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 SC_TEMPORARY_H 30#define SC_TEMPORARY_H 31 32#include <cstddef> // std::size_t 33 34namespace sc_core { 35 36//------------------------------------------------------------------------------ 37// sc_byte_heap - CLASS MANAGING A TEMPORARY HEAP OF BYTES 38// 39// This facility implements a heap of temporary byte allocations. Once an 40// request has been allocated it is not freed. However the entire heap 41// wraps and the storage is reused. This means that no allocations should 42// be assumed as permanent. Allocations are double-word aligned. This is 43// raw storage, so objects which contain virtual methods cannot be allocated 44// with this object. See the sc_vpool object for that type of storage 45// allocation. 46// 47// char* allocate( int size ) 48// This method returns a pointer to block of size bytes. The block 49// returned is the next available one in the heap. If the current heap 50// cannot fullfil the request it will be rewound and storage allocated from 51// its start. All allocations start on an 8-byte boundary. 52// size = number of bytes to be allocated. 53// 54// void initialize( int heap_size=0x100000 ) 55// This method allocates the storage to be managed. If there is already 56// a block of storage under management it is freed. If no argument is 57// provided for the heap size, a megabyte will be allocated. 58// heap_size = number of bytes to allocate for the heap. 59// 60// unsigned int length() 61// This method returns the size of this object's heap in bytes. 62// 63// sc_byte_heap() 64// This is the non-initialized object instance constructor. It does not 65// allocate the heap storage, that is done by the initialize() method. 66// 67// sc_byte_heap(int) 68// This is the initializing object instance constructor. It does allocates 69// a heap of the specified number of bytes. 70// heap_size = number of bytes to allocate for the heap. 71//------------------------------------------------------------------------------ 72class sc_byte_heap { 73 public: 74 char* m_bgn_p; // Beginning of heap storage. 75 char* m_end_p; // End of heap storage. 76 char* m_next_p; // Next heap location to be allocated. 77 78 inline char* allocate( std::size_t bytes_n ) 79 { 80 char* result_p; 81 bytes_n = (bytes_n + 7) & ((std::size_t)(-8)); 82 result_p = m_next_p; 83 m_next_p += bytes_n; 84 if ( m_next_p >= m_end_p ) 85 { 86 result_p = m_bgn_p; 87 m_next_p = m_bgn_p + bytes_n; 88 } 89 return result_p; 90 } 91 92 inline void initialize( std::size_t heap_size=0x100000 ) 93 { 94 delete [] m_bgn_p; 95 m_bgn_p = new char[heap_size]; 96 m_end_p = &m_bgn_p[heap_size]; 97 m_next_p = m_bgn_p; 98 } 99 100 inline std::size_t length() 101 { 102 return (std::size_t)(m_end_p - m_bgn_p); 103 } 104 105 inline sc_byte_heap() : 106 m_bgn_p(0), m_end_p(0), m_next_p(0) 107 { 108 } 109 110 inline sc_byte_heap( std::size_t heap_size ) : 111 m_bgn_p(0), m_end_p(0), m_next_p(0) 112 { 113 initialize( heap_size ); 114 } 115 116 inline ~sc_byte_heap() 117 { 118 delete [] m_bgn_p; 119 } 120 121}; 122 123 124//------------------------------------------------------------------------------ 125// sc_vpool<T> - CLASS MANAGING A TEMPORARY VECTOR OF CLASS T INSTANCES 126// 127// This class implements a fixed pool of objects contained in a vector. These 128// objects are allocated via the allocate() method. An index, m_pool_i, 129// indicates the next object to be allocated. The vector is a power of 2 in 130// size, and this fact is used to wrap the list when m_pool_i reaches the 131// end of the vector. 132// 133// sc_vpool( int log2, T* pool_p=0 ) 134// This is the object instance constructor for this class. It configures 135// the object to manage a vector of 2**log2 entries. If a vector is 136// not supplied one will be allocated. 137// log2 = the log base two of the size of the vector. 138// pool_p -> vector of 2**log2 entries to be managed or 0. 139// 140// ~sc_vpool() 141// This is the object instance destructor for this class. It frees the 142// block of storage which was being managed. 143// 144// T* allocate() 145// This method returns the address of the next entry in the vector, m_pool_p, 146// pointed to by the index, m_pool_i, and updates that index. The index 147// update consists of adding 1 to m_pool_i and masking it by m_wrap. 148// 149// void reset() 150// This method resets the allocation index, m_pool_i, to point to the start 151// of the vector of objects under management. This call is not usually made 152// since there are a fixed number of entries and the index wraps. However, 153// for diagnostics tests it is convenient to be able to reset to the start 154// of the vector. 155// 156// int size() 157// This method returns the number of object instances contained in the 158// vector being managed by this object instance. 159//------------------------------------------------------------------------------ 160template<class T> 161class sc_vpool { 162 protected: 163 std::size_t m_pool_i; // Index of next entry to m_pool_m to provide. 164 T* m_pool_p; // Vector of temporaries. 165 std::size_t m_wrap; // Mask to wrap vector index. 166 167 public: 168 inline sc_vpool( int log2, T* pool_p=0 ); 169 inline ~sc_vpool(); 170 inline T* allocate(); 171 inline void reset(); 172 inline std::size_t size(); 173}; 174 175template<class T> sc_vpool<T>::sc_vpool( int log2, T* pool_p ) 176 : m_pool_i( 0 ) 177 , m_pool_p( pool_p ? pool_p : new T[static_cast<std::size_t>(1) << log2] ) 178 , m_wrap( ~(static_cast<std::size_t>(-1) << log2) ) 179{ 180 // if ( log2 > 32 ) SC_REPORT_ERROR(SC_ID_POOL_SIZE_, ""); 181} 182 183template<class T> sc_vpool<T>::~sc_vpool() 184{ 185 // delete [] m_pool_p; 186} 187 188template<class T> T* 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> void sc_vpool<T>::reset() 198{ 199 m_pool_i = 0; 200} 201 202template<class T> std::size_t sc_vpool<T>::size() 203{ 204 return m_wrap + 1; 205} 206 207} // namespace sc_core 208 209// $Log: sc_temporary.h,v $ 210// Revision 1.4 2011/08/26 20:46:19 acg 211// Andy Goodrich: moved the modification log to the end of the file to 212// eliminate source line number skew when check-ins are done. 213// 214// Revision 1.3 2011/08/24 22:05:56 acg 215// Torsten Maehne: initialization changes to remove warnings. 216// 217// Revision 1.2 2011/02/18 20:38:44 acg 218// Andy Goodrich: Updated Copyright notice. 219// 220// Revision 1.1.1.1 2006/12/15 20:20:06 acg 221// SystemC 2.3 222// 223// Revision 1.3 2006/01/13 18:53:11 acg 224// Andy Goodrich: Added $Log command so that CVS comments are reproduced in 225// the source. 226// 227 228#endif // SC_TEMPORARY_H 229