1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/classes/com/sun/tools/sjavac/server/CompilerPool.java Mon Feb 04 18:08:53 2013 -0500
1.3 @@ -0,0 +1,163 @@
1.4 +/*
1.5 + * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Oracle designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Oracle in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 + * or visit www.oracle.com if you need additional information or have any
1.26 + * questions.
1.27 + */
1.28 +
1.29 +package com.sun.tools.sjavac.server;
1.30 +
1.31 +import java.util.concurrent.ExecutorService;
1.32 +import java.util.concurrent.Executors;
1.33 +import java.util.concurrent.Semaphore;
1.34 +import java.util.Stack;
1.35 +import java.util.concurrent.Future;
1.36 +
1.37 +/** The compiler pool maintains compiler threads.
1.38 + *
1.39 + * <p><b>This is NOT part of any supported API.
1.40 + * If you write code that depends on this, you do so at your own
1.41 + * risk. This code and its internal interfaces are subject to change
1.42 + * or deletion without notice.</b></p>
1.43 + */
1.44 +public class CompilerPool {
1.45 + // The javac server that created this pool.
1.46 + private JavacServer javacServer;
1.47 + // A semaphore protecting the poolsize number of threads.
1.48 + private Semaphore available;
1.49 + // The stack of compiler threads.
1.50 + private Stack<CompilerThread> compilers = new Stack<CompilerThread>();
1.51 + // And the executor server to spawn threads.
1.52 + private final ExecutorService executorPool;
1.53 + // How many requests are active right now?
1.54 + private int concurrentRequests = 0;
1.55 + // When was the last request finished?
1.56 + private long lastRequestFinished = 0;
1.57 + // The total number of requests to this pool.
1.58 + private int numRequests = 0;
1.59 + // Protect access to the three above values.
1.60 + private static final Object conc = new Object();
1.61 +
1.62 + /**
1.63 + * Return the javac server that this pool belongs to.
1.64 + */
1.65 + public JavacServer getJavacServer() {
1.66 + return javacServer;
1.67 + }
1.68 +
1.69 + /**
1.70 + * Return how many threads are running at this very moment.
1.71 + */
1.72 + public int numActiveRequests()
1.73 + {
1.74 + synchronized (conc) {
1.75 + return concurrentRequests;
1.76 + }
1.77 + }
1.78 +
1.79 + /**
1.80 + * Return when the last request was finished.
1.81 + * I.e. the pool has been idle since.
1.82 + */
1.83 + public long lastRequestFinished()
1.84 + {
1.85 + synchronized (conc) {
1.86 + return lastRequestFinished;
1.87 + }
1.88 + }
1.89 +
1.90 + /**
1.91 + * Up the number of active requests.
1.92 + */
1.93 + public int startRequest() {
1.94 + int n;
1.95 + synchronized (conc) {
1.96 + concurrentRequests++;
1.97 + numRequests++;
1.98 + n = numRequests;
1.99 + }
1.100 + return n;
1.101 + }
1.102 +
1.103 + /**
1.104 + * Down the number of active requests. Return the current time.
1.105 + */
1.106 + public long stopRequest() {
1.107 + synchronized (conc) {
1.108 + concurrentRequests--;
1.109 + lastRequestFinished = System.currentTimeMillis();
1.110 + }
1.111 + return lastRequestFinished;
1.112 + }
1.113 +
1.114 + /**
1.115 + * Create a new compiler pool.
1.116 + */
1.117 + CompilerPool(int poolsize, JavacServer server) {
1.118 + available = new Semaphore(poolsize, true);
1.119 + javacServer = server;
1.120 + executorPool = Executors.newFixedThreadPool(poolsize);
1.121 + lastRequestFinished = System.currentTimeMillis();
1.122 + }
1.123 +
1.124 + /**
1.125 + * Execute a compiler thread.
1.126 + */
1.127 + public void execute(CompilerThread ct) {
1.128 + executorPool.execute(ct);
1.129 + }
1.130 +
1.131 + /**
1.132 + * Execute a minor task, for example generating bytecodes and writing them to disk,
1.133 + * that belong to a major compiler thread task.
1.134 + */
1.135 + public Future<?> executeSubtask(CompilerThread t, Runnable r) {
1.136 + return executorPool.submit(r);
1.137 + }
1.138 +
1.139 + /**
1.140 + * Shutdown the pool.
1.141 + */
1.142 + public void shutdown() {
1.143 + executorPool.shutdown();
1.144 + }
1.145 +
1.146 + /**
1.147 + * Acquire a compiler thread from the pool, or block until a thread is available.
1.148 + * If the pools is empty, create a new thread, but never more than is "available".
1.149 + */
1.150 + public CompilerThread grabCompilerThread() throws InterruptedException {
1.151 + available.acquire();
1.152 + if (compilers.empty()) {
1.153 + return new CompilerThread(this);
1.154 + }
1.155 + return compilers.pop();
1.156 + }
1.157 +
1.158 + /**
1.159 + * Return the specified compiler thread to the pool.
1.160 + */
1.161 + public void returnCompilerThread(CompilerThread h) {
1.162 + compilers.push(h);
1.163 + available.release();
1.164 + }
1.165 +}
1.166 +
