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| -rw-r--r-- | libstdc++-v3/doc/html/manual/memory.html | 70 |
1 files changed, 32 insertions, 38 deletions
diff --git a/libstdc++-v3/doc/html/manual/memory.html b/libstdc++-v3/doc/html/manual/memory.html index 8a1129bc6af..24f7381b7bb 100644 --- a/libstdc++-v3/doc/html/manual/memory.html +++ b/libstdc++-v3/doc/html/manual/memory.html @@ -93,7 +93,7 @@ or loading and unloading shared objects in memory. As such, using caching allocators on systems that do not support <code class="function">abi::__cxa_atexit</code> is not recommended. - </p></div><div class="section" title="Implementation"><div class="titlepage"><div><div><h4 class="title"><a id="allocator.impl"/>Implementation</h4></div></div></div><div class="section" title="Interface Design"><div class="titlepage"><div><div><h5 class="title"><a id="id633362"/>Interface Design</h5></div></div></div><p> + </p></div><div class="section" title="Implementation"><div class="titlepage"><div><div><h4 class="title"><a id="allocator.impl"/>Implementation</h4></div></div></div><div class="section" title="Interface Design"><div class="titlepage"><div><div><h5 class="title"><a id="id542426"/>Interface Design</h5></div></div></div><p> The only allocator interface that is supported is the standard C++ interface. As such, all STL containers have been adjusted, and all external allocators have @@ -106,7 +106,7 @@ </p><p> The base class that <code class="classname">allocator</code> is derived from may not be user-configurable. -</p></div><div class="section" title="Selecting Default Allocation Policy"><div class="titlepage"><div><div><h5 class="title"><a id="id633392"/>Selecting Default Allocation Policy</h5></div></div></div><p> +</p></div><div class="section" title="Selecting Default Allocation Policy"><div class="titlepage"><div><div><h5 class="title"><a id="id542456"/>Selecting Default Allocation Policy</h5></div></div></div><p> It's difficult to pick an allocation strategy that will provide maximum utility, without excessively penalizing some behavior. In fact, it's difficult just deciding which typical actions to measure @@ -143,7 +143,7 @@ The current default choice for <code class="classname">allocator</code> is <code class="classname">__gnu_cxx::new_allocator</code>. - </p></div><div class="section" title="Disabling Memory Caching"><div class="titlepage"><div><div><h5 class="title"><a id="id633502"/>Disabling Memory Caching</h5></div></div></div><p> + </p></div><div class="section" title="Disabling Memory Caching"><div class="titlepage"><div><div><h5 class="title"><a id="id542566"/>Disabling Memory Caching</h5></div></div></div><p> In use, <code class="classname">allocator</code> may allocate and deallocate using implementation-specified strategies and heuristics. Because of this, every call to an allocator object's @@ -308,33 +308,33 @@ A high-performance allocator that uses a bit-map to keep track of the used and unused memory locations. It has its own documentation, found <a class="link" href="bitmap_allocator.html" title="Chapter 21. The bitmap_allocator">here</a>. - </p></li></ol></div></div><div class="bibliography" title="Bibliography"><div class="titlepage"><div><div><h4 class="title"><a id="allocator.biblio"/>Bibliography</h4></div></div></div><div class="biblioentry"><a id="id633953"/><p><span class="citetitle"><em class="citetitle"> + </p></li></ol></div></div><div class="bibliography" title="Bibliography"><div class="titlepage"><div><div><h4 class="title"><a id="allocator.biblio"/>Bibliography</h4></div></div></div><div class="biblioentry"><a id="id543017"/><p><span class="citetitle"><em class="citetitle"> ISO/IEC 14882:1998 Programming languages - C++ </em>. </span> isoc++_1998 - <span class="pagenums">20.4 Memory. </span></p></div><div class="biblioentry" title="The Standard Librarian: What Are Allocators Good For?"><a id="id633968"/><p><span class="title"><em> + <span class="pagenums">20.4 Memory. </span></p></div><div class="biblioentry" title="The Standard Librarian: What Are Allocators Good For?"