Java tutorial
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We also recommend that a * file or class name and description of purpose be included on the * same "printed page" as the copyright notice for easier * identification within third-party archives. * * Copyright 2014 Edgar Espina * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.jooby.exec; import com.google.common.base.Splitter; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableMap; import com.google.common.collect.Maps; import com.google.inject.Binder; import com.google.inject.Key; import com.google.inject.name.Names; import com.typesafe.config.Config; import com.typesafe.config.ConfigFactory; import com.typesafe.config.ConfigObject; import com.typesafe.config.ConfigValue; import com.typesafe.config.ConfigValueFactory; import com.typesafe.config.ConfigValueType; import org.jooby.Env; import org.jooby.Jooby.Module; import org.jooby.funzy.Throwing; import org.jooby.funzy.Try; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.lang.reflect.Modifier; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.HashMap; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import java.util.concurrent.Executor; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.ForkJoinPool; import java.util.concurrent.ForkJoinPool.ForkJoinWorkerThreadFactory; import java.util.concurrent.ForkJoinWorkerThread; import java.util.concurrent.ThreadFactory; import java.util.concurrent.atomic.AtomicLong; import java.util.function.BiConsumer; import java.util.function.Supplier; /** * <h1>executor</h1> * <p> * Manage the life cycle of {@link ExecutorService} and build async apps, schedule tasks, etc... * </p> * * <h2>usage</h2> * * <pre>{@code * ... * import org.jooby.exec.Exec; * ... * * { * use(new Exec()); * * get("/", req -> { * ExecutorService executor = req.require(ExecutorService.class); * // work with executor * }); * } * }</pre> * * <p> * The default executor is a {@link Executors#newFixedThreadPool(int)} with threads defined by * {@link Runtime#availableProcessors()} * </p> * * <h2>explicit creation</h2> * <p> * The default {@link ExecutorService} is nice and give you something that just works out of the * box. But, what if you need to control the number of threads? * </p> * <p> * Explicit control is provided via <code>executors</code> which allow the following syntax: * </p> * * <pre> * type (= int)? (, daemon (= boolean)? )? (, priority (= int)? )? * </pre> * * <p> * Let's see some examples: * </p> * * <pre> * # fixed thread pool with a max number of threads equals to the available runtime processors * executors = "fixed" * </pre> * * <pre> * # fixed thread pool with a max number of 10 threads * executors = "fixed = 10" * </pre> * * <pre> * # fixed thread pool with a max number of 10 threads * executors = "fixed = 10" * </pre> * * <pre> * # scheduled thread pool with a max number of 10 threads * executors = "scheduled = 10" * </pre> * * <pre> * # cached thread pool with daemon threads and max priority * executors = "cached, daemon = true, priority = 10" * </pre> * * <pre> * # forkjoin thread pool with asyncMode * executors = "forkjoin, asyncMode = true" * </pre> * * <h2>multiple executors</h2> * <p> * Multiple executors are provided by expanding the <code>executors</code> properties, like: * </p> * * <pre> * executors { * pool1: fixed * jobs: forkjoin * } * </pre> * * <p> * Later, you can request your executor like: * </p> * <pre>{@code * { * get("/", req -> { * ExecutorService pool1 = req.require("pool1", ExecutorService.class); * ExecutorService jobs = req.require("jobs", ExecutorService.class); * }); * } * }</pre> * * <h2>shutdown</h2> * <p> * Any {@link ExecutorService} created by this module will automatically shutdown on application * shutdown time. * </p> * * @author edgar * @since 0.16.0 */ public class Exec implements Module { private static final BiConsumer<String, Executor> NOOP = (n, e) -> { }; /** The logging system. */ private final Logger log = LoggerFactory.getLogger(getClass()); private boolean daemon = true; private int priority = Thread.NORM_PRIORITY; private final Map<String, Throwing.Function4<String, Integer, Supplier<ThreadFactory>, Map<String, Object>, ExecutorService>> f = /** executor factory. */ ImmutableMap.of("cached", (name, n, tf, opts) -> Executors.newCachedThreadPool(tf.get()), "fixed", (name, n, tf, opts) -> Executors.newFixedThreadPool(n, tf.get()), "scheduled", (name, n, tf, opts) -> Executors.newScheduledThreadPool(n, tf.get()), "forkjoin", (name, n, tf, opts) -> { boolean asyncMode = Boolean .parseBoolean(opts.getOrDefault("asyncMode", "false").toString()); return new ForkJoinPool(n, fjwtf(name), null, asyncMode); }); private final String namespace; protected Exec(final String namespace) { this.namespace = namespace; } public Exec() { this("executors"); } /** * Defined the default value for daemon. This value is used when a executor spec doesn't define a * value for daemon. Default is: <code>true</code> * * @param daemon True for default daemon. * @return This module. */ public Exec daemon(final boolean daemon) { this.daemon = daemon; return this; } /** * Defined the default value for priority. This value is used when a executor spec doesn't define * a value for priority. Default is: {@link Thread#NORM_PRIORITY}. * * @param priority One of {@link Thread#MIN_PRIORITY}, {@link Thread#NORM_PRIORITY} or * {@link Thread#MAX_PRIORITY}. * @return This module. */ public Exec priority(final int priority) { this.priority = priority; return this; } @Override public Config config() { return