问题描述
我有一个Gui应用程序，可以在串行热敏打印机上打印票据。当我点击启动此操作的按钮时，我的GUI被冻结。我认为那是因为代码是在EDT上执行的。我使用jstack确定但我不理解下面的结果：
I have a Gui application in swing that prints a ticket on a serial thermal printer. When i hit the button that launch this action, my GUI is frozen. I think that's because the code is executed on the EDT. I used jstack to be sure but i don't understand the results below :
Full thread dump Java HotSpot(TM) Client VM (23.3-b01 mixed mode, sharing):
"Thread-12" prio=6 tid=0x03012000 nid=0xd04 runnable [0x038ef000]
java.lang.Thread.State: RUNNABLE
at gnu.io.RXTXPort.eventLoop(Native Method)
at gnu.io.RXTXPort$MonitorThread.run(RXTXPort.java:1575)
"Thread-6" prio=6 tid=0x0302c400 nid=0x1b0 waiting on condition [0x039ef000]
java.lang.Thread.State: TIMED_WAITING (sleeping)
at java.lang.Thread.sleep(Native Method)
at posO2.Threads.ThreadHorloge.run(ThreadHorloge.java:46)
"Thread-5" prio=6 tid=0x03511c00 nid=0x9e4 waiting on condition [0x0399f000]
java.lang.Thread.State: TIMED_WAITING (sleeping)
at java.lang.Thread.sleep(Native Method)
at posO2.Threads.ThreadIgor.run(ThreadIgor.java:29)
"Thread-7" prio=6 tid=0x034b9800 nid=0xb40 waiting on condition [0x0394f000]
java.lang.Thread.State: TIMED_WAITING (sleeping)
at java.lang.Thread.sleep(Native Method)
at posO2.Threads.ThreadHorloge.run(ThreadHorloge.java:46)
at java.lang.Thread.run(Unknown Source)
"Thread-4" prio=6 tid=0x0318ec00 nid=0xa08 waiting on condition [0x0323f000]
java.lang.Thread.State: TIMED_WAITING (sleeping)
at java.lang.Thread.sleep(Native Method)
at posO2.Threads.ThreadMajProduits.run(ThreadMajProduits.java:49)
"TimerQueue" daemon prio=6 tid=0x03036400 nid=0x9b8 waiting on condition [0x0344
f000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x27e76778> (a java.util.concurrent.locks.Abstra
ctQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject
.await(Unknown Source)
at java.util.concurrent.DelayQueue.take(Unknown Source)
at javax.swing.TimerQueue.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
"DestroyJavaVM" prio=6 tid=0x003c8400 nid=0xfe4 waiting on condition [0x00000000
]
java.lang.Thread.State: RUNNABLE
"AWT-EventQueue-0" prio=6 tid=0x02b6e000 nid=0xcbc runnable [0x033fe000]
java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.io.BufferedInputStream.fill(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
- locked <0x22f33f30> (a java.io.BufferedInputStream)
at java.io.DataInputStream.readByte(Unknown Source)
at org.hsqldb.result.Result.newResult(Unknown Source)
at org.hsqldb.ClientConnection.read(Unknown Source)
at org.hsqldb.ClientConnection.execute(Unknown Source)
- locked <0x22f32700> (a org.hsqldb.ClientConnection)
at org.hsqldb.jdbc.JDBCStatement.fetchResult(Unknown Source)
at org.hsqldb.jdbc.JDBCStatement.executeQuery(Unknown Source)
- locked <0x22be23b0> (a org.hsqldb.jdbc.JDBCStatement)
at posO2.Printer.flash(Printer.java:1058)
at posO2.Printer.bigFlash(Printer.java:1111)
at posO2.Panels.Accueil$5.actionPerformed(Accueil.java:314)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
"AWT-Shutdown" prio=6 tid=0x02b81800 nid=0xefc in Object.wait() [0x033af000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x27c707c0> (a java.lang.Object)
at java.lang.Object.wait(Object.java:503)
at sun.awt.AWTAutoShutdown.run(Unknown Source)
- locked <0x27c707c0> (a java.lang.Object)
at java.lang.Thread.run(Unknown Source)
"AWT-Windows" daemon prio=6 tid=0x03002800 nid=0xe58 runnable [0x0328f000]
java.lang.Thread.State: RUNNABLE
