1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
|
/* Ergo, version 3.5, a program for linear scaling electronic structure
* calculations.
* Copyright (C) 2016 Elias Rudberg, Emanuel H. Rubensson, Pawel Salek,
* and Anastasia Kruchinina.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Primary academic reference:
* KohnâSham Density Functional Theory Electronic Structure Calculations
* with Linearly Scaling Computational Time and Memory Usage,
* Elias Rudberg, Emanuel H. Rubensson, and Pawel Salek,
* J. Chem. Theory Comput. 7, 340 (2011),
* <http://dx.doi.org/10.1021/ct100611z>
*
* For further information about Ergo, see <http://www.ergoscf.org>.
*/
#ifndef MAT_ALLOCATOR_HEADER
#define MAT_ALLOCATOR_HEADER
#include <stdexcept>
namespace mat {
template<class Treal>
class Allocator
{
public:
Allocator(int noOfRealsPerBuffer_,
int noOfBuffers_) :
noOfRealsPerBuffer(noOfRealsPerBuffer_),
noOfBuffers(noOfBuffers_)
{
buffer = new Treal[noOfBuffers * noOfRealsPerBuffer];
nextFreeIndexList = new int[noOfBuffers];
// Initialize nextFreeIndexList to indicate that all slots are free.
for(int i = 0; i < noOfBuffers-1; i++)
nextFreeIndexList[i] = i + 1;
nextFreeIndexList[noOfBuffers-1] = -1; // last one points to -1
firstFreeIndex = 0;
noOfOccupiedSlots = 0;
}
~Allocator()
{
delete [] buffer;
delete [] nextFreeIndexList;
}
Treal* alloc() {
if(firstFreeIndex < 0)
throw std::runtime_error("Error in Allocator::alloc(): no free slots.");
Treal* ptrToReturn = &buffer[firstFreeIndex*noOfRealsPerBuffer];
int firstFreeIndex_new = nextFreeIndexList[firstFreeIndex];
nextFreeIndexList[firstFreeIndex] = -1;
firstFreeIndex = firstFreeIndex_new;
noOfOccupiedSlots++;
return ptrToReturn;
}
void free(Treal* ptr) {
if(ptr < buffer || ptr >= &buffer[noOfBuffers * noOfRealsPerBuffer])
throw std::runtime_error("Error in Allocator::free(): unknown ptr.");
int count = ptr - buffer;
if((count % noOfRealsPerBuffer) != 0)
throw std::runtime_error("Error in Allocator::free(): bad ptr.");
int bufferIdx = count / noOfRealsPerBuffer;
if(nextFreeIndexList[bufferIdx] != -1)
throw std::runtime_error("Error in Allocator::free(): -1 not found.");
nextFreeIndexList[bufferIdx] = firstFreeIndex;
firstFreeIndex = bufferIdx;
noOfOccupiedSlots--;
}
bool isFull() {
if(noOfOccupiedSlots == noOfBuffers)
return true;
return false;
}
bool isEmpty() {
if(noOfOccupiedSlots == 0)
return true;
return false;
}
bool ownsPtr(Treal* ptr) {
if(ptr < buffer || ptr >= &buffer[noOfBuffers * noOfRealsPerBuffer])
return false;
return true;
}
int getNoOfOccupiedSlots() {
return noOfOccupiedSlots;
}
private:
int noOfRealsPerBuffer;
int noOfBuffers;
Treal* buffer;
int* nextFreeIndexList;
int firstFreeIndex;
int noOfOccupiedSlots;
}; // end class Allocator
} /* end namespace mat */
#endif
|
