public abstract class HotSpotAdvice extends Object
A HotSpotInstrumentor locates HotSpots according to its configuration. A HotSpot migh be an invocation, for example. Once hotspot is found HotSpotInstrumentor calls HotSpotAdvice.advice() method.
Body of the HotSpotAdvice.advice() is then copied into instrumented class.
Constructor and Description |
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HotSpotAdvice() |
Modifier and Type | Method and Description |
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abstract void |
advice()
Each extending class must provide advice() method.
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protected void |
doHotSpot()
This method should be called from advice() method, when the actual
processing of hotspot is wanted.
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protected String |
getHotSpotName()
This method should be called only from advice() method.
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public abstract void advice()
The exact location, where method body gets copied into, depends how developer writes the method body.
A call to doHotSpot() in method body, is a tagging method call indicating that current hotspot should be executed.
For example, of we have a method foo()...
public void foo() { bar.doSomeThing(); }...and HotSpotAdvisor.advice():
public void advice() { long l1 = System.currentTimeMillis(); doHotSpot(); long l2 = System.currentTimeMillis(); System.out.println("It took " + (l2 - l1) + " ms"); }...then it would result in instrumented foo() method like
public void foo() { long l1 = System.currentTimeMillis(); bar.doSomething(); long l2 = System.currentTimeMillis(); System.out.println("It took " + (l2-l1) + " ms"); }If a developer does not call doHotSpot() method in implementation of advice() method, corresponding hotspot gets replaced from instrumented class.
doHotSpot()
protected void doHotSpot()
protected String getHotSpotName()
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