/*

 * Copyright (c) 2014, 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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

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 */

/*

 * @test

 * @bug 8044131

 * @summary Makes sure sjavac poolsize option is honored.

 * @build Wrapper

 * @run main Wrapper PooledExecution

 */

import java.io.File;

import java.net.URI;

import java.util.Collections;

import java.util.List;

import java.util.Set;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.atomic.AtomicInteger;

import com.sun.tools.sjavac.comp.PooledSjavac;

import com.sun.tools.sjavac.server.CompilationResult;

import com.sun.tools.sjavac.server.Sjavac;

import com.sun.tools.sjavac.server.SysInfo;

public class PooledExecution {

    public static void main(String[] args) throws InterruptedException {

        new PooledExecutionTest().runTest();

    }

    static class PooledExecutionTest {

        final int POOL_SIZE = 15;

        final int NUM_REQUESTS = 100;

        // Number of tasks that has not yet started

        CountDownLatch leftToStart = new CountDownLatch(NUM_REQUESTS);

        // Highest number of concurrently active request seen

        int highWaterMark = 0;

        public void runTest() throws InterruptedException {

            ConcurrencyLoggingService loggingService = new ConcurrencyLoggingService();

            final Sjavac service = new PooledSjavac(loggingService, POOL_SIZE);

            // Keep track of the number of finished tasks so we can make sure all

            // tasks finishes gracefully upon shutdown.

            Thread[] tasks = new Thread[NUM_REQUESTS];

            final AtomicInteger tasksFinished = new AtomicInteger(0);

            for (int i = 0; i < NUM_REQUESTS; i++) {

                tasks[i] = new Thread() {

                    public void run() {

                        service.compile("",

                                        "",

                                        new String[0],

                                        Collections.<File>emptyList(),

                                        Collections.<URI>emptySet(),

                                        Collections.<URI>emptySet());

                        tasksFinished.incrementAndGet();

                    }

                };

                tasks[i].start();

            }

            // Wait for all tasks to start (but not necessarily run to completion)

            leftToStart.await();

            // Shutdown before all tasks are completed

            System.out.println("Shutting down!");

            service.shutdown();

            // Wait for all tasks to complete

            for (Thread t : tasks)

                t.join();

            if (tasksFinished.get() != NUM_REQUESTS) {

                throw new AssertionError(tasksFinished.get() + " out of " +

                        NUM_REQUESTS + " finished. Broken shutdown?");

            }

            if (highWaterMark > POOL_SIZE) {

                throw new AssertionError("Pool size overused: " + highWaterMark +

                                         " used out of " + POOL_SIZE + " allowed.");

            }

            // Assuming more than POOL_SIZE requests can be processed within 1 sek:

            if (highWaterMark < POOL_SIZE) {

                throw new AssertionError("Pool size underused: " + highWaterMark +

                                         " used out of " + POOL_SIZE + " allowed.");

            }

        }

        private class ConcurrencyLoggingService implements Sjavac {

            // Keeps track of currently active requests

            AtomicInteger activeRequests = new AtomicInteger(0);

            @Override

            public CompilationResult compile(String protocolId,

                                             String invocationId,

                                             String[] args,

                                             List<File> explicitSources,

                                             Set<URI> sourcesToCompile,

                                             Set<URI> visibleSources) {

                leftToStart.countDown();

                int numActiveRequests = activeRequests.incrementAndGet();

                System.out.printf("Left to start: %2d / Currently active: %2d%n",

                                  leftToStart.getCount(),

                                  numActiveRequests);

                highWaterMark = Math.max(highWaterMark, numActiveRequests);

                try {

                    Thread.sleep(1000);

                } catch (InterruptedException ie) {

                    throw new RuntimeException("Interrupted", ie);

                }

                activeRequests.decrementAndGet();

                System.out.println("Task completed");

                return null;

            }

            @Override

            public SysInfo getSysInfo() {

                return null;

            }

            @Override

            public void shutdown() {

            }

            @Override

            public String serverSettings() {

                return "";

            }

        }

    }

}