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  18. <title>Threads (Debugging with GDB)</title>

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  61. 

  62. <body lang="en">

  63. <a name="Threads"></a>

  64. <div class="header">

  65. <p>

  66. Next: <a href="Forks.html#Forks" accesskey="n" rel="next">Forks</a>, Previous: <a href="Inferiors-Connections-and-Programs.html#Inferiors-Connections-and-Programs" accesskey="p" rel="prev">Inferiors Connections and Programs</a>, Up: <a href="Running.html#Running" accesskey="u" rel="up">Running</a> &nbsp; [<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>

  67. </div>

  68. <hr>

  69. <a name="Debugging-Programs-with-Multiple-Threads"></a>

  70. <h3 class="section">4.10 Debugging Programs with Multiple Threads</h3>

  71. 

  72. <a name="index-threads-of-execution"></a>

  73. <a name="index-multiple-threads"></a>

  74. <a name="index-switching-threads"></a>

  75. <p>In some operating systems, such as GNU/Linux and Solaris, a single program

  76. may have more than one <em>thread</em> of execution.  The precise semantics

  77. of threads differ from one operating system to another, but in general

  78. the threads of a single program are akin to multiple processes&mdash;except

  79. that they share one address space (that is, they can all examine and

  80. modify the same variables).  On the other hand, each thread has its own

  81. registers and execution stack, and perhaps private memory.

  82. </p>

  83. <p><small>GDB</small> provides these facilities for debugging multi-thread

  84. programs:

  85. </p>

  86. <ul>

  87. <li> automatic notification of new threads

  88. </li><li> &lsquo;<samp>thread <var>thread-id</var></samp>&rsquo;, a command to switch among threads

  89. </li><li> &lsquo;<samp>info threads</samp>&rsquo;, a command to inquire about existing threads

  90. </li><li> &lsquo;<samp>thread apply [<var>thread-id-list</var> | all] <var>args</var></samp>&rsquo;,

  91. a command to apply a command to a list of threads

  92. </li><li> thread-specific breakpoints

  93. </li><li> &lsquo;<samp>set print thread-events</samp>&rsquo;, which controls printing of 

  94. messages on thread start and exit.

  95. </li><li> &lsquo;<samp>set libthread-db-search-path <var>path</var></samp>&rsquo;, which lets

  96. the user specify which <code>libthread_db</code> to use if the default choice

  97. isn&rsquo;t compatible with the program.

  98. </li></ul>

  99. 

  100. <a name="index-focus-of-debugging"></a>

  101. <a name="index-current-thread"></a>

  102. <p>The <small>GDB</small> thread debugging facility allows you to observe all

  103. threads while your program runs&mdash;but whenever <small>GDB</small> takes

  104. control, one thread in particular is always the focus of debugging.

  105. This thread is called the <em>current thread</em>.  Debugging commands show

  106. program information from the perspective of the current thread.

  107. </p>

  108. <a name="index-New-systag-message"></a>

  109. <a name="index-thread-identifier-_0028system_0029"></a>

  110. <p>Whenever <small>GDB</small> detects a new thread in your program, it displays

  111. the target system&rsquo;s identification for the thread with a message in the

  112. form &lsquo;<samp>[New <var>systag</var>]</samp>&rsquo;, where <var>systag</var> is a thread identifier

  113. whose form varies depending on the particular system.  For example, on

  114. <small>GNU</small>/Linux, you might see

  115. </p>

  116. <div class="smallexample">

  117. <pre class="smallexample">[New Thread 0x41e02940 (LWP 25582)]

  118. </pre></div>

  119. 

  120. <p>when <small>GDB</small> notices a new thread.  In contrast, on other systems,

  121. the <var>systag</var> is simply something like &lsquo;<samp>process 368</samp>&rsquo;, with no

  122. further qualifier.

  123. </p>

  124. 

  125. <a name="thread-numbers"></a><a name="index-thread-number_002c-per-inferior"></a>

  126. <a name="index-thread-identifier-_0028GDB_0029"></a>

  127. <p>For debugging purposes, <small>GDB</small> associates its own thread number

  128. &mdash;always a single integer&mdash;with each thread of an inferior.  This

  129. number is unique between all threads of an inferior, but not unique

  130. between threads of different inferiors.

