62 lines
3.9 KiB
HTML
62 lines
3.9 KiB
HTML
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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE html
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PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<meta name="DC.Title" content="File system considerations for multithreaded programming" />
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<meta name="abstract" content="You should consider several topics when working with file systems in multithreaded programs." />
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<meta name="description" content="You should consider several topics when working with file systems in multithreaded programs." />
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<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
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<title>File system considerations for multithreaded programming</title>
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</head>
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<body id="rzahwfsc-fscco"><a name="rzahwfsc-fscco"><!-- --></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">File system considerations for multithreaded programming</h1>
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<div><p>You should consider several topics when working with file systems
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in multithreaded programs. </p>
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<div class="section"><ul><li>Threadsafe file systems:<p>The Root, QOpenSys, User-Defined (UDFS), QNTC,
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QSYS.LIB, QOPT, and QLANSrv file systems are threadsafe and do not have any
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restrictions. The QDLS, NFS, QFileSvr.400, and QNetWare file systems are not
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threadsafe. If you try to use an integrated file system application programming
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interface (API) or command on a file or file descriptor that represents an
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object in a file system that is not threadsafe, it fails with ENOTSAFE. This
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failure occurs only when multiple threads are in a job.</p>
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<p>An attempt to
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spawn a program from a job that has multiple threads fails with ENOTSAFE if
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you inherit the current working directory or open file descriptors that represent
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files in a file system that is not threadsafe.</p>
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</li>
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<li>Integrated file system APIs:<p>All of the integrated file system APIs
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are threadsafe when directed to an object that resides in a threadsafe file
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system. If you do not know the file system where an object resides, you can
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query the path to see if the threadsafe integrated file system interfaces
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can safely access it. You can use the <span class="apiname">pathconf()</span>, <span class="apiname">fpathconf()</span>, <span class="apiname">statvfs()</span>,
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and <span class="apiname">fstatvfs()</span> APIs to determine whether a path or file
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descriptor refers to an object in one of the threadsafe file systems.</p>
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</li>
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</ul>
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</div>
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</div>
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<div>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="rzahwas4co.htm" title="All programs have at least one thread, referred to as the initial thread. In a program with multiple threads, each thread runs its code independently of the other threads in the program.">Threads on i5/OS</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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