blocks|key|1831689|text|您可能会考虑使用IBM's+MTRAT。预防终究比治疗好。Multicore+Software+Development+Kit还附带了一个死锁检测工具。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1831690|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.sun.com/source/806-3568/ncg_goldberg.html|1|https://web.archive.org/web/20110830183307/http://www.alphaworks.ibm.com/tech/msdk/download^0|8|B|0|T|Y|1|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@$A|O|B|P|1|Q]|$A|R|B|S|1|T]]|C|$]]|$1|D|3|-4|5|6|7|U|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]|L|$5|G|H|I|C|$J|M]]]]

You might want to consider <a href="http://docs.sun.com/source/806-3568/ncg_goldberg.html" rel="nofollow noreferrer">IBM's MTRAT</a>. Prevention is better than cure after all. The <a href="https://web.archive.org/web/20110830183307/http://www.alphaworks.ibm.com/tech/msdk/download" rel="nofollow noreferrer">Multicore Software Development Kit</a> also comes with a deadlock detection tool.

blocks|key|1831703|text|如果你想让它在运行时完成，你可以使用watchdog。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1831704|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Watchdog_timer^0|I|8|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

In case you want it to be done in run-time you can use <a href="http://en.wikipedia.org/wiki/Watchdog_timer" rel="nofollow noreferrer">watchdog</a> for that.

blocks|key|2045906|text|一个对调查有用的提示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2045907|如果您能当场抓住应用程序并怀疑发生了死锁，请转到并在java.exe控制台窗口中按"Ctrl-Break“(或在Solaris/Linux上按"Ctrl-\”)。jvm将转储所有线程的当前状态和堆栈跟踪，找出死锁并精确描述它们。|2045908|它看起来像这样：|2045909|Full+thread+dump+Java+HotSpot(TM)+Client+VM+(1.5.0_09-b03+mixed+mode):

"[Test+Timer]+Request+Queue"+prio=6+tid=0x13d708d0+nid=0x1ec+in+Object.
++++wait()+[0x1b00f000..0x1b00fb68]
++++at+java.lang.Object.wait(Native+Method)
++++at+java.lang.Object.wait(Unknown+Source)
++++at+library.util.AsyncQueue.run(AsyncQueue.java:138)
++++++++-+locked+<0x02e70000>+(a+test.server.scheduler.SchedulerRequestQueue)

++++...

Found+one+Java-level+deadlock:
=============================
"Corba+service":
++waiting+to+lock+monitor+0x13c06684+(object+0x04697d90,+a+java.lang.Object),
++which+is+held+by+"[Server+Connection]+Heartbeat+Timer"
"[Server+Connection]+Heartbeat+Timer":
++waiting+to+lock+monitor+0x13c065c4+(object+0x0467e728,+a+test.proxy.ServerProxy),+which+is+held+by+"Corba+service"

Java+stack+information+for+the+threads+listed+above:
===================================================
"Corba+service":
++++at+test.proxy.ServerProxy.stopHBWatchDog(ServerProxy:695)
++++-+waiting+to+lock+<0x04697d90>+(a+java.lang.Object)
++++...|code-block|syntax|javascript|2045910|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|O|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|P|8|@]|9|@]|A|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

One useful hint for investigation:

If you can catch the application red handed and suspect a deadlock has occurred, go and press "Ctrl-Break" in the java.exe console window (or "Ctrl-\" on Solaris/Linux).
The jvm will dump the current status and stack trace of all threads, find out dead locks and precisely describe them.

It will look something like this:

<pre><code>Full thread dump Java HotSpot(TM) Client VM (1.5.0_09-b03 mixed mode):

"[Test Timer] Request Queue" prio=6 tid=0x13d708d0 nid=0x1ec in Object.
 wait() [0x1b00f000..0x1b00fb68]
 at java.lang.Object.wait(Native Method)
 at java.lang.Object.wait(Unknown Source)
 at library.util.AsyncQueue.run(AsyncQueue.java:138)
 - locked &lt;0x02e70000&gt; (a test.server.scheduler.SchedulerRequestQueue)

 ...

