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diff --git a/share/doc/gdb/Static-Probe-Points.html b/share/doc/gdb/Static-Probe-Points.html new file mode 100644 index 0000000..7f717fc --- /dev/null +++ b/share/doc/gdb/Static-Probe-Points.html @@ -0,0 +1,205 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1988-2023 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." --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>Debugging with GDB: Static Probe Points</title> + +<meta name="description" content="Debugging with GDB: Static Probe Points"> +<meta name="keywords" content="Debugging with GDB: Static Probe Points"> +<meta name="resource-type" content="document"> +<meta name="distribution" content="global"> +<meta name="Generator" content="makeinfo"> +<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> +<link href="index.html#Top" rel="start" title="Top"> +<link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="Breakpoints.html#Breakpoints" rel="up" title="Breakpoints"> +<link href="Error-in-Breakpoints.html#Error-in-Breakpoints" rel="next" title="Error in Breakpoints"> +<link href="Save-Breakpoints.html#Save-Breakpoints" rel="previous" title="Save Breakpoints"> +<style type="text/css"> +<!-- +a.summary-letter {text-decoration: none} +blockquote.smallquotation {font-size: smaller} +div.display {margin-left: 3.2em} +div.example {margin-left: 3.2em} +div.indentedblock {margin-left: 3.2em} +div.lisp {margin-left: 3.2em} +div.smalldisplay {margin-left: 3.2em} +div.smallexample {margin-left: 3.2em} +div.smallindentedblock {margin-left: 3.2em; font-size: smaller} +div.smalllisp {margin-left: 3.2em} +kbd {font-style:oblique} +pre.display {font-family: inherit} +pre.format {font-family: inherit} +pre.menu-comment {font-family: serif} +pre.menu-preformatted {font-family: serif} +pre.smalldisplay {font-family: inherit; font-size: smaller} +pre.smallexample {font-size: smaller} +pre.smallformat {font-family: inherit; font-size: smaller} +pre.smalllisp {font-size: smaller} +span.nocodebreak {white-space:nowrap} +span.nolinebreak {white-space:nowrap} +span.roman {font-family:serif; font-weight:normal} +span.sansserif {font-family:sans-serif; font-weight:normal} +ul.no-bullet {list-style: none} +--> +</style> + + +</head> + +<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> +<a name="Static-Probe-Points"></a> +<div class="header"> +<p> +Next: <a href="Error-in-Breakpoints.html#Error-in-Breakpoints" accesskey="n" rel="next">Error in Breakpoints</a>, Previous: <a href="Save-Breakpoints.html#Save-Breakpoints" accesskey="p" rel="previous">Save Breakpoints</a>, Up: <a href="Breakpoints.html#Breakpoints" accesskey="u" rel="up">Breakpoints</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="Static-Probe-Points-1"></a> +<h4 class="subsection">5.1.10 Static Probe Points</h4> + +<a name="index-static-probe-point_002c-SystemTap"></a> +<a name="index-static-probe-point_002c-DTrace"></a> +<p><small>GDB</small> supports <em>SDT</em> probes in the code. <acronym>SDT</acronym> stands +for Statically Defined Tracing, and the probes are designed to have a tiny +runtime code and data footprint, and no dynamic relocations. +</p> +<p>Currently, the following types of probes are supported on +ELF-compatible systems: +</p> +<ul> +<li> <code>SystemTap</code> (<a href="http://sourceware.org/systemtap/">http://sourceware.org/systemtap/</a>) +<acronym>SDT</acronym> probes<a name="DOCF5" href="#FOOT5"><sup>5</sup></a>. <code>SystemTap</code> probes are usable +from assembly, C and C<tt>++</tt> languages<a name="DOCF6" href="#FOOT6"><sup>6</sup></a>. + +</li><li> <code>DTrace</code> (<a href="http://oss.oracle.com/projects/DTrace">http://oss.oracle.com/projects/DTrace</a>) +<acronym>USDT</acronym> probes. <code>DTrace</code> probes are usable from C and +C<tt>++</tt> languages. +</li></ul> + +<a name="index-semaphores-on-static-probe-points"></a> +<p>Some <code>SystemTap</code> probes have an associated semaphore variable; +for instance, this happens automatically if you defined your probe +using a DTrace-style <samp>.d</samp> file. If your probe has a semaphore, +<small>GDB</small> will automatically enable it when you specify a +breakpoint using the ‘<samp>-probe-stap</samp>’ notation. But, if you put a +breakpoint at a probe’s location by some other method (e.g., +<code>break file:line</code>), then <small>GDB</small> will not automatically set +the semaphore. <code>DTrace</code> probes do not support semaphores. +</p> +<p>You can examine the available static static probes using <code>info +probes</code>, with optional arguments: +</p> +<dl compact="compact"> +<dd><a name="index-info-probes"></a> +</dd> +<dt><code>info probes <span class="roman">[</span><var>type</var><span class="roman">]</span> <span class="roman">[</span><var>provider</var> <span class="roman">[</span><var>name</var> <span class="roman">[</span><var>objfile</var><span class="roman">]</span><span