ConfigFactory.empty("exec.conf").withValue(namespace, ConfigValueFactory.fromAnyRef("fixed")); } @Override public void configure(final Env env, final Config conf, final Binder binder) { configure(env, conf, binder, NOOP); } protected void configure(final Env env, final Config conf, final Binder binder, final BiConsumer<String, Executor> callback) { List<Map<String, Object>> executors = conf.hasPath(namespace) ? executors(conf.getValue(namespace), daemon, priority, Runtime.getRuntime().availableProcessors()) : Collections.emptyList(); List<Entry<String, ExecutorService>> services = new ArrayList<>(executors.size()); for (Map<String, Object> options : executors) { // thread factory options String name = (String) options.remove("name"); log.debug("found executor: {}{}", name, options); Boolean daemon = (Boolean) options.remove("daemon"); Integer priority = (Integer) options.remove("priority"); String type = String.valueOf(options.remove("type")); // number of processors Integer n = (Integer) options.remove(type); // create executor Throwing.Function4<String, Integer, Supplier<ThreadFactory>, Map<String, Object>, ExecutorService> factory = f .get(type); if (factory == null) { throw new IllegalArgumentException("Unknown executor: " + type + " must be one of " + f.keySet()); } ExecutorService executor = factory.apply(type, n, () -> factory(name, daemon, priority), options); bind(binder, name, executor); callback.accept(name, executor); services.add(Maps.immutableEntry(name, executor)); } services.stream().filter(it -> it.getKey().equals("default")).findFirst() .ifPresent(e -> bind(binder, null, e.getValue())); env.onStop(() -> { services.forEach(exec -> Try.run(() -> exec.getValue().shutdown()) .onFailure(cause -> log.error("shutdown of {} resulted in error", exec.getKey(), cause))); services.clear(); }); } @SuppressWarnings({ "rawtypes", "unchecked" }) private static void bind(final Binder binder, final String name, final ExecutorService executor) { Class klass = executor.getClass(); Set<Class> types = collector(klass); for (Class type : types) { Key key = name == null ? Key.get(type) : Key.get(type, Names.named(name)); binder.bind(key).toInstance(executor); } } @SuppressWarnings("rawtypes") private static Set<Class> collector(final Class type) { if (type != null && Executor.class.isAssignableFrom(type)) { Set<Class> types = new HashSet<>(); if (type.isInterface() || !Modifier.isAbstract(type.getModifiers())) { types.add(type); } types.addAll(collector(type.getSuperclass())); Arrays.asList(type.getInterfaces()).forEach(it -> types.addAll(collector(it))); return types; } return Collections.emptySet(); } private static ThreadFactory factory(final String name, final boolean daemon, final int priority) { AtomicLong id = new AtomicLong(0); return r -> { Thread thread = new Thread(r, name + "-" + id.incrementAndGet()); thread.setDaemon(daemon); thread.setPriority(priority); return thread; }; } private static ForkJoinWorkerThreadFactory fjwtf(final String name) { AtomicLong id = new AtomicLong(); return pool -> { ForkJoinWorkerThread thread = ForkJoinPool.defaultForkJoinWorkerThreadFactory.newThread(pool); thread.setName(name + "-" + id.incrementAndGet()); return thread; }; } private static List<Map<String, Object>> executors(final ConfigValue candidate, final boolean daemon, final int priority, final int n) { if (candidate.valueType() == ConfigValueType.STRING) { Map<String, Object> options = executor("default", daemon, priority, n, candidate.unwrapped()); return ImmutableList.of(options); } ConfigObject conf = (ConfigObject) candidate; List<Map<String, Object>> result = new ArrayList<>(); for (Entry<String, ConfigValue> executor : conf.entrySet()) { String name = executor.getKey(); Object value = executor.getValue().unwrapped(); Map<String, Object> options = new HashMap<>(executor(name, daemon, priority, n, value)); result.add(options); } return result; } @SuppressWarnings("unchecked") private static Map<String, Object> executor(final String name, final boolean daemon, final int priority, final int n, final Object value) { Map<String, Object> options = new HashMap<>(); options.put("name", name); options.put("daemon", daemon); options.put("priority", priority); if (value instanceof Map) { Map<String, Object> config = (Map<String, Object>) value; Object rawType = config.get("type"); if (rawType == null) { throw new IllegalArgumentException("Missing executor type"); } String type = rawType.toString(); options.put("type", type); options.put(type, config.containsKey("size") ? Integer.parseInt(config.get("size").toString()) : n); options.put("daemon", config.containsKey("daemon") ? Boolean.parseBoolean(config.get("daemon").toString()) : daemon); options.put("asyncMode", config.containsKey("asyncMode") && Boolean.parseBoolean(config.get("asyncMode").toString())); options.put("priority", config.containsKey("priority") ? Integer.parseInt(config.get("priority").toString()) : priority); } else { Iterable<String> spec = Splitter.on(",").trimResults().omitEmptyStrings().split(value.toString()); for (String option : spec) { String[] opt = option.split("="); String optname = opt[0].trim(); Object optvalue; switch (optname) { case "daemon": optvalue = opt.length > 1 ? Boolean.parseBoolean(opt[1].trim()) : daemon; break; case "asyncMode": optvalue = opt.length > 1 && Boolean.parseBoolean(opt[1].trim()); break; case "priority": optvalue = opt.length > 1 ? Integer.parseInt(opt[1].trim()) : priority; break; default: optvalue = opt.length > 1 ? Integer.parseInt(opt[1].trim()) : n; options.put("type", optname); break; } options.put(optname, optvalue); } } return options; } }