481668695a
2003-07-06 Phil Edwards <pme@gcc.gnu.org> * include/bits/allocator_traits.h: Fix doxygen markup. * include/ext/mt_allocator.h: Likewise. From-SVN: r68994
865 lines
26 KiB
C++
865 lines
26 KiB
C++
// MT-optimized allocator -*- C++ -*-
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// Copyright (C) 2003 Free Software Foundation, Inc.
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 2, or (at your option)
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License along
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// with this library; see the file COPYING. If not, write to the Free
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// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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// USA.
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// As a special exception, you may use this file as part of a free software
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// library without restriction. Specifically, if other files instantiate
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// templates or use macros or inline functions from this file, or you compile
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// this file and link it with other files to produce an executable, this
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// file does not by itself cause the resulting executable to be covered by
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// the GNU General Public License. This exception does not however
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// invalidate any other reasons why the executable file might be covered by
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// the GNU General Public License.
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/** @file ext/mt_allocator.h
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* This file is a GNU extension to the Standard C++ Library.
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* You should only include this header if you are using GCC 3 or later.
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*/
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#ifndef _MT_ALLOCATOR_H
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#define _MT_ALLOCATOR_H 1
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#include <cstdlib>
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#include <bits/functexcept.h>
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#include <bits/stl_threads.h>
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#include <bits/atomicity.h>
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#include <bits/allocator_traits.h>
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namespace __gnu_cxx
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{
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/**
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* This is a fixed size (power of 2) allocator which - when compiled
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* with thread support - will maintain one freelist per size per thread
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* plus a "global" one. Steps are taken to limit the per thread freelist
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* sizes (by returning excess back to "global").
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*
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* Usage examples:
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* @code
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* vector<int, __gnu_cxx::__mt_alloc<0> > v1;
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*
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* typedef std::__allocator<char, __gnu_cxx::__mt_alloc<0> > string_alloc;
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* std::basic_string<char, std::char_traits<char>, string_alloc> s1;
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* @endcode
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*/
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template<int __inst>
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class __mt_alloc
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{
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private:
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/*
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* We need to create the initial lists and set up some variables
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* before we can answer to the first request for memory.
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* The initialization of these variables is done at file scope
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* below class declaration.
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*/
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#ifdef __GTHREADS
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static __gthread_once_t _S_once_mt;
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#endif
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static bool _S_initialized;
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/*
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* Using short int as type for the binmap implies we are never caching
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* blocks larger than 65535 with this allocator
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*/
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typedef unsigned short int binmap_type;
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static binmap_type* _S_binmap;
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static void _S_init();
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/*
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* Variables used to "tune" the behavior of the allocator, assigned
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* and explained in detail below.
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*/
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static size_t _S_max_bytes;
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static size_t _S_chunk_size;
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static size_t _S_max_threads;
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static size_t _S_no_of_bins;
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static size_t _S_freelist_headroom;
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/*
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* Each requesting thread is assigned an id ranging from 1 to
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* _S_max_threads. Thread id 0 is used as a global memory pool.
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* In order to get constant performance on the thread assignment
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* routine, we keep a list of free ids. When a thread first requests
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* memory we remove the first record in this list and stores the address
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* in a __gthread_key. When initializing the __gthread_key
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* we specify a destructor. When this destructor (i.e. the thread dies)
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* is called, we return the thread id to the back of this list.
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*/
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#ifdef __GTHREADS
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struct thread_record
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{
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/*
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* Points to next free thread id record. NULL if last record in list.
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*/
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thread_record* next;
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/*
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* Thread id ranging from 1 to _S_max_threads.
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*/
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size_t id;
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};
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static thread_record* _S_thread_freelist_first;
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static thread_record* _S_thread_freelist_last;
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static __gthread_mutex_t _S_thread_freelist_mutex;
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static void _S_thread_key_destr(void* freelist_pos);
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static __gthread_key_t _S_thread_key;
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static size_t _S_get_thread_id();
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#endif
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struct block_record
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{
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/*
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* Points to the next block_record for its thread_id.
