1 //
2 // Copyright (C) 2010 The Android Open Source Project
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 // http://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 //
16
17 #include "update_engine/payload_generator/cycle_breaker.h"
18
19 #include <set>
20 #include <string>
21 #include <utility>
22 #include <vector>
23
24 #include <base/logging.h>
25 #include <base/stl_util.h>
26 #include <gtest/gtest.h>
27
28 #include "update_engine/payload_generator/graph_types.h"
29
30 using std::make_pair;
31 using std::pair;
32 using std::set;
33 using std::string;
34 using std::vector;
35
36 namespace chromeos_update_engine {
37
38 namespace {
SetOpForNodes(Graph * graph)39 void SetOpForNodes(Graph* graph) {
40 for (Vertex& vertex : *graph) {
41 vertex.aop.op.set_type(InstallOperation::MOVE);
42 }
43 }
44 } // namespace
45
46 class CycleBreakerTest : public ::testing::Test {};
47
TEST(CycleBreakerTest,SimpleTest)48 TEST(CycleBreakerTest, SimpleTest) {
49 int counter = 0;
50 const Vertex::Index n_a = counter++;
51 const Vertex::Index n_b = counter++;
52 const Vertex::Index n_c = counter++;
53 const Vertex::Index n_d = counter++;
54 const Vertex::Index n_e = counter++;
55 const Vertex::Index n_f = counter++;
56 const Vertex::Index n_g = counter++;
57 const Vertex::Index n_h = counter++;
58 const Graph::size_type kNodeCount = counter++;
59
60 Graph graph(kNodeCount);
61 SetOpForNodes(&graph);
62
63 graph[n_a].out_edges.insert(make_pair(n_e, EdgeProperties()));
64 graph[n_a].out_edges.insert(make_pair(n_f, EdgeProperties()));
65 graph[n_b].out_edges.insert(make_pair(n_a, EdgeProperties()));
66 graph[n_c].out_edges.insert(make_pair(n_d, EdgeProperties()));
67 graph[n_d].out_edges.insert(make_pair(n_e, EdgeProperties()));
68 graph[n_d].out_edges.insert(make_pair(n_f, EdgeProperties()));
69 graph[n_e].out_edges.insert(make_pair(n_b, EdgeProperties()));
70 graph[n_e].out_edges.insert(make_pair(n_c, EdgeProperties()));
71 graph[n_e].out_edges.insert(make_pair(n_f, EdgeProperties()));
72 graph[n_f].out_edges.insert(make_pair(n_g, EdgeProperties()));
73 graph[n_g].out_edges.insert(make_pair(n_h, EdgeProperties()));
74 graph[n_h].out_edges.insert(make_pair(n_g, EdgeProperties()));
75
76 CycleBreaker breaker;
77
78 set<Edge> broken_edges;
79 breaker.BreakCycles(graph, &broken_edges);
80
81 // The following cycles must be cut:
82 // A->E->B
83 // C->D->E
84 // G->H
85
86 EXPECT_TRUE(base::ContainsKey(broken_edges, make_pair(n_a, n_e)) ||
87 base::ContainsKey(broken_edges, make_pair(n_e, n_b)) ||
88 base::ContainsKey(broken_edges, make_pair(n_b, n_a)));
89 EXPECT_TRUE(base::ContainsKey(broken_edges, make_pair(n_c, n_d)) ||
90 base::ContainsKey(broken_edges, make_pair(n_d, n_e)) ||
91 base::ContainsKey(broken_edges, make_pair(n_e, n_c)));
92 EXPECT_TRUE(base::ContainsKey(broken_edges, make_pair(n_g, n_h)) ||
93 base::ContainsKey(broken_edges, make_pair(n_h, n_g)));
94 EXPECT_EQ(3U, broken_edges.size());
95 }
96
97 namespace {
EdgeWithWeight(Vertex::Index dest,uint64_t weight)98 pair<Vertex::Index, EdgeProperties> EdgeWithWeight(Vertex::Index dest,
99 uint64_t weight) {
100 EdgeProperties props;
101 props.extents.resize(1);
102 props.extents[0].set_num_blocks(weight);
103 return make_pair(dest, props);
104 }
105 } // namespace
106
107 // This creates a bunch of cycles like this:
108 //
109 // root <------.
