The Collector tool collects performance data using a statistical method called profiling and by tracing function calls. The data can include call stacks, microstate accounting information, thread synchronization delay data, hardware counter overflow data, Message Passing Interface (MPI) function call data, memory allocation data, and summary information for the operating system and the process. The Collector can collect all kinds of data for C, C++ and Fortran programs, and it can collect profiling data for applications written in the JavaTM programming language. It can collect data for dynamically-generated functions and for descendant processes. See Chapter 2, Performance Data for information about the data collected and Chapter 3, Collecting Performance Data for detailed information about the Collector. The Collector can be run from the Performance Analyzer GUI, from the IDE, from the dbx command line tool, and using the collect command.