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*/
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block_record* next;
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/*
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* The thread id of the thread which has requested this block.
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* All blocks are initially "owned" by global pool thread id 0.
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*/
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size_t thread_id;
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};
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struct bin_record
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{
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/*
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* An "array" of pointers to the first/last free block for each
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* thread id. Memory to these "arrays" is allocated in _S_init()
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* for _S_max_threads + global pool 0.
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*/
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block_record** first;
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block_record** last;
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/*
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* An "array" of counters used to keep track of the amount of blocks
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* that are on the freelist/used for each thread id.
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* Memory to these "arrays" is allocated in _S_init()
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* for _S_max_threads + global pool 0.
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*/
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size_t* free;
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size_t* used;
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/*
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* Each bin has its own mutex which is used to ensure data integrity
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* while changing "ownership" on a block.
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* The mutex is initialized in _S_init().
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*/
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#ifdef __GTHREADS
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__gthread_mutex_t* mutex;
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#endif
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};
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/*
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* An "array" of bin_records each of which represents a specific
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* power of 2 size. Memory to this "array" is allocated in _S_init().
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*/
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static bin_record* _S_bin;
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public:
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static void*
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allocate(size_t __n)
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{
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/*
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* Requests larger than _S_max_bytes are handled by
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* malloc/free directly
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*/
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if (__n > _S_max_bytes)
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{
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void* __ret = malloc(__n);
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if (!__ret)
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__throw_bad_alloc();
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return __ret;
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}
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/*
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* Although the test in __gthread_once() would suffice, we
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* wrap test of the once condition in our own unlocked
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* check. This saves one function call to pthread_once()
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* (which itself only tests for the once value unlocked anyway
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* and immediately returns if set)
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*/
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if (!_S_initialized)
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{
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#ifdef __GTHREADS
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if (__gthread_active_p())
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__gthread_once(&_S_once_mt, _S_init);
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else
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#endif
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{
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_S_max_threads = 0;
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_S_init();
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}
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}
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/*
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* Round up to power of 2 and figure out which bin to use
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*/
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size_t bin = _S_binmap[__n];
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#ifdef __GTHREADS
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size_t thread_id = _S_get_thread_id();
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#else
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size_t thread_id = 0;
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#endif
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block_record* block;
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/*
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* Find out if we have blocks on our freelist.
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* If so, go ahead and use them directly without
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* having to lock anything.
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*/
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if (_S_bin[bin].first[thread_id] == NULL)
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{
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/*
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* Are we using threads?
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* - Yes, lock and check if there are free blocks on the global
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* list (and if not add new ones), get the first one
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* and change owner.
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* - No, all operations are made directly to global pool 0
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* no need to lock or change ownership but check for free
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* blocks on global list (and if not add new ones) and
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* get the first one.
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*/
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#ifdef __GTHREADS
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if (__gthread_active_p())
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{
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__gthread_mutex_lock(_S_bin[bin].mutex);
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if (_S_bin[bin].first[0] == NULL)
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{
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_S_bin[bin].first[0] =
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(block_record*)malloc(_S_chunk_size);
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if (!_S_bin[bin].first[0])
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{
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__gthread_mutex_unlock(_S_bin[bin].mutex);
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__throw_bad_alloc();
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}
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size_t bin_t = 1 << bin;
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size_t block_count =
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_S_chunk_size /(bin_t + sizeof(block_record));
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_S_bin[bin].free[0] = block_count;
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block_count--;
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block = _S_bin[bin].first[0];
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while (block_count > 0)
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{
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block->next = (block_record*)((char*)block +
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(bin_t + sizeof(block_record)));
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block = block->next;
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block_count--;
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}
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block->next = NULL;
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_S_bin[bin].last[0] = block;
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}
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block = _S_bin[bin].first[0];
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/*
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* Remove from list and count down the available counter on
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* global pool 0.
