The User Representation

The User representation shows compiled and interpreted Java methods by name, and shows native methods in their natural form. During execution, there might be many instances of a particular Java method executed: the interpreted version, and, perhaps, one or more compiled versions. In the Java representation all methods are shown aggregated as a single method. This representation is selected in the Analyzer by default.

A PC for a Java method in the Java representation corresponds to the method-id and a bytecode index into that method; a PC for a native function correspond to a machine PC. The call stack for a Java thread may have a mixture of Java PCs and machine PCs. It does not have any frames corresponding to Java housekeeping code, which does not have a Java representation. Under some circumstances, the JVM software cannot unwind the Java stack, and a single frame with the special function, <no Java callstack recorded>, is returned. Typically, it amounts to no more than 5-10% of the total time.

The function list in the Java representation shows metrics against the Java methods and any native methods called. The caller-callee panel shows the calling relationships in the Java representation.

Source for a Java method corresponds to the source code in the .java file from which it was compiled, with metrics on each source line. The disassembly of any Java method shows the bytecode generated for it, with metrics against each bytecode, and interleaved Java source, where available.

The Timeline in the Java representation shows only Java threads. The call stack for each thread is shown with its Java methods.

Data space profiling in the Java representation is not currently supported.