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LogStacktraceCallable xref
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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  
19  package org.apache.giraph.utils;
20  
21  import java.util.concurrent.Callable;
22  import org.apache.log4j.Logger;
23  
24  /**
25   * A wrapper to improve debugging. It passes the call() invocation to the
26   * provided callable, and upon any exception logs the stacktrace and rethrows
27   * the exception. The logging functionality is missing in FutureTask.
28   *
29   * @param <V> Return type of call()
30   */
31  public class LogStacktraceCallable<V> implements Callable<V> {
32    /** Class logger */
33    private static final Logger LOG =
34        Logger.getLogger(LogStacktraceCallable.class);
35  
36    /** Pass call() to this callable. */
37    private final Callable<V> callable;
38    /** Uncaught exception handler, if any */
39    private final Thread.UncaughtExceptionHandler uncaughtExceptionHandler;
40  
41    /**
42     * Construct an instance that will pass call() to the given callable.
43     *
44     * @param callable Callable
45     */
46    public LogStacktraceCallable(Callable<V> callable) {
47      this(callable, null);
48    }
49  
50    /**
51     * Construct an instance that will pass call() to the given callable.
52     *
53     * @param callable Callable
54     * @param uncaughtExceptionHandler Uncaught exception handler, if any
55     *
56     *
57     */
58    public LogStacktraceCallable(Callable<V> callable,
59        Thread.UncaughtExceptionHandler uncaughtExceptionHandler) {
60      this.callable = callable;
61      this.uncaughtExceptionHandler = uncaughtExceptionHandler;
62    }
63  
64    @Override
65    public V call() throws Exception {
66      try {
67        return callable.call();
68        // We catch, log stack trace of, and rethrow all exceptions. It's OK to
69        // skip style check.
70        // CHECKSTYLE: stop IllegalCatch
71      } catch (Exception e) {
72        // CHECKSTYLE: resume IllegalCatch
73        LOG.error("Execution of callable failed", e);
74        if (uncaughtExceptionHandler != null) {
75          uncaughtExceptionHandler.uncaughtException(Thread.currentThread(), e);
76        }
77        throw e;
78      }
79    }
80  }