  131. </p>

  132. <a name="index-qualified-thread-ID"></a>

  133. <p>You can refer to a given thread in an inferior using the qualified

  134. <var>inferior-num</var>.<var>thread-num</var> syntax, also known as

  135. <em>qualified thread ID</em>, with <var>inferior-num</var> being the inferior

  136. number and <var>thread-num</var> being the thread number of the given

  137. inferior.  For example, thread <code>2.3</code> refers to thread number 3 of

  138. inferior 2.  If you omit <var>inferior-num</var> (e.g., <code>thread 3</code>),

  139. then <small>GDB</small> infers you&rsquo;re referring to a thread of the current

  140. inferior.

  141. </p>

  142. <p>Until you create a second inferior, <small>GDB</small> does not show the

  143. <var>inferior-num</var> part of thread IDs, even though you can always use

  144. the full <var>inferior-num</var>.<var>thread-num</var> form to refer to threads

  145. of inferior 1, the initial inferior.

  146. </p>

  147. <a name="thread-ID-lists"></a><a name="index-thread-ID-lists"></a>

  148. <p>Some commands accept a space-separated <em>thread ID list</em> as

  149. argument.  A list element can be:

  150. </p>

  151. <ol>

  152. <li> A thread ID as shown in the first field of the &lsquo;<samp>info threads</samp>&rsquo;

  153. display, with or without an inferior qualifier.  E.g., &lsquo;<samp>2.1</samp>&rsquo; or

  154. &lsquo;<samp>1</samp>&rsquo;.

  155. 

  156. </li><li> A range of thread numbers, again with or without an inferior

  157. qualifier, as in <var>inf</var>.<var>thr1</var>-<var>thr2</var> or

  158. <var>thr1</var>-<var>thr2</var>.  E.g., &lsquo;<samp>1.2-4</samp>&rsquo; or &lsquo;<samp>2-4</samp>&rsquo;.

  159. 

  160. </li><li> All threads of an inferior, specified with a star wildcard, with or

  161. without an inferior qualifier, as in <var>inf</var>.<code>*</code> (e.g.,

  162. &lsquo;<samp>1.*</samp>&rsquo;) or <code>*</code>.  The former refers to all threads of the

  163. given inferior, and the latter form without an inferior qualifier

  164. refers to all threads of the current inferior.

  165. 

  166. </li></ol>

  167. 

  168. <p>For example, if the current inferior is 1, and inferior 7 has one

  169. thread with ID 7.1, the thread list &lsquo;<samp>1 2-3 4.5 6.7-9 7.*</samp>&rsquo;

  170. includes threads 1 to 3 of inferior 1, thread 5 of inferior 4, threads

  171. 7 to 9 of inferior 6 and all threads of inferior 7.  That is, in

  172. expanded qualified form, the same as &lsquo;<samp>1.1 1.2 1.3 4.5 6.7 6.8 6.9

  173. 7.1</samp>&rsquo;.

  174. </p>

  175. 

  176. <a name="global-thread-numbers"></a><a name="index-global-thread-number"></a>

  177. <a name="index-global-thread-identifier-_0028GDB_0029"></a>

  178. <p>In addition to a <em>per-inferior</em> number, each thread is also

  179. assigned a unique <em>global</em> number, also known as <em>global

  180. thread ID</em>, a single integer.  Unlike the thread number component of

  181. the thread ID, no two threads have the same global ID, even when

  182. you&rsquo;re debugging multiple inferiors.

  183. </p>

  184. <p>From <small>GDB</small>&rsquo;s perspective, a process always has at least one

  185. thread.  In other words, <small>GDB</small> assigns a thread number to the

  186. program&rsquo;s &ldquo;main thread&rdquo; even if the program is not multi-threaded.

  187. </p>

  188. <a name="index-_0024_005fthread_002c-convenience-variable"></a>

  189. <a name="index-_0024_005fgthread_002c-convenience-variable"></a>

  190. <p>The debugger convenience variables &lsquo;<samp>$_thread</samp>&rsquo; and

  191. &lsquo;<samp>$_gthread</samp>&rsquo; contain, respectively, the per-inferior thread number

  192. and the global thread number of the current thread.  You may find this

  193. useful in writing breakpoint conditional expressions, command scripts,

  194. and so forth.  See <a href="Convenience-Vars.html#Convenience-Vars">Convenience Variables</a>, for

  195. general information on convenience variables.

  196. </p>

  197. <p>If <small>GDB</small> detects the program is multi-threaded, it augments the

  198. usual message about stopping at a breakpoint with the ID and name of

  199. the thread that hit the breakpoint.

