1 /*
2 * Copyright (c) 2012-2024, jcabi.com
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met: 1) Redistributions of source code must retain the above
8 * copyright notice, this list of conditions and the following
9 * disclaimer. 2) Redistributions in binary form must reproduce the above
10 * copyright notice, this list of conditions and the following
11 * disclaimer in the documentation and/or other materials provided
12 * with the distribution. 3) Neither the name of the jcabi.com nor
13 * the names of its contributors may be used to endorse or promote
14 * products derived from this software without specific prior written
15 * permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
19 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
22 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
28 * OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30 package com.jcabi.aspects.aj;
31
32 import java.util.concurrent.ExecutorService;
33 import java.util.concurrent.Executors;
34 import java.util.concurrent.Future;
35 import org.aspectj.lang.ProceedingJoinPoint;
36 import org.aspectj.lang.annotation.Around;
37 import org.aspectj.lang.annotation.Aspect;
38 import org.aspectj.lang.reflect.MethodSignature;
39
40 /**
41 * Execute method asynchronously.
42 *
43 * <p>It is an AspectJ aspect and you are not supposed to use it directly. It
44 * is instantiated by AspectJ runtime framework when your code is annotated
45 * with {@link com.jcabi.aspects.Async} annotation.
46 *
47 * @since 0.16
48 */
49 @Aspect
50 public final class MethodAsyncRunner {
51
52 /**
53 * Thread pool for asynchronous execution.
54 */
55 private final transient ExecutorService executor =
56 Executors.newFixedThreadPool(
57 Runtime.getRuntime().availableProcessors(),
58 new NamedThreads(
59 "async",
60 "Asynchronous method execution"
61 )
62 );
63
64 /**
65 * Execute method asynchronously.
66 *
67 * <p>This aspect should be used only on {@code void} or
68 * {@link Future} returning methods.
69 *
70 * <p>Try NOT to change the signature of this method, in order to keep
71 * it backward compatible.
72 *
73 * @param point Joint point
74 * @return The result of call
75 */
76 @Around("execution(@com.jcabi.aspects.Async * * (..))")
77 @SuppressWarnings("PMD.AvoidCatchingThrowable")
78 public Object wrap(final ProceedingJoinPoint point) {
79 final Class<?> returned = ((MethodSignature) point.getSignature()).getMethod()
80 .getReturnType();
81 if (!Future.class.isAssignableFrom(returned)
82 && !returned.equals(Void.TYPE)) {
83 // @checkstyle LineLength (3 lines)
84 throw new IllegalStateException(
85 String.format(
86 "%s: Return type is %s, not void or Future, cannot use @Async",
87 Mnemos.toText(point, true, true),
88 returned.getCanonicalName()
89 )
90 );
91 }
92 final Future<?> result = this.executor.submit(
93 // @checkstyle AnonInnerLength (23 lines)
94 () -> {
95 Object ret = null;
96 try {
97 final Object res = point.proceed();
98 if (res instanceof Future) {
99 ret = ((Future<?>) res).get();
100 }
101 // @checkstyle IllegalCatch (1 line)
102 } catch (final Throwable ex) {
103 throw new IllegalStateException(
104 String.format(
105 "%s: Exception thrown",
106 Mnemos.toText(point, true, true)
107 ),
108 ex
109 );
110 }
111 return ret;
112 }
113 );
114 Object res = null;
115 if (Future.class.isAssignableFrom(returned)) {
116 res = result;
117 }
118 return res;
119 }
120
121 }