355 lines
11 KiB
HTML
355 lines
11 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
|
<html>
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
|
<meta name="Copyright" content="Copyright (c) 2006 by IBM Corporation">
|
|
<title>Qp0zDumpTargetStack()--Dump Formatted Stack Trace Data of the Target
|
|
Thread</title>
|
|
<!-- Begin Header Records ========================================== -->
|
|
<!-- All rights reserved. Licensed Materials Property of IBM -->
|
|
<!-- US Government Users Restricted Rights -->
|
|
<!-- Use, duplication or disclosure restricted by -->
|
|
<!-- GSA ADP Schedule Contract with IBM Corp. -->
|
|
<!-- Change History: -->
|
|
<!-- YYMMDD USERID Change description -->
|
|
<!-- Direct1 SCRIPT J converted by B2H R4.1 (346) (CMS) by V2KEA304 -->
|
|
<!-- at RCHVMW2 on 17 Feb 1999 at 11:05:09 -->
|
|
<!-- Edited by Kersten Feb 02 -->
|
|
<!-- This file has undergone html cleanup May 2002 by JET -->
|
|
<!-- End Header Records -->
|
|
<link rel="stylesheet" type="text/css" href="../rzahg/ic.css">
|
|
</head>
|
|
<body>
|
|
<!-- Java sync-link -->
|
|
<script type="text/javascript" language="Javascript" src="../rzahg/synch.js">
|
|
</script>
|
|
|
|
<a name="Top_Of_Page"></a>
|
|
|
|
<h2>Qp0zDumpTargetStack()--Dump Formatted Stack Trace Data of the Target
|
|
Thread</h2>
|
|
|
|
<div class="box" style="width: 60%;">
|
|
<br>
|
|
Syntax<br>
|
|
<pre>
|
|
#include <qp0ztrc.h>
|
|
|
|
int Qp0zDumpTargetStack(int <em>handle</em>,
|
|
const char <em>*label</em>);
|
|
</pre>
|
|
|
|
<br>
|
|
Service Program Name: QP0ZCPA<br>
|
|
<!-- iddvc RMBR -->
|
|
<br>
|
|
Default Public Authority: *USE<br>
|
|
<!-- iddvc RMBR -->
|
|
<br>
|
|
Threadsafe: Conditional; see <a href="#USAGE_NOTES">Usage Notes</a>.<br>
|
|
<!-- iddvc RMBR -->
|
|
<br>
|
|
</div>
|
|
|
|
<p>The <strong>Qp0zDumpTargetStack()</strong> function dumps a formatted
|
|
representation of the call stack of the target thread to the user trace. The
|
|
target thread is specified by <em>handle</em>, which can be filled in using the
|
|
<em>pthread_t</em> structure. The formatted call stack is labeled with the text
|
|
string specified by <em>label</em>. The formatted call stack shows the library,
|
|
program, module, and procedure information associated with each frame on the
|
|
call stack at the time the function was called.</p>
|
|
|
|
<p>The formatted dump of the target call stack shows the oldest entries first,
|
|
followed by newer entries.</p>
|
|
|
|
<p>For consistent results, ensure that the target thread specified in the <em>
|
|
handle</em> parameter is blocked or waiting for some resource and not actively
|
|
running.</p>
|
|
|
|
<p>If a target thread that is actively running is specified, the stack trace
|
|
information may be inconsistent.</p>
|
|
|
|
<p>An application should not use the tracing function in performance critical
|
|
code. These functions are intended for debugging exception or error conditions.