Found one Java-level deadlock:
=============================
"Corba service":
 waiting to lock monitor 0x13c06684 (object 0x04697d90, a java.lang.Object),
 which is held by "[Server Connection] Heartbeat Timer"
"[Server Connection] Heartbeat Timer":
 waiting to lock monitor 0x13c065c4 (object 0x0467e728, a test.proxy.ServerProxy), which is held by "Corba service"

Java stack information for the threads listed above:
===================================================
"Corba service":
 at test.proxy.ServerProxy.stopHBWatchDog(ServerProxy:695)
 - waiting to lock &lt;0x04697d90&gt; (a java.lang.Object)
 ...
</code></pre>

blocks|key|1831848|text|您可以使用JDK附带的ThreadMXBean以编程方式完成此操作：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1831849|ThreadMXBean+bean+=+ManagementFactory.getThreadMXBean();
long[]+threadIds+=+bean.findDeadlockedThreads();+//+Returns+null+if+no+threads+are+deadlocked.

if+(threadIds+!=+null)+{
++++ThreadInfo[]+infos+=+bean.getThreadInfo(threadIds);

++++for+(ThreadInfo+info+:+infos)+{
++++++++StackTraceElement[]+stack+=+info.getStackTrace();
++++++++//+Log+or+store+stack+trace+information.
++++}
}|code-block|syntax|javascript|1831850|显然，您应该尝试隔离正在执行此死锁检查的任何线程-否则，如果该线程死锁，它将无法运行检查！|1831851|顺便说一句，这就是JConsole在幕后使用的。|1831852|entityMap^0|B|C|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|N|5|6|7|V|8|@]|D|@]|E|$]]|$1|O|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|P|$]]

You can do this programmatically using the <code>ThreadMXBean</code> that ships with the JDK:

<pre><code>ThreadMXBean bean = ManagementFactory.getThreadMXBean();
long[] threadIds = bean.findDeadlockedThreads(); // Returns null if no threads are deadlocked.

if (threadIds != null) {
 ThreadInfo[] infos = bean.getThreadInfo(threadIds);

 for (ThreadInfo info : infos) {
 StackTraceElement[] stack = info.getStackTrace();
 // Log or store stack trace information.
 }
}
</code></pre>

Obviously you should try to isolate whichever thread is performing this deadlock check - Otherwise if that thread deadlocks it won't be able to run the check!

Incidentally this is what JConsole is using under the covers.

blocks|key|1831888|text|tempus-fugit还通过编程线程转储类实现了它。它是使用上面提到的mbean机制实现的，并提供了一个即插即用的超级复制解决方案。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1831889|entityMap|0|LINK|mutability|MUTABLE|url|http://tempusfugitlibrary.org/^0|0|C|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

<a href="http://tempusfugitlibrary.org/" rel="nofollow noreferrer">tempus-fugit</a> also implements it along with a programmatic thread dumping class. It's implemented using the mbean mechanism mentioned above and offers a drop in, out-of-the-box super duper solution.

blocks|key|2046320|text|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2046321|魔术发生在ThreadMonitor.findDeadlock()中|offset|length|style|CODE|2046322|++public+boolean+findDeadlock()+{
++++long[]+tids;
++++if+(findDeadlocksMethodName.equals("findDeadlockedThreads")
++++++++&&+tmbean.isSynchronizerUsageSupported())+{
++++++tids+=+tmbean.findDeadlockedThreads();
++++++if+(tids+==+null)+{
++++++++return+false;
++++++}

++++++System.out.println("Deadlock+found+:-");
++++++ThreadInfo[]+infos+=+tmbean.getThreadInfo(tids,+true,+true);
++++++for+(ThreadInfo+ti+:+infos)+{
++++++++printThreadInfo(ti);
++++++++printLockInfo(ti.getLockedSynchronizers());
++++++++System.out.println();
++++++}
++++}+else+{
++++++tids+=+tmbean.findMonitorDeadlockedThreads();
++++++if+(tids+==+null)+{
++++++++return+false;
++++++}
++++++ThreadInfo[]+infos+=+tmbean.getThreadInfo(tids,+Integer.MAX_VALUE);
++++++for+(ThreadInfo+ti+:+infos)+{
++++++++//+print+thread+information
++++++++printThreadInfo(ti);
++++++}
++++}

