java.lang.Object | ||
↳ | sun.jvmstat.perfdata.monitor.AbstractPerfDataBufferPrologue | |
↳ | sun.jvmstat.perfdata.monitor.v2_0.PerfDataBufferPrologue |
Class representing the 2.0 version of the HotSpot PerfData instrumentation buffer header.
The PerfDataBufferPrologue class supports parsing of the version specific portions of the PerfDataPrologue C structure:
typedef struct { ... // handled by superclass jint used; // number of PerfData memory bytes used jint overflow; // number of bytes of overflow jlong mod_time_stamp; // time stamp of the last structural modification jint entry_offset; // offset of the first PerfDataEntry jint num_entries; // number of allocated PerfData entries } PerfDataPrologue
[Expand]
Inherited Constants | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
From class
sun.jvmstat.perfdata.monitor.AbstractPerfDataBufferPrologue
|
[Expand]
Inherited Fields | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
From class
sun.jvmstat.perfdata.monitor.AbstractPerfDataBufferPrologue
|
Public Constructors | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Create an instance of PerfDataBufferPrologue from the given
ByteBuffer object.
|
Public Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Get the size of the instrumentation memory buffer.
| |||||||||||
Get the offset of the first PerfDataEntry.
| |||||||||||
Get the time of last modification for the instrumentation
memory buffer.
| |||||||||||
Get the offset of the first PerfDataEntry.
| |||||||||||
Get the buffer overflow amount.
| |||||||||||
Get the size of the header portion of the instrumentation buffer.
| |||||||||||
Get the utilization of the instrumentation memory buffer.
| |||||||||||
Get the accessible flag.
| |||||||||||
Test if the accessible flag is supported by this version of
the PerfDataBufferPrologue.
|
[Expand]
Inherited Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
From class
sun.jvmstat.perfdata.monitor.AbstractPerfDataBufferPrologue
| |||||||||||
From class
java.lang.Object
|
Create an instance of PerfDataBufferPrologue from the given ByteBuffer object.
byteBuffer | the buffer containing the binary header data |
---|
MonitorException |
---|
Get the size of the instrumentation memory buffer.
Get the offset of the first PerfDataEntry.
Get the time of last modification for the instrumentation memory buffer. This method returns the time, as ticks since the start of the target JVM, of the last structural modification to the instrumentation buffer. Structural modifications correspond to the addition or deletion of instrumentation objects. Updates to counter values are not structural modifications.
Get the offset of the first PerfDataEntry.
Get the buffer overflow amount. This value is non-zero if the HotSpot JVM has overflowed the instrumentation memory buffer. The target JVM can be restarted with -XX:PerfDataMemSize=X to create a larger memory buffer.
Get the size of the header portion of the instrumentation buffer.
Get the utilization of the instrumentation memory buffer.
Get the accessible flag. If supported, it indicates that the shared memory region is sufficiently initialized for client acccess.
Test if the accessible flag is supported by this version of the PerfDataBufferPrologue. Although not an abstract method, this method should be overridden by version specific subclasses.