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diff --git a/share/doc/gdb/Remote-Non_002dStop.html b/share/doc/gdb/Remote-Non_002dStop.html new file mode 100644 index 0000000..2d27e06 --- /dev/null +++ b/share/doc/gdb/Remote-Non_002dStop.html @@ -0,0 +1,133 @@ +<!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: Remote Non-Stop</title> + +<meta name="description" content="Debugging with GDB: Remote Non-Stop"> +<meta name="keywords" content="Debugging with GDB: Remote Non-Stop"> +<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="Remote-Protocol.html#Remote-Protocol" rel="up" title="Remote Protocol"> +<link href="Packet-Acknowledgment.html#Packet-Acknowledgment" rel="next" title="Packet Acknowledgment"> +<link href="Notification-Packets.html#Notification-Packets" rel="previous" title="Notification Packets"> +<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="Remote-Non_002dStop"></a> +<div class="header"> +<p> +Next: <a href="Packet-Acknowledgment.html#Packet-Acknowledgment" accesskey="n" rel="next">Packet Acknowledgment</a>, Previous: <a href="Notification-Packets.html#Notification-Packets" accesskey="p" rel="previous">Notification Packets</a>, Up: <a href="Remote-Protocol.html#Remote-Protocol" accesskey="u" rel="up">Remote Protocol</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="Remote-Protocol-Support-for-Non_002dStop-Mode"></a> +<h3 class="section">E.10 Remote Protocol Support for Non-Stop Mode</h3> + +<p><small>GDB</small>’s remote protocol supports non-stop debugging of +multi-threaded programs, as described in <a href="Non_002dStop-Mode.html#Non_002dStop-Mode">Non-Stop Mode</a>. If the stub +supports non-stop mode, it should report that to <small>GDB</small> by including +‘<samp>QNonStop+</samp>’ in its ‘<samp>qSupported</samp>’ response (see <a href="General-Query-Packets.html#qSupported">qSupported</a>). +</p> +<p><small>GDB</small> typically sends a ‘<samp>QNonStop</samp>’ packet only when +establishing a new connection with the stub. Entering non-stop mode +does not alter the state of any currently-running threads, but targets +must stop all threads in any already-attached processes when entering +all-stop mode. <small>GDB</small> uses the ‘<samp>?</samp>’ packet as necessary to +probe the target state after a mode change. +</p> +<p>In non-stop mode, when an attached process encounters an event that +would otherwise be reported with a stop reply, it uses the +asynchronous notification mechanism (see <a href="Notification-Packets.html#Notification-Packets">Notification Packets</a>) to +inform <small>GDB</small>. In contrast to all-stop mode, where all threads +in all processes are stopped when a stop reply is sent, in non-stop +mode only the thread reporting the stop event is stopped. That is, +when reporting a ‘<samp>S</samp>’ or ‘<samp>T</samp>’ response to indicate completion +of a step operation, hitting a breakpoint, or a fault, only the +affected thread is stopped; any other still-running threads continue +to run. When reporting a ‘<samp>W</samp>’ or ‘<samp>X</samp>’ response, all running +threads belonging to other attached processes continue to run. +</p> +<p>In non-stop mode, the target shall respond to the ‘<samp>?</samp>’ packet as +follows. First, any incomplete stop reply notification/‘<samp>vStopped</samp>’ +sequence in progress is abandoned. The target must begin a new +sequence reporting stop events for all stopped threads, whether or not +it has previously reported those events to <small>GDB</small>. The first +stop reply is sent as a synchronous reply to the ‘<samp>?</samp>’ packet, and +subsequent stop replies are sent as responses to ‘<samp>vStopped</samp>’ packets +using the mechanism described above. The target must not send +asynchronous stop reply notifications until the sequence is complete. +If all threads are running when the target receives the ‘<samp>?</samp>’ packet, +or if the target is not attached to any process, it shall respond +‘<samp>OK</samp>’. +</p> +<p>If the stub supports non-stop mode, it should also support the +‘<samp>swbreak</samp>’ stop reason if software breakpoints are supported, and +the ‘<samp>hwbreak</samp>’ stop reason if hardware breakpoints are supported +(see <a href="Stop-Reply-Packets.html#swbreak-stop-reason">swbreak stop reason</a>). This is because given the asynchronous +nature of non-stop mode, between the time a thread hits a breakpoint +and the time the event is finally processed by <small>GDB</small>, the +breakpoint may have already been removed from the target. Due to +this, <small>GDB</small> needs to be able to tell whether a trap stop was +caused by a delayed breakpoint event, which should be ignored, as +opposed to a random trap signal, which should be reported to the user. +Note the ‘<samp>swbreak</samp>’ feature implies that the target is responsible +for adjusting the PC when a software breakpoint triggers, if +necessary, such as on the x86 architecture. +</p> +<hr> +<div class="header"> +<p> +Next: <a href="Packet-Acknowledgment.html#Packet-Acknowledgment" accesskey="n" rel="next">Packet Acknowledgment</a>, Previous: <a href="Notification-Packets.html#Notification-Packets" accesskey="p" rel="previous">Notification Packets</a>, Up: <a href="Remote-Protocol.html#Remote-Protocol" accesskey="u" rel="up">Remote Protocol</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> |