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| -rw-r--r-- | ChangeLog | 8 | ||||
| -rw-r--r-- | NEWS | 7 | ||||
| -rw-r--r-- | doc/vmintegration.texinfo | 97 |
3 files changed, 111 insertions, 1 deletions
@@ -1,4 +1,12 @@ 2006-07-01 Andrew John Hughes <gnu_andrew@member.fsf.org> + + * NEWS: + Mention threading bean and getState(). + * doc/vmintegration.texinfo: + Update documentation for threading bean and new + method of VMThread. + +2006-07-01 Andrew John Hughes <gnu_andrew@member.fsf.org> * examples/gnu/classpath/examples/management/TestClassLoading.java, * examples/gnu/classpath/examples/management/TestOS.java, @@ -54,6 +54,13 @@ Runtime interface changes: are currently loaded, how many have been unloaded and whether verbose class loading output is on or off. Provision should also be made for the latter to be toggled at runtime. +* VMThreadMXBeanImpl is used to implement the low-level support + of the thread management bean. Providing this interface requires + providing a fair amount of information about threads, including + optional time and contention monitoring, and instances of the + new ThreadInfo class in java.lang.management. getState() has also + been added to the VMThread interface; this is required by the bean + as well as java.lang.Thread. New in release 0.91 (May 15, 2006) diff --git a/doc/vmintegration.texinfo b/doc/vmintegration.texinfo index 7c0c0b521..5107d5c3d 100644 --- a/doc/vmintegration.texinfo +++ b/doc/vmintegration.texinfo @@ -705,6 +705,9 @@ to allow the setting to flow down to the native thread. @item @code{nativeStop(Throwable)} -- The VM should stop the thread abnormally and throw the specified exception. This is clearly deprecated, due to the ambiguous state an abruptly-stopped thread may leave. +@item @code{getState()} -- Returns the VM's impression of the current state +of the thread. The applicable states are supplied by the @code{State} +enumeration in @code{java.lang.Thread}. @end itemize @item Mandatory Class Methods @itemize @bullet @@ -1268,6 +1271,7 @@ implementations of the management beans. @menu * gnu.java.lang.management.VMRuntimeMXBeanImpl:: * gnu.java.lang.management.VMClassLoadingMXBeanImpl:: +* gnu.java.lang.management.VMThreadMXBeanImpl:: @end menu @node gnu.java.lang.management.VMRuntimeMXBeanImpl,gnu.java.lang.management.VMClassLoadingMXBeanImpl,,gnu.java.lang.management @@ -1312,7 +1316,7 @@ The virtual machine also needs to provide either the property in order to support the optional boot class path retrieval functionality. -@node gnu.java.lang.management.VMClassLoadingMXBeanImpl,,gnu.java.lang.management.VMRuntimeMXBeanImpl,gnu.java.lang.management +@node gnu.java.lang.management.VMClassLoadingMXBeanImpl,gnu.java.lang.management.VMThreadMXBeanImpl,gnu.java.lang.management.VMRuntimeMXBeanImpl,gnu.java.lang.management @subsection @code{gnu.java.lang.management.VMClassLoadingMXBeanImpl} The @code{gnu.java.lang.management.ClassLoadingMXBeanImpl} provides an @@ -1339,6 +1343,97 @@ output is turned or not, respectively. verbose class loading output to be turned on and off. @end itemize +@node gnu.java.lang.management.VMThreadMXBeanImpl,,gnu.java.lang.management.VMClassLoadingMXBeanImpl,gnu.java.lang.management +@subsection @code{gnu.java.lang.management.VMThreadMXBeanImpl} + +The @code{gnu.java.lang.management.ThreadMXBeanImpl} provides an +implementation of the @code{java.lang.management.ThreadMXBean} interface, +and is supported by VM functionality in the form of +@code{gnu.java.lang.management.VMThreadMXBeanImpl}. This provides a +series of methods, which should be implemented by the virtual machine +in order to provide the required information for the bean. Implementing +this bean requires the VM to monitor thread-related statistics such as +how often the blocked and waiting states have been entered, as well as +additional optional support for time and contention monitoring. + +Optional support is determined by the following properties: + +@itemize @bullet +@item @code{gnu.java.lang.management.CurrentThreadTimeSupport} -- +This property should be present if the VM supports monitoring the +time used by the current thread. If time monitoring for all threads +is supported, this need not be provided. +@item @code{gnu.java.lang.management.ThreadTimeSupport} -- +This property should be present if the VM supports monitoring the +time used by all threads. +@item @code{gnu.java.lang.management.ThreadContentionSupport} -- +This property should be present if the VM supports thread contention +monitoring. +@end itemize + +In addition, the property +@code{gnu.java.lang.management.ThreadTimeInitallyEnabled} may be +set to the @code{String} value, @code{"true"}, if time monitoring +is enabled at startup. + +The methods are as follows: + +@itemize @bullet +@item @code{(findMonitorDeadlockedThreads())} -- This should return +an array of thread identifiers which match threads involved in +deadlock cycles (where each thread is waiting to obtain a lock +held by one of the others). This is specified as a native method +in the reference implementation. +@item @code{(getAllThreads())} -- This should return an array of +all live threads and set the @code{filled} variable to the number +found. A default implementation is provided. +@item @code{(getAllThreadIds())} -- This should return an array of +all live thread identifiers. An implementation is provided against +@code{getAllThreads()} by default. +@item @code{(getCurrentThreadCpuTime())} -- This should return the +approximate number of nanoseconds of CPU time the current thread +has used. This is an optional native method, which is used by VMs +supporting time monitoring. +@item @code{(getCurrentThreadUserTime())} -- This should return the +approximate number of nanoseconds of user time the current thread +has used. This is an optional native method, which is used by VMs +supporting time monitoring. +@item @code{(getDaemonThreadCount())} -- This should return the number +of live daemon threads. A default implementation is provided, based +on @code{getAllThreads()}. +@item @code{(getPeakThreadCount())} -- The VM should maintain a record +of the peak number of live threads, and return it when this method is +called. This is specified as a native method in the reference +implementation. +@item @code{(resetPeakThreadCount())} -- This should reset the record +of the peak number of live threads to the current number of live +threads. This is specified as a native method in the reference +implementation. +@item @code{(getThreadCount())} -- This should return the number of +live threads. A default implementation is provided, based on +@code{getAllThreads()}. +@item @code{(getThreadCpuTime(long))} -- This should return the +approximate number of nanoseconds of CPU time the specified thread +has used. This is an optional native method, which is used by VMs +supporting time monitoring. +@item @code{(getThreadUserTime(long))} -- This should return the +approximate number of nanoseconds of CPU time the specified thread +has used. This is an optional native method, which is used by VMs +supporting time monitoring. +@item @code{(getThreadInfoForId(long, int))} -- This return an instance +of @code{java.lang.management.ThreadInfo} for the specified thread. +The class includes a private constructor which VMs should use to initialise +it with the appropriate values for the thread. The second argument +given here specifies the depth of the stack trace supplied on construction +of the instance. Special values are 0 (return an empty array) and +@code{Integer.MAX_VALUE} (return the maximum depth possible). This +is specified as a native method in the reference implementation. +@item @code{(getTotalStartedThreadCount())} -- This should return the +total number of threads that have been started by the VM, including ones +that have died. This is specified as a native method in the reference +implementation. +@end itemize + @node Classpath Callbacks, , gnu.java.lang.management, Classpath Hooks Some of the classes you implement for the VM will need to call back to package-private methods in Classpath: |