  200. </p>

  201. <div class="smallexample">

  202. <pre class="smallexample">Thread 2 &quot;client&quot; hit Breakpoint 1, send_message () at client.c:68

  203. </pre></div>

  204. 

  205. <p>Likewise when the program receives a signal:

  206. </p>

  207. <div class="smallexample">

  208. <pre class="smallexample">Thread 1 &quot;main&quot; received signal SIGINT, Interrupt.

  209. </pre></div>

  210. 

  211. <dl compact="compact">

  212. <dd><a name="index-info-threads"></a>

  213. </dd>

  214. <dt><code>info threads <span class="roman">[</span><var>thread-id-list</var><span class="roman">]</span></code></dt>

  215. <dd>

  216. <p>Display information about one or more threads.  With no arguments

  217. displays information about all threads.  You can specify the list of

  218. threads that you want to display using the thread ID list syntax

  219. (see <a href="#thread-ID-lists">thread ID lists</a>).

  220. </p>

  221. <p><small>GDB</small> displays for each thread (in this order):

  222. </p>

  223. <ol>

  224. <li> the per-inferior thread number assigned by <small>GDB</small>

  225. 

  226. </li><li> the global thread number assigned by <small>GDB</small>, if the &lsquo;<samp>-gid</samp>&rsquo;

  227. option was specified

  228. 

  229. </li><li> the target system&rsquo;s thread identifier (<var>systag</var>)

  230. 

  231. </li><li> the thread&rsquo;s name, if one is known.  A thread can either be named by

  232. the user (see <code>thread name</code>, below), or, in some cases, by the

  233. program itself.

  234. 

  235. </li><li> the current stack frame summary for that thread

  236. </li></ol>

  237. 

  238. <p>An asterisk &lsquo;<samp>*</samp>&rsquo; to the left of the <small>GDB</small> thread number

  239. indicates the current thread.

  240. </p>

  241. <p>For example,

  242. </p></dd>

  243. </dl>

  244. 

  245. <div class="smallexample">

  246. <pre class="smallexample">(gdb) info threads

  247.   Id   Target Id             Frame

  248. * 1    process 35 thread 13  main (argc=1, argv=0x7ffffff8)

  249.   2    process 35 thread 23  0x34e5 in sigpause ()

  250.   3    process 35 thread 27  0x34e5 in sigpause ()

  251.     at threadtest.c:68

  252. </pre></div>

  253. 

  254. <p>If you&rsquo;re debugging multiple inferiors, <small>GDB</small> displays thread

  255. IDs using the qualified <var>inferior-num</var>.<var>thread-num</var> format.

  256. Otherwise, only <var>thread-num</var> is shown.

  257. </p>

  258. <p>If you specify the &lsquo;<samp>-gid</samp>&rsquo; option, <small>GDB</small> displays a column

  259. indicating each thread&rsquo;s global thread ID:

  260. </p>

  261. <div class="smallexample">

  262. <pre class="smallexample">(gdb) info threads

  263.   Id   GId  Target Id             Frame

  264.   1.1  1    process 35 thread 13  main (argc=1, argv=0x7ffffff8)

  265.   1.2  3    process 35 thread 23  0x34e5 in sigpause ()

  266.   1.3  4    process 35 thread 27  0x34e5 in sigpause ()

  267. * 2.1  2    process 65 thread 1   main (argc=1, argv=0x7ffffff8)

  268. </pre></div>

  269. 

  270. <p>On Solaris, you can display more information about user threads with a

  271. Solaris-specific command:

  272. </p>

  273. <dl compact="compact">

  274. <dt><code>maint info sol-threads</code></dt>

  275. <dd><a name="index-maint-info-sol_002dthreads"></a>

  276. <a name="index-thread-info-_0028Solaris_0029"></a>

  277. <p>Display info on Solaris user threads.

  278. </p></dd>

  279. </dl>

  280. 

  281. <dl compact="compact">

  282. <dd><a name="index-thread-thread_002did"></a>

  283. </dd>

  284. <dt><code>thread <var>thread-id</var></code></dt>

  285. <dd><p>Make thread ID <var>thread-id</var> the current thread.  The command

  286. argument <var>thread-id</var> is the <small>GDB</small> thread ID, as shown in

  287. the first field of the &lsquo;<samp>info threads</samp>&rsquo; display, with or without an

  288. inferior qualifier (e.g., &lsquo;<samp>2.1</samp>&rsquo; or &lsquo;<samp>1</samp>&rsquo;).

