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diff --git a/libstdc++-v3/doc/html/manual/using_concurrency.html b/libstdc++-v3/doc/html/manual/using_concurrency.html index f18aec31d8f..a0ca2a651af 100644 --- a/libstdc++-v3/doc/html/manual/using_concurrency.html +++ b/libstdc++-v3/doc/html/manual/using_concurrency.html @@ -1,10 +1,10 @@ <?xml version="1.0" encoding="UTF-8" standalone="no"?> -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> -<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Concurrency</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><meta name="keywords" content=" ISO C++ , library " /><link rel="home" href="../spine.html" title="The GNU C++ Library Documentation" /><link rel="up" href="using.html" title="Chapter 3. Using" /><link rel="prev" href="using_dynamic_or_shared.html" title="Linking" /><link rel="next" href="using_exceptions.html" title="Exceptions" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Concurrency</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="using_dynamic_or_shared.html">Prev</a> </td><th width="60%" align="center">Chapter 3. Using</th><td width="20%" align="right"> <a accesskey="n" href="using_exceptions.html">Next</a></td></tr></table><hr /></div><div class="sect1" title="Concurrency"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="manual.intro.using.concurrency"></a>Concurrency</h2></div></div></div><p>This section discusses issues surrounding the proper compilation +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml"><head><title>Concurrency</title><meta name="generator" content="DocBook XSL-NS Stylesheets V1.76.1"/><meta name="keywords" content=" ISO C++ , library "/><link rel="home" href="../spine.html" title="The GNU C++ Library"/><link rel="up" href="using.html" title="Chapter 3. Using"/><link rel="prev" href="using_dynamic_or_shared.html" title="Linking"/><link rel="next" href="using_exceptions.html" title="Exceptions"/></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Concurrency</th></tr><tr><td align="left"><a accesskey="p" href="using_dynamic_or_shared.html">Prev</a> </td><th width="60%" align="center">Chapter 3. Using</th><td align="right"> <a accesskey="n" href="using_exceptions.html">Next</a></td></tr></table><hr/></div><div class="section" title="Concurrency"><div class="titlepage"><div><div><h2 class="title"><a id="manual.intro.using.concurrency"/>Concurrency</h2></div></div></div><p>This section discusses issues surrounding the proper compilation of multithreaded applications which use the Standard C++ library. This information is GCC-specific since the C++ standard does not address matters of multithreaded applications. - </p><div class="sect2" title="Prerequisites"><div class="titlepage"><div><div><h3 class="title"><a id="manual.intro.using.concurrency.prereq"></a>Prerequisites</h3></div></div></div><p>All normal disclaimers aside, multithreaded C++ application are + </p><div class="section" title="Prerequisites"><div class="titlepage"><div><div><h3 class="title"><a id="manual.intro.using.concurrency.prereq"/>Prerequisites</h3></div></div></div><p>All normal disclaimers aside, multithreaded C++ application are only supported when libstdc++ and all user code was built with compilers which report (via <code class="code"> gcc/g++ -v </code>) the same thread model and that model is not <span class="emphasis"><em>single</em></span>. As long as your @@ -33,11 +33,11 @@ -pthread is honored. Some other ports use other switches. AFAIK, none of this is properly documented anywhere other than in ``gcc -dumpspecs'' (look at lib and cpp entries). - </p></div><div class="sect2" title="Thread Safety"><div class="titlepage"><div><div><h3 class="title"><a id="manual.intro.using.concurrency.thread_safety"></a>Thread Safety</h3></div></div></div><p> -We currently use the <a class="ulink" href="http://www.sgi.com/tech/stl/thread_safety.html" target="_top">SGI STL</a> definition of thread safety. + </p></div><div class="section" title="Thread Safety"><div class="titlepage"><div><div><h3 class="title"><a