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Diffstat (limited to 'absl/random/seed_sequences_test.cc')
-rw-r--r-- | absl/random/seed_sequences_test.cc | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/absl/random/seed_sequences_test.cc b/absl/random/seed_sequences_test.cc new file mode 100644 index 00000000..2cc8b0e6 --- /dev/null +++ b/absl/random/seed_sequences_test.cc @@ -0,0 +1,127 @@ +// 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/random/seed_sequences.h" + +#include <iterator> +#include <random> + +#include "gmock/gmock.h" +#include "gtest/gtest.h" +#include "absl/random/internal/nonsecure_base.h" +#include "absl/random/random.h" +namespace { + +TEST(SeedSequences, Examples) { + { + absl::SeedSeq seed_seq({1, 2, 3}); + absl::BitGen bitgen(seed_seq); + + EXPECT_NE(0, bitgen()); + } + { + absl::BitGen engine; + auto seed_seq = absl::CreateSeedSeqFrom(&engine); + absl::BitGen bitgen(seed_seq); + + EXPECT_NE(engine(), bitgen()); + } + { + auto seed_seq = absl::MakeSeedSeq(); + std::mt19937 random(seed_seq); + + EXPECT_NE(0, random()); + } +} + +TEST(CreateSeedSeqFrom, CompatibleWithStdTypes) { + using ExampleNonsecureURBG = + absl::random_internal::NonsecureURBGBase<std::minstd_rand0>; + + // Construct a URBG instance. + ExampleNonsecureURBG rng; + + // Construct a Seed Sequence from its variates. + auto seq_from_rng = absl::CreateSeedSeqFrom(&rng); + + // Ensure that another URBG can be validly constructed from the Seed Sequence. + std::mt19937_64{seq_from_rng}; +} + +TEST(CreateSeedSeqFrom, CompatibleWithBitGenerator) { + // Construct a URBG instance. + absl::BitGen rng; + + // Construct a Seed Sequence from its variates. + auto seq_from_rng = absl::CreateSeedSeqFrom(&rng); + + // Ensure that another URBG can be validly constructed from the Seed Sequence. + std::mt19937_64{seq_from_rng}; +} + +TEST(CreateSeedSeqFrom, CompatibleWithInsecureBitGen) { + // Construct a URBG instance. + absl::InsecureBitGen rng; + + // Construct a Seed Sequence from its variates. + auto seq_from_rng = absl::CreateSeedSeqFrom(&rng); + + // Ensure that another URBG can be validly constructed from the Seed Sequence. + std::mt19937_64{seq_from_rng}; +} + +TEST(CreateSeedSeqFrom, CompatibleWithRawURBG) { + // Construct a URBG instance. + std::random_device urandom; + + // Construct a Seed Sequence from its variates, using 64b of seed-material. + auto seq_from_rng = absl::CreateSeedSeqFrom(&urandom); + + // Ensure that another URBG can be validly constructed from the Seed Sequence. + std::mt19937_64{seq_from_rng}; +} + +template <typename URBG> +void TestReproducibleVariateSequencesForNonsecureURBG() { + const size_t kNumVariates = 1000; + + // Master RNG instance. + URBG rng; + // Reused for both RNG instances. + auto reusable_seed = absl::CreateSeedSeqFrom(&rng); + + typename URBG::result_type variates[kNumVariates]; + { + URBG child(reusable_seed); + for (auto& variate : variates) { + variate = child(); + } + } + // Ensure that variate-sequence can be "replayed" by identical RNG. + { + URBG child(reusable_seed); + for (auto& variate : variates) { + ASSERT_EQ(variate, child()); + } + } +} + +TEST(CreateSeedSeqFrom, ReproducesVariateSequencesForInsecureBitGen) { + TestReproducibleVariateSequencesForNonsecureURBG<absl::InsecureBitGen>(); +} + +TEST(CreateSeedSeqFrom, ReproducesVariateSequencesForBitGenerator) { + TestReproducibleVariateSequencesForNonsecureURBG<absl::BitGen>(); +} +} // namespace |