  289. </p>

  290. <p><small>GDB</small> responds by displaying the system identifier of the

  291. thread you selected, and its current stack frame summary:

  292. </p>

  293. <div class="smallexample">

  294. <pre class="smallexample">(gdb) thread 2

  295. [Switching to thread 2 (Thread 0xb7fdab70 (LWP 12747))]

  296. #0  some_function (ignore=0x0) at example.c:8

  297. 8	    printf (&quot;hello\n&quot;);

  298. </pre></div>

  299. 

  300. <p>As with the &lsquo;<samp>[New &hellip;]</samp>&rsquo; message, the form of the text after

  301. &lsquo;<samp>Switching to</samp>&rsquo; depends on your system&rsquo;s conventions for identifying

  302. threads.

  303. </p>

  304. <a name="thread-apply-all"></a><a name="index-thread-apply"></a>

  305. <a name="index-apply-command-to-several-threads"></a>

  306. </dd>

  307. <dt><code>thread apply [<var>thread-id-list</var> | all [-ascending]] [<var>flag</var>]&hellip; <var>command</var></code></dt>

  308. <dd><p>The <code>thread apply</code> command allows you to apply the named

  309. <var>command</var> to one or more threads.  Specify the threads that you

  310. want affected using the thread ID list syntax (see <a href="#thread-ID-lists">thread ID lists</a>), or specify <code>all</code> to apply to all threads.  To apply a

  311. command to all threads in descending order, type <kbd>thread apply all

  312. <var>command</var></kbd>.  To apply a command to all threads in ascending order,

  313. type <kbd>thread apply all -ascending <var>command</var></kbd>.

  314. </p>

  315. <p>The <var>flag</var> arguments control what output to produce and how to handle

  316. errors raised when applying <var>command</var> to a thread.  <var>flag</var>

  317. must start with a <code>-</code> directly followed by one letter in

  318. <code>qcs</code>.  If several flags are provided, they must be given

  319. individually, such as <code>-c -q</code>.

  320. </p>

  321. <p>By default, <small>GDB</small> displays some thread information before the

  322. output produced by <var>command</var>, and an error raised during the

  323. execution of a <var>command</var> will abort <code>thread apply</code>.  The

  324. following flags can be used to fine-tune this behavior:

  325. </p>

  326. <dl compact="compact">

  327. <dt><code>-c</code></dt>

  328. <dd><p>The flag <code>-c</code>, which stands for &lsquo;<samp>continue</samp>&rsquo;, causes any

  329. errors in <var>command</var> to be displayed, and the execution of

  330. <code>thread apply</code> then continues.

  331. </p></dd>

  332. <dt><code>-s</code></dt>

  333. <dd><p>The flag <code>-s</code>, which stands for &lsquo;<samp>silent</samp>&rsquo;, causes any errors

  334. or empty output produced by a <var>command</var> to be silently ignored.

  335. That is, the execution continues, but the thread information and errors

  336. are not printed.

  337. </p></dd>

  338. <dt><code>-q</code></dt>

  339. <dd><p>The flag <code>-q</code> (&lsquo;<samp>quiet</samp>&rsquo;) disables printing the thread

  340. information.

  341. </p></dd>

  342. </dl>

  343. 

  344. <p>Flags <code>-c</code> and <code>-s</code> cannot be used together.

  345. </p>

  346. <a name="index-taas"></a>

  347. <a name="index-apply-command-to-all-threads-_0028ignoring-errors-and-empty-output_0029"></a>

  348. </dd>

  349. <dt><code>taas [<var>option</var>]&hellip; <var>command</var></code></dt>

  350. <dd><p>Shortcut for <code>thread apply all -s [<var>option</var>]&hellip; <var>command</var></code>.

  351. Applies <var>command</var> on all threads, ignoring errors and empty output.

  352. </p>

  353. <p>The <code>taas</code> command accepts the same options as the <code>thread

  354. apply all</code> command.  See <a href="#thread-apply-all">thread apply all</a>.

  355. </p>

  356. <a name="index-tfaas"></a>

  357. <a name="index-apply-a-command-to-all-frames-of-all-threads-_0028ignoring-errors-and-empty-output_0029"></a>

  358. </dd>

  359. <dt><code>tfaas [<var>option</var>]&hellip; <var>command</var></code></dt>

  360. <dd><p>Shortcut for <code>thread apply all -s -- frame apply all -s [<var>option</var>]&hellip; <var>command</var></code>.