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*/
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_S_bin[bin].first[0] = _S_bin[bin].first[0]->next;
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_S_bin[bin].free[0]--;
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__gthread_mutex_unlock(_S_bin[bin].mutex);
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/*
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* Now that we have removed the block from the global
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* freelist we can change owner and update the used
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* counter for this thread without locking.
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*/
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block->thread_id = thread_id;
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_S_bin[bin].used[thread_id]++;
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}
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else
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#endif
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{
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_S_bin[bin].first[0] = (block_record*)malloc(_S_chunk_size);
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if (!_S_bin[bin].first[0])
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__throw_bad_alloc();
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size_t bin_t = 1 << bin;
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size_t block_count =
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_S_chunk_size / (bin_t + sizeof(block_record));
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_S_bin[bin].free[0] = block_count;
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block_count--;
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block = _S_bin[bin].first[0];
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while (block_count > 0)
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{
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block->next = (block_record*)((char*)block +
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(bin_t + sizeof(block_record)));
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block = block->next;
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block_count--;
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}
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block->next = NULL;
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_S_bin[bin].last[0] = block;
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block = _S_bin[bin].first[0];
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/*
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* Remove from list and count down the available counter on
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* global pool 0 and increase it's used counter.
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*/
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_S_bin[bin].first[0] = _S_bin[bin].first[0]->next;
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_S_bin[bin].free[0]--;
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_S_bin[bin].used[0]++;
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}
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}
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else
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{
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/*
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* "Default" operation - we have blocks on our own freelist
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* grab the first record and update the counters.
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*/
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block = _S_bin[bin].first[thread_id];
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_S_bin[bin].first[thread_id] = _S_bin[bin].first[thread_id]->next;
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_S_bin[bin].free[thread_id]--;
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_S_bin[bin].used[thread_id]++;
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}
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return (void*)((char*)block + sizeof(block_record));
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}
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static void
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deallocate(void* __p, size_t __n)
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{
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/*
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* Requests larger than _S_max_bytes are handled by
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* malloc/free directly
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*/
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if (__n > _S_max_bytes)
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{
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free(__p);
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return;
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}
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/*
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* Round up to power of 2 and figure out which bin to use
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*/
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size_t bin = _S_binmap[__n];
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#ifdef __GTHREADS
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size_t thread_id = _S_get_thread_id();
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#else
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size_t thread_id = 0;
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#endif
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block_record* block = (block_record*)((char*)__p
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- sizeof(block_record));
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/*
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* This block will always be at the back of a list and thus
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* we set its next pointer to NULL.
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*/
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block->next = NULL;
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#ifdef __GTHREADS
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if (__gthread_active_p())
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{
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/*
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* Calculate the number of records to remove from our freelist
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*/
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int remove = _S_bin[bin].free[thread_id] -
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(_S_bin[bin].used[thread_id] / _S_freelist_headroom);
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/*
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* The calculation above will almost always tell us to
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* remove one or two records at a time, but this creates
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* too much contention when locking and therefore we
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* wait until the number of records is "high enough".
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*/
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if (remove > (int)(100 * (_S_no_of_bins - bin)) &&
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remove > (int)(_S_bin[bin].free[thread_id] /
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_S_freelist_headroom))
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{
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__gthread_mutex_lock(_S_bin[bin].mutex);
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while (remove > 0)
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{
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if (_S_bin[bin].first[0] == NULL)
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_S_bin[bin].first[0] = _S_bin[bin].first[thread_id];
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else
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_S_bin[bin].last[0]->next = _S_bin[bin].first[thread_id];
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_S_bin[bin].last[0] = _S_bin[bin].first[thread_id];
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_S_bin[bin].first[thread_id] =
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_S_bin[bin].first[thread_id]->next;
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_S_bin[bin].free[0]++;
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_S_bin[bin].free[thread_id]--;
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remove--;
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}
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_S_bin[bin].last[0]->next = NULL;
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__gthread_mutex_unlock(_S_bin[bin].mutex);
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}
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/*
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* Did we allocate this block?