><a id="id543032"/><p><span class="title"><em> <a class="link" href="http://www.drdobbs.com/cpp/184403759"> The Standard Librarian: What Are Allocators Good For? </a> </em>. </span><span class="author"><span class="firstname">Matt</span> <span class="surname">Austern</span>. </span><span class="publisher"><span class="publishername"> C/C++ Users Journal - . </span></span></p></div><div class="biblioentry" title="The Hoard Memory Allocator"><a id="id633999"/><p><span class="title"><em> + . </span></span></p></div><div class="biblioentry" title="The Hoard Memory Allocator"><a id="id543063"/><p><span class="title"><em> <a class="link" href="http://www.cs.umass.edu/~emery/hoard"> The Hoard Memory Allocator </a> - </em>. </span><span class="author"><span class="firstname">Emery</span> <span class="surname">Berger</span>. </span></p></div><div class="biblioentry" title="Reconsidering Custom Memory Allocation"><a id="id634022"/><p><span class="title"><em> + </em>. </span><span class="author"><span class="firstname">Emery</span> <span class="surname">Berger</span>. </span></p></div><div class="biblioentry" title="Reconsidering Custom Memory Allocation"><a id="id543087"/><p><span class="title"><em> <a class="link" href="http://www.cs.umass.edu/~emery/pubs/berger-oopsla2002.pdf"> Reconsidering Custom Memory Allocation </a> - </em>. </span><span class="author"><span class="firstname">Emery</span> <span class="surname">Berger</span>. </span><span class="author"><span class="firstname">Ben</span> <span class="surname">Zorn</span>. </span><span class="author"><span class="firstname">Kathryn</span> <span class="surname">McKinley</span>. </span><span class="copyright">Copyright © 2002 OOPSLA. </span></p></div><div class="biblioentry" title="Allocator Types"><a id="id634074"/><p><span class="title"><em> + </em>. </span><span class="author"><span class="firstname">Emery</span> <span class="surname">Berger</span>. </span><span class="author"><span class="firstname">Ben</span> <span class="surname">Zorn</span>. </span><span class="author"><span class="firstname">Kathryn</span> <span class="surname">McKinley</span>. </span><span class="copyright">Copyright © 2002 OOPSLA. </span></p></div><div class="biblioentry" title="Allocator Types"><a id="id543138"/><p><span class="title"><em> <a class="link" href="http://www.angelikalanger.com/Articles/C++Report/Allocators/Allocators.html"> Allocator Types </a> </em>. </span><span class="author"><span class="firstname">Klaus</span> <span class="surname">Kreft</span>. </span><span class="author"><span class="firstname">Angelika</span> <span class="surname">Langer</span>. </span><span class="publisher"><span class="publishername"> C/C++ Users Journal - . </span></span></p></div><div class="biblioentry"><a id="id634113"/><p><span class="citetitle"><em class="citetitle">The C++ Programming Language</em>. </span><span class="author"><span class="firstname">Bjarne</span> <span class="surname">Stroustrup</span>. </span><span class="copyright">Copyright © 2000 . </span><span class="pagenums">19.4 Allocators. </span><span class="publisher"><span class="publishername"> + . </span></span></p></div><div class="biblioentry"><a id="id543177"/><p><span class="citetitle"><em class="citetitle">The C++ Programming Language</em>. </span><span class="author"><span class="firstname">Bjarne</span> <span class="surname">Stroustrup</span>. </span><span class="copyright">Copyright © 2000 . </span><span class="pagenums">19.4 Allocators. </span><span class="publisher"><span class="publishername"> Addison Wesley - . </span></span></p></div><div class="biblioentry"><a id="id634150"/><p><span class="citetitle"><em class="citetitle">Yalloc: A Recycling C++ Allocator</em>. </span><span class="author"><span class="firstname">Felix</span> <span class="surname">Yen</span>. </span></p></div></div></div><div class="section" title="auto_ptr"><div class="titlepage"><div><div><h3 class="title"><a id="std.util.memory.auto_ptr"/>auto_ptr</h3></div></div></div><div class="section" title="Limitations"><div class="titlepage"><div><div><h4 class="title"><a id="auto_ptr.limitations"/>Limitations</h4></div></div></div><p>Explaining all of the fun and delicious things that can + . </span></span></p></div><div class="biblioentry"><a id="id543214"/><p><span class="citetitle"><em class="citetitle">Yalloc: A Recycling C++ Allocator</em>. </span><span class="author"><span class="firstname">Felix</span> <span class="surname">Yen</span>. </span></p></div></div></div><div class="section" title="auto_ptr"><div class="titlepage"><div><div><h3 class="title"><a id="std.util.memory.auto_ptr"/>auto_ptr</h3></div></div></div><div class="section" title="Limitations"><div class="titlepage"><div><div><h4 class="title"><a id="auto_ptr.limitations"/>Limitations</h4></div></div></div><p>Explaining all of the fun and delicious things that can happen with misuse of the <code class="classname">auto_ptr</code> class template (called <acronym class="acronym">AP</acronym> here) would take some time. Suffice it to say that the use of <acronym class="acronym">AP</acronym> @@ -430,12 +430,6 @@ and implements shared ownership semantics. implementation, allowing other techniques such as a circular-linked-list. </p><p> - At the time of writing the C++0x working paper doesn't mention how - threads affect shared_ptr, but it is likely to follow the existing - practice set by <code class="classname">boost::shared_ptr</code>. The - shared_ptr in libstdc++ is derived from Boost's, so the same rules - apply. - </p><p> </p></div><div class="section" title="Design Issues"><div class="titlepage"><div><div><h4 class="title"><a id="shared_ptr.design_issues"/>Design Issues</h4></div></div></div><p> The <code class="classname">shared_ptr</code> code is kindly donated to GCC by the Boost project and the original authors of the code. The basic design and @@ -450,7 +444,7 @@ drops to zero. Derived classes override those functions to destroy resources in a context where the correct dynamic type is known. This is an application of the technique known as type erasure. - </p></div><div class="section" title="Implementation"><div class="titlepage"><div><div><h4 class="title"><a id="shared_ptr.impl"/>Implementation</h4></div></div></div><div class="section" title="Class Hierarchy"><div class="titlepage"><div><div><h5 class="title"><a id="id634511"/>Class Hierarchy</h5></div></div></div><p> + </p></div><div class="section" title="Implementation"><div class="titlepage"><div><div><h4 class="title"><a id="shared_ptr.impl"/>Implementation</h4></div></div></div><div class="section" title="Class Hierarchy"><div class="titlepage"><div><div><h5 class="title"><a id="id543565"/>Class Hierarchy</h5></div></div></div><p> A <code class="classname">shared_ptr<T></code> contains a pointer of type <span class="type">T*</span> and an object of type <code class="classname">__shared_count</code>. The shared_count contains a @@ -492,11 +486,11 @@ be forwarded to <span class="type">Tp</span>'s constructor. Unlike the other <code class="classname">_Sp_counted_*</code> classes, this one is parameterized on the type of object, not the type of pointer; this is purely a convenience that simplifies the implementation slightly. - </p></dd></dl></div></div><div class="section" title="Thread Safety"><div class="titlepage"><div><div><h5 class="title"><a id="id634689"/>Thread Safety</h5></div></div></div><p> -C++0x-only features are: rvalue-ref/move support, allocator support, + </p></dd></dl></div></div><div class="section" title="Thread Safety"><div class="titlepage"><div><div><h5 class="title"><a id="id543744"/>Thread Safety</h5></div></div></div><p> +C++11-only features are: rvalue-ref/move support, allocator support, aliasing constructor, make_shared & allocate_shared. Additionally, the constructors taking <code class="classname">auto_ptr</code> parameters are -deprecated in C++0x mode. +deprecated in C++11 mode. </p><p> The <a class="link" href="http://boost.org/libs/smart_ptr/shared_ptr.htm#ThreadSafety">Thread @@ -542,7 +536,7 @@ compiler, standard library, platform etc. For the version of shared_ptr in libstdc++ the compiler and library are fixed, which makes things much simpler: we have an atomic CAS or we don't, see Lock Policy below for details. -</p></div><div class="section" title="Selecting Lock Policy"><div class="titlepage"><div><div><h5 class="title"><a id="id634759"/>Selecting Lock Policy</h5></div></div></div><p> +</p></div><div class="section" title="Selecting Lock Policy"><div