++++return+true;
++}|code-block|syntax|javascript|2046323|这将调用在Java5和6中具有不同名称(因此称为外部if())的ThreadMXBean的API。|2046324|代码示例还允许中断锁，因此您甚至可以打破死锁。|2046325|entityMap^0|0|5|S|0|0|Q|4|W|C|0|0^^$0|@$1|2|3|-4|4|5|6|R|7|@]|8|@]|9|$]]|$1|A|3|B|4|5|6|S|7|@$C|T|D|U|E|F]]|8|@]|9|$]]|$1|G|3|H|4|I|6|V|7|@]|8|@]|9|$J|K]]|$1|L|3|M|4|5|6|W|7|@$C|X|D|Y|E|F]|$C|Z|D|10|E|F]]|8|@]|9|$]]|$1|N|3|O|4|5|6|11|7|@]|8|@]|9|$]]|$1|P|3|-4|4|5|6|12|7|@]|8|@]|9|$]]]|Q|$]]

There is code here: <a href="http://www.java2s.com/Code/Java/Development-Class/PerformingdeadlockdetectionprogrammaticallywithintheapplicationusingthejavalangmanagementAPI.htm" rel="nofollow">http://www.java2s.com/Code/Java/Development-Class/PerformingdeadlockdetectionprogrammaticallywithintheapplicationusingthejavalangmanagementAPI.htm</a>

The magic happens in <code>ThreadMonitor.findDeadlock()</code>:

<pre><code> public boolean findDeadlock() {
 long[] tids;
 if (findDeadlocksMethodName.equals("findDeadlockedThreads")
 &amp;&amp; tmbean.isSynchronizerUsageSupported()) {
 tids = tmbean.findDeadlockedThreads();
 if (tids == null) {
 return false;
 }

 System.out.println("Deadlock found :-");
 ThreadInfo[] infos = tmbean.getThreadInfo(tids, true, true);
 for (ThreadInfo ti : infos) {
 printThreadInfo(ti);
 printLockInfo(ti.getLockedSynchronizers());
 System.out.println();
 }
 } else {
 tids = tmbean.findMonitorDeadlockedThreads();
 if (tids == null) {
 return false;
 }
 ThreadInfo[] infos = tmbean.getThreadInfo(tids, Integer.MAX_VALUE);
 for (ThreadInfo ti : infos) {
 // print thread information
 printThreadInfo(ti);
 }
 }

 return true;
 }
</code></pre>

This calls an API of the <code>ThreadMXBean</code> which has a different name in Java 5 and 6 (hence the outer <code>if()</code>).

The code example also allows to interrupt the locks, so you can even break the deadlock.