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* - Yes, return it to our freelist
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* - No, return it to global pool
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*/
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if (thread_id == block->thread_id)
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{
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if (_S_bin[bin].first[thread_id] == NULL)
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_S_bin[bin].first[thread_id] = block;
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else
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_S_bin[bin].last[thread_id]->next = block;
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_S_bin[bin].last[thread_id] = block;
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_S_bin[bin].free[thread_id]++;
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_S_bin[bin].used[thread_id]--;
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}
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else
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{
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__gthread_mutex_lock(_S_bin[bin].mutex);
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if (_S_bin[bin].first[0] == NULL)
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_S_bin[bin].first[0] = block;
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else
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_S_bin[bin].last[0]->next = block;
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_S_bin[bin].last[0] = block;
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_S_bin[bin].free[0]++;
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_S_bin[bin].used[block->thread_id]--;
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__gthread_mutex_unlock(_S_bin[bin].mutex);
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}
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}
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else
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#endif
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{
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/*
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* Single threaded application - return to global pool
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*/
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if (_S_bin[bin].first[0] == NULL)
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_S_bin[bin].first[0] = block;
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else
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_S_bin[bin].last[0]->next = block;
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_S_bin[bin].last[0] = block;
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_S_bin[bin].free[0]++;
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_S_bin[bin].used[0]--;
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}
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}
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};
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template<int __inst>
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void
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__mt_alloc<__inst>::
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_S_init()
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{
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/*
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* Calculate the number of bins required based on _S_max_bytes,
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* _S_no_of_bins is initialized to 1 below.
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*/
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{
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size_t bin_t = 1;
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while (_S_max_bytes > bin_t)
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{
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bin_t = bin_t << 1;
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_S_no_of_bins++;
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}
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}
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/*
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* Setup the bin map for quick lookup of the relevant bin
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*/
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_S_binmap = (binmap_type*)
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malloc ((_S_max_bytes + 1) * sizeof(binmap_type));
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if (!_S_binmap)
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__throw_bad_alloc();
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binmap_type* bp_t = _S_binmap;
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binmap_type bin_max_t = 1;
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binmap_type bin_t = 0;
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for (binmap_type ct = 0; ct <= _S_max_bytes; ct++)
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{
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if (ct > bin_max_t)
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{
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bin_max_t <<= 1;
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bin_t++;
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}
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*bp_t++ = bin_t;
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}
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|
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/*
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* If __gthread_active_p() create and initialize the list of
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* free thread ids. Single threaded applications use thread id 0
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* directly and have no need for this.
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*/
|
|
#ifdef __GTHREADS
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|
if (__gthread_active_p())
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{
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_S_thread_freelist_first =
|
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(thread_record*)malloc(sizeof(thread_record) * _S_max_threads);
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|
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if (!_S_thread_freelist_first)
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__throw_bad_alloc();
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|
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/*
|
|
* NOTE! The first assignable thread id is 1 since the global
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|
* pool uses id 0
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|
*/
|
|
size_t i;
|
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for (i = 1; i < _S_max_threads; i++)
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{
|
|
_S_thread_freelist_first[i - 1].next =
|
|
&_S_thread_freelist_first[i];
|
|
|
|
_S_thread_freelist_first[i - 1].id = i;
|
|
}
|
|
|
|
/*
|
|
* Set last record and pointer to this
|
|
*/
|
|
_S_thread_freelist_first[i - 1].next = NULL;
|
|
_S_thread_freelist_first[i - 1].id = i;
|
|
_S_thread_freelist_last = &_S_thread_freelist_first[i - 1];
|
|
|
|
/*
|
|
* Initialize per thread key to hold pointer to
|
|
* _S_thread_freelist NOTE! Here's an ugly workaround - if
|
|
* _S_thread_key_destr is not explicitly called at least
|
|
* once it won't be linked into the application. This is the
|
|
* behavior of template methods and __gthread_key_create()
|
|
* takes only a pointer to the function and does not cause
|
|
* the compiler to create an instance.
