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.
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18 *****************************************************************************/
19
20/*****************************************************************************
21
22  sc_pq.cpp - Simple heap implementation of priority queue.
23
24  Original Author: Stan Y. Liao, Synopsys, Inc.
25
26  CHANGE LOG AT END OF FILE
27 *****************************************************************************/
28
29// $Log: sc_pq.cpp,v $
30// Revision 1.4  2011/08/26 20:46:18  acg
31//  Andy Goodrich: moved the modification log to the end of the file to
32//  eliminate source line number skew when check-ins are done.
33//
34
35#include "sysc/utils/sc_pq.h"
36
37namespace sc_core {
38
39sc_ppq_base::sc_ppq_base( int sz, int (*cmp)( const void*, const void* ) )
40    : m_heap(0), m_size_alloc( sz ), m_heap_size( 0 ), m_compar( cmp )
41{
42    // m_size_alloc must be at least 2, otherwise resizing doesn't work
43    if( m_size_alloc < 2 ) {
44	m_size_alloc = 2;
45    }
46    // allocate
47    m_heap = new void*[m_size_alloc + 1];
48    // initialize
49    for( int i = 0; i < m_size_alloc; ++ i ) {
50	m_heap[i] = 0;
51    }
52}
53
54sc_ppq_base::~sc_ppq_base()
55{
56    delete[] m_heap;
57}
58
59void*
60sc_ppq_base::extract_top()
61{
62    assert( m_heap_size > 0 );
63    void* topelem = m_heap[1];
64    m_heap[1] = m_heap[m_heap_size];
65    m_heap_size --;
66    heapify( 1 );
67    return topelem;
68}
69
70void
71sc_ppq_base::insert( void* elem )
72{
73    m_heap_size ++;
74    int i = m_heap_size;
75
76    // resize the heap in case there's not enough memory
77    if( m_heap_size > m_size_alloc ) {
78        m_size_alloc += m_size_alloc / 2;
79        void** new_heap = new void*[m_size_alloc + 1];
80        for( int j = 1; j < m_heap_size; ++ j ) {
81            new_heap[j] = m_heap[j];
82        }
83        delete[] m_heap;
84        m_heap = new_heap;
85    }
86
87    while( (i > 1) && (m_compar( m_heap[parent( i )], elem ) < 0) ) {
88        m_heap[i] = m_heap[parent( i )];
89        i = parent( i );
90    }
91    m_heap[i] = elem;
92}
93
94void
95sc_ppq_base::heapify( int i )
96{
97    int l;
98    while( l = left( i ), l <= m_heap_size ) {
99        int largest = (m_compar( m_heap[l], m_heap[i] ) > 0) ? l : i;
100
101        int r = right( i );
102        if( (r <= m_heap_size) &&
103	    (m_compar( m_heap[r], m_heap[largest] ) > 0) ) {
104            largest = r;
105	}
106
107        if( largest != i ) {
108            void* tmp = m_heap[i];
109            m_heap[i] = m_heap[largest];
110            m_heap[largest] = tmp;
111            i = largest;
112        } else {
113            break;
114	}
115    }
116}
117
118} // namespace sc_core
119
120// Revision 1.3  2011/08/24 22:05:56  acg
121//  Torsten Maehne: initialization changes to remove warnings.
122//
123// Revision 1.2  2011/02/18 20:38:44  acg
124//  Andy Goodrich: Updated Copyright notice.
125//
126// Revision 1.1.1.1  2006/12/15 20:20:06  acg
127// SystemC 2.3
128//
129// Revision 1.3  2006/01/13 18:53:11  acg
130// Andy Goodrich: Added $Log command so that CVS comments are reproduced in
131// the source.
132
133// taf
134