1<html lang="en"> 2<head> 3<title>Thread Stops - Debugging with GDB</title> 4<meta http-equiv="Content-Type" content="text/html"> 5<meta name="description" content="Debugging with GDB"> 6<meta name="generator" content="makeinfo 4.13"> 7<link title="Top" rel="start" href="index.html#Top"> 8<link rel="up" href="Stopping.html#Stopping" title="Stopping"> 9<link rel="prev" href="Signals.html#Signals" title="Signals"> 10<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 11<!-- 12Copyright (C) 1988-2013 Free Software Foundation, Inc. 13 14Permission is granted to copy, distribute and/or modify this document 15under the terms of the GNU Free Documentation License, Version 1.3 or 16any later version published by the Free Software Foundation; with the 17Invariant Sections being ``Free Software'' and ``Free Software Needs 18Free Documentation'', with the Front-Cover Texts being ``A GNU Manual,'' 19and with the Back-Cover Texts as in (a) below. 20 21(a) The FSF's Back-Cover Text is: ``You are free to copy and modify 22this GNU Manual. Buying copies from GNU Press supports the FSF in 23developing GNU and promoting software freedom.'' 24--> 25<meta http-equiv="Content-Style-Type" content="text/css"> 26<style type="text/css"><!-- 27 pre.display { font-family:inherit } 28 pre.format { font-family:inherit } 29 pre.smalldisplay { font-family:inherit; font-size:smaller } 30 pre.smallformat { font-family:inherit; font-size:smaller } 31 pre.smallexample { font-size:smaller } 32 pre.smalllisp { font-size:smaller } 33 span.sc { font-variant:small-caps } 34 span.roman { font-family:serif; font-weight:normal; } 35 span.sansserif { font-family:sans-serif; font-weight:normal; } 36--></style> 37<link rel="stylesheet" type="text/css" href="../cs.css"> 38</head> 39<body> 40<div class="node"> 41<a name="Thread-Stops"></a> 42<p> 43Previous: <a rel="previous" accesskey="p" href="Signals.html#Signals">Signals</a>, 44Up: <a rel="up" accesskey="u" href="Stopping.html#Stopping">Stopping</a> 45<hr> 46</div> 47 48<h3 class="section">5.5 Stopping and Starting Multi-thread Programs</h3> 49 50<p><a name="index-stopped-threads-346"></a><a name="index-threads_002c-stopped-347"></a> 51<a name="index-continuing-threads-348"></a><a name="index-threads_002c-continuing-349"></a> 52<span class="sc">gdb</span> supports debugging programs with multiple threads 53(see <a href="Threads.html#Threads">Debugging Programs with Multiple Threads</a>). There 54are two modes of controlling execution of your program within the 55debugger. In the default mode, referred to as <dfn>all-stop mode</dfn>, 56when any thread in your program stops (for example, at a breakpoint 57or while being stepped), all other threads in the program are also stopped by 58<span class="sc">gdb</span>. On some targets, <span class="sc">gdb</span> also supports 59<dfn>non-stop mode</dfn>, in which other threads can continue to run freely while 60you examine the stopped thread in the debugger. 61 62<ul class="menu"> 63<li><a accesskey="1" href="All_002dStop-Mode.html#All_002dStop-Mode">All-Stop Mode</a>: All threads stop when GDB takes control 64<li><a accesskey="2" href="Non_002dStop-Mode.html#Non_002dStop-Mode">Non-Stop Mode</a>: Other threads continue to execute 65<li><a accesskey="3" href="Background-Execution.html#Background-Execution">Background Execution</a>: Running your program asynchronously 66<li><a accesskey="4" href="Thread_002dSpecific-Breakpoints.html#Thread_002dSpecific-Breakpoints">Thread-Specific Breakpoints</a>: Controlling breakpoints 67<li><a accesskey="5" href="Interrupted-System-Calls.html#Interrupted-System-Calls">Interrupted System Calls</a>: GDB may interfere with system calls 68<li><a accesskey="6" href="Observer-Mode.html#Observer-Mode">Observer Mode</a>: GDB does not alter program behavior 69</ul> 70 71 </body></html> 72 73