1 /*
2 * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.tools.javac.api;
27
28 import java.io.PrintStream;
29 import java.io.Writer;
30 import java.util.ArrayList;
31 import java.util.Collection;
32 import java.util.Collections;
33 import java.util.HashMap;
34
35 import com.sun.source.tree.ClassTree;
36 import com.sun.source.tree.CompilationUnitTree;
37 import com.sun.source.util.JavacTask;
38 import com.sun.source.util.TaskEvent;
39 import com.sun.source.util.TaskEvent.Kind;
40 import com.sun.source.util.TaskListener;
41 import com.sun.source.util.TreeScanner;
42 import com.sun.tools.javac.code.Kinds;
43 import com.sun.tools.javac.code.Symbol;
44 import com.sun.tools.javac.code.Symtab;
45 import com.sun.tools.javac.code.Type;
46 import com.sun.tools.javac.code.Type.ClassType;
47 import com.sun.tools.javac.code.TypeTag;
48 import com.sun.tools.javac.code.Types;
49 import com.sun.tools.javac.comp.Annotate;
50 import com.sun.tools.javac.comp.Check;
51 import com.sun.tools.javac.comp.CompileStates;
52 import com.sun.tools.javac.comp.Enter;
53 import com.sun.tools.javac.comp.Modules;
54 import com.sun.tools.javac.main.Arguments;
55 import com.sun.tools.javac.main.JavaCompiler;
56 import com.sun.tools.javac.tree.JCTree.JCClassDecl;
57
58 import javax.tools.Diagnostic;
59 import javax.tools.DiagnosticListener;
60 import javax.tools.JavaFileManager;
61 import javax.tools.JavaFileObject;
62
63 import java.util.HashSet;
64 import java.util.List;
65 import java.util.Map;
66 import java.util.Set;
67 import java.util.stream.Collectors;
68 import java.util.stream.StreamSupport;
69
70 import com.sun.tools.javac.model.JavacElements;
71 import com.sun.tools.javac.util.Context;
72 import com.sun.tools.javac.util.DefinedBy;
73 import com.sun.tools.javac.util.DefinedBy.Api;
74 import com.sun.tools.javac.util.Log;
75
76 /**
77 * A pool of reusable JavacTasks. When a task is no valid anymore, it is returned to the pool,
78 * and its Context may be reused for future processing in some cases. The reuse is achieved
79 * by replacing some components (most notably JavaCompiler and Log) with reusable counterparts,
80 * and by cleaning up leftovers from previous compilation.
81 * <p>
82 * For each combination of options, a separate task/context is created and kept, as most option
83 * values are cached inside components themselves.
84 * <p>
85 * When the compilation redefines sensitive classes (e.g. classes in the the java.* packages), the
86 * task/context is not reused.
87 * <p>
88 * When the task is reused, then packages that were already listed won't be listed again.
89 * <p>
90 * Care must be taken to only return tasks that won't be used by the original caller.
91 * <p>
92 * Care must also be taken when custom components are installed, as those are not cleaned when the
93 * task/context is reused, and subsequent getTask may return a task based on a context with these
94 * custom components.
95 *
96 * <p><b>This is NOT part of any supported API.
97 * If you write code that depends on this, you do so at your own risk.
98 * This code and its internal interfaces are subject to change or
99 * deletion without notice.</b>
100 */
101 public class JavacTaskPool {
102
103 private static final JavacTool systemProvider = JavacTool.create();
104
105 private final int maxPoolSize;
106 private final Map<List<String>, List<ReusableContext>> options2Contexts = new HashMap<>();
107 private int id;
108
109 private int statReused = 0;
110 private int statNew = 0;
111 private int statPolluted = 0;
112 private int statRemoved = 0;
113
114 /**Creates the pool.
115 *
116 * @param maxPoolSize maximum number of tasks/context that will be kept in the pool.
117 */
118 public JavacTaskPool(int maxPoolSize) {
119 this.maxPoolSize = maxPoolSize;
120 }
121
122 /**Creates a new task as if by {@link javax.tools.JavaCompiler#getTask} and runs the provided
123 * worker with it. The task is only valid while the worker is running. The internal structures
124 * may be reused from some previous compilation.
