HP Fortran Programmer Guide (766160-001, March 2014)

T-Z thread An independent flow of control within a single process, having its
own register set and program counter. The HP-UX operating system supports
multiple-executing threads within the same process.
Thread Trace
Visualizer
See ttv
trap A change in system state that is caused by an exception and that may be
detected by the executing program that took the exception. Traps are
hardware features that may be enabled or disabled. If traps are enabled,
they can change the flow of control in the program that took the exception.
In response to a trap, the system may generate a signal (for example,
SIGFPE), which the program can detect. Such a program can be designed
to handle traps. HP Fortran 90 provides the ONstatement to handle traps.
ttv A tool for analyzing parallel-executing programs.
tty buffering A method for efficiently processing data that is directed to standard output
by capturing it in a buffer before sending it to the screen.
underflow An
exception
condition that occurs when the result of a floating-point operation is smaller
than the smallest normalized number. On systems that support it, fast
underflow is an efficient method of handling this exception.
vectorization An optimization technique that replaces eligible program loops that operate
on arrays with calls to specially tuned routines that perform the same
operation.
wall-clock time Time spent by an executing program that includes system time as well as
process time. In contrast, virtual time takes into account process time only.
Profilers (such as CXperf) that track both virtual time and wall-clock time
provide information about when a program is blocked as well as when it
is running.
HP WDB The HP Wildebeest Debugger (WDB) is an HP-supported implementation
of the Open Source GNU debugger (GDB).
158 Glossary