252 lines
7.4 KiB
HTML
252 lines
7.4 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>C++ destructors and Pthread termination</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 -->
|
||
|
|
<!-- NETMG2 SCRIPT A converted by B2H R4.1 (346) (CMS) by HOLTJM at -->
|
||
|
|
<!-- RCHVMW2 on 29 Jan 1999 at 10:01:37 -->
|
||
|
|
<!--File Edited November 2001 -->
|
||
|
|
<!--End Header Records -->
|
||
|
|
<link rel="stylesheet" type="text/css" href="../rzahg/ic.css">
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
<!-- Java sync-link -->
|
||
|
|
<script language="Javascript" src="../rzahg/synch.js" type="text/javascript">
|
||
|
|
</script>
|
||
|
|
|
||
|
|
<a name="Top_Of_Page"></a>
|
||
|
|
|
||
|
|
<h2>C++ destructors and Pthread termination</h2>
|
||
|
|
|
||
|
|
<p>Unlike some other implementations of threads, C++ destructors for automatic
|
||
|
|
objects are allowed to run in a well defined and consistent manner when a
|
||
|
|
thread is terminated.</p>
|
||
|
|
|
||
|
|
<p>The following list includes some of the causes of thread termination:</p>
|
||
|
|
|
||
|
|
<ul>
|
||
|
|
<li>A thread calls <strong>pthread_exit</strong>() or returns from the thread
|
||
|
|
start routine.</li>
|
||
|
|
|
||
|
|
<li>A thread is the target of <strong>pthread_cancel</strong>().</li>
|
||
|
|
|
||
|
|
<li>A thread is ended due to an unhandled exception.</li>
|
||
|
|
|
||
|
|
<li>A thread is in a process that contains another thread that calls <strong>
|
||
|
|
exit</strong>() or <strong>abort</strong>().</li>
|
||
|
|
|
||
|
|
<li>A thread is in a process that is terminated by the system
|
||
|
|
administrator.</li>
|
||
|
|
|
||
|
|
<li>A thread is being terminated by the system administrator.</li>
|
||
|
|
</ul>
|
||
|
|
|
||
|
|
<p>When a thread terminates, the following occurs:</p>
|
||
|
|
|
||
|
|
<ol>
|
||
|
|
<li>If the thread was ended using <strong>pthread_exit</strong>(), <strong>
|
||
|
|
pthread_cancel</strong>() or return from the thread start routine, then
|
||
|
|
cancellation cleanup handlers and data destructors are run.</li>
|
||
|
|
|
||
|
|
<li>The thread is terminated. At the time that the thread is terminated, both
|
||
|
|
C++ destructors for automatic objects and i5/OS cancel handlers run.</li>
|
||
|
|
</ol>
|
||
|
|
|
||
|
|
<p>If a Pthread is terminated using a non-Pthread method (an i5/OS exception,
|
||
|
|
a different thread termination primitive provided by the system, <strong>
|
||
|
|
exit</strong>() or <strong>abort</strong>(), or other job termination method),
|
||
|
|
Pthread cancellation cleanup handlers and data destructors do not run.</p>
|
||
|
|
|
||
|
|
<br>
|
||
|
|
<h3>Example</h3>
|
||
|
|
|
||
|
|
<p>This example shows the relationship between C++ destructors and Pthread
|
||
|
|
cleanup mechanisms.</p>
|
||
|
|
|
||
|
|
<p>See <a href="../apiref/aboutapis.htm#codedisclaimer">Code disclaimer information</a>
|
||
|
|
for information pertaining to code examples.</p>
|
||
|
|
|
||
|
|
<pre>
|
||
|
|
#define _MULTI_THREADED
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <qp0z1170.h>
|
||
|
|
#include <time.h>
|
||
|
|
#include <pthread.h>
|
||
|
|
#include "check.h"
|
||
|
|
|
||
|
|
#define bufferSize 100
|
||
|
|
#define threadRc 55
|
||
|
|
|
||
|
|
pthread_key_t tlskey;
|
||
|
|
|
||
|
|
void dataDestructor(void *parm);
|
||
|
|
void cancelHandler(void *parm);
|
||
|
|
void *threadfunc(void *parm);
|
||
|
|
void level2(void);
|
||
|
|
void level3(void);
|
||
|
|
|
||
|
|
|
||
|
|
class A {
|
||
|
|
public:
|
||
|
|
A(char *label);
|
||
|
|
~A();
|
||
|
|
private:
|
||
|
|
pthread_id_np_t tid;
|
||
|
|
char buffer[bufferSize];
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
void dataDestructor(void *parm) {
|
||
|
|
printf("In data destructor\n");
|
||
|
|
pthread_setspecific(tlskey, NULL);
|
||
|
|
}
|
||
|
|
|
||
|
|
void cancelHandler(void *parm) {
|
||
|
|
printf("In cancellation cleanup handler\n");
|
||
|
|
}
|
||
|
|
|
||
|
|
void *threadfunc(void *parm) {
|
||
|
|
A object("start routine object");
|
||
|
|
level2();
|
||
|
|
return NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
void level2(void) {
|
||
|
|
A object("Second level object");
|
||
|
|
level3();
|
||
|
|
}
|
||
|
|
|
||
|
|
void level3(void) {
|
||
|
|
int rc;
|
||
|
|
struct timespec ts = {5, 0};
|
||
|
|
A object("Third level object");
|
||
|
|
|
