Breakpoint

Breakpoint

A breakpoint, in software development, is an intentional stopping or pausing place in a program, put in place for debugging purposes. More generally, a breakpoint is a means of acquiring knowledge about a program during its execution. During the interruption, the programmer inspects the test environment (logs, memory, files, etc.) to find out whether the program functions as expected.

In practice, a breakpoint consists of one or more conditions that determine when a program's execution should be interrupted.

The most common form of a breakpoint is one where the program's execution is interrupted before a programmer-specified instruction is executed. This is often referred to as an "instruction breakpoint".

Other kinds of conditions can also be used, such as the reading, writing, or modification of a specific location in an area of memory. This is often referred to as a "data breakpoint", or a "watchpoint".

Breakpoints can also be used to interrupt execution at a particular time, or upon a keystroke etc.

Many processors include hardware support for breakpoints (typically instruction and data breakpoints). Such hardware may include limitations, for example not allowing breakpoints on instructions located in branch delay slots. This kind of limitation is imposed by the microarchitecture of the processor, so varies from processor to processor.

Without hardware support, debuggers have to implement breakpoints in software. For instruction breakpoints, this is a comparatively simple task of replacing the instruction at the location of the breakpoint. But implementing data breakpoints in software can greatly reduce the performance of the application being debugged. [ [http://sources.redhat.com/gdb/current/onlinedocs/gdbint_3.html#SEC15 GDB Internals -- Watchpoints] ]

Some programming language implementations expose their debugging functions for use by other programs.For example, some FORTRAN dialects have an AT statement, which was originally intended to act as an instruction breakpoint.
Python implements a debugger accessible from a Python program. [ [http://docs.python.org/lib/module-pdb.html Python Library Reference: The Python Debugger] ] These facilities can be and are [ [http://entrian.com/goto/ entrian.com - goto and comefrom for Python] ] abused to act like the COMEFROM statement.

ee also

* IBM OLIVER (CICS interactive test/debug)
* SIMON (Batch Interactive test/debug)
* SIMMON

References


Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Breakpoint — 2005 Breakpoint  немецкая демопати. Проводится ежегодно в середине весны, начиная с 2003 года, в восточной части Бингена. Breakpoint является наследником легендарной …   Википедия

  • Breakpoint —   [dt. »Haltepunkt«] der, Stelle in einem Computerprogramm, für die ein bedingter Halt programmiert ist. Im normalen Programmablauf wird das Programm dort nicht unterbrochen, bei der Fehlersuche (Debugger) lässt sich das Programm an dieser Stelle …   Universal-Lexikon

  • Breakpoint — Die Haupthalle während der BP 2005. Die Breakpoint (BP) war zwischen 2003 und 2010 das größte Treffen der Demoszene in Deutschland (und zeitweise auch weltweit) und fand jährlich über Ostern in Bingen am Rhein statt.[1] …   Deutsch Wikipedia

  • breakpoint — For mutual funds, the point at which the amount invested reduces the sales charge is called the breakpoint. Each mutual fund may have several breakpoints; the larger the investment, the greater the discount. Note that the actual reduction in the… …   Financial and business terms

  • Breakpoint — For load mutual funds, the dollar amount for the purchase of the fund s shares that qualifies the investor for a reduced sales charge (load). The purchase may either be made in a lump sum or by staggering payments within a prescribed period of… …   Investment dictionary

  • breakpoint — trūkio taškas statusas T sritis automatika atitikmenys: angl. breakpoint; point of discontinuity vok. Abschaltpunkt, m; Knickpunkt, m; Untätigkeitspunkt, m rus. точка разрыва, f pranc. point anguleux, m; point de discontinuité, m; point de… …   Automatikos terminų žodynas

  • breakpoint — stabdos taškas statusas T sritis automatika atitikmenys: angl. break point; breakpoint vok. Anhaltepunkt, m; Fixpunkt, m rus. точка останова, f pranc. point d arrêt, m; point d interruption, m …   Automatikos terminų žodynas

  • breakpoint — pertraukties taškas statusas T sritis automatika atitikmenys: angl. breakpoint vok. Unterbrechungspunkt, m rus. точка прерывания, f pranc. point d entrelacement, m; point d interruption, m …   Automatikos terminų žodynas

  • breakpoint — stabdos taškas statusas T sritis informatika apibrėžtis Pažymėta vieta programoje, ties kuria jos vykdymas sustabdomas. Į pasirinktą programos vietą įterpia ↑derintuvė arba kitokia ↑derinimo funkcijas atliekanti programa (pvz., ↑transliatorius),… …   Enciklopedinis kompiuterijos žodynas

  • Breakpoint (demo party) — Breakpoint 2004 the real party is outside Breakpoint was a German demoscene party. From 2003 to 2010, it took place annually at Easter in Bingen. Breakpoint was the successor to the legendary Mekka Symposium. With over 1000 visitors, it was the… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”