72 lines
5.8 KiB
HTML
72 lines
5.8 KiB
HTML
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<meta name="DC.Title" content="Function calls that are not thread safe" />
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<meta name="abstract" content="Your multithreaded application at times requires access to functions or system services that are not thread safe. There are few completely safe alternatives for calling these functions." />
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<title>Function calls that are not thread safe</title>
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</head>
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<body id="rzahwnon-nonco"><a name="rzahwnon-nonco"><!-- --></a>
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<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
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<h1 class="topictitle1">Function calls that are not thread safe</h1>
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<div><p>Your multithreaded application at times requires access to functions
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or system services that are not thread safe. There are few completely safe
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alternatives for calling these functions.</p>
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<p>To illustrate the alternatives, consider the example of a program that
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calls API <span class="apiname">foo()</span>. Because
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function <span class="apiname">foo()</span> is listed as not being thread
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safe, you need to find a safe way to call it. Two common options are using
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a global mutual exclusion (mutex) or using a separate job to run the function
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that is not thread safe.</p>
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</div>
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<div>
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<ul class="ullinks">
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<li class="ulchildlink"><strong><a href="rzahwgloco.htm">Use global mutexes to run functions that are not threadsafe</a></strong><br />
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One alternative you should consider when you need to call a function that is not threadsafe is using a global mutual exclusion (mutex) to run these functions.</li>
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<li class="ulchildlink"><strong><a href="rzahwjobco.htm">Use separate jobs to run functions that are not threadsafe</a></strong><br />
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There are several threadsafe mechanisms to submit a new job to complete the processing you need.</li>
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</ul>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="rzahwmulco.htm" title="If you are going to write multithreaded applications or server applications for i5/OS, you should be familiar with several techniques.">Multithreaded programming techniques</a></div>
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</div>
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<div class="relconcepts"><strong>Related concepts</strong><br />
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<div><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>
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<div><a href="rzahwsynco.htm" title="When you create code that is threadsafe but still benefits from sharing data or resources between threads, the most important aspect of programming becomes the ability to synchronize threads.">Synchronization techniques among threads</a></div>
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<div><a href="rzahwoneco.htm" title="At times, you might want to defer the initialization of resources until a thread requires them. However, your application might require that multiple threads use a certain resource, which requires you to initialize the resource only once in a threadsafe way.">One-time initialization and thread safety</a></div>
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<div><a href="rzahwcomco.htm" title="Several programming errors often occur when writing multithreaded applications.">Common multithreaded programming errors</a></div>
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</div>
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<div class="relref"><strong>Related reference</strong><br />
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<div><a href="rzahwclcco.htm" title="The Integrated Language Environment (ILE) CL run time and compiler-generated code are threadsafe. Original program model (OPM) CL programs are not threadsafe.">CL commands and thread safety</a></div>
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<div><a href="rzahwileco.htm" title="You can create an Integrated Language Environment (ILE) COBOL or ILE RPG module that will run safely in a multithreaded environment by serializing access to the module.">Threads considerations for ILE COBOL and RPG language</a></div>
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</div>
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</div>
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</body>
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</html>
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