||
|
|
pthread_setspecific(tlskey, &tlskey);
|
||
|
|
pthread_cleanup_push(cancelHandler, NULL);
|
||
|
|
printf("Thread blocked\n");
|
||
|
|
rc = pthread_delay_np(&ts);
|
||
|
|
if (rc != 0) {
|
||
|
|
printf("pthread_delay_np() - return code %d\n", rc);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
printf("Calling pthread_exit()\n");
|
||
|
|
pthread_exit(__VOID(threadRc));
|
||
|
|
pthread_cleanup_pop(0);
|
||
|
|
}
|
||
|
|
|
||
|
|
int main(int argc, char **argv)
|
||
|
|
{
|
||
|
|
int rc=0;
|
||
|
|
int i;
|
||
|
|
pthread_t threadid;
|
||
|
|
void *status;
|
||
|
|
int fail=0;
|
||
|
|
|
||
|
|
printf("Enter Testcase - %s\n", argv[0]);
|
||
|
|
rc = pthread_key_create(&tlskey, dataDestructor);
|
||
|
|
checkResults("pthread_key_create()\n", rc);
|
||
|
|
|
||
|
|
printf("----------- Start pthread_cancel() example -------------\n");
|
||
|
|
printf("Create a thread\n");
|
||
|
|
rc = pthread_create(&threadid, NULL, threadfunc, NULL);
|
||
|
|
checkResults("pthread_create()\n", rc);
|
||
|
|
|
||
|
|
sleep(2);
|
||
|
|
rc = pthread_cancel(threadid);
|
||
|
|
checkResults("pthread_cancel()\n", rc);
|
||
|
|
|
||
|
|
rc = pthread_join(threadid, &status);
|
||
|
|
checkResults("pthread_join()\n", rc);
|
||
|
|
if (status != PTHREAD_CANCELED) {
|
||
|
|
printf("Canceled thread did not return the expected results\n");
|
||
|
|
fail = 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
printf("----------- Start pthread_exit() example -------------\n");
|
||
|
|
printf("Create a thread\n");
|
||
|
|
rc = pthread_create(&threadid, NULL, threadfunc, NULL);
|
||
|
|
checkResults("pthread_create()\n", rc);
|
||
|
|
|
||
|
|
rc = pthread_join(threadid, &status);
|
||
|
|
checkResults("pthread_join()\n", rc);
|
||
|
|
if (__INT(status) != threadRc) {
|
||
|
|
printf("pthread_exit() thread did not return the expected results\n");
|
||
|
|
fail = 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
pthread_key_delete(tlskey);
|
||
|
|
if (fail) {
|
||
|
|
printf("At least one thread failed!\n");
|
||
|
|
exit(1);
|
||
|
|
}
|
||
|
|
printf("Main completed\n");
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
A::A(char *label) {
|
||
|
|
strncpy(buffer, label, bufferSize);
|
||
|
|
pthread_t me;
|
||
|
|
me = pthread_self();
|
||
|
|
pthread_getunique_np(&me, &tid);
|
||
|
|
printf("`%s' instantiated in thread 0x%.8x %.8x\n",
|
||
|
|
buffer, tid);
|
||
|
|
}
|
||
|
|
A::~A() {
|
||
|
|
printf("`%s' destroyed in thread 0x%.8x %.8x\n",
|
||
|
|
buffer, tid);
|
||
|
|
}
|
||
|
|
</pre>
|
||
|
|
|
||
|
|
<p><strong>Output:</strong></p>
|
||
|
|
|
||
|
|
<pre>
|
||
|
|
Enter Testcase - QP0WTEST/TPCPP0
|
||
|
|
----------- Start pthread_cancel() example -------------
|
||
|
|
Create a thread
|
||
|
|
`start routine object' instantiated in thread 0x00000000 00000161
|
||
|
|
`Second level object' instantiated in thread 0x00000000 00000161
|
||
|
|
`Third level object' instantiated in thread 0x00000000 00000161
|
||
|
|
Thread blocked
|
||
|
|
In cancellation cleanup handler
|
||
|
|
In data destructor
|
||
|
|
`Third level object' destroyed in thread 0x00000000 00000161
|
||
|
|
`Second level object' destroyed in thread 0x00000000 00000161
|
||
|
|
`start routine object' destroyed in thread 0x00000000 00000161
|
||
|
|
----------- Start pthread_exit() example -------------
|
||
|
|
Create a thread
|
||
|
|
`start routine object' instantiated in thread 0x00000000 00000162
|
||
|
|
`Second level object' instantiated in thread 0x00000000 00000162
|
||
|
|
`Third level object' instantiated in thread 0x00000000 00000162
|
||
|
|
Thread blocked
|
||
|
|
Calling pthread_exit()
|
||
|
|
In cancellation cleanup handler
|
||
|
|
In data destructor
|
||
|
|
`Third level object' destroyed in thread 0x00000000 00000162
|
||
|
|
`Second level object' destroyed in thread 0x00000000 00000162
|
||
|
|
`start routine object' destroyed in thread 0x00000000 00000162
|
||
|
|
Main completed
|
||
|
|
</pre>
|
||
|
|
|
||
|
|
<hr>
|
||
|
|
<center>
|
||
|
|
<table cellpadding="2" cellspacing="2">
|
||
|
|
<tr align="center">
|
||
|
|
<td valign="middle" align="center">
|
||
|
|
<a href="#Top_Of_Page">Top</a> |
|
||
|
|
<a href="rzah4mst.htm">Pthread APIs</a> |
|
||
|
|
<a href="aplist.htm">APIs by category</a></td>
|
||
|
|
</tr>
|
||
|
|
</table>
|
||
|
|
</center>
|
||
|
|
</body>
|
||
|
|
</html>
|
||
|
|
|