--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/api/JavacTaskPool.java Fri Sep 01 14:04:20 2017 +0200
@@ -0,0 +1,390 @@
+/*
+ * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package com.sun.tools.javac.api;
+
+import java.io.PrintStream;
+import java.io.Writer;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+
+import com.sun.source.tree.ClassTree;
+import com.sun.source.tree.CompilationUnitTree;
+import com.sun.source.util.JavacTask;
+import com.sun.source.util.TaskEvent;
+import com.sun.source.util.TaskEvent.Kind;
+import com.sun.source.util.TaskListener;
+import com.sun.source.util.TreeScanner;
+import com.sun.tools.javac.code.Kinds;
+import com.sun.tools.javac.code.Symbol;
+import com.sun.tools.javac.code.Symtab;
+import com.sun.tools.javac.code.Type;
+import com.sun.tools.javac.code.Type.ClassType;
+import com.sun.tools.javac.code.TypeTag;
+import com.sun.tools.javac.code.Types;
+import com.sun.tools.javac.comp.Annotate;
+import com.sun.tools.javac.comp.Check;
+import com.sun.tools.javac.comp.CompileStates;
+import com.sun.tools.javac.comp.Enter;
+import com.sun.tools.javac.comp.Modules;
+import com.sun.tools.javac.main.Arguments;
+import com.sun.tools.javac.main.JavaCompiler;
+import com.sun.tools.javac.tree.JCTree.JCClassDecl;
+
+import javax.tools.Diagnostic;
+import javax.tools.DiagnosticListener;
+import javax.tools.JavaFileManager;
+import javax.tools.JavaFileObject;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
+
+import com.sun.tools.javac.model.JavacElements;
+import com.sun.tools.javac.util.Context;
+import com.sun.tools.javac.util.DefinedBy;
+import com.sun.tools.javac.util.DefinedBy.Api;
+import com.sun.tools.javac.util.Log;
+
+/**
+ * A pool of reusable JavacTasks. When a task is no valid anymore, it is returned to the pool,
+ * and its Context may be reused for future processing in some cases. The reuse is achieved
+ * by replacing some components (most notably JavaCompiler and Log) with reusable counterparts,
+ * and by cleaning up leftovers from previous compilation.
+ * <p>
+ * For each combination of options, a separate task/context is created and kept, as most option
+ * values are cached inside components themselves.
+ * <p>
+ * When the compilation redefines sensitive classes (e.g. classes in the the java.* packages), the
+ * task/context is not reused.
+ * <p>
+ * When the task is reused, then packages that were already listed won't be listed again.
+ * <p>
+ * Care must be taken to only return tasks that won't be used by the original caller.
+ * <p>
+ * Care must also be taken when custom components are installed, as those are not cleaned when the
+ * task/context is reused, and subsequent getTask may return a task based on a context with these
+ * custom components.
+ *
+ * <p><b>This is NOT part of any supported API.
+ * If you write code that depends on this, you do so at your own risk.
+ * This code and its internal interfaces are subject to change or
+ * deletion without notice.</b>
+ */
+public class JavacTaskPool {
+
+ private static final JavacTool systemProvider = JavacTool.create();
+
+ private final int maxPoolSize;
+ private final Map<List<String>, List<ReusableContext>> options2Contexts = new HashMap<>();
+ private int id;
+
+ private int statReused = 0;
+ private int statNew = 0;
+ private int statPolluted = 0;
+ private int statRemoved = 0;
+
+ /**Creates the pool.
+ *
+ * @param maxPoolSize maximum number of tasks/context that will be kept in the pool.
+ */
+ public JavacTaskPool(int maxPoolSize) {
+ this.maxPoolSize = maxPoolSize;
+ }
+
+ /**Creates a new task as if by {@link javax.tools.JavaCompiler#getTask} and runs the provided
+ * worker with it. The task is only valid while the worker is running. The internal structures
+ * may be reused from some previous compilation.