id="manual.intro.using.concurrency.thread_safety"/>Thread Safety</h3></div></div></div><p> +We currently use the <a class="link" href="http://www.sgi.com/tech/stl/thread_safety.html">SGI STL</a> definition of thread safety. </p><p>The library strives to be thread-safe when all of the following conditions are met: - </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>The system's libc is itself thread-safe, + </p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"><p>The system's libc is itself thread-safe, </p></li><li class="listitem"><p> The compiler in use reports a thread model other than 'single'. This can be tested via output from <code class="code">gcc @@ -53,7 +53,7 @@ gcc version 4.1.2 20070925 (Red Hat 4.1.2-33) Requisite command-line flags are used for atomic operations and threading. Examples of this include <code class="code">-pthread</code> and <code class="code">-march=native</code>, although specifics vary - depending on the host environment. See <a class="ulink" href="http://gcc.gnu.org/onlinedocs/gcc/Option-Summary.html" target="_top">Machine + depending on the host environment. See <a class="link" href="http://gcc.gnu.org/onlinedocs/gcc/Option-Summary.html">Machine Dependent Options</a>. </p></li><li class="listitem"><p> An implementation of atomicity.h functions @@ -89,9 +89,9 @@ gcc version 4.1.2 20070925 (Red Hat 4.1.2-33) this requirement includes both read and write access to objects; unless otherwise documented as safe, do not assume that two threads may access a shared standard library object at the same time. - </p></div><div class="sect2" title="Atomics"><div class="titlepage"><div><div><h3 class="title"><a id="manual.intro.using.concurrency.atomics"></a>Atomics</h3></div></div></div><p> - </p></div><div class="sect2" title="IO"><div class="titlepage"><div><div><h3 class="title"><a id="manual.intro.using.concurrency.io"></a>IO</h3></div></div></div><p>This gets a bit tricky. Please read carefully, and bear with me. - </p><div class="sect3" title="Structure"><div class="titlepage"><div><div><h4 class="title"><a id="concurrency.io.structure"></a>Structure</h4></div></div></div><p>A wrapper + </p></div><div class="section" title="Atomics"><div class="titlepage"><div><div><h3 class="title"><a id="manual.intro.using.concurrency.atomics"/>Atomics</h3></div></div></div><p> + </p></div><div class="section" title="IO"><div class="titlepage"><div><div><h3 class="title"><a id="manual.intro.using.concurrency.io"/>IO</h3></div></div></div><p>This gets a bit tricky. Please read carefully, and bear with me. + </p><div class="section" title="Structure"><div class="titlepage"><div><div><h4 class="title"><a id="concurrency.io.structure"/>Structure</h4></div></div></div><p>A wrapper type called <code class="code">__basic_file</code> provides our abstraction layer for the <code class="code">std::filebuf</code> classes. Nearly all decisions dealing with actual input and output must be made in <code class="code">__basic_file</code>. @@ -99,7 +99,7 @@ gcc version 4.1.2 20070925 (Red Hat 4.1.2-33) but is not used in the current code. Providing locking at any higher level is akin to providing locking within containers, and is not done for the same reasons (see the links above). - </p></div><div class="sect3" title="Defaults"><div class="titlepage"><div><div><h4 class="title"><a id="concurrency.io.defaults"></a>Defaults</h4></div></div></div><p>The __basic_file type is simply a collection of small wrappers around + </p></div><div class="section" title="Defaults"><div class="titlepage"><div><div><h4 class="title"><a id="concurrency.io.defaults"/>Defaults</h4></div></div></div><p>The __basic_file type is simply a collection of small wrappers around the C stdio layer (again, see the link under Structure). We do no locking ourselves, but simply pass through to calls to <code class="code">fopen</code>, <code class="code">fwrite</code>, and so forth. @@ -121,7 +121,7 @@ gcc version 4.1.2 20070925 (Red Hat 4.1.2-33) contained in the stream formatting classes (e.g., setting up callbacks inside an <code class="code">std::ofstream</code>), you