class="roman">]</span><span class="roman">]</span></code></dt> +<dd><p>If given, <var>type</var> is either <code>stap</code> for listing +<code>SystemTap</code> probes or <code>dtrace</code> for listing <code>DTrace</code> +probes. If omitted all probes are listed regardless of their types. +</p> +<p>If given, <var>provider</var> is a regular expression used to match against provider +names when selecting which probes to list. If omitted, probes by all +probes from all providers are listed. +</p> +<p>If given, <var>name</var> is a regular expression to match against probe names +when selecting which probes to list. If omitted, probe names are not +considered when deciding whether to display them. +</p> +<p>If given, <var>objfile</var> is a regular expression used to select which +object files (executable or shared libraries) to examine. If not +given, all object files are considered. +</p> +</dd> +<dt><code>info probes all</code></dt> +<dd><p>List the available static probes, from all types. +</p></dd> +</dl> + +<a name="index-enabling-and-disabling-probes"></a> +<p>Some probe points can be enabled and/or disabled. The effect of +enabling or disabling a probe depends on the type of probe being +handled. Some <code>DTrace</code> probes can be enabled or +disabled, but <code>SystemTap</code> probes cannot be disabled. +</p> +<p>You can enable (or disable) one or more probes using the following +commands, with optional arguments: +</p> +<dl compact="compact"> +<dd><a name="index-enable-probes"></a> +</dd> +<dt><code>enable probes <span class="roman">[</span><var>provider</var> <span class="roman">[</span><var>name</var> <span class="roman">[</span><var>objfile</var><span class="roman">]</span><span class="roman">]</span><span class="roman">]</span></code></dt> +<dd><p>If given, <var>provider</var> is a regular expression used to match against +provider names when selecting which probes to enable. If omitted, +all probes from all providers are enabled. +</p> +<p>If given, <var>name</var> is a regular expression to match against probe +names when selecting which probes to enable. If omitted, probe names +are not considered when deciding whether to enable them. +</p> +<p>If given, <var>objfile</var> is a regular expression used to select which +object files (executable or shared libraries) to examine. If not +given, all object files are considered. +</p> +<a name="index-disable-probes"></a> +</dd> +<dt><code>disable probes <span class="roman">[</span><var>provider</var> <span class="roman">[</span><var>name</var> <span class="roman">[</span><var>objfile</var><span class="roman">]</span><span class="roman">]</span><span class="roman">]</span></code></dt> +<dd><p>See the <code>enable probes</code> command above for a description of the +optional arguments accepted by this command. +</p></dd> +</dl> + +<a name="index-_0024_005fprobe_005farg_002c-convenience-variable"></a> +<p>A probe may specify up to twelve arguments. These are available at the +point at which the probe is defined—that is, when the current PC is +at the probe’s location. The arguments are available using the +convenience variables (see <a href="Convenience-Vars.html#Convenience-Vars">Convenience Vars</a>) +<code>$_probe_arg0</code>…<code>$_probe_arg11</code>. In <code>SystemTap</code> +probes each probe argument is an integer of the appropriate size; +types are not preserved. In <code>DTrace</code> probes types are preserved +provided that they are recognized as such by <small>GDB</small>; otherwise +the value of the probe argument will be a long integer. The +convenience variable <code>$_probe_argc</code> holds the number of arguments +at the current probe point. +</p> +<p>These variables are always available, but attempts to access them at +any location other than a probe point will cause <small>GDB</small> to give +an error message. +</p> + +<div class="footnote"> +<hr> +<h4 class="footnotes-heading">Footnotes</h4> + +<h3><a name="FOOT5" href="#DOCF5">(5)</a></h3> +<p>See +<a href="http://sourceware.org/systemtap/wiki/AddingUserSpaceProbingToApps">http://sourceware.org/systemtap/wiki/AddingUserSpaceProbingToApps</a> +for more information on how to add <code>SystemTap</code> <acronym>SDT</acronym> +probes in your applications.</p> +<h3><a name="FOOT6" href="#DOCF6">(6)</a></h3> +<p>See +<a href="http://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation">http://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation</a> +for a good reference on how the <acronym>SDT</acronym> probes are implemented.</p> +</div> +<hr> +<div class="header"> +<p> +Next: <a href="Error-in-Breakpoints.html#Error-in-Breakpoints" accesskey="n" rel="next">Error in Breakpoints</a>, Previous: <a href="Save-Breakpoints.html#Save-Breakpoints" accesskey="p" rel="previous">Save Breakpoints</a>, Up: <a href="Breakpoints.html#Breakpoints" accesskey="u" rel="up">Breakpoints</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |