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diff --git a/share/doc/gdb/The-Ctrl_002dC-Message.html b/share/doc/gdb/The-Ctrl_002dC-Message.html new file mode 100644 index 0000000..88000b7 --- /dev/null +++ b/share/doc/gdb/The-Ctrl_002dC-Message.html @@ -0,0 +1,116 @@ +<!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: The Ctrl-C Message</title> + +<meta name="description" content="Debugging with GDB: The Ctrl-C Message"> +<meta name="keywords" content="Debugging with GDB: The Ctrl-C Message"> +<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="File_002dI_002fO-Remote-Protocol-Extension.html#File_002dI_002fO-Remote-Protocol-Extension" rel="up" title="File-I/O Remote Protocol Extension"> +<link href="Console-I_002fO.html#Console-I_002fO" rel="next" title="Console I/O"> +<link href="The-F-Reply-Packet.html#The-F-Reply-Packet" rel="previous" title="The F Reply Packet"> +<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="The-Ctrl_002dC-Message"></a> +<div class="header"> +<p> +Next: <a href="Console-I_002fO.html#Console-I_002fO" accesskey="n" rel="next">Console I/O</a>, Previous: <a href="The-F-Reply-Packet.html#The-F-Reply-Packet" accesskey="p" rel="previous">The F Reply Packet</a>, Up: <a href="File_002dI_002fO-Remote-Protocol-Extension.html#File_002dI_002fO-Remote-Protocol-Extension" accesskey="u" rel="up">File-I/O Remote Protocol Extension</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="The-Ctrl_002dC-Message-1"></a> +<h4 class="subsection">E.13.5 The ‘<samp>Ctrl-C</samp>’ Message</h4> +<a name="index-ctrl_002dc-message_002c-in-file_002di_002fo-protocol"></a> + +<p>If the ‘<samp>Ctrl-C</samp>’ flag is set in the <small>GDB</small> +reply packet (see <a href="The-F-Reply-Packet.html#The-F-Reply-Packet">The F Reply Packet</a>), +the target should behave as if it had +gotten a break message. The meaning for the target is “system call +interrupted by <code>SIGINT</code>”. Consequentially, the target should actually stop +(as with a break message) and return to <small>GDB</small> with a <code>T02</code> +packet. +</p> +<p>It’s important for the target to know in which +state the system call was interrupted. There are two possible cases: +</p> +<ul> +<li> The system call hasn’t been performed on the host yet. + +</li><li> The system call on the host has been finished. + +</li></ul> + +<p>These two states can be distinguished by the target by the value of the +returned <code>errno</code>. If it’s the protocol representation of <code>EINTR</code>, the system +call hasn’t been performed. This is equivalent to the <code>EINTR</code> handling +on POSIX systems. In any other case, the target may presume that the +system call has been finished — successfully or not — and should behave +as if the break message arrived right after the system call. +</p> +<p><small>GDB</small> must behave reliably. If the system call has not been called +yet, <small>GDB</small> may send the <code>F</code> reply immediately, setting <code>EINTR</code> as +<code>errno</code> in the packet. If the system call on the host has been finished +before the user requests a break, the full action must be finished by +<small>GDB</small>. This requires sending <code>M</code> or <code>X</code> packets as necessary. +The <code>F</code> packet may only be sent when either nothing has happened +or the full action has been completed. +</p> +<hr> +<div class="header"> +<p> +Next: <a href="Console-I_002fO.html#Console-I_002fO" accesskey="n" rel="next">Console I/O</a>, Previous: <a href="The-F-Reply-Packet.html#The-F-Reply-Packet" accesskey="p" rel="previous">The F Reply Packet</a>, Up: <a href="File_002dI_002fO-Remote-Protocol-Extension.html#File_002dI_002fO-Remote-Protocol-Extension" accesskey="u" rel="up">File-I/O Remote Protocol Extension</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> |