|
|
The user trace is a permanent user space object named <em>
|
|
QP0Z<jobnumber></em> in the QUSRSYS library. The user trace is created
|
|
the first time any thread in a job writes trace output. See the Change User
|
|
Trace (CHGUSRTRC), Dump User Trace (DMPUSRTRC) and Delete User Trace
|
|
(DLTUSRTRC) CL commands for information about manipulating the user trace
|
|
properties and objects.</p>
|
|
|
|
<br>
|
|
<h3>Parameters</h3>
|
|
|
|
<dl>
|
|
<dt><strong><em>handle</em></strong></dt>
|
|
|
|
<dd>(Input) A handle to the target thread.<br>
|
|
<br>
|
|
</dd>
|
|
|
|
<dt><strong><em>label</em></strong></dt>
|
|
|
|
<dd>(Input) A pointer to a string that is used to label the stack dump.</dd>
|
|
</dl>
|
|
|
|
<br>
|
|
<h3>Authorities</h3>
|
|
|
|
<p>None.</p>
|
|
|
|
<br>
|
|
<h3>Return Value</h3>
|
|
|
|
<table cellpadding="5">
|
|
<!-- cols="10 90" -->
|
|
<tr>
|
|
<td align="left" valign="top"><em>0</em></td>
|
|
<td align="left" valign="top"><strong>Qp0zDumpTargetStack()</strong> was
|
|
successful.</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td align="left" valign="top"><em>value</em></td>
|
|
<td align="left" valign="top"><strong>Qp0zDumpTargetStack()</strong> was not
|
|
successful. The value returned is an errno indicating the failure.</td>
|
|
</tr>
|
|
</table>
|
|
|
|
<br>
|
|
<br>
|
|
<h3>Error Conditions</h3>
|
|
|
|
<p>If <strong>Qp0zDumpTargetStack()</strong> is not successful, the return
|
|
value usually indicates one of the following errors. Under some conditions, the
|
|
return value could indicate an error other than those listed here.</p>
|
|
|
|
<dl>
|
|
<dt><em>[EFAULT]</em></dt>
|
|
|
|
<dd>
|
|
<p>The address used for an argument is not correct.</p>
|
|
|
|
<p>In attempting to use an argument in a call, the system detected an address
|
|
that is not valid.</p>
|
|
|
|
<p>While attempting to access a parameter passed to this function, the system
|
|
detected an address that is not valid.</p>
|
|
</dd>
|
|
|
|
<dt><em>[ESRCH]</em></dt>
|
|
|
|
<dd>
|
|
<p>No item could be found that matches the specified value.</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
<br>
|
|
<br>
|
|
<h3><a name="USAGE_NOTES">Usage Notes</a></h3>
|
|
|
|
<ol>
|
|
<li>No locks are held on the user trace between calls to the tracing functions.
|
|
The user trace can be deleted while in use. The next function that produces
|
|
trace output will create the user trace again.<br>
|
|
<br>
|
|
</li>
|
|
|
|
<li>If another job on the system has the same job number as an existing user
|
|
trace, the existing trace data is cleared, and the trace data from the new job
|
|
replaces it.<br>
|
|
<br>
|
|
</li>
|
|
|
|
<li>The <strong>Qp0zDumpTargetStack()</strong> can only safely be used against
|
|
a thread that is stopped or waiting for some activity to occur. If <strong>
|
|
Qp0zDumpTargetStack()</strong> is used with a thread that is actively running,
|
|
the output stack trace may show an inconsistent view of the call stack.<br>
|
|
<br>
|
|
</li>
|
|
|
|
<li>If the target thread has more than 128 call stack entries, <strong>