blocks|key|2046367|text|JArmus是一个用于检测和避免死锁的库。它支持：Thread.join、CyclicBarrier、CountDownLatch、Phaser和ReentrantLock。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2046368|要使用JArmus，您需要检测您的代码。通过其插入指令的类之一或使用JArmus指令集jarmusc自动执行。|2046369|java+-jar+jarmusc.jar+yourprogram.jar+checkedprogram.jar|2046370|输入yourprogram.jar是您要检查的程序。输出是带有自动查找死锁的检查的同一个程序。|2046371|障碍需要一些帮助|2046372|用类CyclicBarrier、CountDownLatch、Phaser验证死锁有点棘手-例如，JConsole无法检测到这些类型的死锁。JArmus需要您的一些帮助:您必须指定哪些线程正在影响同步，我们将这些线程称为注册线程。|2046373|线程必须尽快将自身标记为已注册。标记已注册线程的一个好地方是开始的方法Runnable.run。JArmus.register(latch);|2046374|示例|2046375|JArmus可以正确识别以下程序的死锁：|2046376|final+CountDownLatch+latch+=+new+CountDownLatch(2);
final+CyclicBarrier+barrier+=+new+CyclicBarrier(2);
final+Queue<Exception>+exceptions+=+new+ArrayDeque<>();
Thread+t1+=+new+Thread(new+Runnable()+{
++++@Override
++++public+void+run()+{
++++++++try+{
++++++++++++JArmus.register(barrier);+//+do+not+forget+to+register!
++++++++++++JArmus.register(latch);+//+do+not+forget+to+register!
++++++++++++latch.countDown();
++++++++++++latch.await();
++++++++++++barrier.await();
++++++++}+catch+(Exception+e)+{
++++++++++++exceptions.add(e);
++++++++}
++++}
});
Thread+t2+=+new+Thread(new+Runnable()+{
++++@Override
++++public+void+run()+{
++++++++try+{
++++++++++++JArmus.register(barrier);+//+do+not+forget+to+register!
++++++++++++JArmus.register(latch);+//+do+not+forget+to+register!
++++++++++++barrier.await();
++++++++++++latch.countDown();
++++++++++++latch.await();
++++++++}+catch+(Exception+e)+{
++++++++++++exceptions.add(e);
++++++++}
++++}
});
t1.start();
t2.start();|code-block|syntax|javascript|2046377|entityMap|0|LINK|mutability|MUTABLE|url|https://bitbucket.org/cogumbreiro/jarmus/^0|P|B|11|D|1F|E|1U|6|21|D|0|6|0|0|17|7|0|0|1K|0|2|F|0|0|2|D|G|E|V|6|0|Z|C|1C|N|0|0|0|0^^$0|@$1|2|3|4|5|6|7|18|8|@$9|19|A|1A|B|C]|$9|1B|A|1C|B|C]|$9|1D|A|1E|B|C]|$9|1F|A|1G|B|C]|$9|1H|A|1I|B|C]]|D|@$9|1J|A|1K|1|1L]]|E|$]]|$1|F|3|G|5|6|7|1M|8|@$9|1N|A|1O|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|1P|8|@$9|1Q|A|1R|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|1S|8|@$9|1T|A|1U|B|C]]|D|@]|E|$]]|$1|L|3|M|5|6|7|1V|8|@]|D|@]|E|$]]|$1|N|3|O|5|6|7|1W|8|@$9|1X|A|1Y|B|C]|$9|1Z|A|20|B|C]|$9|21|A|22|B|C]]|D|@]|E|$]]|$1|P|3|Q|5|6|7|23|8|@$9|24|A|25|B|C]|$9|26|A|27|B|C]]|D|@]|E|$]]|$1|R|3|S|5|6|7|28|8|@]|D|@]|E|$]]|$1|T|3|U|5|6|7|29|8|@]|D|@]|E|$]]|$1|V|3|W|5|X|7|2A|8|@]|D|@]|E|$Y|Z]]|$1|10|3|-4|5|6|7|2B|8|@]|D|@]|E|$]]]|11|$12|$5|13|14|15|E|$16|17]]]]

<a href="https://bitbucket.org/cogumbreiro/jarmus/" rel="nofollow">JArmus</a> is a library for deadlock detection and avoidance. It includes support for:
<code>Thread.join</code>, <code>CyclicBarrier</code>, <code>CountDownLatch</code>, <code>Phaser</code>, and
<code>ReentrantLock</code>.

To use JArmus you need to instrument your code. Either through one of its instrumented classes or automatically with the JArmus instrumentar <code>jarmusc</code>.

<code>
java -jar jarmusc.jar yourprogram.jar checkedprogram.jar
</code>

The input <code>yourprogram.jar</code> is the program you want to check.
The output is the same program with checks to automatically find any deadlock.

<h2>Barriers need some help</h2>

Verifying deadlocks with classes <code>CyclicBarrier</code>, <code>CountDownLatch</code>, <code>Phaser</code> is a bit tricky --- for example, JConsole cannot detect these types of deadlocks. JArmus needs a little help from you: you must specify which threads are influencing synchronization, we call these registered threads. 

