ManagementFactory クラスを介して取得できるMXBeanの一つが実装するインタフェース。
- java.lang.management パッケージ - ManagementFactory クラス - HHeLiBeXの日記 正道編
- ThreadMXBean (Java 2 Platform SE 5.0)
文字通りスレッドに関連する情報を取得するためのMXBean。
スレッドに関する情報はアプリケーションの実行とともに動的に変わっていくので、とりあえず今回はJava VM実行開始直後の情報を取得して表示するということだけをやってみる。また、ThreadMXBeanやそこから取得できるThreadInfoにはサポートされないかもしれない操作が数多くあるので注意が必要。
実際にやってみる。
今回用いたのは、次のJava VM。
import java.lang.management.ManagementFactory; import java.lang.management.ThreadInfo; import java.lang.management.ThreadMXBean; public class Main { /** * @param args */ public static void main(String[] args) { System.out.printf("%-23s = %s\n", "java.version", System.getProperty("java.version")); System.out.printf("%-23s = %s\n", "java.vendor", System.getProperty("java.vendor")); System.out.printf("%-23s = %s\n", "java.runtime.version", System.getProperty("java.runtime.version")); System.out.printf("%-23s = %s\n", "os.name", System.getProperty("os.name")); System.out.println("========"); ThreadMXBean threadMXBean = ManagementFactory.getThreadMXBean(); System.out.printf("%-32s: %s\n", "isThreadContentionMonitoringSupported", threadMXBean.isThreadContentionMonitoringSupported()); if (threadMXBean.isThreadContentionMonitoringSupported()) { System.out.printf("%-32s: %s\n", "isThreadContentionMonitoringEnabled", threadMXBean.isThreadContentionMonitoringEnabled()); threadMXBean.setThreadContentionMonitoringEnabled(true); } System.out.printf("%-32s: %s\n", "isThreadCpuTimeSupported", threadMXBean.isThreadCpuTimeSupported()); if (threadMXBean.isThreadCpuTimeSupported()) { System.out.printf("%-32s: %s\n", "isThreadCpuTimeEnabled", threadMXBean.isThreadCpuTimeEnabled()); threadMXBean.setThreadCpuTimeEnabled(true); } System.out.printf("%-32s:\n", "findMonitorDeadlockedThreads"); { long[] monitorDeadlockedThreads = threadMXBean.findMonitorDeadlockedThreads(); if (monitorDeadlockedThreads != null) { int i = 0; for (long id : monitorDeadlockedThreads) { System.out.printf(" [%2d]: %20d\n", i, id); ++i; } } } System.out.printf("%-32s:\n", "AllThreadIds"); { long[] allThreadIds = threadMXBean.getAllThreadIds(); int i = 0; for (long id : allThreadIds) { System.out.printf(" [%2d]: %20d\n", i, id); if (threadMXBean.isThreadCpuTimeSupported()) { System.out.printf(" %-32s: %s\n", "ThreadCpuTime", threadMXBean.getThreadCpuTime(id)); System.out.printf(" %-32s: %s\n", "ThreadUserTime", threadMXBean.getThreadUserTime(id)); } System.out.printf(" %-32s:\n", "ThreadInfo"); { ThreadInfo threadInfo = threadMXBean.getThreadInfo(id); System.out.printf(" %-32s: %20d\n", "BlockedCount", threadInfo.getBlockedCount()); if (threadMXBean.isThreadContentionMonitoringSupported()) { System.out.printf(" %-32s: %20d\n", "BlockedTime", threadInfo.getBlockedTime()); } System.out.printf(" %-32s: %s\n", "LockName", threadInfo.getLockName()); System.out.printf(" %-32s: %20d\n", "LockOwnerId", threadInfo.getLockOwnerId()); System.out.printf(" %-32s: %s\n", "LockOwnerName", threadInfo.getLockOwnerName()); System.out.printf(" %-32s:\n", "StackTrace (omit the details)"); { StackTraceElement[] stackTrace = threadInfo.getStackTrace(); System.out.printf(" %-32s: %d\n", "# of stack trace", stackTrace.length); } System.out.printf(" %-32s: %20d\n", "ThreadId", threadInfo.getThreadId()); System.out.printf(" %-32s: %s\n", "ThreadName", threadInfo.getThreadName()); System.out.printf(" %-32s: %s\n", "ThreadState", threadInfo.getThreadState()); System.out.printf(" %-32s: %20d\n", "WaitedCount", threadInfo.getWaitedCount()); if (threadMXBean.isThreadContentionMonitoringSupported()) { System.out.printf(" %-32s: %20d\n", "WaitedTime", threadInfo.getWaitedTime()); } System.out.printf(" %-32s: %s\n", "isInNative", threadInfo.isInNative()); System.out.printf(" %-32s: %s\n", "isSuspended", threadInfo.isSuspended()); } ++i; } } System.out.printf("%-32s: %s\n", "isCurrentThreadCpuTimeSupported", threadMXBean.isCurrentThreadCpuTimeSupported()); if (threadMXBean.isCurrentThreadCpuTimeSupported()) { System.out.printf("%-32s: %20d\n", "CurrentThreadCpuTime", threadMXBean.getCurrentThreadCpuTime()); System.out.printf("%-32s: %20d\n", "CurrentThreadUserTime", threadMXBean.getCurrentThreadUserTime()); } System.out.printf("%-32s: %10d\n", "DaemonThreadCount", threadMXBean.getDaemonThreadCount()); System.out.printf("%-32s: %10d\n", "PeakThreadCount", threadMXBean.getPeakThreadCount()); System.out.printf("%-32s: %10d\n", "ThreadCount", threadMXBean.getThreadCount()); System.out.printf("%-32s: %20d\n", "TotalStartedThreadCount", threadMXBean.getTotalStartedThreadCount()); // threadMXBean.resetPeakThreadCount(); // threadMXBean.getThreadInfo(ids); // threadMXBean.getThreadInfo(id, maxDepth); // threadMXBean.getThreadInfo(ids, maxDepth); } }
java.version = 1.5.0_22
java.vendor = Sun Microsystems Inc.