at sun.awt.windows.WToolkit.eventLoop(Native Method)
at sun.awt.windows.WToolkit.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
"Java2D Disposer" daemon prio=10 tid=0x03000400 nid=0x4d0 in Object.wait() [0x03
1ef000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x27c2bf18> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(Unknown Source)
- locked <0x27c2bf18> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(Unknown Source)
at sun.java2d.Disposer.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
"Service Thread" daemon prio=6 tid=0x02b63000 nid=0xb94 runnable [0x00000000]
java.lang.Thread.State: RUNNABLE
"C1 CompilerThread0" daemon prio=10 tid=0x02b54c00 nid=0x3f0 waiting on conditio
n [0x00000000]
java.lang.Thread.State: RUNNABLE
"Attach Listener" daemon prio=10 tid=0x02b53400 nid=0x924 waiting on condition [
0x00000000]
java.lang.Thread.State: RUNNABLE
"Signal Dispatcher" daemon prio=10 tid=0x02b52000 nid=0xb88 runnable [0x00000000
]
java.lang.Thread.State: RUNNABLE
"Finalizer" daemon prio=8 tid=0x02b43c00 nid=0xfc8 in Object.wait() [0x02dff000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x27c2c148> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(Unknown Source)
- locked <0x27c2c148> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(Unknown Source)
at java.lang.ref.Finalizer$FinalizerThread.run(Unknown Source)
"Reference Handler" daemon prio=10 tid=0x02b3f000 nid=0x488 in Object.wait() [0x
02daf000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x27c2bdd8> (a java.lang.ref.Reference$Lock)
at java.lang.Object.wait(Object.java:503)
at java.lang.ref.Reference$ReferenceHandler.run(Unknown Source)
- locked <0x27c2bdd8> (a java.lang.ref.Reference$Lock)
"VM Thread" prio=10 tid=0x02b3d400 nid=0xa6c runnable
"VM Periodic Task Thread" prio=10 tid=0x02b76800 nid=0xf30 waiting on condition
JNI global references: 426
有人可以向我解释一下，由于第一个帖子Thread-12，我的GUI被冻结了。
Can someone explain to me where i can see that my GUI is frozen because of the first thread "Thread-12".
其次是什么Thread-6和Thread-7之间的区别，只要我确定我只运行了一次该线程。
And secondly what's the difference between "Thread-6" and "Thread-7" as long as I'm sure i only ran this thread once.
推荐答案
AWT-EventQueue-0 是您的事件派发线程，它确实被阻止通过 RXTX hsqldb 。你应该按照@Kumar的建议使用 SwingWorker 。可以在和。我发现在中查看这些示例是有帮助的。
AWT-EventQueue-0 is your event dispatch thread, and it is indeed blocked reading from a socket via hsqldb. You should use SwingWorker, as suggested by @Kumar. Examples may be found here and here. I found it helpful to examine such examples in a profiler for study.
Thread-6 和 Thread-7 似乎属于您的应用程序，作为 Threads.ThreadHorloge in posO2 。关于线程名称：
Thread-6 and Thread-7 appear to belong to your application as instances of Threads.ThreadHorloge in posO2. Regarding thread names:
请注意 SwingWorker 和执行者通常包含文本 pool -n ，其中 n 是序列号。
Note that SwingWorker and Executors typically include the text pool-n, where n is a sequence number.
附录：我的EDT位于 RUNNABLE 州，所以从我粘贴的代码中你在哪里发现它被阻止了;你在哪里发现通过RXTX的阅读是阻塞原因？
对不起，我的错误;以上更正。 EDT在 Thread.STATE 等待监视器锁定的意义上不是 BLOCKED ;它在等待数据库响应的意义上被阻止，至少足以在发送 -QUIT 信号时在调用堆栈顶部看到它。不应在EDT上安排串行或网络操作。
Sorry, my mistake; corrected above. The EDT isn't BLOCKED in the Thread.STATE sense of waiting for a monitor lock; it's blocked in the sense that it's waiting for the database to respond, at least long enough to be seen atop the call stack when you send the -QUIT signal. Neither serial nor network operations should be scheduled on the EDT.
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