As soon as possible, the thread must mark itself as registered. A good place to mark registered threads is at the beginning method <code>Runnable.run</code>.
<code>
JArmus.register(latch);
</code>

<h2>Example</h2>

The following program that deadlocks is correctly identified by 
JArmus:

<pre><code>final CountDownLatch latch = new CountDownLatch(2);
final CyclicBarrier barrier = new CyclicBarrier(2);
final Queue&lt;Exception&gt; exceptions = new ArrayDeque&lt;&gt;();
Thread t1 = new Thread(new Runnable() {
 @Override
 public void run() {
 try {
 JArmus.register(barrier); // do not forget to register!
 JArmus.register(latch); // do not forget to register!
 latch.countDown();
 latch.await();
 barrier.await();
 } catch (Exception e) {
 exceptions.add(e);
 }
 }
});
Thread t2 = new Thread(new Runnable() {
 @Override
 public void run() {
 try {
 JArmus.register(barrier); // do not forget to register!
 JArmus.register(latch); // do not forget to register!
 barrier.await();
 latch.countDown();
 latch.await();
 } catch (Exception e) {
 exceptions.add(e);
 }
 }
});
t1.start();
t2.start();
</code></pre>

blocks|key|1832333|text|您可以使用ThreadMXBean+class.Here以编程方式检测死锁线程，|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1832334|++++ThreadMXBean+bean+=+ManagementFactory.getThreadMXBean();

++++long+ids[]+=+bean.findMonitorDeadlockedThreads();

++++if(ids+!=+null)
++++{
++++++++ThreadInfo+threadInfo[]+=+bean.getThreadInfo(ids);

++++++++for+(ThreadInfo+threadInfo1+:+threadInfo)
++++++++{
++++++++++++System.out.println(threadInfo1.getThreadId());++++//Prints+the+ID+of+deadlocked+thread

++++++++++++System.out.println(threadInfo1.getThreadName());++//Prints+the+name+of+deadlocked+thread

++++++++++++System.out.println(threadInfo1.getLockName());++++//Prints+the+string+representation+of+an+object+for+which+thread+has+entered+into+deadlock.

++++++++++++System.out.println(threadInfo1.getLockOwnerId());++//Prints+the+ID+of+thread+which+currently+owns+the+object+lock

++++++++++++System.out.println(threadInfo1.getLockOwnerName());++//Prints+name+of+the+thread+which+currently+owns+the+object+lock.
++++++++}
++++}
++++else
++++{
++++++++System.out.println("No+Deadlocked+Threads");
++++}|code-block|syntax|javascript|1832335|有关如何检测死锁线程的详细信息，请单击here。|offset|length|1832336|entityMap|0|LINK|mutability|MUTABLE|url|http://javaconceptoftheday.com/detect-deadlocked-threads-using-threadmxbean-class-java/^0|0|0|J|4|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

You can detect the deadlocked threads programmatically using ThreadMXBean class.Here is the code,

<pre><code> ThreadMXBean bean = ManagementFactory.getThreadMXBean();

 long ids[] = bean.findMonitorDeadlockedThreads();

 if(ids != null)
 {
 ThreadInfo threadInfo[] = bean.getThreadInfo(ids);

 for (ThreadInfo threadInfo1 : threadInfo)
 {
 System.out.println(threadInfo1.getThreadId()); //Prints the ID of deadlocked thread

 System.out.println(threadInfo1.getThreadName()); //Prints the name of deadlocked thread

 System.out.println(threadInfo1.getLockName()); //Prints the string representation of an object for which thread has entered into deadlock.

 System.out.println(threadInfo1.getLockOwnerId()); //Prints the ID of thread which currently owns the object lock

 System.out.println(threadInfo1.getLockOwnerName()); //Prints name of the thread which currently owns the object lock.
 }
 }
 else
 {
 System.out.println("No Deadlocked Threads");
 }
</code></pre>

Click <a href="http://javaconceptoftheday.com/detect-deadlocked-threads-using-threadmxbean-class-java/" rel="noreferrer">here</a> for more info on how to detect the deadlocked threads.

How can I programmatically detect that a deadlock has occurred in a Java program?

Programmatic deadlock detection in java

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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