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The Profile Mode extension is not used by anybody, nor maintained by anybody. The containers do not support the full API specified in recent standards, and so enabling Profile Mode is not source compatible with much modern C++ code. The heuristics that would check the profile information and make useful suggestions never materialized, so it isn't useful. It should be removed. Remove Profile Mode, deprecated since 7.1.0 * doc/Makefile.am: Remove XML file for profile mode docs. * doc/Makefile.in: Regenerate. * doc/xml/authors.xml: Remove authors of profile mode docs. * doc/xml/manual/appendix_contributing.xml: Remove mention of profile mode. * doc/xml/manual/debug.xml: Likewise. * doc/xml/manual/evolution.xml: Document removal of profile mode. * doc/xml/manual/profile_mode.xml: Remove profile mode docs. * doc/xml/manual/spine.xml: Remove profile mode author credit. * doc/xml/manual/test.xml: Remove docs for dg-require-profile-mode directive. * doc/xml/manual/using.xml: Remove docs for profile mode headers and macro. * doc/html/*: Regenerate. * include/Makefile.am: Remove profile mode headers. * include/Makefile.in: Regenerate. * include/bits/c++config (std::__profile): Remove namespace. [_GLIBCXX_PROFILE]: Remove checks for macro. * include/profile/array: Remove. * include/profile/base.h: Remove. * include/profile/bitset: Remove. * include/profile/deque: Remove. * include/profile/forward_list: Remove. * include/profile/impl/profiler.h: Remove. * include/profile/impl/profiler_algos.h: Remove. * include/profile/impl/profiler_container_size.h: Remove. * include/profile/impl/profiler_hash_func.h: Remove. * include/profile/impl/profiler_hashtable_size.h: Remove. * include/profile/impl/profiler_list_to_slist.h: Remove. * include/profile/impl/profiler_list_to_vector.h: Remove. * include/profile/impl/profiler_map_to_unordered_map.h: Remove. * include/profile/impl/profiler_node.h: Remove. * include/profile/impl/profiler_state.h: Remove. * include/profile/impl/profiler_trace.h: Remove. * include/profile/impl/profiler_vector_size.h: Remove. * include/profile/impl/profiler_vector_to_list.h: Remove. * include/profile/iterator_tracker.h: Remove. * include/profile/list: Remove. * include/profile/map: Remove. * include/profile/map.h: Remove. * include/profile/multimap.h: Remove. * include/profile/multiset.h: Remove. * include/profile/ordered_base.h: Remove. * include/profile/set: Remove. * include/profile/set.h: Remove. * include/profile/unordered_base.h: Remove. * include/profile/unordered_map: Remove. * include/profile/unordered_set: Remove. * include/profile/vector: Remove. * scripts/run_doxygen: Do not process profile mode headers. * testsuite/23_containers/array/element_access/60497.cc: Don't use profile mode type. * testsuite/23_containers/array/specialized_algorithms/swap_cxx17.cc: Remove dg-skip-if for profile mode. * testsuite/23_containers/forward_list/capacity/1.cc: Remove preprocessor check for profile mode. * testsuite/23_containers/list/capacity/29134.cc: Likewise. * testsuite/23_containers/map/modifiers/extract.cc: Remove dg-skip-if for profile mode. * testsuite/23_containers/map/modifiers/insert_or_assign/1.cc: Likewise. * testsuite/23_containers/map/modifiers/try_emplace/1.cc: Likewise. * testsuite/23_containers/multimap/modifiers/extract.cc: Likewise. * testsuite/23_containers/multiset/modifiers/extract.cc: Likewise. * testsuite/23_containers/set/modifiers/extract.cc: Likewise. * testsuite/23_containers/unordered_map/modifiers/extract.cc: Likewise. * testsuite/23_containers/unordered_multimap/modifiers/extract.cc: Likewise. * testsuite/23_containers/unordered_multiset/modifiers/extract.cc: Likewise. * testsuite/23_containers/unordered_set/modifiers/extract.cc: Likewise. * testsuite/23_containers/vector/bool/capacity/29134.cc: Remove preprocessor check for profile mode. * testsuite/23_containers/vector/bool/modifiers/insert/31370.cc: Likewise. * testsuite/23_containers/vector/modifiers/insert_vs_emplace.cc: Remove dg-skip-if for profile mode. * testsuite/25_algorithms/binary_search/partitioned.cc: Likewise. * testsuite/25_algorithms/equal_range/partitioned.cc: Likewise. * testsuite/25_algorithms/lexicographical_compare/71545.cc: Likewise. * testsuite/25_algorithms/lower_bound/partitioned.cc: Likewise. * testsuite/25_algorithms/upper_bound/partitioned.cc: Likewise. * testsuite/Makefile.am: Remove profile_flags variable and * testsuite/Makefile.am: Remove profile_flags variable and check-profile target. * testsuite/Makefile.in: Regenerate. * testsuite/ext/profile/all.cc: Remove. * testsuite/ext/profile/mutex_extensions_neg.cc: Remove. * testsuite/ext/profile/profiler_algos.cc: Remove. * testsuite/ext/profile/replace_new.cc: Remove. * testsuite/ext/throw_allocator/deallocate_global.cc: Remove preprocessor check for profile mode. * testsuite/ext/throw_allocator/deallocate_local.cc: Likewise. * testsuite/lib/libstdc++.exp (check_v3_target_profile_mode): Remove. (check_v3_target_normal_mode): Do not check for profile mode macro. * testsuite/libstdc++-prettyprinters/80276.cc: Remove dg-skip-if for profile mode. * testsuite/libstdc++-prettyprinters/compat.cc: Likewise. * testsuite/libstdc++-prettyprinters/cxx11.cc: Likewise. * testsuite/libstdc++-prettyprinters/cxx17.cc: Likewise. * testsuite/libstdc++-prettyprinters/debug.cc: Likewise. * testsuite/libstdc++-prettyprinters/debug_cxx11.cc: Likewise. * testsuite/libstdc++-prettyprinters/libfundts.cc: Likewise. * testsuite/libstdc++-prettyprinters/simple.cc: Likewise. * testsuite/libstdc++-prettyprinters/simple11.cc: Likewise. * testsuite/libstdc++-prettyprinters/whatis.cc: Likewise. * testsuite/libstdc++-prettyprinters/whatis2.cc: Likewise. From-SVN: r271120
56 lines
4.9 KiB
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56 lines
4.9 KiB
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<?xml version="1.0" encoding="UTF-8" standalone="no"?>
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<!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>Interacting with C</title><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><meta name="keywords" content="ISO C++, library" /><meta name="keywords" content="ISO C++, runtime, library" /><link rel="home" href="../index.html" title="The GNU C++ Library" /><link rel="up" href="io.html" title="Chapter 13. Input and Output" /><link rel="prev" href="fstreams.html" title="File Based Streams" /><link rel="next" href="atomics.html" title="Chapter 14. Atomics" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Interacting with C</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="fstreams.html">Prev</a> </td><th width="60%" align="center">Chapter 13.