java.runtime.version = 1.5.0_22-b03
os.name = Windows Vista
========
isThreadContentionMonitoringSupported: true
isThreadContentionMonitoringEnabled: false
isThreadCpuTimeSupported : true
isThreadCpuTimeEnabled : true
findMonitorDeadlockedThreads :
AllThreadIds :
[ 0]: 4
ThreadCpuTime : 0
ThreadUserTime : 0
ThreadInfo :
BlockedCount : 0
BlockedTime : 0
LockName : null
LockOwnerId : -1
LockOwnerName : null
StackTrace (omit the details) :
# of stack trace : 0
ThreadId : 4
ThreadName : Signal Dispatcher
ThreadState : RUNNABLE
WaitedCount : 0
WaitedTime : 0
isInNative : false
isSuspended : false
[ 1]: 3
ThreadCpuTime : 0
ThreadUserTime : 0
ThreadInfo :
BlockedCount : 0
BlockedTime : 0
LockName : java.lang.ref.ReferenceQueue$Lock@60aeb0
LockOwnerId : -1
LockOwnerName : null
StackTrace (omit the details) :
# of stack trace : 0
ThreadId : 3
ThreadName : Finalizer
ThreadState : WAITING
WaitedCount : 1
WaitedTime : 0
isInNative : false
isSuspended : false
[ 2]: 2
ThreadCpuTime : 0
ThreadUserTime : 0
ThreadInfo :
BlockedCount : 0
BlockedTime : 0
LockName : java.lang.ref.Reference$Lock@16caf43
LockOwnerId : -1
LockOwnerName : null
StackTrace (omit the details) :
# of stack trace : 0
ThreadId : 2
ThreadName : Reference Handler
ThreadState : WAITING
WaitedCount : 1
WaitedTime : 0
isInNative : false
isSuspended : false
[ 3]: 1
ThreadCpuTime : 234001500
ThreadUserTime : 187201200
ThreadInfo :
BlockedCount : 0
BlockedTime : 0
LockName : null
LockOwnerId : -1
LockOwnerName : null
StackTrace (omit the details) :
# of stack trace : 0
ThreadId : 1
ThreadName : main
ThreadState : RUNNABLE
WaitedCount : 0
WaitedTime : 0
isInNative : false
isSuspended : false
isCurrentThreadCpuTimeSupported : true
CurrentThreadCpuTime : 234001500
CurrentThreadUserTime : 187201200
DaemonThreadCount : 3
PeakThreadCount : 4
ThreadCount : 4
TotalStartedThreadCount : 4
java.version = 1.5.0
java.vendor = IBM Corporation
java.runtime.version = pwi32dev-20090707 (SR10 )
os.name = Windows Vista
========
isThreadContentionMonitoringSupported: true
isThreadContentionMonitoringEnabled: false
isThreadCpuTimeSupported : true
isThreadCpuTimeEnabled : true
findMonitorDeadlockedThreads :
AllThreadIds :
[ 0]: 1
ThreadCpuTime : 530403400
ThreadUserTime : 436802800
ThreadInfo :
BlockedCount : 0
BlockedTime : 0
LockName : null
LockOwnerId : -1
LockOwnerName : null
StackTrace (omit the details) :
# of stack trace : 0
ThreadId : 1
ThreadName : main
ThreadState : RUNNABLE
WaitedCount : 0
WaitedTime : 0
isInNative : true
isSuspended : false
[ 1]: 3
ThreadCpuTime : 124800800
ThreadUserTime : 124800800
ThreadInfo :
BlockedCount : 0
BlockedTime : 0
LockName : null
LockOwnerId : -1
LockOwnerName : null
StackTrace (omit the details) :
# of stack trace : 0
ThreadId : 3
ThreadName : JIT Compilation Thread
ThreadState : RUNNABLE
WaitedCount : 0
WaitedTime : 0
isInNative : false
isSuspended : false
[ 2]: 2
ThreadCpuTime : 0
ThreadUserTime : 0
ThreadInfo :
BlockedCount : 0
BlockedTime : 0
LockName : null
LockOwnerId : -1
LockOwnerName : null
StackTrace (omit the details) :
# of stack trace : 0
ThreadId : 2
ThreadName : Signal Dispatcher
ThreadState : RUNNABLE
WaitedCount : 0
WaitedTime : 0
isInNative : true
isSuspended : false
[ 3]: 4
ThreadCpuTime : 0
ThreadUserTime : 0
ThreadInfo :
BlockedCount : 0
BlockedTime : 0
LockName : null
LockOwnerId : -1
LockOwnerName : null
StackTrace (omit the details) :
# of stack trace : 0
ThreadId : 4
ThreadName : Gc Slave Thread
ThreadState : RUNNABLE
WaitedCount : 0
WaitedTime : 0
isInNative : false
isSuspended : false
isCurrentThreadCpuTimeSupported : true
CurrentThreadCpuTime : 577203700
CurrentThreadUserTime : 483603100
DaemonThreadCount : 3
PeakThreadCount : 4
ThreadCount : 4
TotalStartedThreadCount : 4
- とりあえず、サポートされない操作はなかったようで。
- findMonitorDeadlockedThreads
- まぁ、スレッドを起こしてないのだから、該当するものはないわな。
- StackTrace
動的に変わっていく各々の項目については次回以降にいろいろ試すということで。
