Clear computable when value is calculated and CallOnceFunction is added

Relates to #KT-35256

compiler/frontend/src/org/jetbrains/kotlin/resolve/LazyExplicitImportScope.kt

@@ -24,6 +24,7 @@ import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.scopes.BaseImportingScope
 import org.jetbrains.kotlin.resolve.scopes.DescriptorKindFilter
 import org.jetbrains.kotlin.resolve.scopes.MemberScope
+import org.jetbrains.kotlin.utils.CallOnceFunction
 import org.jetbrains.kotlin.utils.Printer
 import org.jetbrains.kotlin.utils.addIfNotNull
 
@@ -32,7 +33,7 @@ class LazyExplicitImportScope(
     private val packageFragmentForVisibilityCheck: PackageFragmentDescriptor?,
     private val declaredName: Name,
     private val aliasName: Name,
-    private val storeReferences: (Collection<DeclarationDescriptor>) -> Unit
+    private val storeReferences: CallOnceFunction<Collection<DeclarationDescriptor>, Unit>
 ) : BaseImportingScope(null) {
 
     override fun getContributedClassifier(name: Name, location: LookupLocation): ClassifierDescriptor? {

compiler/frontend/src/org/jetbrains/kotlin/resolve/QualifiedExpressionResolver.kt

@@ -45,6 +45,7 @@ import org.jetbrains.kotlin.resolve.scopes.utils.memberScopeAsImportingScope
 import org.jetbrains.kotlin.resolve.source.KotlinSourceElement
 import org.jetbrains.kotlin.types.expressions.ExpressionTypingContext
 import org.jetbrains.kotlin.types.expressions.isWithoutValueArguments
+import org.jetbrains.kotlin.utils.CallOnceFunction
 
 class QualifiedExpressionResolver(val languageVersionSettings: LanguageVersionSettings) {
     fun resolvePackageHeader(
@@ -310,22 +311,22 @@ class QualifiedExpressionResolver(val languageVersionSettings: LanguageVersionSe
             packageOrClassDescriptor,
             packageFragmentForVisibilityCheck,
             lastPart.name,
-            aliasName
-        ) { candidates ->
-
-            if (candidates.isNotEmpty()) {
-                storeResult(
-                    trace,
-                    lastPart.expression,
-                    candidates,
-                    packageFragmentForVisibilityCheck,
-                    position = QualifierPosition.IMPORT,
-                    isQualifier = false
-                )
-            } else {
-                tryResolveDescriptorsWhichCannotBeImported(trace, moduleDescriptor, packageOrClassDescriptor, lastPart)
+            aliasName,
+            CallOnceFunction(Unit) { candidates ->
+                if (candidates.isNotEmpty()) {
+                    storeResult(
+                        trace,
+                        lastPart.expression,
+                        candidates,
+                        packageFragmentForVisibilityCheck,
+                        position = QualifierPosition.IMPORT,
+                        isQualifier = false
+                    )
+                } else {
+                    tryResolveDescriptorsWhichCannotBeImported(trace, moduleDescriptor, packageOrClassDescriptor, lastPart)
+                }
             }
-        }
+        )
     }
 
     private fun tryResolveDescriptorsWhichCannotBeImported(

core/util.runtime/src/org/jetbrains/kotlin/storage/LockBasedStorageManager.java

@@ -305,7 +305,10 @@ public class LockBasedStorageManager implements StorageManager {
 
     private static class LockBasedLazyValue<T> implements NullableLazyValue<T> {
         private final LockBasedStorageManager storageManager;
-        private final Function0<? extends T> computable;
+        /**
+         * Computable function is <code>null</code> when value has been calculated
+         */
+        private Function0<? extends T> computable;
 
         @Nullable
         private volatile Object value = NotValue.NOT_COMPUTED;
@@ -359,6 +362,7 @@ public class LockBasedStorageManager implements StorageManager {
                     postCompute(typedValue);
 
                     value = typedValue;
+                    computable = null;
                     return typedValue;
                 }
                 catch (Throwable throwable) {

core/util.runtime/src/org/jetbrains/kotlin/utils/CallOnceFunction.kt

@@ -0,0 +1,14 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.utils
+
+import java.util.concurrent.atomic.AtomicReference
+
+class CallOnceFunction<F, T>(private val defaultValue: T, delegate: Function1<F, T>) : Function1<F, T> {
+    private val functionRef: AtomicReference<Function1<F, T>?> = AtomicReference(delegate)
+
+    override fun invoke(p1: F): T = functionRef.getAndSet(null)?.invoke(p1) ?: defaultValue
+}