The Performance Analyzer relates performance metrics to program structure at several levels: at the load object level, at the function level, at the source line level and at the instruction (or PC) level.
The highest level of program structure is the load object. Load objects include the executable itself and any shared libraries used by the program, such as system libraries. Load objects are represented by the load object basename in italic font inside angle brackets, for example <libc.so>. The Performance Analyzer constructs some artificial load objects, which are described in the following table.
Load object | Description |
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<Total> | Sum of all load objects, represents the program as a whole. |
<Unknown> | Collects all PCs for which the load object name cannot be determined. |
<DYNAMIC_FUNCTIONS> | Includes all dynamically compiled functions other than JavaTM compiled methods. |
<JAVA_CLASSES> | Includes all interpreted Java methods |
<JAVA_COMPILED_METHODS> | Includes all dynamically-compiled Java methods |
The next level of program structure is the function. The term functions includes C functions, Fortran functions and subroutines, C++ functions and methods and Java methods. The Performance Analyzer constructs two artificial functions: <Total>, which includes all functions, and <Unknown>, which includes all PCs for which the function name cannot be determined. Functions can have aliased names. C++ functions can be shown in long or short form. Function names can also appear in mangled or demangled form. The Analyzer demangles names of C++ functions, cloned functions, compiler-generated body functions, and outline functions. Complete information on the function is given in the Summary tab.
The next level of program structure is the source line. Source lines are represented in the Lines tab by the function name, the source file and the line number in the source file. If source line information is not available, metrics are aggregated for the function from which the PC came, and the aggregate is represented by the function name and a message in parentheses that gives the reason that source line information is not available. In the Source tab, the source lines themselves are displayed.
The lowest level of program structure is the instruction or PC. PCs are represented in the PCs tab by the function name and the offset within the function.
The Performance Analyzer tabs can show different levels of program structure in the same tab. For example, the Functions tab can show functions and load objects, and the Disassembly tab can show source lines and instructions.
When one of these program structure elements is selected in any of the tabs, the element`s metrics and other information are displayed in the Summary tab.
See also | |
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The Functions Tab The Lines Tab The PCs Tab The Summary Tab Showing and Hiding Functions |