  361. Applies <var>command</var> on all frames of all threads, ignoring errors

  362. and empty output.  Note that the flag <code>-s</code> is specified twice:

  363. The first <code>-s</code> ensures that <code>thread apply</code> only shows the thread

  364. information of the threads for which <code>frame apply</code> produces

  365. some output.  The second <code>-s</code> is needed to ensure that <code>frame

  366. apply</code> shows the frame information of a frame only if the

  367. <var>command</var> successfully produced some output.

  368. </p>

  369. <p>It can for example be used to print a local variable or a function

  370. argument without knowing the thread or frame where this variable or argument

  371. is, using:

  372. </p><div class="smallexample">

  373. <pre class="smallexample">(gdb) tfaas p some_local_var_i_do_not_remember_where_it_is

  374. </pre></div>

  375. 

  376. <p>The <code>tfaas</code> command accepts the same options as the <code>frame

  377. apply</code> command.  See <a href="Frame-Apply.html#Frame-Apply">frame apply</a>.

  378. </p>

  379. <a name="index-thread-name"></a>

  380. <a name="index-name-a-thread"></a>

  381. </dd>

  382. <dt><code>thread name [<var>name</var>]</code></dt>

  383. <dd><p>This command assigns a name to the current thread.  If no argument is

  384. given, any existing user-specified name is removed.  The thread name

  385. appears in the &lsquo;<samp>info threads</samp>&rsquo; display.

  386. </p>

  387. <p>On some systems, such as <small>GNU</small>/Linux, <small>GDB</small> is able to

  388. determine the name of the thread as given by the OS.  On these

  389. systems, a name specified with &lsquo;<samp>thread name</samp>&rsquo; will override the

  390. system-give name, and removing the user-specified name will cause

  391. <small>GDB</small> to once again display the system-specified name.

  392. </p>

  393. <a name="index-thread-find"></a>

  394. <a name="index-search-for-a-thread"></a>

  395. </dd>

  396. <dt><code>thread find [<var>regexp</var>]</code></dt>

  397. <dd><p>Search for and display thread ids whose name or <var>systag</var>

  398. matches the supplied regular expression.

  399. </p>

  400. <p>As well as being the complement to the &lsquo;<samp>thread name</samp>&rsquo; command, 

  401. this command also allows you to identify a thread by its target 

  402. <var>systag</var>.  For instance, on <small>GNU</small>/Linux, the target <var>systag</var>

  403. is the LWP id.

  404. </p>

  405. <div class="smallexample">

  406. <pre class="smallexample">(GDB) thread find 26688

  407. Thread 4 has target id 'Thread 0x41e02940 (LWP 26688)'

  408. (GDB) info thread 4

  409.   Id   Target Id         Frame 

  410.   4    Thread 0x41e02940 (LWP 26688) 0x00000031ca6cd372 in select ()

  411. </pre></div>

  412. 

  413. <a name="index-set-print-thread_002devents"></a>

  414. <a name="index-print-messages-on-thread-start-and-exit"></a>

  415. </dd>

  416. <dt><code>set print thread-events</code></dt>

  417. <dt><code>set print thread-events on</code></dt>

  418. <dt><code>set print thread-events off</code></dt>

  419. <dd><p>The <code>set print thread-events</code> command allows you to enable or

  420. disable printing of messages when <small>GDB</small> notices that new threads have

  421. started or that threads have exited.  By default, these messages will

  422. be printed if detection of these events is supported by the target.

  423. Note that these messages cannot be disabled on all targets.

  424. </p>

  425. <a name="index-show-print-thread_002devents"></a>

  426. </dd>

  427. <dt><code>show print thread-events</code></dt>

  428. <dd><p>Show whether messages will be printed when <small>GDB</small> detects that threads

  429. have started and exited.

  430. </p></dd>

  431. </dl>

  432. 

  433. <p>See <a href="Thread-Stops.html#Thread-Stops">Stopping and Starting Multi-thread Programs</a>, for

  434. more information about how <small>GDB</small> behaves when you stop and start

  435. programs with multiple threads.

  436. </p>

  437. <p>See <a href="Set-Watchpoints.html#Set-Watchpoints">Setting Watchpoints</a>, for information about

  438. watchpoints in programs with multiple threads.

