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Diffstat (limited to 'src/systemc/ext/dt/sc_temporary.hh')
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diff --git a/src/systemc/ext/dt/sc_temporary.hh b/src/systemc/ext/dt/sc_temporary.hh new file mode 100644 index 000000000..c462b7fe0 --- /dev/null +++ b/src/systemc/ext/dt/sc_temporary.hh @@ -0,0 +1,227 @@ +/***************************************************************************** + + Licensed to Accellera Systems Initiative Inc. (Accellera) under one or + more contributor license agreements. See the NOTICE file distributed + with this work for additional information regarding copyright ownership. + Accellera licenses this file to you under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with the + License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or + implied. See the License for the specific language governing + permissions and limitations under the License. + + *****************************************************************************/ + +/***************************************************************************** + + sc_temporary.h -- Temporary value pool classes. + + Original Author: Andy Goodrich, Forte Design Systems, Inc. + + CHANGE LOG AT END OF FILE + *****************************************************************************/ + +#ifndef __SYSTEMC_EXT_DT_SC_TEMPORARY_HH__ +#define __SYSTEMC_EXT_DT_SC_TEMPORARY_HH__ + +#include <cstddef> // std::size_t + +namespace sc_core +{ + +//----------------------------------------------------------------------------- +// sc_byte_heap - CLASS MANAGING A TEMPORARY HEAP OF BYTES +// +// This facility implements a heap of temporary byte allocations. Once an +// request has been allocated it is not freed. However the entire heap +// wraps and the storage is reused. This means that no allocations should +// be assumed as permanent. Allocations are double-word aligned. This is +// raw storage, so objects which contain virtual methods cannot be allocated +// with this object. See the sc_vpool object for that type of storage +// allocation. +// +// char* allocate( int size ) +// This method returns a pointer to block of size bytes. The block +// returned is the next available one in the heap. If the current heap +// cannot fullfil the request it will be rewound and storage allocated from +// its start. All allocations start on an 8-byte boundary. +// size = number of bytes to be allocated. +// +// void initialize( int heap_size=0x100000 ) +// This method allocates the storage to be managed. If there is already +// a block of storage under management it is freed. If no argument is +// provided for the heap size, a megabyte will be allocated. +// heap_size = number of bytes to allocate for the heap. +// +// unsigned int length() +// This method returns the size of this object's heap in bytes. +// +// sc_byte_heap() +// This is the non-initialized object instance constructor. It does not +// allocate the heap storage, that is done by the initialize() method. +// +// sc_byte_heap(int) +// This is the initializing object instance constructor. It does allocates +// a heap of the specified number of bytes. +// heap_size = number of bytes to allocate for the heap. +//----------------------------------------------------------------------------- +class sc_byte_heap +{ + public: + char *m_bgn_p; // Beginning of heap storage. + char *m_end_p; // End of heap storage. + char *m_next_p; // Next heap location to be allocated. + + inline char * + allocate(std::size_t bytes_n) + { + char *result_p; + bytes_n = (bytes_n + 7) & ((std::size_t)(-8)); + result_p = m_next_p; + m_next_p += bytes_n; + if (m_next_p >= m_end_p) { + result_p = m_bgn_p; + m_next_p = m_bgn_p + bytes_n; + } + return result_p; + } + + inline void + initialize(std::size_t heap_size=0x100000) + { + delete [] m_bgn_p; + m_bgn_p = new char[heap_size]; + m_end_p = &m_bgn_p[heap_size]; + m_next_p = m_bgn_p; + } + + inline std::size_t + length() + { + return (std::size_t)(m_end_p - m_bgn_p); + } + + inline sc_byte_heap() : m_bgn_p(0), m_end_p(0), m_next_p(0) {} + + inline sc_byte_heap(std::size_t heap_size) : + m_bgn_p(0), m_end_p(0), m_next_p(0) + { + initialize(heap_size); + } + + inline ~sc_byte_heap() { delete [] m_bgn_p; } +}; + + +//----------------------------------------------------------------------------- +// sc_vpool<T> - CLASS MANAGING A TEMPORARY VECTOR OF CLASS T INSTANCES +// +// This class implements a fixed pool of objects contained in a vector. These +// objects are allocated via the allocate() method. An index, m_pool_i, +// indicates the next object to be allocated. The vector is a power of 2 in +// size, and this fact is used to wrap the list when m_pool_i reaches the +// end of the vector. +// +// sc_vpool( int log2, T* pool_p=0 ) +// This is the object instance constructor for this class. It configures +// the object to manage a vector of 2**log2 entries. If a vector is +// not supplied one will be allocated. +// log2 = the log base two of the size of the vector. +// pool_p -> vector of 2**log2 entries to be managed or 0. +// +// ~sc_vpool() +// This is the object instance destructor for this class. It frees the +// block of storage which was being managed. +// +// T* allocate() +// This method returns the address of the next entry in the vector, m_pool_p, +// pointed to by the index, m_pool_i, and updates that index. The index +// update consists of adding 1 to m_pool_i and masking it by m_wrap. +// +// void reset() +// This method resets the allocation index, m_pool_i, to point to the start +// of the vector of objects under management. This call is not usually made +// since there are a fixed number of entries and the index wraps. However, +// for diagnostics tests it is convenient to be able to reset to the start +// of the vector. +// +// int size() +// This method returns the number of object instances contained in the +// vector being managed by this object instance. +//----------------------------------------------------------------------------- +template<class T> +class sc_vpool +{ + protected: + std::size_t m_pool_i; // Index of next entry to m_pool_m to provide. + T *m_pool_p; // Vector of temporaries. + std::size_t m_wrap; // Mask to wrap vector index. + + public: + inline sc_vpool(int log2, T *pool_p=0); + inline ~sc_vpool(); + inline T *allocate(); + inline void reset(); + inline std::size_t size(); +}; + +template<class T> +sc_vpool<T>::sc_vpool(int log2, T *pool_p) : m_pool_i(0), + m_pool_p(pool_p ? pool_p : new T[static_cast<std::size_t>(1) << log2]), + m_wrap(~(static_cast<std::size_t>(-1) << log2)) +{ + // if (log2 > 32) SC_REPORT_ERROR(SC_ID_POOL_SIZE_, ""); +} + +template<class T> +sc_vpool<T>::~sc_vpool() +{ + // delete [] m_pool_p; +} + +template<class T> +T *sc_vpool<T>::allocate() +{ + T *result_p; // Entry to return. + + result_p = &m_pool_p[m_pool_i]; + m_pool_i = (m_pool_i + 1) & m_wrap; + return result_p; +} + +template<class T> +void sc_vpool<T>::reset() +{ + m_pool_i = 0; +} + +template<class T> +std::size_t sc_vpool<T>::size() { return m_wrap + 1; } + +} // namespace sc_core + +// $Log: sc_temporary.h,v $ +// Revision 1.4 2011/08/26 20:46:19 acg +// Andy Goodrich: moved the modification log to the end of the file to +// eliminate source line number skew when check-ins are done. +// +// Revision 1.3 2011/08/24 22:05:56 acg +// Torsten Maehne: initialization changes to remove warnings. +// +// Revision 1.2 2011/02/18 20:38:44 acg +// Andy Goodrich: Updated Copyright notice. +// +// Revision 1.1.1.1 2006/12/15 20:20:06 acg +// SystemC 2.3 +// +// Revision 1.3 2006/01/13 18:53:11 acg +// Andy Goodrich: Added $Log command so that CVS comments are reproduced in +// the source. +// + +#endif // __SYSTEMC_EXT_DT_SC_TEMPORARY_HH__ |