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Input and Output
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</th><td width="20%" align="right"> <a accesskey="n" href="atomics.html">Next</a></td></tr></table><hr /></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="std.io.c"></a>Interacting with C</h2></div></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="std.io.c.FILE"></a>Using FILE* and file descriptors</h3></div></div></div><p>
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See the <a class="link" href="ext_io.html" title="Chapter 27. Input and Output">extensions</a> for using
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<span class="type">FILE</span> and <span class="type">file descriptors</span> with
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<code class="classname">ofstream</code> and
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<code class="classname">ifstream</code>.
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</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="std.io.c.sync"></a>Performance</h3></div></div></div><p>
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Pathetic Performance? Ditch C.
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</p><p>It sounds like a flame on C, but it isn't. Really. Calm down.
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I'm just saying it to get your attention.
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</p><p>Because the C++ library includes the C library, both C-style and
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C++-style I/O have to work at the same time. For example:
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</p><pre class="programlisting">
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#include <iostream>
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#include <cstdio>
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std::cout << "Hel";
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std::printf ("lo, worl");
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std::cout << "d!\n";
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</pre><p>This must do what you think it does.
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</p><p>Alert members of the audience will immediately notice that buffering
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is going to make a hash of the output unless special steps are taken.
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</p><p>The special steps taken by libstdc++, at least for version 3.0,
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involve doing very little buffering for the standard streams, leaving
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most of the buffering to the underlying C library. (This kind of
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thing is tricky to get right.)
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The upside is that correctness is ensured. The downside is that
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writing through <code class="code">cout</code> can quite easily lead to awful
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performance when the C++ I/O library is layered on top of the C I/O
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library (as it is for 3.0 by default). Some patches have been applied
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which improve the situation for 3.1.
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</p><p>However, the C and C++ standard streams only need to be kept in sync
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when both libraries' facilities are in use. If your program only uses
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C++ I/O, then there's no need to sync with the C streams. The right
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thing to do in this case is to call
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</p><pre class="programlisting">
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#include <span class="emphasis"><em>any of the I/O headers such as ios, iostream, etc</em></span>
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std::ios::sync_with_stdio(false);
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</pre><p>You must do this before performing any I/O via the C++ stream objects.
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Once you call this, the C++ streams will operate independently of the
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(unused) C streams. For GCC 3.x, this means that <code class="code">cout</code> and
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company will become fully buffered on their own.
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</p><p>Note, by the way, that the synchronization requirement only applies to
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the standard streams (<code class="code">cin</code>, <code class="code">cout</code>,
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<code class="code">cerr</code>,
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<code class="code">clog</code>, and their wide-character counterparts). File stream
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objects that you declare yourself have no such requirement and are fully
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buffered.
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</p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="fstreams.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="io.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="atomics.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">File Based Streams </td><td width="20%" align="center"><a accesskey="h" href="../index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 14.
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Atomics
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</td></tr></table></div></body></html> |