daemon/src/org/jetbrains/kotlin/daemon/CompileServiceImpl.kt

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.daemon
 import com.intellij.openapi.vfs.impl.ZipHandler
 import org.jetbrains.kotlin.cli.common.CLICompiler
 import org.jetbrains.kotlin.cli.common.ExitCode
+import org.jetbrains.kotlin.cli.common.KOTLIN_COMPILER_ENVIRONMENT_KEEPALIVE_PROPERTY
 import org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment
 import org.jetbrains.kotlin.config.Services
 import org.jetbrains.kotlin.daemon.common.*
@@ -75,6 +76,10 @@ class CompileServiceImpl(
         val onShutdown: () -> Unit
 ) : CompileService {
 
+    init {
+        System.setProperty(KOTLIN_COMPILER_ENVIRONMENT_KEEPALIVE_PROPERTY, "true")
+    }
+
     // wrapped in a class to encapsulate alive check logic
     private class ClientOrSessionProxy(val aliveFlagPath: String?) {
         val registered = nowSeconds()

jps-plugin/src/org/jetbrains/kotlin/compilerRunner/CompilerRunnerUtil.java

@@ -70,7 +70,7 @@ public class CompilerRunnerUtil {
     }
 
     @Nullable
-    public synchronized static Object invokeExecMethod(
+    public static Object invokeExecMethod(
             @NotNull String compilerClassName,
             @NotNull String[] arguments,
             @NotNull CompilerEnvironment environment,

jps-plugin/src/org/jetbrains/kotlin/compilerRunner/KotlinCompilerRunner.kt

@@ -17,6 +17,7 @@
 package org.jetbrains.kotlin.compilerRunner
 
 import com.intellij.util.xmlb.XmlSerializerUtil
+import org.jetbrains.jps.api.GlobalOptions
 import org.jetbrains.kotlin.cli.common.ExitCode
 import org.jetbrains.kotlin.cli.common.KOTLIN_COMPILER_ENVIRONMENT_KEEPALIVE_PROPERTY
 import org.jetbrains.kotlin.cli.common.arguments.CommonCompilerArguments
@@ -117,9 +118,8 @@ public object KotlinCompilerRunner {
                 val stream = ByteArrayOutputStream()
                 val out = PrintStream(stream)
 
-// Uncomment after resolving problems with parallel compilation and tests
-//                if (System.getProperty(KOTLIN_COMPILER_ENVIRONMENT_KEEPALIVE_PROPERTY) == null)
-//                    System.setProperty(KOTLIN_COMPILER_ENVIRONMENT_KEEPALIVE_PROPERTY, "")
+                if (java.lang.Boolean.parseBoolean(System.getProperty(GlobalOptions.COMPILE_PARALLEL_OPTION, "false")))
+                    System.setProperty(KOTLIN_COMPILER_ENVIRONMENT_KEEPALIVE_PROPERTY, "true")
 
                 val rc = CompilerRunnerUtil.invokeExecMethod(compilerClassName, argsArray, environment, messageCollector, out)
 
@@ -188,7 +188,7 @@ public object KotlinCompilerRunner {
             KotlinBuilder.LOG.debug("Try to connect to daemon")
             val connection = getDaemonConnection(environment, messageCollector)
 
-            if (connection?.daemon != null) {
+            if (connection.daemon != null) {
                 KotlinBuilder.LOG.info("Connected to daemon")
 
                 val compilerOut = ByteArrayOutputStream()
@@ -203,7 +203,7 @@ public object KotlinCompilerRunner {
                     K2JS_COMPILER -> CompileService.TargetPlatform.JS
                     else -> throw IllegalArgumentException("Unknown compiler type $compilerClassName")
                 }
-                val res = KotlinCompilerClient.incrementalCompile(connection!!.daemon!!, connection.sessionId, targetPlatform, argsArray, services, compilerOut, daemonOut)
+                val res = KotlinCompilerClient.incrementalCompile(connection.daemon!!, connection.sessionId, targetPlatform, argsArray, services, compilerOut, daemonOut)
 
                 processCompilerOutput(messageCollector, collector, compilerOut, res.toString())
                 BufferedReader(StringReader(daemonOut.toString())).forEachLine {