+ *
+ * @param out a Writer for additional output from the compiler;
+ * use {@code System.err} if {@code null}
+ * @param fileManager a file manager; if {@code null} use the
+ * compiler's standard filemanager
+ * @param diagnosticListener a diagnostic listener; if {@code
+ * null} use the compiler's default method for reporting
+ * diagnostics
+ * @param options compiler options, {@code null} means no options
+ * @param classes names of classes to be processed by annotation
+ * processing, {@code null} means no class names
+ * @param compilationUnits the compilation units to compile, {@code
+ * null} means no compilation units
+ * @param worker that should be run with the task
+ * @return an object representing the compilation
+ * @throws RuntimeException if an unrecoverable error
+ * occurred in a user supplied component. The
+ * {@linkplain Throwable#getCause() cause} will be the error in
+ * user code.
+ * @throws IllegalArgumentException if any of the options are invalid,
+ * or if any of the given compilation units are of other kind than
+ * {@linkplain JavaFileObject.Kind#SOURCE source}
+ */
+ public <Z> Z getTask(Writer out,
+ JavaFileManager fileManager,
+ DiagnosticListener<? super JavaFileObject> diagnosticListener,
+ Iterable<String> options,
+ Iterable<String> classes,
+ Iterable<? extends JavaFileObject> compilationUnits,
+ Worker<Z> worker) {
+ List<String> opts =
+ StreamSupport.stream(options.spliterator(), false)
+ .collect(Collectors.toCollection(ArrayList::new));
+
+ ReusableContext ctx;
+
+ synchronized (this) {
+ List<ReusableContext> cached =
+ options2Contexts.getOrDefault(opts, Collections.emptyList());
+
+ if (cached.isEmpty()) {
+ ctx = new ReusableContext(opts);
+ statNew++;
+ } else {
+ ctx = cached.remove(0);
+ statReused++;
+ }
+ }
+
+ ctx.useCount++;
+
+ JavacTaskImpl task =
+ (JavacTaskImpl) systemProvider.getTask(out, fileManager, diagnosticListener,
+ opts, classes, compilationUnits, ctx);
+
+ task.addTaskListener(ctx);
+
+ Z result = worker.withTask(task);
+
+ //not returning the context to the pool if task crashes with an exception
+ //the task/context may be in a broken state
+ ctx.clear();
+ if (ctx.polluted) {
+ statPolluted++;
+ } else {
+ task.cleanup();
+ synchronized (this) {
+ while (cacheSize() + 1 > maxPoolSize) {
+ ReusableContext toRemove =
+ options2Contexts.values()
+ .stream()
+ .flatMap(Collection::stream)
+ .sorted((c1, c2) -> c1.timeStamp < c2.timeStamp ? -1 : 1)
+ .findFirst()
+ .get();
+ options2Contexts.get(toRemove.arguments).remove(toRemove);
+ statRemoved++;
+ }
+ options2Contexts.computeIfAbsent(ctx.arguments, x -> new ArrayList<>()).add(ctx);
+ ctx.timeStamp = id++;
+ }
+ }
+
+ return result;
+ }
+ //where:
+ private long cacheSize() {
+ return options2Contexts.values().stream().flatMap(Collection::stream).count();
+ }
+
+ public void printStatistics(PrintStream out) {
+ out.println(statReused + " reused Contexts");
+ out.println(statNew + " newly created Contexts");
+ out.println(statPolluted + " polluted Contexts");
+ out.println(statRemoved + " removed Contexts");
+ }
+
+ public interface Worker<Z> {
+ public Z withTask(JavacTask task);
+ }
+
+ static class ReusableContext extends Context implements TaskListener {
+
+ Set<CompilationUnitTree> roots = new HashSet<>();
+
+ List<String> arguments;
+ boolean polluted = false;
+
+ int useCount;
+ long timeStamp;
+
+ ReusableContext(List<String> arguments) {
+ super();
+ this.arguments = arguments;
+ put(Log.logKey, ReusableLog.factory);
+ put(JavaCompiler.compilerKey, ReusableJavaCompiler.factory);
+ }
+
+ void clear() {
+ drop(Arguments.argsKey);
+ drop(DiagnosticListener.class);
+ drop(Log.outKey);
+ drop(Log.errKey);
+ drop(JavaFileManager.class);
+ drop(JavacTask.class);
+ drop(JavacTrees.class);
+ drop(JavacElements.class);
+
+ if (ht.get(Log.logKey) instanceof ReusableLog) {
+ //log already inited - not first round
+ ((ReusableLog)Log.instance(this)).clear();
+ Enter.instance(this).newRound();
+ ((ReusableJavaCompiler)ReusableJavaCompiler.instance(this)).clear();
+ Types.instance(this).newRound();
+ Check.instance(this).newRound();
+ Modules.instance(this).newRound();
+ Annotate.instance(this).newRound();
+ CompileStates.instance(this).clear();
+ MultiTaskListener.instance(this).clear();
+
+ //find if any of the roots have redefined java.* classes
+ Symtab syms = Symtab.instance(this);
+ pollutionScanner.scan(roots, syms);
+ roots.clear();
+ }
+ }
+
+ /**
+ * This scanner detects as to whether the shared context has been polluted. This happens
+ * whenever a compiled program redefines a core class (in 'java.*' package) or when
+ * (typically because of cyclic inheritance) the symbol kind of a core class has been touched.
