langtools/test/tools/javac/T8000316/T8000316.java
author sadayapalam
Tue, 13 Oct 2015 09:48:03 +0530
changeset 33020 7ed4f7ff42c5
permissions -rw-r--r--
8000316: Huge performance bottleneck in com.sun.tools.javac.comp.Check.localClassName Summary: Speed up Check.localClassName by avoiding generating names known to be in use already Reviewed-by: mcimadamore, jlahoda, sadayapalam Contributed-by: dmitry.chuyko@oracle.com

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * under the terms of the GNU General Public License version 2 only, as
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 *
 * 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).
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 * questions.
 */

/*
 * @test
 * @bug 8000316
 * @summary Huge performance bottleneck in com.sun.tools.javac.comp.Check.localClassName
 * @modules jdk.compiler
 * @run main T8000316
 */

import com.sun.source.util.JavacTask;
import java.net.URI;
import java.util.List;
import java.util.ArrayList;
import java.util.Locale;
import javax.tools.Diagnostic;
import javax.tools.JavaCompiler;
import javax.tools.JavaFileObject;
import javax.tools.SimpleJavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;

public class T8000316 {

    final static int N_METHODS = 1024;
    final static int N_CLASSES = 8;

    static class TestClass extends SimpleJavaFileObject {

        String methTemplate = "    public static Runnable get#N() {\n" +
                              "        return new Runnable() {\n" +
                              "            @Override\n" +
                              "            public void run() {\n" +
                              "                return;\n" +
                              "            }\n" +
                              "        };\n" +
                              "    }\n";

        String classTemplate = "\n\nclass Chain#N {\n\n#M }";

        String source;

        public TestClass() {
            super(URI.create("myfo:/Test.java"), JavaFileObject.Kind.SOURCE);
            StringBuilder buf = new StringBuilder();
            StringBuilder fileBuf = new StringBuilder();

            for (int i = 0 ; i < N_CLASSES ; i++) {
                for (int j = 0; j < N_METHODS; j++) {
                    buf.append(methTemplate.replace("#N", String.valueOf(j)));
                    buf.append("\n");
                }
                fileBuf.append(classTemplate.replace("#M", buf.toString()).replace("#N", String.valueOf(i)));
                buf = new StringBuilder();
                source = fileBuf.toString();
            }
        }

        @Override
        public CharSequence getCharContent(boolean ignoreEncodingErrors) {
            return source;
        }
    }

    public static void main(String... args) throws Exception {
        ArrayList<JavaFileObject> sources = new ArrayList<>();
        sources.add(new TestClass());
        new T8000316().run(sources);
    }

    void run(List<JavaFileObject> sources) throws Exception {
        javax.tools.DiagnosticListener<JavaFileObject> dc = (diagnostic) -> {
            if (diagnostic.getKind() == Diagnostic.Kind.ERROR) {
                throw new AssertionError("unexpected diagnostic: " + diagnostic.getMessage(Locale.getDefault()));
            }
        };
        JavaCompiler comp = ToolProvider.getSystemJavaCompiler();
        try (StandardJavaFileManager fm = comp.getStandardFileManager(null, null, null)) {
            JavacTask ct = (JavacTask)comp.getTask(null, fm, dc,
                    null, null, sources);
            ct.analyze();
        }
    }
}