|
|
*/
|
|
_S_thread_key_destr(NULL);
|
|
__gthread_key_create(&_S_thread_key, _S_thread_key_destr);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Initialize _S_bin and its members
|
|
*/
|
|
_S_bin = (bin_record*)malloc(sizeof(bin_record) * _S_no_of_bins);
|
|
|
|
if (!_S_bin)
|
|
__throw_bad_alloc();
|
|
|
|
for (size_t bin = 0; bin < _S_no_of_bins; bin++)
|
|
{
|
|
_S_bin[bin].first = (block_record**)
|
|
malloc(sizeof(block_record*) * (_S_max_threads + 1));
|
|
|
|
if (!_S_bin[bin].first)
|
|
__throw_bad_alloc();
|
|
|
|
_S_bin[bin].last = (block_record**)
|
|
malloc(sizeof(block_record*) * (_S_max_threads + 1));
|
|
|
|
if (!_S_bin[bin].last)
|
|
__throw_bad_alloc();
|
|
|
|
_S_bin[bin].free = (size_t*)
|
|
malloc(sizeof(size_t) * (_S_max_threads + 1));
|
|
|
|
if (!_S_bin[bin].free)
|
|
__throw_bad_alloc();
|
|
|
|
_S_bin[bin].used = (size_t*)
|
|
malloc(sizeof(size_t) * (_S_max_threads + 1));
|
|
|
|
if (!_S_bin[bin].used)
|
|
__throw_bad_alloc();
|
|
|
|
/*
|
|
* Ugly workaround of what at the time of writing seems to be
|
|
* a parser problem - see PR c++/9779 for more info.
|
|
*/
|
|
#ifdef __GTHREADS
|
|
size_t s = sizeof(__gthread_mutex_t);
|
|
_S_bin[bin].mutex = (__gthread_mutex_t*)malloc(s);
|
|
|
|
if (!_S_bin[bin].mutex)
|
|
__throw_bad_alloc();
|
|
|
|
#ifdef __GTHREAD_MUTEX_INIT
|
|
{
|
|
// Do not copy a POSIX/gthr mutex once in use.
|
|
__gthread_mutex_t __tmp = __GTHREAD_MUTEX_INIT;
|
|
*_S_bin[bin].mutex = __tmp;
|
|
}
|
|
#else
|
|
{ __GTHREAD_MUTEX_INIT_FUNCTION (_S_bin[bin].mutex); }
|
|
#endif
|
|
#endif
|
|
|
|
for (size_t thread = 0; thread <= _S_max_threads; thread++)
|
|
{
|
|
_S_bin[bin].first[thread] = NULL;
|
|
_S_bin[bin].last[thread] = NULL;
|
|
_S_bin[bin].free[thread] = 0;
|
|
_S_bin[bin].used[thread] = 0;
|
|
}
|
|
}
|
|
|
|
_S_initialized = true;
|
|
}
|
|
|
|
#ifdef __GTHREADS
|
|
template<int __inst>
|
|
void
|
|
__mt_alloc<__inst>::
|
|
_S_thread_key_destr(void* freelist_pos)
|
|
{
|
|
/*
|
|
* This is due to the ugly workaround mentioned in _S_init()
|
|
*/
|
|
if (freelist_pos == NULL)
|
|
return;
|
|
|
|
/*
|
|
* If the thread - when it dies - still have records on its
|
|
* freelist we return them to the global pool here.