class="titlepage"><div><div><h5 class="title"><a id="id543814"/>Selecting Lock Policy</h5></div></div></div><p> </p><p> There is a single <code class="classname">_Sp_counted_base</code> class, which is a template parameterized on the enum @@ -583,30 +577,30 @@ used when libstdc++ is built without <code class="literal">--enable-threads</cod <code class="filename">ext/atomicity.h</code>, which detect if the program is multi-threaded. If only one thread of execution exists in the program then less expensive non-atomic operations are used. - </p></div><div class="section" title="Dual C++0x and TR1 Implementation"><div class="titlepage"><div><div><h5 class="title"><a id="id634881"/>Dual C++0x and TR1 Implementation</h5></div></div></div><p> -The interface of <code class="classname">tr1::shared_ptr</code> was extended for C++0x + </p></div><div class="section" title="Dual C++11 and TR1 Implementation"><div class="titlepage"><div><div><h5 class="title"><a id="id543936"/>Dual C++11 and TR1 Implementation</h5></div></div></div><p> +The interface of <code class="classname">tr1::shared_ptr</code> was extended for C++11 with support for rvalue-references and the other features from N2351. The <code class="classname">_Sp_counted_base</code> base class is implemented in <code class="filename">tr1/boost_sp_shared_count.h</code> and is common to the TR1 -and C++0x versions of <code class="classname">shared_ptr</code>. +and C++11 versions of <code class="classname">shared_ptr</code>. </p><p> The classes derived from <code class="classname">_Sp_counted_base</code> (see Class Hierarchy -above) and <code class="classname">__shared_count</code> are implemented separately for C++0x +above) and <code class="classname">__shared_count</code> are implemented separately for C++11 and TR1, in <code class="filename">bits/shared_ptr.h</code> and <code class="filename">tr1/shared_ptr.h</code> respectively. </p><p> The TR1 implementation is considered relatively stable, so is unlikely to change unless bug fixes require it. If the code that is common to both -C++0x and TR1 modes needs to diverge further then it might be necessary to +C++11 and TR1 versions needs to diverge further then it might be necessary to duplicate <code class="classname">_Sp_counted_base</code> and only make changes to -the C++0x version. -</p></div><div class="section" title="Related functions and classes"><div class="titlepage"><div><div><h5 class="title"><a id="id634937"/>Related functions and classes</h5></div></div></div><div class="variablelist"><dl><dt><span class="term"><code class="code">dynamic_pointer_cast</code>, <code class="code">static_pointer_cast</code>, +the C++11 version. +</p></div><div class="section" title="Related functions and classes"><div class="titlepage"><div><div><h5 class="title"><a id="id543992"/>Related functions and classes</h5></div></div></div><div class="variablelist"><dl><dt><span class="term"><code class="code">dynamic_pointer_cast</code>, <code class="code">static_pointer_cast</code>, <code class="code">const_pointer_cast</code></span></dt><dd><p> As noted in N2351, these functions can be implemented non-intrusively using the alias constructor. However the aliasing constructor is only available -in C++0x mode, so in TR1 mode these casts rely on three non-standard +in C++11 mode, so in TR1 mode these casts rely on three non-standard constructors in shared_ptr and __shared_ptr. -In C++0x mode these constructors and the related tag types are not needed. +In C++11 mode these constructors and the related tag types are not needed. </p></dd><dt><span class="term"><code class="code">enable_shared_from_this</code></span></dt><dd><p> The clever overload to detect a base class of type <code class="code">enable_shared_from_this</code> comes straight from Boost. @@ -633,15 +627,15 @@ is called. Users should not try to use this. As well as the extra constructors, this implementation also needs some members of _Sp_counted_deleter to be protected where they could otherwise be private. - </p></dd></dl></div></div></div><div class="section" title="Use"><div class="titlepage"><div><div><h4 class="title"><a id="shared_ptr.using"/>Use</h4></div></div></div><div class="section" title="Examples"><div