| <html lang="en"> |
| <head> |
| <title>Analyze Collected Data - Debugging with GDB</title> |
| <meta http-equiv="Content-Type" content="text/html"> |
| <meta name="description" content="Debugging with GDB"> |
| <meta name="generator" content="makeinfo 4.13"> |
| <link title="Top" rel="start" href="index.html#Top"> |
| <link rel="up" href="Tracepoints.html#Tracepoints" title="Tracepoints"> |
| <link rel="prev" href="Set-Tracepoints.html#Set-Tracepoints" title="Set Tracepoints"> |
| <link rel="next" href="Tracepoint-Variables.html#Tracepoint-Variables" title="Tracepoint Variables"> |
| <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> |
| <!-- |
| Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, |
| 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 |
| Free Software Foundation, Inc. |
| |
| Permission is granted to copy, distribute and/or modify this document |
| under the terms of the GNU Free Documentation License, Version 1.3 or |
| any later version published by the Free Software Foundation; with the |
| Invariant Sections being ``Free Software'' and ``Free Software Needs |
| Free Documentation'', with the Front-Cover Texts being ``A GNU Manual,'' |
| and with the Back-Cover Texts as in (a) below. |
| |
| (a) The FSF's Back-Cover Text is: ``You are free to copy and modify |
| this GNU Manual. Buying copies from GNU Press supports the FSF in |
| developing GNU and promoting software freedom.''--> |
| <meta http-equiv="Content-Style-Type" content="text/css"> |
| <style type="text/css"><!-- |
| pre.display { font-family:inherit } |
| pre.format { font-family:inherit } |
| pre.smalldisplay { font-family:inherit; font-size:smaller } |
| pre.smallformat { font-family:inherit; font-size:smaller } |
| pre.smallexample { font-size:smaller } |
| pre.smalllisp { font-size:smaller } |
| span.sc { font-variant:small-caps } |
| span.roman { font-family:serif; font-weight:normal; } |
| span.sansserif { font-family:sans-serif; font-weight:normal; } |
| --></style> |
| <link rel="stylesheet" type="text/css" href="../cs.css"> |
| </head> |
| <body> |
| <div class="node"> |
| <a name="Analyze-Collected-Data"></a> |
| <p> |
| Next: <a rel="next" accesskey="n" href="Tracepoint-Variables.html#Tracepoint-Variables">Tracepoint Variables</a>, |
| Previous: <a rel="previous" accesskey="p" href="Set-Tracepoints.html#Set-Tracepoints">Set Tracepoints</a>, |
| Up: <a rel="up" accesskey="u" href="Tracepoints.html#Tracepoints">Tracepoints</a> |
| <hr> |
| </div> |
| |
| <h3 class="section">13.2 Using the Collected Data</h3> |
| |
| <p>After the tracepoint experiment ends, you use <span class="sc">gdb</span> commands |
| for examining the trace data. The basic idea is that each tracepoint |
| collects a trace <dfn>snapshot</dfn> every time it is hit and another |
| snapshot every time it single-steps. All these snapshots are |
| consecutively numbered from zero and go into a buffer, and you can |
| examine them later. The way you examine them is to <dfn>focus</dfn> on a |
| specific trace snapshot. When the remote stub is focused on a trace |
| snapshot, it will respond to all <span class="sc">gdb</span> requests for memory and |
| registers by reading from the buffer which belongs to that snapshot, |
| rather than from <em>real</em> memory or registers of the program being |
| debugged. This means that <strong>all</strong> <span class="sc">gdb</span> commands |
| (<code>print</code>, <code>info registers</code>, <code>backtrace</code>, etc.) will |
| behave as if we were currently debugging the program state as it was |
| when the tracepoint occurred. Any requests for data that are not in |
| the buffer will fail. |
| |
| <ul class="menu"> |
| <li><a accesskey="1" href="tfind.html#tfind">tfind</a>: How to select a trace snapshot |
| <li><a accesskey="2" href="tdump.html#tdump">tdump</a>: How to display all data for a snapshot |
| <li><a accesskey="3" href="save-tracepoints.html#save-tracepoints">save tracepoints</a>: How to save tracepoints for a future run |
| </ul> |
| |
| </body></html> |
| |