|
|
*/
|
|
for (size_t bin = 0; bin < _S_no_of_bins; bin++)
|
|
{
|
|
block_record* block =
|
|
_S_bin[bin].first[((thread_record*)freelist_pos)->id];
|
|
|
|
if (block != NULL)
|
|
{
|
|
__gthread_mutex_lock(_S_bin[bin].mutex);
|
|
|
|
while (block != NULL)
|
|
{
|
|
if (_S_bin[bin].first[0] == NULL)
|
|
_S_bin[bin].first[0] = block;
|
|
else
|
|
_S_bin[bin].last[0]->next = block;
|
|
|
|
_S_bin[bin].last[0] = block;
|
|
|
|
block = block->next;
|
|
|
|
_S_bin[bin].free[0]++;
|
|
}
|
|
|
|
_S_bin[bin].last[0]->next = NULL;
|
|
|
|
__gthread_mutex_unlock(_S_bin[bin].mutex);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Return this thread id record to thread_freelist
|
|
*/
|
|
__gthread_mutex_lock(&_S_thread_freelist_mutex);
|
|
|
|
_S_thread_freelist_last->next = (thread_record*)freelist_pos;
|
|
_S_thread_freelist_last = (thread_record*)freelist_pos;
|
|
_S_thread_freelist_last->next = NULL;
|
|
|
|
__gthread_mutex_unlock(&_S_thread_freelist_mutex);
|
|
|
|
}
|
|
|
|
template<int __inst>
|
|
size_t
|
|
__mt_alloc<__inst>::
|
|
_S_get_thread_id()
|
|
{
|
|
/*
|
|
* If we have thread support and it's active we check the thread
|
|
* key value and return it's id or if it's not set we take the
|
|
* first record from _S_thread_freelist and sets the key and
|
|
* returns it's id.
|
|
*/
|
|
if (__gthread_active_p())
|
|
{
|
|
thread_record* freelist_pos;
|
|
|
|
if ((freelist_pos =
|
|
(thread_record*)__gthread_getspecific(_S_thread_key)) == NULL)
|
|
{
|
|
__gthread_mutex_lock(&_S_thread_freelist_mutex);
|
|
|
|
/*
|
|
* Since _S_max_threads must be larger than the
|
|
* theoretical max number of threads of the OS the list
|
|
* can never be empty.
|
|
*/
|
|
freelist_pos = _S_thread_freelist_first;
|
|
_S_thread_freelist_first = _S_thread_freelist_first->next;
|
|
|
|
__gthread_mutex_unlock(&_S_thread_freelist_mutex);
|
|
|
|
__gthread_setspecific(_S_thread_key, (void*)freelist_pos);
|
|
|
|
/*
|
|
* Since thread_ids may/will be reused (espcially in
|
|
* producer/consumer applications) we make sure that the
|
|
* list pointers and free counter is reset BUT as the
|
|
* "old" thread may still be owner of some memory (which
|
|
* is referred to by other threads and thus not freed)
|
|
* we don't reset the used counter.
|
|
*/
|
|
for (size_t bin = 0; bin < _S_no_of_bins; bin++)
|
|
{
|
|
_S_bin[bin].first[freelist_pos->id] = NULL;
|
|
_S_bin[bin].last[freelist_pos->id] = NULL;
|
|
_S_bin[bin].free[freelist_pos->id] = 0;
|
|
}
|
|
}
|
|
|
|
return freelist_pos->id;
|
|
}
|
|
|
|
/*
|
|
* Otherwise (no thread support or inactive) all requests are
|
|
* served from the global pool 0.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
template<int __inst> __gthread_once_t
|
|
__mt_alloc<__inst>::_S_once_mt = __GTHREAD_ONCE_INIT;
|
|
#endif
|
|
|
|
template<int __inst> bool
|
|
__mt_alloc<__inst>::_S_initialized = false;
|
|
|
|
template<int __inst> typename __mt_alloc<__inst>::binmap_type*
|
|
__mt_alloc<__inst>::_S_binmap = NULL;
|
|
|
|
/*
|
|
* Allocation requests (after round-up to power of 2) below this
|
|
* value will be handled by the allocator. A raw malloc/free() call
|
|
* will be used for requests larger than this value.