125 *
126 * @param out a Writer for additional output from the compiler;
127 * use {@code System.err} if {@code null}
128 * @param fileManager a file manager; if {@code null} use the
129 * compiler's standard filemanager
130 * @param diagnosticListener a diagnostic listener; if {@code
131 * null} use the compiler's default method for reporting
132 * diagnostics
133 * @param options compiler options, {@code null} means no options
134 * @param classes names of classes to be processed by annotation
135 * processing, {@code null} means no class names
136 * @param compilationUnits the compilation units to compile, {@code
137 * null} means no compilation units
138 * @param worker that should be run with the task
139 * @return an object representing the compilation
140 * @throws RuntimeException if an unrecoverable error
141 * occurred in a user supplied component. The
142 * {@linkplain Throwable#getCause() cause} will be the error in
143 * user code.
144 * @throws IllegalArgumentException if any of the options are invalid,
145 * or if any of the given compilation units are of other kind than
146 * {@linkplain JavaFileObject.Kind#SOURCE source}
147 */
148 public <Z> Z getTask(Writer out,
149 JavaFileManager fileManager,
150 DiagnosticListener<? super JavaFileObject> diagnosticListener,
151 Iterable<String> options,
152 Iterable<String> classes,
153 Iterable<? extends JavaFileObject> compilationUnits,
154 Worker<Z> worker) {
155 List<String> opts =
156 StreamSupport.stream(options.spliterator(), false)
157 .collect(Collectors.toCollection(ArrayList::new));
158
159 ReusableContext ctx;
160
161 synchronized (this) {
162 List<ReusableContext> cached =
163 options2Contexts.getOrDefault(opts, Collections.emptyList());
164
165 if (cached.isEmpty()) {
166 ctx = new ReusableContext(opts);
167 statNew++;
168 } else {
169 ctx = cached.remove(0);
170 statReused++;
171 }
172 }
173
174 ctx.useCount++;
175
176 JavacTaskImpl task =
177 (JavacTaskImpl) systemProvider.getTask(out, fileManager, diagnosticListener,
178 opts, classes, compilationUnits, ctx);
179
180 task.addTaskListener(ctx);
181
182 Z result = worker.withTask(task);
183
184 //not returning the context to the pool if task crashes with an exception
185 //the task/context may be in a broken state
186 ctx.clear();
187 if (ctx.polluted) {
188 statPolluted++;
189 } else {
190 task.cleanup();
191 synchronized (this) {
192 while (cacheSize() + 1 > maxPoolSize) {
193 ReusableContext toRemove =
194 options2Contexts.values()
195 .stream()
196 .flatMap(Collection::stream)
197 .sorted((c1, c2) -> c1.timeStamp < c2.timeStamp ? -1 : 1)
198 .findFirst()
199 .get();
200 options2Contexts.get(toRemove.arguments).remove(toRemove);
201 statRemoved++;
202 }
203 options2Contexts.computeIfAbsent(ctx.arguments, x -> new ArrayList<>()).add(ctx);
204 ctx.timeStamp = id++;
205 }
206 }
207
208 return result;
209 }
210 //where:
211 private long cacheSize() {
212 return options2Contexts.values().stream().flatMap(Collection::stream).count();
213 }
214
215 public void printStatistics(PrintStream out) {
216 out.println(statReused + " reused Contexts");
217 out.println(statNew + " newly created Contexts");
218 out.println(statPolluted + " polluted Contexts");
219 out.println(statRemoved + " removed Contexts");
220 }
221
222 public interface Worker<Z> {
223 public Z withTask(JavacTask task);
224 }
225
226 static class ReusableContext extends Context implements TaskListener {
227
228 Set<CompilationUnitTree> roots = new HashSet<>();
229
230 List<String> arguments;
231 boolean polluted = false;
232
233 int useCount;
234 long timeStamp;
235
236 ReusableContext(List<String> arguments) {
237 super();
238 this.arguments = arguments;
239 put(Log.logKey, ReusableLog.factory);
240 put(JavaCompiler.compilerKey, ReusableJavaCompiler.factory);
241 }
242
243 void clear() {
244 drop(Arguments.argsKey);
245 drop(DiagnosticListener.class);
246 drop(Log.outKey);
247 drop(Log.errKey);
248 drop(JavaFileManager.class);
249 drop(JavacTask.class);
250 drop(JavacTrees.class);
251 drop(JavacElements.class);
252
253 if (ht.get(Log.logKey) instanceof ReusableLog) {
254 //log already inited - not first round
255 ((ReusableLog)Log.instance(this)).clear();
256 Enter.instance(this).newRound();
257 ((ReusableJavaCompiler)ReusableJavaCompiler.instance(this)).clear();
258 Types.instance(this).newRound();
259 Check.instance(this).newRound();
260 Modules.instance(this).newRound();
261 Annotate.instance(this).newRound();
262 CompileStates.instance(this).clear();
263 MultiTaskListener.instance(this).clear();
264
265 //find if any of the roots have redefined java.* classes
266 Symtab syms = Symtab.instance(this);
267 pollutionScanner.scan(roots, syms);
268 roots.clear();
269 }
270 }
271
272 /**
273 * This scanner detects as to whether the shared context has been polluted. This happens
274 * whenever a compiled program redefines a core class (in 'java.*' package) or when
275 * (typically because of cyclic inheritance) the symbol kind of a core class has been touched.