|
|
Qp0zDumpTargetStack()</strong> returns after dumping the first 128 entries of
|
|
the call stack.<br>
|
|
<br>
|
|
</li>
|
|
|
|
<li>As the format of the user trace records can change, only the following CL
|
|
commands can be used to manipulate the user trace properties and objects:<br>
|
|
<ul>
|
|
<li>Change User Trace (CHGUSRTRC) can be used to change the characteristics of
|
|
the user trace.<br>
|
|
<br>
|
|
</li>
|
|
|
|
<li>Dump User Trace (DMPUSRTRC) can be used to dump trace records to a file or
|
|
to standard output.<br>
|
|
<br>
|
|
</li>
|
|
|
|
<li>Delete User Trace (DLTUSRTRC) can be used to delete the user trace
|
|
objects.</li>
|
|
</ul>
|
|
</li>
|
|
</ol>
|
|
|
|
<br>
|
|
<h3>Related Information</h3>
|
|
|
|
<ul>
|
|
<li><a href="p0zdmp.htm">Qp0zDump()</a>--Dump Formatted Storage Trace Data<br>
|
|
<br>
|
|
</li>
|
|
|
|
<li><a href="p0zdmps.htm">Qp0zDumpStack()</a>--Dump Formatted Stack Trace
|
|
Data<br>
|
|
<br>
|
|
</li>
|
|
|
|
<li><a href="p0zlog.htm">Qp0zLprintf()</a>--Print Formatted Job Log Data<br>
|
|
<br>
|
|
</li>
|
|
|
|
<li><a href="p0zprnt.htm">Qp0zUprintf()</a>--Print Formatted User Trace
|
|
Data</li>
|
|
</ul>
|
|
|
|
<br>
|
|
<h3>Example</h3>
|
|
|
|
<p>See <a href="../apiref/aboutapis.htm#codedisclaimer">Code disclaimer information</a>
|
|
for information pertaining to code examples.</p>
|
|
|
|
<p>The following example uses <strong>Qp0zDumpTargetStack()</strong> and
|
|
<strong>Qp0zUprintf()</strong> functions to produce trace output.</p>
|
|
|
|
<pre>
|
|
#define _MULTI_THREADED
|
|
#include <pthread.h>
|
|
#include <milib.h>
|
|
#include <stdio.h>
|
|
#include <errno.h>
|
|
#include <unistd.h>
|
|
#include <qp0ztrc.h>
|
|
|
|
void *threadfunc(void *);
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
int rc=0;
|
|
pthread_t thread;
|
|
|
|
Qp0zUprintf("Entering Testcase\n");
|
|
rc = pthread_create(&thread, NULL, threadfunc, NULL);
|
|
sleep(2); /* Let the thread block */
|
|
|
|
/* If the other thread ends or is actively running (that is */
|
|
/* changing the call stack, you may get meaningless results in the*/
|
|
/* stack dump for the target thread.) */
|
|
Qp0zDumpTargetStack(thread.reservedHandle,
|
|
"Dumping target thread's stack\n");
|
|
Qp0zUprintf("Exit with return code of 0\n");
|
|
return 0;
|
|
}
|
|
|
|
|
|
void foo(void);
|
|
void bar(void);
|
|
void *threadfunc(void *parm)
|
|
{
|
|
Qp0zUprintf("Inside secondary thread\n");
|
|
foo();
|
|
return NULL;
|
|
}
|
|
|
|
void foo(void)
|
|
{
|
|
bar();
|
|
}
|
|
|
|
void bar(void)
|
|
{
|
|
Qp0zDumpStack("Thread dumping my own stack\n");
|
|
sleep(10); /* Ensure the thread is blocked */
|
|
}
|
|
|
|
</pre>
|
|
|
|
<br>
|
|
<h3>Trace Output:</h3>
|
|
|
|
<p>This trace output was generated after the test case was run by using the CL
|
|
command <strong>DMPUSRTRC JOB(107141/USER/TPZTSTK0) OUTPUT(*STDOUT)</strong>.
|
|
The above example program ran as job 107141/USER/TPZTSTK0.</p>
|
|
|
|
<p>Note the following in the trace output:</p>
|
|
|
|
<ol>
|
|
<li>Each trace record is indented by several spaces to aid in readability.
