70 lines
4.2 KiB
HTML
70 lines
4.2 KiB
HTML
|
<?xml version="1.0" encoding="UTF-8"?>
|
||
|
|
<!DOCTYPE html
|
||
|
|
PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
||
|
|
<html lang="en-us" xml:lang="en-us">
|
||
|
|
<head>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
||
|
|
<meta name="security" content="public" />
|
||
|
|
<meta name="Robots" content="index,follow" />
|
||
|
|
<meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' />
|
||
|
|
<meta name="DC.Type" content="reference" />
|
||
|
|
<meta name="DC.Title" content="API thread safety classifications" />
|
||
|
|
<meta name="abstract" content="Before using an API, you should determine if it is safe to call that API in your multithreaded program." />
|
||
|
|
<meta name="description" content="Before using an API, you should determine if it is safe to call that API in your multithreaded program." />
|
||
|
|
<meta name="DC.Relation" scheme="URI" content="rzahwsafco.htm" />
|
||
|
|
<meta name="DC.Relation" scheme="URI" content="../apiref/api.htm" />
|
||
|
|
<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
|
||
|
|
<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 1998, 2006" />
|
||
|
|
<meta name="DC.Format" content="XHTML" />
|
||
|
|
<meta name="DC.Identifier" content="rzahwapi-apico" />
|
||
|
|
<meta name="DC.Language" content="en-us" />
|
||
|
|
<!-- 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. -->
|
||
|
|
<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
|
||
|
|
<link rel="stylesheet" type="text/css" href="./ic.css" />
|
||
|
|
<title>API thread safety classifications</title>
|
||
|
|
</head>
|
||
|
|
<body id="rzahwapi-apico"><a name="rzahwapi-apico"><!-- --></a>
|
||
|
|
<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
|
||
|
|
<h1 class="topictitle1">API thread safety classifications</h1>
|
||
|
|
<div><p><span>Before using an API, you should determine if
|
||
|
|
it is safe to call that API in your multithreaded program.</span></p>
|
||
|
|
<div class="section"><div class="p">Each API has a threadsafe classification. The
|
||
|
|
three types of threadsafe classifications are as follows:<ul><li>Threadsafe: yes<p>This classification indicates that you can safely call
|
||
|
|
the API simultaneously in multiple threads without restrictions. This classification
|
||
|
|
also indicates that all functions called by this API are threadsafe. </p>
|
||
|
|
</li>
|
||
|
|
<li>Threadsafe: conditional<p>This classification indicates that not all functions
|
||
|
|
provided by the API are threadsafe. The Usage Notes section of the API provides
|
||
|
|
information that relates to thread safety limitations. Many APIs are classified
|
||
|
|
conditionally threadsafe because either some underlying system support is
|
||
|
|
not threadsafe or the API can call an exit point. For example, many of the
|
||
|
|
file system APIs are completely threadsafe when used with files in a threadsafe
|
||
|
|
file system. Some conditionally threadsafe APIs might deny access under some
|
||
|
|
circumstances. The API usage notes describe the conditions that cause the
|
||
|
|
function to deny access. </p>
|
||
|
|
</li>
|
||
|
|
<li>Threadsafe: no<p>This classification indicates that the API is not threadsafe
|
||
|
|
and that the API should not be used in a multithreaded program. While some
|
||
|
|
APIs that are not threadsafe might deny access, most APIs that are not threadsafe
|
||
|
|
do not. Unlike in CL commands, no diagnostic message is in the job log to
|
||
|
|
indicate that an API that is not threadsafe has been called (other than APIs
|
||
|
|
that deny access). There are techniques for calling functions that are not
|
||
|
|
threadsafe in multithreaded programs. </p>
|
||
|
|
</li>
|
||
|
|
</ul>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
<div>
|
||
|
|
<div class="familylinks">
|
||
|
|
<div class="parentlink"><strong>Parent topic:</strong> <a href="rzahwsafco.htm" title="A function is threadsafe if you can start it simultaneously in multiple threads within the same process. A function is threadsafe if and only if all the functions it calls are also threadsafe.">Thread safety</a></div>
|
||
|
|
</div>
|
||
|
|
<div class="relinfo"><strong>Related information</strong><br />
|
||
|
|
<div><a href="../apiref/api.htm">Application Programming Interfaces</a></div>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|