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
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdint.h>
#include <omp.h>
#include "../../support/common.h"
#include "../../support/graph.h"
#include "../../support/params.h"
#include "../../support/timer.h"
#include "../../support/utils.h"
int main(int argc, char** argv) {
// Process parameters
struct Params p = input_params(argc, argv);
// Initialize BFS data structures
PRINT_INFO(p.verbosity >= 1, "Reading graph %s", p.fileName);
struct COOGraph cooGraph = readCOOGraph(p.fileName);
PRINT_INFO(p.verbosity >= 1, " Graph has %d nodes and %d edges", cooGraph.numNodes, cooGraph.numEdges);
struct CSRGraph csrGraph = coo2csr(cooGraph);
uint32_t* nodeLevel = (uint32_t*) malloc(csrGraph.numNodes*sizeof(uint32_t));
uint32_t* nodeLevelRef = (uint32_t*) malloc(csrGraph.numNodes*sizeof(uint32_t));
for(uint32_t i = 0; i < csrGraph.numNodes; ++i) {
nodeLevel[i] = UINT32_MAX; // Unreachable
nodeLevelRef[i] = UINT32_MAX; // Unreachable
}
uint32_t srcNode = 0;
// Initialize frontier double buffers
uint32_t* buffer1 = (uint32_t*) malloc(csrGraph.numNodes*sizeof(uint32_t));
uint32_t* buffer2 = (uint32_t*) malloc(csrGraph.numNodes*sizeof(uint32_t));
uint32_t* prevFrontier = buffer1;
uint32_t* currFrontier = buffer2;
// Calculating result on CPU
PRINT_INFO(p.verbosity >= 1, "Calculating result on CPU (OpenMP)");
omp_set_num_threads(4);
Timer timer;
startTimer(&timer);
nodeLevel[srcNode] = 0;
prevFrontier[0] = srcNode;
uint32_t numPrevFrontier = 1;
for(uint32_t level = 1; numPrevFrontier > 0; ++level) {
uint32_t numCurrFrontier = 0;
// Visit nodes in the previous frontier
#pragma omp parallel for
for(uint32_t i = 0; i < numPrevFrontier; ++i) {
uint32_t node = prevFrontier[i];
for(uint32_t edge = csrGraph.nodePtrs[node]; edge < csrGraph.nodePtrs[node + 1]; ++edge) {
uint32_t neighbor = csrGraph.neighborIdxs[edge];
uint32_t justVisited = 0;
#pragma omp critical
{
if(nodeLevel[neighbor] == UINT32_MAX) { // Node not previously visited
nodeLevel[neighbor] = level;
justVisited = 1;
}
}
if(justVisited) {
uint32_t currFrontierIdx;
#pragma omp critical
{
currFrontierIdx = numCurrFrontier++;
}
currFrontier[currFrontierIdx] = neighbor;
}
}
}
// Swap buffers
uint32_t* tmp = prevFrontier;
prevFrontier = currFrontier;
currFrontier = tmp;
numPrevFrontier = numCurrFrontier;
}
stopTimer(&timer);
if(p.verbosity == 0) PRINT("%f", getElapsedTime(timer)*1e3);
PRINT_INFO(p.verbosity >= 1, "Elapsed time: %f ms", getElapsedTime(timer)*1e3);
// Calculating result on CPU sequentially
PRINT_INFO(p.verbosity >= 1, "Calculating result on CPU (sequential)");
startTimer(&timer);
nodeLevelRef[srcNode] = 0;
prevFrontier[0] = srcNode;
numPrevFrontier = 1;
for(uint32_t level = 1; numPrevFrontier > 0; ++level) {
uint32_t numCurrFrontier = 0;
// Visit nodes in the previous frontier
for(uint32_t i = 0; i < numPrevFrontier; ++i) {
uint32_t node = prevFrontier[i];
for(uint32_t edge = csrGraph.nodePtrs[node]; edge < csrGraph.nodePtrs[node + 1]; ++edge) {
uint32_t neighbor = csrGraph.neighborIdxs[edge];
uint32_t justVisited = 0;
if(nodeLevelRef[neighbor] == UINT32_MAX) { // Node not previously visited
nodeLevelRef[neighbor] = level;
justVisited = 1;
}
if(justVisited) {
uint32_t currFrontierIdx;
currFrontierIdx = numCurrFrontier++;
currFrontier[currFrontierIdx] = neighbor;
}
}
}
// Swap buffers
uint32_t* tmp = prevFrontier;
prevFrontier = currFrontier;
currFrontier = tmp;
numPrevFrontier = numCurrFrontier;
}
stopTimer(&timer);
if(p.verbosity == 0) PRINT("%f", getElapsedTime(timer)*1e3);
PRINT_INFO(p.verbosity >= 1, "Elapsed time: %f ms", getElapsedTime(timer)*1e3);
// Verifying result
PRINT_INFO(p.verbosity >= 1, "Verifying the result");
for(uint32_t nodeIdx = 0; nodeIdx < csrGraph.numNodes; ++nodeIdx) {
if(nodeLevel[nodeIdx] != nodeLevelRef[nodeIdx]) {
PRINT_ERROR("Mismatch at node %u (CPU sequential result = level %u, CPU parallel result = level %u)", nodeIdx, nodeLevelRef[nodeIdx], nodeLevel[nodeIdx]);
}
}
// Deallocate data structures
freeCOOGraph(cooGraph);
freeCSRGraph(csrGraph);
free(nodeLevel);
free(buffer1);
free(buffer2);
return 0;
}
|
