1/***************************************************************************** 2 3 Licensed to Accellera Systems Initiative Inc. (Accellera) under one or 4 more contributor license agreements. See the NOTICE file distributed 5 with this work for additional information regarding copyright ownership. 6 Accellera licenses this file to you under the Apache License, Version 2.0 7 (the "License"); you may not use this file except in compliance with the 8 License. You may obtain a copy of the License at 9 10 http://www.apache.org/licenses/LICENSE-2.0 11 12 Unless required by applicable law or agreed to in writing, software 13 distributed under the License is distributed on an "AS IS" BASIS, 14 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 15 implied. See the License for the specific language governing 16 permissions and limitations under the License. 17 18 *****************************************************************************/ 19 20/***************************************************************************** 21 22 sc_temporary.h -- Temporary value pool classes. 23 24 Original Author: Andy Goodrich, Forte Design Systems, Inc. 25 26 CHANGE LOG AT END OF FILE 27 *****************************************************************************/ 28 29#ifndef __SYSTEMC_EXT_DT_SC_TEMPORARY_HH__ 30#define __SYSTEMC_EXT_DT_SC_TEMPORARY_HH__ 31 32#include <cstddef> // std::size_t 33 34namespace sc_core 35{ 36 37//----------------------------------------------------------------------------- 38// sc_byte_heap - CLASS MANAGING A TEMPORARY HEAP OF BYTES 39// 40// This facility implements a heap of temporary byte allocations. Once an 41// request has been allocated it is not freed. However the entire heap 42// wraps and the storage is reused. This means that no allocations should 43// be assumed as permanent. Allocations are double-word aligned. This is 44// raw storage, so objects which contain virtual methods cannot be allocated 45// with this object. See the sc_vpool object for that type of storage 46// allocation. 47// 48// char* allocate( int size ) 49// This method returns a pointer to block of size bytes. The block 50// returned is the next available one in the heap. If the current heap 51// cannot fullfil the request it will be rewound and storage allocated from 52// its start. All allocations start on an 8-byte boundary. 53// size = number of bytes to be allocated. 54// 55// void initialize( int heap_size=0x100000 ) 56// This method allocates the storage to be managed. If there is already 57// a block of storage under management it is freed. If no argument is 58// provided for the heap size, a megabyte will be allocated. 59// heap_size = number of bytes to allocate for the heap. 60// 61// unsigned int length() 62// This method returns the size of this object's heap in bytes. 63// 64// sc_byte_heap() 65// This is the non-initialized object instance constructor. It does not 66// allocate the heap storage, that is done by the initialize() method. 67// 68// sc_byte_heap(int) 69// This is the initializing object instance constructor. It does allocates 70// a heap of the specified number of bytes. 71// heap_size = number of bytes to allocate for the heap. 72//----------------------------------------------------------------------------- 73class sc_byte_heap 74{ 75 public: 76 char *m_bgn_p; // Beginning of heap storage. 77 char *m_end_p; // End of heap storage. 78 char *m_next_p; // Next heap location to be allocated. 