  439. </p>

  440. <a name="set-libthread_002ddb_002dsearch_002dpath"></a><dl compact="compact">

  441. <dd><a name="index-set-libthread_002ddb_002dsearch_002dpath"></a>

  442. <a name="index-search-path-for-libthread_005fdb"></a>

  443. </dd>

  444. <dt><code>set libthread-db-search-path <span class="roman">[</span><var>path</var><span class="roman">]</span></code></dt>

  445. <dd><p>If this variable is set, <var>path</var> is a colon-separated list of

  446. directories <small>GDB</small> will use to search for <code>libthread_db</code>.

  447. If you omit <var>path</var>, &lsquo;<samp>libthread-db-search-path</samp>&rsquo; will be reset to

  448. its default value (<code>$sdir:$pdir</code> on <small>GNU</small>/Linux and Solaris systems).

  449. Internally, the default value comes from the <code>LIBTHREAD_DB_SEARCH_PATH</code>

  450. macro.

  451. </p>

  452. <p>On <small>GNU</small>/Linux and Solaris systems, <small>GDB</small> uses a &ldquo;helper&rdquo;

  453. <code>libthread_db</code> library to obtain information about threads in the

  454. inferior process.  <small>GDB</small> will use &lsquo;<samp>libthread-db-search-path</samp>&rsquo;

  455. to find <code>libthread_db</code>.  <small>GDB</small> also consults first if inferior

  456. specific thread debugging library loading is enabled

  457. by &lsquo;<samp>set auto-load libthread-db</samp>&rsquo; (see <a href="libthread_005fdb_002eso_002e1-file.html#libthread_005fdb_002eso_002e1-file">libthread_db.so.1 file</a>).

  458. </p>

  459. <p>A special entry &lsquo;<samp>$sdir</samp>&rsquo; for &lsquo;<samp>libthread-db-search-path</samp>&rsquo;

  460. refers to the default system directories that are

  461. normally searched for loading shared libraries.  The &lsquo;<samp>$sdir</samp>&rsquo; entry

  462. is the only kind not needing to be enabled by &lsquo;<samp>set auto-load libthread-db</samp>&rsquo;

  463. (see <a href="libthread_005fdb_002eso_002e1-file.html#libthread_005fdb_002eso_002e1-file">libthread_db.so.1 file</a>).

  464. </p>

  465. <p>A special entry &lsquo;<samp>$pdir</samp>&rsquo; for &lsquo;<samp>libthread-db-search-path</samp>&rsquo;

  466. refers to the directory from which <code>libpthread</code>

  467. was loaded in the inferior process.

  468. </p>

  469. <p>For any <code>libthread_db</code> library <small>GDB</small> finds in above directories,

  470. <small>GDB</small> attempts to initialize it with the current inferior process.

  471. If this initialization fails (which could happen because of a version

  472. mismatch between <code>libthread_db</code> and <code>libpthread</code>), <small>GDB</small>

  473. will unload <code>libthread_db</code>, and continue with the next directory.

  474. If none of <code>libthread_db</code> libraries initialize successfully,

  475. <small>GDB</small> will issue a warning and thread debugging will be disabled.

  476. </p>

  477. <p>Setting <code>libthread-db-search-path</code> is currently implemented

  478. only on some platforms.

  479. </p>

  480. <a name="index-show-libthread_002ddb_002dsearch_002dpath"></a>

  481. </dd>

  482. <dt><code>show libthread-db-search-path</code></dt>

  483. <dd><p>Display current libthread_db search path.

  484. </p>

  485. <a name="index-set-debug-libthread_002ddb"></a>

  486. <a name="index-show-debug-libthread_002ddb"></a>

  487. <a name="index-debugging-libthread_005fdb"></a>

  488. </dd>

  489. <dt><code>set debug libthread-db</code></dt>

  490. <dt><code>show debug libthread-db</code></dt>

  491. <dd><p>Turns on or off display of <code>libthread_db</code>-related events.

  492. Use <code>1</code> to enable, <code>0</code> to disable.

  493. </p></dd>

  494. </dl>

  495. 

  496. <hr>

  497. <div class="header">

  498. <p>

  499. Next: <a href="Forks.html#Forks" accesskey="n" rel="next">Forks</a>, Previous: <a href="Inferiors-Connections-and-Programs.html#Inferiors-Connections-and-Programs" accesskey="p" rel="prev">Inferiors Connections and Programs</a>, Up: <a href="Running.html#Running" accesskey="u" rel="up">Running</a> &nbsp; [<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>

  500. </div>

  501. 

  502. 

  503. 

  504. </body>

  505. </html>