need to guard such accesses like any other critical shared resource. - </p></div><div class="sect3" title="Future"><div class="titlepage"><div><div><h4 class="title"><a id="concurrency.io.future"></a>Future</h4></div></div></div><p> A + </p></div><div class="section" title="Future"><div class="titlepage"><div><div><h4 class="title"><a id="concurrency.io.future"/>Future</h4></div></div></div><p> A second choice may be available for I/O implementations: libio. This is disabled by default, and in fact will not currently work due to other issues. It will be revisited, however. @@ -146,10 +146,10 @@ gcc version 4.1.2 20070925 (Red Hat 4.1.2-33) version will see calls from libstdc++ directly into the glibc already installed. For other platforms, a copy of the libio subsection will be built and included in libstdc++. - </p></div><div class="sect3" title="Alternatives"><div class="titlepage"><div><div><h4 class="title"><a id="concurrency.io.alt"></a>Alternatives</h4></div></div></div><p>Don't forget that other cstdio implementations are possible. You could + </p></div><div class="section" title="Alternatives"><div class="titlepage"><div><div><h4 class="title"><a id="concurrency.io.alt"/>Alternatives</h4></div></div></div><p>Don't forget that other cstdio implementations are possible. You could easily write one to perform your own forms of locking, to solve your "interesting" problems. - </p></div></div><div class="sect2" title="Containers"><div class="titlepage"><div><div><h3 class="title"><a id="manual.intro.using.concurrency.containers"></a>Containers</h3></div></div></div><p>This section discusses issues surrounding the design of + </p></div></div><div class="section" title="Containers"><div class="titlepage"><div><div><h3 class="title"><a id="manual.intro.using.concurrency.containers"/>Containers</h3></div></div></div><p>This section discusses issues surrounding the design of multithreaded applications which use Standard C++ containers. All information in this section is current as of the gcc 3.0 release and all later point releases. Although earlier gcc @@ -161,9 +161,9 @@ gcc version 4.1.2 20070925 (Red Hat 4.1.2-33) threaded and non-threaded code), see Chapter 17. </p><p>Two excellent pages to read when working with the Standard C++ containers and threads are - <a class="ulink" href="http://www.sgi.com/tech/stl/thread_safety.html" target="_top">SGI's + <a class="link" href="http://www.sgi.com/tech/stl/thread_safety.html">SGI's http://www.sgi.com/tech/stl/thread_safety.html</a> and - <a class="ulink" href="http://www.sgi.com/tech/stl/Allocators.html" target="_top">SGI's + <a class="link" href="http://www.sgi.com/tech/stl/Allocators.html">SGI's http://www.sgi.com/tech/stl/Allocators.html</a>. </p><p><span class="emphasis"><em>However, please ignore all discussions about the user-level configuration of the lock implementation inside the STL @@ -202,4 +202,4 @@ gcc version 4.1.2 20070925 (Red Hat 4.1.2-33) useful are details on <a class="link" href="memory.html#std.util.memory.allocator" title="Allocators">allocator</a> options and capabilities. - </p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="using_dynamic_or_shared.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="using.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="using_exceptions.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Linking </td><td width="20%" align="center"><a accesskey="h" href="../spine.html">Home</a></td><td width="40%" align="right" valign="top"> Exceptions</td></tr></table></div></body></html> + </p></div></div><div class="navfooter"><hr/><table width="100%" summary="Navigation footer"><tr><td align="left"><a accesskey="p" href="using_dynamic_or_shared.html">Prev</a> </td><td align="center"><a accesskey="u" href="using.html">Up</a></td><td align="right"> <a accesskey="n" href="using_exceptions.html">Next</a></td></tr><tr><td align="left" valign="top">Linking </td><td align="center"><a accesskey="h" href="../spine.html">Home</a></td><td align="right" valign="top"> Exceptions</td></tr></table></div></body></html> |
