diff options
Diffstat (limited to 'libstdc++-v3/include/ext/mt_allocator.h')
| -rw-r--r-- | libstdc++-v3/include/ext/mt_allocator.h | 103 |
1 files changed, 23 insertions, 80 deletions
diff --git a/libstdc++-v3/include/ext/mt_allocator.h b/libstdc++-v3/include/ext/mt_allocator.h index b4498feddf3..78fe2b9ec92 100644 --- a/libstdc++-v3/include/ext/mt_allocator.h +++ b/libstdc++-v3/include/ext/mt_allocator.h @@ -1,6 +1,6 @@ // MT-optimized allocator -*- C++ -*- -// Copyright (C) 2003 Free Software Foundation, Inc. +// Copyright (C) 2003, 2004 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the @@ -179,11 +179,10 @@ namespace __gnu_cxx /* * Points to the next block_record for its thread_id. */ - block_record* next; + block_record* volatile next; /* * The thread id of the thread which has requested this block. - * All blocks are initially "owned" by global pool thread id 0. */ size_t thread_id; }; @@ -195,8 +194,8 @@ namespace __gnu_cxx * thread id. Memory to these "arrays" is allocated in _S_init() * for _S_max_threads + global pool 0. */ - block_record** first; - block_record** last; + block_record** volatile first; + block_record** volatile last; /* * An "array" of counters used to keep track of the amount of blocks @@ -204,8 +203,8 @@ namespace __gnu_cxx * Memory to these "arrays" is allocated in _S_init() * for _S_max_threads + global pool 0. */ - size_t* free; - size_t* used; + size_t* volatile free; + size_t* volatile used; /* * Each bin has its own mutex which is used to ensure data integrity @@ -221,7 +220,7 @@ namespace __gnu_cxx * An "array" of bin_records each of which represents a specific * power of 2 size. Memory to this "array" is allocated in _S_init(). */ - static bin_record* _S_bin; + static bin_record* volatile _S_bin; public: pointer @@ -478,37 +477,24 @@ namespace __gnu_cxx } /* - * Did we allocate this block? - * - Yes, return it to our freelist - * - No, return it to global pool + * Return this block to our list and update + * counters and owner id as needed */ - if (thread_id == block->thread_id) - { - if (_S_bin[bin].first[thread_id] == NULL) - _S_bin[bin].first[thread_id] = block; - else - _S_bin[bin].last[thread_id]->next = block; - - _S_bin[bin].last[thread_id] = block; - - _S_bin[bin].free[thread_id]++; - _S_bin[bin].used[thread_id]--; - } + if (_S_bin[bin].first[thread_id] == NULL) + _S_bin[bin].first[thread_id] = block; else - { - __gthread_mutex_lock(_S_bin[bin].mutex); + _S_bin[bin].last[thread_id]->next = block; - 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[thread_id] = block; - _S_bin[bin].last[0] = block; + _S_bin[bin].free[thread_id]++; - _S_bin[bin].free[0]++; + if (thread_id == block->thread_id) + _S_bin[bin].used[thread_id]--; + else + { _S_bin[bin].used[block->thread_id]--; - - __gthread_mutex_unlock(_S_bin[bin].mutex); + block->thread_id = thread_id; } } else @@ -639,13 +625,14 @@ namespace __gnu_cxx if (!_S_bin[bin].free) __throw_bad_alloc(); + _S_bin[bin].used = (size_t*) malloc(sizeof(size_t) * __n); if (!_S_bin[bin].used) __throw_bad_alloc(); #ifdef __GTHREADS - _S_bin[bin].mutex =(__gthread_mutex_t*) malloc(sizeof(__gthread_mutex_t)); + _S_bin[bin].mutex =(__gthread_mutex_t*) malloc(sizeof(__gthread_mutex_t)); #ifdef __GTHREAD_MUTEX_INIT { @@ -677,35 +664,6 @@ namespace __gnu_cxx _S_thread_key_destr(void* freelist_pos) { /* - * If the thread - when it dies - still has 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 front of thread_freelist */ __gthread_mutex_lock(&_S_thread_freelist_mutex); @@ -727,7 +685,7 @@ namespace __gnu_cxx */ if (__gthread_active_p()) { - thread_record* volatile freelist_pos; + thread_record* freelist_pos; if ((freelist_pos = (thread_record*)__gthread_getspecific(_S_thread_key)) == NULL) @@ -743,21 +701,6 @@ namespace __gnu_cxx __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; @@ -839,7 +782,7 @@ namespace __gnu_cxx #endif template<typename _Tp> typename __mt_alloc<_Tp>::bin_record* - __mt_alloc<_Tp>::_S_bin = NULL; + volatile __mt_alloc<_Tp>::_S_bin = NULL; } // namespace __gnu_cxx #endif |