|
|
*/
|
|
template<int __inst> size_t
|
|
__mt_alloc<__inst>::_S_max_bytes = 128;
|
|
|
|
/*
|
|
* In order to avoid fragmenting and minimize the number of malloc()
|
|
* calls we always request new memory using this value. Based on
|
|
* previous discussions on the libstdc++ mailing list we have
|
|
* choosen the value below. See
|
|
* http://gcc.gnu.org/ml/libstdc++/2001-07/msg00077.html
|
|
*/
|
|
template<int __inst> size_t
|
|
__mt_alloc<__inst>::_S_chunk_size = 4096 - 4 * sizeof(void*);
|
|
|
|
/*
|
|
* The maximum number of supported threads. Our Linux 2.4.18 reports
|
|
* 4070 in /proc/sys/kernel/threads-max
|
|
*/
|
|
template<int __inst> size_t
|
|
__mt_alloc<__inst>::_S_max_threads = 4096;
|
|
|
|
/*
|
|
* Actual value calculated in _S_init()
|
|
*/
|
|
template<int __inst> size_t
|
|
__mt_alloc<__inst>::_S_no_of_bins = 1;
|
|
|
|
/*
|
|
* Each time a deallocation occurs in a threaded application we make
|
|
* sure that there are no more than _S_freelist_headroom % of used
|
|
* memory on the freelist. If the number of additional records is
|
|
* more than _S_freelist_headroom % of the freelist, we move these
|
|
* records back to the global pool.
|
|
*/
|
|
template<int __inst> size_t
|
|
__mt_alloc<__inst>::_S_freelist_headroom = 10;
|
|
|
|
/*
|
|
* Actual initialization in _S_init()
|
|
*/
|
|
#ifdef __GTHREADS
|
|
template<int __inst> typename __mt_alloc<__inst>::thread_record*
|
|
__mt_alloc<__inst>::_S_thread_freelist_first = NULL;
|
|
|
|
template<int __inst> typename __mt_alloc<__inst>::thread_record*
|
|
__mt_alloc<__inst>::_S_thread_freelist_last = NULL;
|
|
|
|
template<int __inst> __gthread_mutex_t
|
|
__mt_alloc<__inst>::_S_thread_freelist_mutex = __GTHREAD_MUTEX_INIT;
|
|
|
|
/*
|
|
* Actual initialization in _S_init()
|
|
*/
|
|
template<int __inst> __gthread_key_t
|
|
__mt_alloc<__inst>::_S_thread_key;
|
|
#endif
|
|
|
|
template<int __inst> typename __mt_alloc<__inst>::bin_record*
|
|
__mt_alloc<__inst>::_S_bin = NULL;
|
|
|
|
template<int __inst>
|
|
inline bool
|
|
operator==(const __mt_alloc<__inst>&, const __mt_alloc<__inst>&)
|
|
{ return true; }
|
|
|
|
template<int __inst>
|
|
inline bool
|
|
operator!=(const __mt_alloc<__inst>&, const __mt_alloc<__inst>&)
|
|
{ return false; }
|
|
} // namespace __gnu_cxx
|
|
|
|
namespace std
|
|
{
|
|
template<typename _Tp, int __inst>
|
|
struct _Alloc_traits<_Tp, __gnu_cxx::__mt_alloc<__inst> >
|
|
{
|
|
static const bool _S_instanceless = true;
|
|
typedef __gnu_cxx:: __mt_alloc<__inst> base_alloc_type;
|
|
typedef __simple_alloc<_Tp, base_alloc_type> _Alloc_type;
|
|
typedef __allocator<_Tp, base_alloc_type> allocator_type;
|
|
};
|
|
|
|
template<typename _Tp, typename _Tp1, int __inst>
|
|
struct _Alloc_traits<_Tp,
|
|
__allocator<_Tp1, __gnu_cxx::__mt_alloc<__inst> > >
|
|
{
|
|
static const bool _S_instanceless = true;
|
|
typedef __gnu_cxx:: __mt_alloc<__inst> base_alloc_type;
|
|
typedef __simple_alloc<_Tp, base_alloc_type> _Alloc_type;
|
|
typedef __allocator<_Tp, base_alloc_type> allocator_type;
|
|
};
|
|
} // namespace std
|
|
|
|
#endif
|