| /* |
| * Copyright (c) 2012, 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 |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.tools.sjavac.server; |
| |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.Semaphore; |
| import java.util.Stack; |
| import java.util.concurrent.Future; |
| |
| /** The compiler pool maintains compiler threads. |
| * |
| * <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></p> |
| */ |
| public class CompilerPool { |
| // The javac server that created this pool. |
| private JavacServer javacServer; |
| // A semaphore protecting the poolsize number of threads. |
| private Semaphore available; |
| // The stack of compiler threads. |
| private Stack<CompilerThread> compilers = new Stack<>(); |
| // And the executor server to spawn threads. |
| private final ExecutorService executorPool; |
| // How many requests are active right now? |
| private int concurrentRequests = 0; |
| // When was the last request finished? |
| private long lastRequestFinished = 0; |
| // The total number of requests to this pool. |
| private int numRequests = 0; |
| // Protect access to the three above values. |
| private static final Object conc = new Object(); |
| |
| /** |
| * Return the javac server that this pool belongs to. |
| */ |
| public JavacServer getJavacServer() { |
| return javacServer; |
| } |
| |
| /** |
| * Return how many threads are running at this very moment. |
| */ |
| public int numActiveRequests() |
| { |
| synchronized (conc) { |
| return concurrentRequests; |
| } |
| } |
| |
| /** |
| * Return when the last request was finished. |
| * I.e. the pool has been idle since. |
| */ |
| public long lastRequestFinished() |
| { |
| synchronized (conc) { |
| return lastRequestFinished; |
| } |
| } |
| |
| /** |
| * Up the number of active requests. |
| */ |
| public int startRequest() { |
| int n; |
| synchronized (conc) { |
| concurrentRequests++; |
| numRequests++; |
| n = numRequests; |
| } |
| return n; |
| } |
| |
| /** |
| * Down the number of active requests. Return the current time. |
| */ |
| public long stopRequest() { |
| synchronized (conc) { |
| concurrentRequests--; |
| lastRequestFinished = System.currentTimeMillis(); |
| } |
| return lastRequestFinished; |
| } |
| |
| /** |
| * Create a new compiler pool. |
| */ |
| CompilerPool(int poolsize, JavacServer server) { |
| available = new Semaphore(poolsize, true); |
| javacServer = server; |
| executorPool = Executors.newFixedThreadPool(poolsize); |
| lastRequestFinished = System.currentTimeMillis(); |
| } |
| |
| /** |
| * Execute a compiler thread. |
| */ |
| public void execute(CompilerThread ct) { |
| executorPool.execute(ct); |
| } |
| |
| /** |
| * Execute a minor task, for example generating bytecodes and writing them to disk, |
| * that belong to a major compiler thread task. |
| */ |
| public Future<?> executeSubtask(CompilerThread t, Runnable r) { |
| return executorPool.submit(r); |
| } |
| |
| /** |
| * Shutdown the pool. |
| */ |
| public void shutdown() { |
| executorPool.shutdown(); |
| } |
| |
| /** |
| * Acquire a compiler thread from the pool, or block until a thread is available. |
| * If the pools is empty, create a new thread, but never more than is "available". |
| */ |
| public CompilerThread grabCompilerThread() throws InterruptedException { |
| available.acquire(); |
| if (compilers.empty()) { |
| return new CompilerThread(this); |
| } |
| return compilers.pop(); |
| } |
| |
| /** |
| * Return the specified compiler thread to the pool. |
| */ |
| public void returnCompilerThread(CompilerThread h) { |
| compilers.push(h); |
| available.release(); |
| } |
| } |
| |