110 // (t)-> / | \ |
111 // V V V |
112 // N N N |
113 // \ | / |
114 // VVV |
115 // N |
116 // / | \ |
117 // V V V |
118 // N N N |
119 // ... |
120 // (s)-> \ | / |
121 // VVV |
122 // N |
123 // \_________/
124 //
125 // such that the original cutting algo would cut edges (s). We changed
126 // the algorithm to cut cycles (t) instead, since they are closer to the
127 // root, and that can massively speed up cycle cutting.
TEST(CycleBreakerTest,AggressiveCutTest)128 TEST(CycleBreakerTest, AggressiveCutTest) {
129 size_t counter = 0;
130
131 const int kNodesPerGroup = 4;
132 const int kGroups = 33;
133
134 Graph graph(kGroups * kNodesPerGroup + 1); // + 1 for the root node
135 SetOpForNodes(&graph);
136
137 const Vertex::Index n_root = counter++;
138
139 Vertex::Index last_hub = n_root;
140 for (int i = 0; i < kGroups; i++) {
141 uint64_t weight = 5;
142 if (i == 0)
143 weight = 2;
144 else if (i == (kGroups - 1))
145 weight = 1;
146
147 const Vertex::Index next_hub = counter++;
148
149 for (int j = 0; j < (kNodesPerGroup - 1); j++) {
150 const Vertex::Index node = counter++;
151 graph[last_hub].out_edges.insert(EdgeWithWeight(node, weight));
152 graph[node].out_edges.insert(EdgeWithWeight(next_hub, weight));
153 }
154 last_hub = next_hub;
155 }
156
157 graph[last_hub].out_edges.insert(EdgeWithWeight(n_root, 5));
158
159 EXPECT_EQ(counter, graph.size());
160
161 CycleBreaker breaker;
162
163 set<Edge> broken_edges;
164 LOG(INFO) << "If this hangs for more than 1 second, the test has failed.";
165 breaker.BreakCycles(graph, &broken_edges);
166
167 set<Edge> expected_cuts;
168
169 for (Vertex::EdgeMap::const_iterator it = graph[n_root].out_edges.begin(),
170 e = graph[n_root].out_edges.end();
171 it != e;
172 ++it) {
173 expected_cuts.insert(make_pair(n_root, it->first));
174 }
175
176 EXPECT_TRUE(broken_edges == expected_cuts);
177 }
178
TEST(CycleBreakerTest,WeightTest)179 TEST(CycleBreakerTest, WeightTest) {
180 size_t counter = 0;
181 const Vertex::Index n_a = counter++;
182 const Vertex::Index n_b = counter++;
183 const Vertex::Index n_c = counter++;
184 const Vertex::Index n_d = counter++;
185 const Vertex::Index n_e = counter++;
186 const Vertex::Index n_f = counter++;
187 const Vertex::Index n_g = counter++;
188 const Vertex::Index n_h = counter++;
189 const Vertex::Index n_i = counter++;
190 const Vertex::Index n_j = counter++;
191 const Graph::size_type kNodeCount = counter++;
192
193 Graph graph(kNodeCount);
194 SetOpForNodes(&graph);
195
196 graph[n_a].out_edges.insert(EdgeWithWeight(n_b, 4));
197 graph[n_a].out_edges.insert(EdgeWithWeight(n_f, 3));
198 graph[n_a].out_edges.insert(EdgeWithWeight(n_h, 2));
199 graph[n_b].out_edges.insert(EdgeWithWeight(n_a, 3));
200 graph[n_b].out_edges.insert(EdgeWithWeight(n_c, 4));
201 graph[n_c].out_edges.insert(EdgeWithWeight(n_b, 5));
202 graph[n_c].out_edges.insert(EdgeWithWeight(n_d, 3));
203 graph[n_d].out_edges.insert(EdgeWithWeight(n_a, 6));