|
|
Trace records from different threads have different indentation levels.<br>
|
|
<br>
|
|
</li>
|
|
|
|
<li>Each trace record is identified by the hexadecimal thread ID, a colon, and
|
|
a timestamp. The timestamp can be used to aid in debugging of waiting or
|
|
looping threads. For example, the third trace record shown below, (the Entering
|
|
Testcase trace point) was created by thread 0x36, and occurred 0.595584 seconds
|
|
after the last full date and time label. This means that the trace record was
|
|
created on 23 January 1998 at 12:38:10.595584. A full date and time label is
|
|
placed between those trace points that occur during different whole
|
|
seconds.</li>
|
|
</ol>
|
|
|
|
<br>
|
|
<br>
|
|
<pre>
|
|
User Trace Dump for job 107141/USER/TPZTSTK0. Size: 300K, Wrapped 0 times.
|
|
--- 01/23/1998 12:38:10 ---
|
|
00000036:595584 Entering Testcase
|
|
00000037:598832 Inside secondary thread
|
|
00000037:599024 Stack Dump For Current Thread
|
|
00000037:599200 Stack: Thread dumping my own stack
|
|
00000037:695440 Stack: Library / Program Module Stmt Procedure
|
|
00000037:752984 Stack: QSYS / QLESPI QLECRTTH 774 : LE_Create_Thread2__FP12crtth_parm_t
|
|
00000037:805664 Stack: QSYS / QP0WPTHR QP0WPTHR 1006 : pthread_create_part2
|
|
00000037:805888 Stack: QP0WTEST / TPZTSTK0 TPZTSTK0 2 : threadfunc
|
|
00000037:806088 Stack: QP0WTEST / TPZTSTK0 TPZTSTK0 1 : foo
|
|
00000037:806288 Stack: QP0WTEST / TPZTSTK0 TPZTSTK0 1 : bar
|
|
00000037:806496 Stack: QSYS / QP0ZCPA QP0ZUDBG 85 : Qp0zDumpStack
|
|
00000037:848280 Stack: QSYS / QP0ZSCPA QP0ZSCPA 274 : Qp0zSUDumpStack
|
|
00000037:848504 Stack: QSYS / QP0ZSCPA QP0ZSCPA 285 : Qp0zSUDumpTargetStack
|
|
00000037:848616 Stack: Completed
|
|
--- 01/23/1998 12:38:12 ---
|
|
00000036:628272 Stack Dump For Target Thread: Handle 7 (0x00000007)
|
|
00000036:628464 Stack: Dumping target thread's stack
|
|
00000036:651608 Stack: Library / Program Module Stmt Procedure
|
|
00000036:651872 Stack: QSYS / QLESPI QLECRTTH 774 : LE_Create_Thread2__FP12crtth_parm_t
|
|
00000036:652088 Stack: QSYS / QP0WPTHR QP0WPTHR 1006 : pthread_create_part2
|
|
00000036:652304 Stack: QP0WTEST / TPZTSTK0 TPZTSTK0 2 : threadfunc
|
|
00000036:652512 Stack: QP0WTEST / TPZTSTK0 TPZTSTK0 1 : foo
|
|
00000036:652712 Stack: QP0WTEST / TPZTSTK0 TPZTSTK0 2 : bar
|
|
00000036:677456 Stack: QSYS / QP0SSRV1 QP0SLIB 1061 : sleep
|
|
00000036:700096 Stack: QSYS / QP0SSRV2 QP0SWAIT 248 : qp0swait__FP13qp0ssigwait_t
|
|
00000036:700216 Stack: Completed
|
|
00000036:700408 Exit with return code of 0
|
|
Press ENTER to end terminal session.
|
|
</pre>
|
|
|
|
|
|
<br>
|
|
<hr>
|
|
API introduced: V4R3
|
|
|
|
<hr>
|
|
<center>
|
|
<table cellpadding="2" cellspacing="2">
|
|
<tr align="center">
|
|
<td valign="middle" align="center"><a href="#Top_Of_Page">Top</a> | <a href=
|
|
"unix.htm">UNIX-Type APIs</a> | <a href="aplist.htm">APIs by category</a></td>
|
|
</tr>
|
|
</table>
|
|
</center>
|
|
</body>
|
|
</html>
|
|
|