+ */
+ TreeScanner<Void, Symtab> pollutionScanner = new TreeScanner<Void, Symtab>() {
+ @Override @DefinedBy(Api.COMPILER_TREE)
+ public Void visitClass(ClassTree node, Symtab syms) {
+ Symbol sym = ((JCClassDecl)node).sym;
+ if (sym != null) {
+ syms.removeClass(sym.packge().modle, sym.flatName());
+ Type sup = supertype(sym);
+ if (isCoreClass(sym) ||
+ (sup != null && isCoreClass(sup.tsym) && sup.tsym.kind != Kinds.Kind.TYP)) {
+ polluted = true;
+ }
+ }
+ return super.visitClass(node, syms);
+ }
+
+ private boolean isCoreClass(Symbol s) {
+ return s.flatName().toString().startsWith("java.");
+ }
+
+ private Type supertype(Symbol s) {
+ if (s.type == null ||
+ !s.type.hasTag(TypeTag.CLASS)) {
+ return null;
+ } else {
+ ClassType ct = (ClassType)s.type;
+ return ct.supertype_field;
+ }
+ }
+ };
+
+ @Override @DefinedBy(Api.COMPILER_TREE)
+ public void finished(TaskEvent e) {
+ if (e.getKind() == Kind.PARSE) {
+ roots.add(e.getCompilationUnit());
+ }
+ }
+
+ @Override @DefinedBy(Api.COMPILER_TREE)
+ public void started(TaskEvent e) {
+ //do nothing
+ }
+
+ <T> void drop(Key<T> k) {
+ ht.remove(k);
+ }
+
+ <T> void drop(Class<T> c) {
+ ht.remove(key(c));
+ }
+
+ /**
+ * Reusable JavaCompiler; exposes a method to clean up the component from leftovers associated with
+ * previous compilations.
+ */
+ static class ReusableJavaCompiler extends JavaCompiler {
+
+ final static Factory<JavaCompiler> factory = ReusableJavaCompiler::new;
+
+ ReusableJavaCompiler(Context context) {
+ super(context);
+ }
+
+ @Override
+ public void close() {
+ //do nothing
+ }
+
+ void clear() {
+ newRound();
+ }
+
+ @Override
+ protected void checkReusable() {
+ //do nothing - it's ok to reuse the compiler
+ }
+ }
+
+ /**
+ * Reusable Log; exposes a method to clean up the component from leftovers associated with
+ * previous compilations.
+ */
+ static class ReusableLog extends Log {
+
+ final static Factory<Log> factory = ReusableLog::new;
+
+ Context context;
+
+ ReusableLog(Context context) {
+ super(context);
+ this.context = context;
+ }
+
+ void clear() {
+ recorded.clear();
+ sourceMap.clear();
+ nerrors = 0;
+ nwarnings = 0;
+ //Set a fake listener that will lazily lookup the context for the 'real' listener. Since
+ //this field is never updated when a new task is created, we cannot simply reset the field
+ //or keep old value. This is a hack to workaround the limitations in the current infrastructure.
+ diagListener = new DiagnosticListener<JavaFileObject>() {
+ DiagnosticListener<JavaFileObject> cachedListener;
+
+ @Override @DefinedBy(Api.COMPILER)
+ @SuppressWarnings("unchecked")
+ public void report(Diagnostic<? extends JavaFileObject> diagnostic) {
+ if (cachedListener == null) {
+ cachedListener = context.get(DiagnosticListener.class);
+ }
+ cachedListener.report(diagnostic);
+ }
+ };
+ }
+ }
+ }
+}