79 80 inline char * 81 allocate(std::size_t bytes_n) 82 { 83 char *result_p; 84 bytes_n = (bytes_n + 7) & ((std::size_t)(-8)); 85 result_p = m_next_p; 86 m_next_p += bytes_n; 87 if (m_next_p >= m_end_p) { 88 result_p = m_bgn_p; 89 m_next_p = m_bgn_p + bytes_n; 90 } 91 return result_p; 92 } 93 94 inline void 95 initialize(std::size_t heap_size=0x100000) 96 { 97 delete [] m_bgn_p; 98 m_bgn_p = new char[heap_size]; 99 m_end_p = &m_bgn_p[heap_size]; 100 m_next_p = m_bgn_p; 101 } 102 103 inline std::size_t 104 length() 105 { 106 return (std::size_t)(m_end_p - m_bgn_p); 107 } 108 109 inline sc_byte_heap() : m_bgn_p(0), m_end_p(0), m_next_p(0) {} 110 111 inline sc_byte_heap(std::size_t heap_size) : 112 m_bgn_p(0), m_end_p(0), m_next_p(0) 113 { 114 initialize(heap_size); 115 } 116 117 inline ~sc_byte_heap() { delete [] m_bgn_p; } 118}; 119 120 121//----------------------------------------------------------------------------- 122// sc_vpool<T> - CLASS MANAGING A TEMPORARY VECTOR OF CLASS T INSTANCES 123// 124// This class implements a fixed pool of objects contained in a vector. These 125// objects are allocated via the allocate() method. An index, m_pool_i, 126// indicates the next object to be allocated. The vector is a power of 2 in 127// size, and this fact is used to wrap the list when m_pool_i reaches the 128// end of the vector. 129// 130// sc_vpool( int log2, T* pool_p=0 ) 131// This is the object instance constructor for this class. It configures 132// the object to manage a vector of 2**log2 entries. If a vector is 133// not supplied one will be allocated. 134// log2 = the log base two of the size of the vector. 135// pool_p -> vector of 2**log2 entries to be managed or 0. 136// 137// ~sc_vpool() 138// This is the object instance destructor for this class. It frees the 139// block of storage which was being managed. 140// 141// T* allocate() 142// This method returns the address of the next entry in the vector, m_pool_p, 143// pointed to by the index, m_pool_i, and updates that index. The index 144// update consists of adding 1 to m_pool_i and masking it by m_wrap. 145// 146// void reset() 147// This method resets the allocation index, m_pool_i, to point to the start 148// of the vector of objects under management. This call is not usually made 149// since there are a fixed number of entries and the index wraps. However, 150// for diagnostics tests it is convenient to be able to reset to the start 151// of the vector. 152// 153// int size() 154// This method returns the number of object instances contained in the 155// vector being managed by this object instance. 156//----------------------------------------------------------------------------- 157template<class T> 158class sc_vpool 159{ 160 protected: 161 std::size_t m_pool_i; // Index of next entry to m_pool_m to provide. 162 T *m_pool_p; // Vector of temporaries. 163 std::size_t m_wrap; // Mask to wrap vector index. 164 165 public: 166 inline sc_vpool(int log2, T *pool_p=0); 167 inline ~sc_vpool(); 168 inline T *allocate(); 169 inline void reset(); 170 inline std::size_t size(); 171}; 172 173template<class T> 174sc_vpool<T>::sc_vpool(int log2, T *pool_p) : m_pool_i(0), 175 m_pool_p(pool_p ? pool_p : new T[static_cast<std::size_t>(1) << log2]), 176 m_wrap(~(static_cast<std::size_t>(-1) << log2)) 177{ 178 // if (log2 > 32) SC_REPORT_ERROR(SC_ID_POOL_SIZE_, ""); 179} 180 181template<class T> 182sc_vpool<T>::~sc_vpool() 183{ 184 // delete [] m_pool_p; 185} 186 187template<class T> 188T *sc_vpool<T>::allocate() 189{ 190 T *result_p; // Entry to return. 191 192 result_p = &m_pool_p[m_pool_i]; 193 m_pool_i = (m_pool_i + 1) & m_wrap; 194 return result_p; 195} 196 197template<class T> 198void sc_vpool<T>::reset() 199{ 200 m_pool_i = 0; 201} 202 203template<class T> 204std::size_t sc_vpool<T>::size() { return m_wrap + 1; } 205 206} // namespace sc_core 207 208// $Log: sc_temporary.h,v $ 209// Revision 1.4 2011/08/26 20:46:19 acg 210// Andy Goodrich: moved the modification log to the end of the file to 211// eliminate source line number skew when check-ins are done. 212// 213// Revision 1.3 2011/08/24 22:05:56 acg 214// Torsten Maehne: initialization changes to remove warnings. 215// 216// Revision 1.2 2011/02/18 20:38:44 acg 217// Andy Goodrich: Updated Copyright notice. 218// 219// Revision 1.1.1.1 2006/12/15 20:20:06 acg 220// SystemC 2.3 221// 222// Revision 1.3 2006/01/13 18:53:11 acg 223// Andy Goodrich: Added $Log command so that CVS comments are reproduced in 224// the source. 225// 226 227#endif // __SYSTEMC_EXT_DT_SC_TEMPORARY_HH__ 228