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Diffstat (limited to 'third_party/abseil_cpp/absl/synchronization/internal/graphcycles_test.cc')
| -rw-r--r-- | third_party/abseil_cpp/absl/synchronization/internal/graphcycles_test.cc | 464 |
1 files changed, 0 insertions, 464 deletions
diff --git a/third_party/abseil_cpp/absl/synchronization/internal/graphcycles_test.cc b/third_party/abseil_cpp/absl/synchronization/internal/graphcycles_test.cc deleted file mode 100644 index 74eaffe7a8..0000000000 --- a/third_party/abseil_cpp/absl/synchronization/internal/graphcycles_test.cc +++ /dev/null @@ -1,464 +0,0 @@ -// Copyright 2017 The Abseil Authors. -// -// Licensed 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 -// -// https://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. - -#include "absl/synchronization/internal/graphcycles.h" - -#include <map> -#include <random> -#include <unordered_set> -#include <utility> -#include <vector> - -#include "gtest/gtest.h" -#include "absl/base/internal/raw_logging.h" -#include "absl/base/macros.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace synchronization_internal { - -// We emulate a GraphCycles object with a node vector and an edge vector. -// We then compare the two implementations. - -using Nodes = std::vector<int>; -struct Edge { - int from; - int to; -}; -using Edges = std::vector<Edge>; -using RandomEngine = std::mt19937_64; - -// Mapping from integer index to GraphId. -typedef std::map<int, GraphId> IdMap; -static GraphId Get(const IdMap& id, int num) { - auto iter = id.find(num); - return (iter == id.end()) ? InvalidGraphId() : iter->second; -} - -// Return whether "to" is reachable from "from". -static bool IsReachable(Edges *edges, int from, int to, - std::unordered_set<int> *seen) { - seen->insert(from); // we are investigating "from"; don't do it again - if (from == to) return true; - for (const auto &edge : *edges) { - if (edge.from == from) { - if (edge.to == to) { // success via edge directly - return true; - } else if (seen->find(edge.to) == seen->end() && // success via edge - IsReachable(edges, edge.to, to, seen)) { - return true; - } - } - } - return false; -} - -static void PrintEdges(Edges *edges) { - ABSL_RAW_LOG(INFO, "EDGES (%zu)", edges->size()); - for (const auto &edge : *edges) { - int a = edge.from; - int b = edge.to; - ABSL_RAW_LOG(INFO, "%d %d", a, b); - } - ABSL_RAW_LOG(INFO, "---"); -} - -static void PrintGCEdges(Nodes *nodes, const IdMap &id, GraphCycles *gc) { - ABSL_RAW_LOG(INFO, "GC EDGES"); - for (int a : *nodes) { - for (int b : *nodes) { - if (gc->HasEdge(Get(id, a), Get(id, b))) { - ABSL_RAW_LOG(INFO, "%d %d", a, b); - } - } - } - ABSL_RAW_LOG(INFO, "---"); -} - -static void PrintTransitiveClosure(Nodes *nodes, Edges *edges) { - ABSL_RAW_LOG(INFO, "Transitive closure"); - for (int a : *nodes) { - for (int b : *nodes) { - std::unordered_set<int> seen; - if (IsReachable(edges, a, b, &seen)) { - ABSL_RAW_LOG(INFO, "%d %d", a, b); - } - } - } - ABSL_RAW_LOG(INFO, "---"); -} - -static void PrintGCTransitiveClosure(Nodes *nodes, const IdMap &id, - GraphCycles *gc) { - ABSL_RAW_LOG(INFO, "GC Transitive closure"); - for (int a : *nodes) { - for (int b : *nodes) { - if (gc->IsReachable(Get(id, a), Get(id, b))) { - ABSL_RAW_LOG(INFO, "%d %d", a, b); - } - } - } - ABSL_RAW_LOG(INFO, "---"); -} - -static void CheckTransitiveClosure(Nodes *nodes, Edges *edges, const IdMap &id, - GraphCycles *gc) { - std::unordered_set<int> seen; - for (const auto &a : *nodes) { - for (const auto &b : *nodes) { - seen.clear(); - bool gc_reachable = gc->IsReachable(Get(id, a), Get(id, b)); - bool reachable = IsReachable(edges, a, b, &seen); - if (gc_reachable != reachable) { - PrintEdges(edges); - PrintGCEdges(nodes, id, gc); - PrintTransitiveClosure(nodes, edges); - PrintGCTransitiveClosure(nodes, id, gc); - ABSL_RAW_LOG(FATAL, "gc_reachable %s reachable %s a %d b %d", - gc_reachable ? "true" : "false", - reachable ? "true" : "false", a, b); - } - } - } -} - -static void CheckEdges(Nodes *nodes, Edges *edges, const IdMap &id, - GraphCycles *gc) { - int count = 0; - for (const auto &edge : *edges) { - int a = edge.from; - int b = edge.to; - if (!gc->HasEdge(Get(id, a), Get(id, b))) { - PrintEdges(edges); - PrintGCEdges(nodes, id, gc); - ABSL_RAW_LOG(FATAL, "!gc->HasEdge(%d, %d)", a, b); - } - } - for (const auto &a : *nodes) { - for (const auto &b : *nodes) { - if (gc->HasEdge(Get(id, a), Get(id, b))) { - count++; - } - } - } - if (count != edges->size()) { - PrintEdges(edges); - PrintGCEdges(nodes, id, gc); - ABSL_RAW_LOG(FATAL, "edges->size() %zu count %d", edges->size(), count); - } -} - -static void CheckInvariants(const GraphCycles &gc) { - if (ABSL_PREDICT_FALSE(!gc.CheckInvariants())) - ABSL_RAW_LOG(FATAL, "CheckInvariants"); -} - -// Returns the index of a randomly chosen node in *nodes. -// Requires *nodes be non-empty. -static int RandomNode(RandomEngine* rng, Nodes *nodes) { - std::uniform_int_distribution<int> uniform(0, nodes->size()-1); - return uniform(*rng); -} - -// Returns the index of a randomly chosen edge in *edges. -// Requires *edges be non-empty. -static int RandomEdge(RandomEngine* rng, Edges *edges) { - std::uniform_int_distribution<int> uniform(0, edges->size()-1); - return uniform(*rng); -} - -// Returns the index of edge (from, to) in *edges or -1 if it is not in *edges. -static int EdgeIndex(Edges *edges, int from, int to) { - int i = 0; - while (i != edges->size() && - ((*edges)[i].from != from || (*edges)[i].to != to)) { - i++; - } - return i == edges->size()? -1 : i; -} - -TEST(GraphCycles, RandomizedTest) { - int next_node = 0; - Nodes nodes; - Edges edges; // from, to - IdMap id; - GraphCycles graph_cycles; - static const int kMaxNodes = 7; // use <= 7 nodes to keep test short - static const int kDataOffset = 17; // an offset to the node-specific data - int n = 100000; - int op = 0; - RandomEngine rng(testing::UnitTest::GetInstance()->random_seed()); - std::uniform_int_distribution<int> uniform(0, 5); - - auto ptr = [](intptr_t i) { - return reinterpret_cast<void*>(i + kDataOffset); - }; - - for (int iter = 0; iter != n; iter++) { - for (const auto &node : nodes) { - ASSERT_EQ(graph_cycles.Ptr(Get(id, node)), ptr(node)) << " node " << node; - } - CheckEdges(&nodes, &edges, id, &graph_cycles); - CheckTransitiveClosure(&nodes, &edges, id, &graph_cycles); - op = uniform(rng); - switch (op) { - case 0: // Add a node - if (nodes.size() < kMaxNodes) { - int new_node = next_node++; - GraphId new_gnode = graph_cycles.GetId(ptr(new_node)); - ASSERT_NE(new_gnode, InvalidGraphId()); - id[new_node] = new_gnode; - ASSERT_EQ(ptr(new_node), graph_cycles.Ptr(new_gnode)); - nodes.push_back(new_node); - } - break; - - case 1: // Remove a node - if (nodes.size() > 0) { - int node_index = RandomNode(&rng, &nodes); - int node = nodes[node_index]; - nodes[node_index] = nodes.back(); - nodes.pop_back(); - graph_cycles.RemoveNode(ptr(node)); - ASSERT_EQ(graph_cycles.Ptr(Get(id, node)), nullptr); - id.erase(node); - int i = 0; - while (i != edges.size()) { - if (edges[i].from == node || edges[i].to == node) { - edges[i] = edges.back(); - edges.pop_back(); - } else { - i++; - } - } - } - break; - - case 2: // Add an edge - if (nodes.size() > 0) { - int from = RandomNode(&rng, &nodes); - int to = RandomNode(&rng, &nodes); - if (EdgeIndex(&edges, nodes[from], nodes[to]) == -1) { - if (graph_cycles.InsertEdge(id[nodes[from]], id[nodes[to]])) { - Edge new_edge; - new_edge.from = nodes[from]; - new_edge.to = nodes[to]; - edges.push_back(new_edge); - } else { - std::unordered_set<int> seen; - ASSERT_TRUE(IsReachable(&edges, nodes[to], nodes[from], &seen)) - << "Edge " << nodes[to] << "->" << nodes[from]; - } - } - } - break; - - case 3: // Remove an edge - if (edges.size() > 0) { - int i = RandomEdge(&rng, &edges); - int from = edges[i].from; - int to = edges[i].to; - ASSERT_EQ(i, EdgeIndex(&edges, from, to)); - edges[i] = edges.back(); - edges.pop_back(); - ASSERT_EQ(-1, EdgeIndex(&edges, from, to)); - graph_cycles.RemoveEdge(id[from], id[to]); - } - break; - - case 4: // Check a path - if (nodes.size() > 0) { - int from = RandomNode(&rng, &nodes); - int to = RandomNode(&rng, &nodes); - GraphId path[2*kMaxNodes]; - int path_len = graph_cycles.FindPath(id[nodes[from]], id[nodes[to]], - ABSL_ARRAYSIZE(path), path); - std::unordered_set<int> seen; - bool reachable = IsReachable(&edges, nodes[from], nodes[to], &seen); - bool gc_reachable = - graph_cycles.IsReachable(Get(id, nodes[from]), Get(id, nodes[to])); - ASSERT_EQ(path_len != 0, reachable); - ASSERT_EQ(path_len != 0, gc_reachable); - // In the following line, we add one because a node can appear - // twice, if the path is from that node to itself, perhaps via - // every other node. - ASSERT_LE(path_len, kMaxNodes + 1); - if (path_len != 0) { - ASSERT_EQ(id[nodes[from]], path[0]); - ASSERT_EQ(id[nodes[to]], path[path_len-1]); - for (int i = 1; i < path_len; i++) { - ASSERT_TRUE(graph_cycles.HasEdge(path[i-1], path[i])); - } - } - } - break; - - case 5: // Check invariants - CheckInvariants(graph_cycles); - break; - - default: - ABSL_RAW_LOG(FATAL, "op %d", op); - } - - // Very rarely, test graph expansion by adding then removing many nodes. - std::bernoulli_distribution one_in_1024(1.0 / 1024); - if (one_in_1024(rng)) { - CheckEdges(&nodes, &edges, id, &graph_cycles); - CheckTransitiveClosure(&nodes, &edges, id, &graph_cycles); - for (int i = 0; i != 256; i++) { - int new_node = next_node++; - GraphId new_gnode = graph_cycles.GetId(ptr(new_node)); - ASSERT_NE(InvalidGraphId(), new_gnode); - id[new_node] = new_gnode; - ASSERT_EQ(ptr(new_node), graph_cycles.Ptr(new_gnode)); - for (const auto &node : nodes) { - ASSERT_NE(node, new_node); - } - nodes.push_back(new_node); - } - for (int i = 0; i != 256; i++) { - ASSERT_GT(nodes.size(), 0); - int node_index = RandomNode(&rng, &nodes); - int node = nodes[node_index]; - nodes[node_index] = nodes.back(); - nodes.pop_back(); - graph_cycles.RemoveNode(ptr(node)); - id.erase(node); - int j = 0; - while (j != edges.size()) { - if (edges[j].from == node || edges[j].to == node) { - edges[j] = edges.back(); - edges.pop_back(); - } else { - j++; - } - } - } - CheckInvariants(graph_cycles); - } - } -} - -class GraphCyclesTest : public ::testing::Test { - public: - IdMap id_; - GraphCycles g_; - - static void* Ptr(int i) { - return reinterpret_cast<void*>(static_cast<uintptr_t>(i)); - } - - static int Num(void* ptr) { - return static_cast<int>(reinterpret_cast<uintptr_t>(ptr)); - } - - // Test relies on ith NewNode() call returning Node numbered i - GraphCyclesTest() { - for (int i = 0; i < 100; i++) { - id_[i] = g_.GetId(Ptr(i)); - } - CheckInvariants(g_); - } - - bool AddEdge(int x, int y) { - return g_.InsertEdge(Get(id_, x), Get(id_, y)); - } - - void AddMultiples() { - // For every node x > 0: add edge to 2*x, 3*x - for (int x = 1; x < 25; x++) { - EXPECT_TRUE(AddEdge(x, 2*x)) << x; - EXPECT_TRUE(AddEdge(x, 3*x)) << x; - } - CheckInvariants(g_); - } - - std::string Path(int x, int y) { - GraphId path[5]; - int np = g_.FindPath(Get(id_, x), Get(id_, y), ABSL_ARRAYSIZE(path), path); - std::string result; - for (int i = 0; i < np; i++) { - if (i >= ABSL_ARRAYSIZE(path)) { - result += " ..."; - break; - } - if (!result.empty()) result.push_back(' '); - char buf[20]; - snprintf(buf, sizeof(buf), "%d", Num(g_.Ptr(path[i]))); - result += buf; - } - return result; - } -}; - -TEST_F(GraphCyclesTest, NoCycle) { - AddMultiples(); - CheckInvariants(g_); -} - -TEST_F(GraphCyclesTest, SimpleCycle) { - AddMultiples(); - EXPECT_FALSE(AddEdge(8, 4)); - EXPECT_EQ("4 8", Path(4, 8)); - CheckInvariants(g_); -} - -TEST_F(GraphCyclesTest, IndirectCycle) { - AddMultiples(); - EXPECT_TRUE(AddEdge(16, 9)); - CheckInvariants(g_); - EXPECT_FALSE(AddEdge(9, 2)); - EXPECT_EQ("2 4 8 16 9", Path(2, 9)); - CheckInvariants(g_); -} - -TEST_F(GraphCyclesTest, LongPath) { - ASSERT_TRUE(AddEdge(2, 4)); - ASSERT_TRUE(AddEdge(4, 6)); - ASSERT_TRUE(AddEdge(6, 8)); - ASSERT_TRUE(AddEdge(8, 10)); - ASSERT_TRUE(AddEdge(10, 12)); - ASSERT_FALSE(AddEdge(12, 2)); - EXPECT_EQ("2 4 6 8 10 ...", Path(2, 12)); - CheckInvariants(g_); -} - -TEST_F(GraphCyclesTest, RemoveNode) { - ASSERT_TRUE(AddEdge(1, 2)); - ASSERT_TRUE(AddEdge(2, 3)); - ASSERT_TRUE(AddEdge(3, 4)); - ASSERT_TRUE(AddEdge(4, 5)); - g_.RemoveNode(g_.Ptr(id_[3])); - id_.erase(3); - ASSERT_TRUE(AddEdge(5, 1)); -} - -TEST_F(GraphCyclesTest, ManyEdges) { - const int N = 50; - for (int i = 0; i < N; i++) { - for (int j = 1; j < N; j++) { - ASSERT_TRUE(AddEdge(i, i+j)); - } - } - CheckInvariants(g_); - ASSERT_TRUE(AddEdge(2*N-1, 0)); - CheckInvariants(g_); - ASSERT_FALSE(AddEdge(10, 9)); - CheckInvariants(g_); -} - -} // namespace synchronization_internal -ABSL_NAMESPACE_END -} // namespace absl |