204 graph[n_d].out_edges.insert(EdgeWithWeight(n_e, 3));
205 graph[n_e].out_edges.insert(EdgeWithWeight(n_d, 4));
206 graph[n_e].out_edges.insert(EdgeWithWeight(n_g, 5));
207 graph[n_f].out_edges.insert(EdgeWithWeight(n_g, 2));
208 graph[n_g].out_edges.insert(EdgeWithWeight(n_f, 3));
209 graph[n_g].out_edges.insert(EdgeWithWeight(n_d, 5));
210 graph[n_h].out_edges.insert(EdgeWithWeight(n_i, 8));
211 graph[n_i].out_edges.insert(EdgeWithWeight(n_e, 4));
212 graph[n_i].out_edges.insert(EdgeWithWeight(n_h, 9));
213 graph[n_i].out_edges.insert(EdgeWithWeight(n_j, 6));
214
215 CycleBreaker breaker;
216
217 set<Edge> broken_edges;
218 breaker.BreakCycles(graph, &broken_edges);
219
220 // These are required to be broken:
221 EXPECT_TRUE(base::ContainsKey(broken_edges, make_pair(n_b, n_a)));
222 EXPECT_TRUE(base::ContainsKey(broken_edges, make_pair(n_b, n_c)));
223 EXPECT_TRUE(base::ContainsKey(broken_edges, make_pair(n_d, n_e)));
224 EXPECT_TRUE(base::ContainsKey(broken_edges, make_pair(n_f, n_g)));
225 EXPECT_TRUE(base::ContainsKey(broken_edges, make_pair(n_h, n_i)));
226 }
227
TEST(CycleBreakerTest,UnblockGraphTest)228 TEST(CycleBreakerTest, UnblockGraphTest) {
229 size_t counter = 0;
230 const Vertex::Index n_a = counter++;
231 const Vertex::Index n_b = counter++;
232 const Vertex::Index n_c = counter++;
233 const Vertex::Index n_d = counter++;
234 const Graph::size_type kNodeCount = counter++;
235
236 Graph graph(kNodeCount);
237 SetOpForNodes(&graph);
238
239 graph[n_a].out_edges.insert(EdgeWithWeight(n_b, 1));
240 graph[n_a].out_edges.insert(EdgeWithWeight(n_c, 1));
241 graph[n_b].out_edges.insert(EdgeWithWeight(n_c, 2));
242 graph[n_c].out_edges.insert(EdgeWithWeight(n_b, 2));
243 graph[n_b].out_edges.insert(EdgeWithWeight(n_d, 2));
244 graph[n_d].out_edges.insert(EdgeWithWeight(n_a, 2));
245
246 CycleBreaker breaker;
247
248 set<Edge> broken_edges;
249 breaker.BreakCycles(graph, &broken_edges);
250
251 // These are required to be broken:
252 EXPECT_TRUE(base::ContainsKey(broken_edges, make_pair(n_a, n_b)));
253 EXPECT_TRUE(base::ContainsKey(broken_edges, make_pair(n_a, n_c)));
254 }
255
TEST(CycleBreakerTest,SkipOpsTest)256 TEST(CycleBreakerTest, SkipOpsTest) {
257 size_t counter = 0;
258 const Vertex::Index n_a = counter++;
259 const Vertex::Index n_b = counter++;
260 const Vertex::Index n_c = counter++;
261 const Graph::size_type kNodeCount = counter++;
262
263 Graph graph(kNodeCount);
264 SetOpForNodes(&graph);
265 graph[n_a].aop.op.set_type(InstallOperation::REPLACE_BZ);
266 graph[n_c].aop.op.set_type(InstallOperation::REPLACE);
267
268 graph[n_a].out_edges.insert(EdgeWithWeight(n_b, 1));
269 graph[n_c].out_edges.insert(EdgeWithWeight(n_b, 1));
270
271 CycleBreaker breaker;
272
273 set<Edge> broken_edges;
274 breaker.BreakCycles(graph, &broken_edges);
275
276 EXPECT_EQ(2U, breaker.skipped_ops());
277 }
278
279 } // namespace chromeos_update_engine
280