276 */
277 TreeScanner<Void, Symtab> pollutionScanner = new TreeScanner<Void, Symtab>() {
278 @Override @DefinedBy(Api.COMPILER_TREE)
279 public Void visitClass(ClassTree node, Symtab syms) {
280 Symbol sym = ((JCClassDecl)node).sym;
281 if (sym != null) {
282 syms.removeClass(sym.packge().modle, sym.flatName());
283 Type sup = supertype(sym);
284 if (isCoreClass(sym) ||
285 (sup != null && isCoreClass(sup.tsym) && sup.tsym.kind != Kinds.Kind.TYP)) {
286 polluted = true;
287 }
288 }
289 return super.visitClass(node, syms);
290 }
291
292 private boolean isCoreClass(Symbol s) {
293 return s.flatName().toString().startsWith("java.");
294 }
295
296 private Type supertype(Symbol s) {
297 if (s.type == null ||
298 !s.type.hasTag(TypeTag.CLASS)) {
299 return null;
300 } else {
301 ClassType ct = (ClassType)s.type;
302 return ct.supertype_field;
303 }
304 }
305 };
306
307 @Override @DefinedBy(Api.COMPILER_TREE)
308 public void finished(TaskEvent e) {
309 if (e.getKind() == Kind.PARSE) {
310 roots.add(e.getCompilationUnit());
311 }
312 }
313
314 @Override @DefinedBy(Api.COMPILER_TREE)
315 public void started(TaskEvent e) {
316 //do nothing
317 }
318
319 <T> void drop(Key<T> k) {
320 ht.remove(k);
321 }
322
323 <T> void drop(Class<T> c) {
324 ht.remove(key(c));
325 }
326
327 /**
328 * Reusable JavaCompiler; exposes a method to clean up the component from leftovers associated with
329 * previous compilations.
330 */
331 static class ReusableJavaCompiler extends JavaCompiler {
332
333 final static Factory<JavaCompiler> factory = ReusableJavaCompiler::new;
334
335 ReusableJavaCompiler(Context context) {
336 super(context);
337 }
338
339 @Override
340 public void close() {
341 //do nothing
342 }
343
344 void clear() {
345 newRound();
346 }
347
348 @Override
349 protected void checkReusable() {
350 //do nothing - it's ok to reuse the compiler
351 }
352 }
353
354 /**
355 * Reusable Log; exposes a method to clean up the component from leftovers associated with
356 * previous compilations.
357 */
358 static class ReusableLog extends Log {
359
360 final static Factory<Log> factory = ReusableLog::new;
361
362 Context context;
363
364 ReusableLog(Context context) {
365 super(context);
366 this.context = context;
367 }
368
369 void clear() {
370 recorded.clear();
371 sourceMap.clear();
372 nerrors = 0;
373 nwarnings = 0;
374 //Set a fake listener that will lazily lookup the context for the 'real' listener. Since
375 //this field is never updated when a new task is created, we cannot simply reset the field
376 //or keep old value. This is a hack to workaround the limitations in the current infrastructure.
377 diagListener = new DiagnosticListener<JavaFileObject>() {
378 DiagnosticListener<JavaFileObject> cachedListener;
379
380 @Override @DefinedBy(Api.COMPILER)
381 @SuppressWarnings("unchecked")
382 public void report(Diagnostic<? extends JavaFileObject> diagnostic) {
383 if (cachedListener == null) {
384 cachedListener = context.get(DiagnosticListener.class);
385 }
386 cachedListener.report(diagnostic);
387 }
388 };
389 }
390 }
391 }
392 }