class="titlepage"><div><div><h5 class="title"><a id="id635086"/>Examples</h5></div></div></div><p> + </p></dd></dl></div></div></div><div class="section" title="Use"><div class="titlepage"><div><div><h4 class="title"><a id="shared_ptr.using"/>Use</h4></div></div></div><div class="section" title="Examples"><div class="titlepage"><div><div><h5 class="title"><a id="id556361"/>Examples</h5></div></div></div><p> Examples of use can be found in the testsuite, under <code class="filename">testsuite/tr1/2_general_utilities/shared_ptr</code>, <code class="filename">testsuite/20_util/shared_ptr</code> and <code class="filename">testsuite/20_util/weak_ptr</code>. - </p></div><div class="section" title="Unresolved Issues"><div class="titlepage"><div><div><h5 class="title"><a id="id635116"/>Unresolved Issues</h5></div></div></div><p> + </p></div><div class="section" title="Unresolved Issues"><div class="titlepage"><div><div><h5 class="title"><a id="id556391"/>Unresolved Issues</h5></div></div></div><p> The <span class="emphasis"><em><code class="classname">shared_ptr</code> atomic access</em></span> - clause in the C++0x working draft is not implemented in GCC. + clause in the C++11 standard is not implemented in GCC. </p><p> The <span class="type">_S_single</span> policy uses atomics when used in MT code, because it uses the same dispatcher functions that check @@ -651,7 +645,7 @@ be private. </p><p> Unlike Boost, this implementation does not use separate classes for the pointer+deleter and pointer+deleter+allocator cases in - C++0x mode, combining both into _Sp_counted_deleter and using + C++11 mode, combining both into _Sp_counted_deleter and using <code class="classname">allocator</code> when the user doesn't specify an allocator. If it was found to be beneficial an additional class could easily be added. With the current implementation, @@ -680,25 +674,25 @@ be private. code to work with, Peter Dimov in particular for his help and invaluable advice on thread safety. Phillip Jordan and Paolo Carlini for the lock policy implementation. - </p></div><div class="bibliography" title="Bibliography"><div class="titlepage"><div><div><h4 class="title"><a id="shared_ptr.biblio"/>Bibliography</h4></div></div></div><div class="biblioentry" title="Improving shared_ptr for C++0x, Revision 2"><a id="id635209"/><p><span class="title"><em> + </p></div><div class="bibliography" title="Bibliography"><div class="titlepage"><div><div><h4 class="title"><a id="shared_ptr.biblio"/>Bibliography</h4></div></div></div><div class="biblioentry" title="Improving shared_ptr for C++0x, Revision 2"><a id="id556484"/><p><span class="title"><em> <a class="link" href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2351.htm"> Improving shared_ptr for C++0x, Revision 2 </a> </em>. </span><span class="subtitle"> N2351 - . </span></p></div><div class="biblioentry" title="C++ Standard Library Active Issues List"><a id="id635228"/><p><span class="title"><em> + . </span></p></div><div class="biblioentry" title="C++ Standard Library Active Issues List"><a id="id556504"/><p><span class="title"><em> <a class="link" href="http://open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2456.html"> C++ Standard Library Active Issues List </a> </em>. </span><span class="subtitle"> N2456 - . </span></p></div><div class="biblioentry" title="Working Draft, Standard for Programming Language C++"><a id="id635248"/><p><span class="title"><em> + . </span></p></div><div class="biblioentry" title="Working Draft, Standard for Programming Language C++"><a id="id556523"/><p><span class="title"><em> <a class="link" href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2461.pdf"> Working Draft, Standard for Programming Language C++ </a> </em>. </span><span class="subtitle"> N2461 - . </span></p></div><div class="biblioentry" title="Boost C++ Libraries documentation, shared_ptr"><a id="id635267"/><p><span class="title"><em> + . </span></p></div><div class="biblioentry" title="Boost C++ Libraries documentation, shared_ptr"><a id="id556542"/><p><span class="title"><em> <a class="link" href="http://boost.org/libs/smart_ptr/shared_ptr.htm"> Boost C++ Libraries documentation, shared_ptr </a> |