Menes/Pooling.hpp

   1 /* Cycript - Optimizing JavaScript Compiler/Runtime
   2  * Copyright (C) 2009-2015  Jay Freeman (saurik)
   3 */
   4
   5 /* GNU Affero General Public License, Version 3 {{{ */
   6 /*
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 **/
  20 /* }}} */
  21
  22 #ifndef Menes_Pooling_HPP
  23 #define Menes_Pooling_HPP
  24
  25 #include <cstdarg>
  26 #include <cstdio>
  27 #include <cstdlib>
  28 #include <cstring>
  29
  30 #include <algorithm>
  31
  32 #include <stdint.h>
  33
  34 class CYPool;
  35 _finline void *operator new(size_t size, CYPool &pool);
  36 _finline void *operator new [](size_t size, CYPool &pool);
  37
  38 class CYPool {
  39   private:
  40     uint8_t *data_;
  41     size_t size_;
  42
  43     struct Cleaner {
  44         Cleaner *next_;
  45         void (*code_)(void *);
  46         void *data_;
  47
  48         Cleaner(Cleaner *next, void (*code)(void *), void *data) :
  49             next_(next),
  50             code_(code),
  51             data_(data)
  52         {
  53         }
  54     } *cleaner_;
  55
  56     static _finline size_t align(size_t size) {
  57         // XXX: alignment is more complex than this
  58         return (size + 7) & ~0x3;
  59     }
  60
  61     template <typename Type_>
  62     static void delete_(void *data) {
  63         reinterpret_cast<Type_ *>(data)->~Type_();
  64     }
  65
  66     CYPool(const CYPool &);
  67
  68   public:
  69     CYPool() :
  70         data_(NULL),
  71         size_(0),
  72         cleaner_(NULL)
  73     {
  74     }
  75
  76     ~CYPool() {
  77         for (Cleaner *cleaner(cleaner_); cleaner != NULL; ) {
  78             Cleaner *next(cleaner->next_);
  79             (*cleaner->code_)(cleaner->data_);
  80             cleaner = next;
  81         }
  82     }
  83
  84     template <typename Type_>
  85     Type_ *malloc(size_t size) {
  86         size = align(size);
  87
  88         if (size > size_) {
  89             // XXX: is this an optimal malloc size?
  90             size_ = std::max<size_t>(size, size + align(sizeof(Cleaner)));
  91             data_ = reinterpret_cast<uint8_t *>(::malloc(size_));
  92             atexit(free, data_);
  93             _assert(size <= size_);
  94         }
  95
  96         void *data(data_);
  97         data_ += size;
  98         size_ -= size;
  99         return reinterpret_cast<Type_ *>(data);
 100     }
 101
 102     void atexit(void (*code)(void *), void *data = NULL);
 103 };
 104
 105 _finline void *operator new(size_t size, CYPool &pool) {
 106     return pool.malloc<void>(size);
 107 }
 108
 109 _finline void *operator new [](size_t size, CYPool &pool) {
 110     return pool.malloc<void>(size);
 111 }
 112
 113 _finline void CYPool::atexit(void (*code)(void *), void *data) {
 114     cleaner_ = new(*this) Cleaner(cleaner_, code, data);
 115 }
 116
 117 #endif/*Menes_Pooling_HPP*/