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Diffstat (limited to 'src/leveldb/db/skiplist_test.cc')
-rw-r--r-- | src/leveldb/db/skiplist_test.cc | 378 |
1 files changed, 0 insertions, 378 deletions
diff --git a/src/leveldb/db/skiplist_test.cc b/src/leveldb/db/skiplist_test.cc deleted file mode 100644 index c78f4b4fb1..0000000000 --- a/src/leveldb/db/skiplist_test.cc +++ /dev/null @@ -1,378 +0,0 @@ -// Copyright (c) 2011 The LevelDB Authors. All rights reserved. -// Use of this source code is governed by a BSD-style license that can be -// found in the LICENSE file. See the AUTHORS file for names of contributors. - -#include "db/skiplist.h" -#include <set> -#include "leveldb/env.h" -#include "util/arena.h" -#include "util/hash.h" -#include "util/random.h" -#include "util/testharness.h" - -namespace leveldb { - -typedef uint64_t Key; - -struct Comparator { - int operator()(const Key& a, const Key& b) const { - if (a < b) { - return -1; - } else if (a > b) { - return +1; - } else { - return 0; - } - } -}; - -class SkipTest { }; - -TEST(SkipTest, Empty) { - Arena arena; - Comparator cmp; - SkipList<Key, Comparator> list(cmp, &arena); - ASSERT_TRUE(!list.Contains(10)); - - SkipList<Key, Comparator>::Iterator iter(&list); - ASSERT_TRUE(!iter.Valid()); - iter.SeekToFirst(); - ASSERT_TRUE(!iter.Valid()); - iter.Seek(100); - ASSERT_TRUE(!iter.Valid()); - iter.SeekToLast(); - ASSERT_TRUE(!iter.Valid()); -} - -TEST(SkipTest, InsertAndLookup) { - const int N = 2000; - const int R = 5000; - Random rnd(1000); - std::set<Key> keys; - Arena arena; - Comparator cmp; - SkipList<Key, Comparator> list(cmp, &arena); - for (int i = 0; i < N; i++) { - Key key = rnd.Next() % R; - if (keys.insert(key).second) { - list.Insert(key); - } - } - - for (int i = 0; i < R; i++) { - if (list.Contains(i)) { - ASSERT_EQ(keys.count(i), 1); - } else { - ASSERT_EQ(keys.count(i), 0); - } - } - - // Simple iterator tests - { - SkipList<Key, Comparator>::Iterator iter(&list); - ASSERT_TRUE(!iter.Valid()); - - iter.Seek(0); - ASSERT_TRUE(iter.Valid()); - ASSERT_EQ(*(keys.begin()), iter.key()); - - iter.SeekToFirst(); - ASSERT_TRUE(iter.Valid()); - ASSERT_EQ(*(keys.begin()), iter.key()); - - iter.SeekToLast(); - ASSERT_TRUE(iter.Valid()); - ASSERT_EQ(*(keys.rbegin()), iter.key()); - } - - // Forward iteration test - for (int i = 0; i < R; i++) { - SkipList<Key, Comparator>::Iterator iter(&list); - iter.Seek(i); - - // Compare against model iterator - std::set<Key>::iterator model_iter = keys.lower_bound(i); - for (int j = 0; j < 3; j++) { - if (model_iter == keys.end()) { - ASSERT_TRUE(!iter.Valid()); - break; - } else { - ASSERT_TRUE(iter.Valid()); - ASSERT_EQ(*model_iter, iter.key()); - ++model_iter; - iter.Next(); - } - } - } - - // Backward iteration test - { - SkipList<Key, Comparator>::Iterator iter(&list); - iter.SeekToLast(); - - // Compare against model iterator - for (std::set<Key>::reverse_iterator model_iter = keys.rbegin(); - model_iter != keys.rend(); - ++model_iter) { - ASSERT_TRUE(iter.Valid()); - ASSERT_EQ(*model_iter, iter.key()); - iter.Prev(); - } - ASSERT_TRUE(!iter.Valid()); - } -} - -// We want to make sure that with a single writer and multiple -// concurrent readers (with no synchronization other than when a -// reader's iterator is created), the reader always observes all the -// data that was present in the skip list when the iterator was -// constructor. Because insertions are happening concurrently, we may -// also observe new values that were inserted since the iterator was -// constructed, but we should never miss any values that were present -// at iterator construction time. -// -// We generate multi-part keys: -// <key,gen,hash> -// where: -// key is in range [0..K-1] -// gen is a generation number for key -// hash is hash(key,gen) -// -// The insertion code picks a random key, sets gen to be 1 + the last -// generation number inserted for that key, and sets hash to Hash(key,gen). -// -// At the beginning of a read, we snapshot the last inserted -// generation number for each key. We then iterate, including random -// calls to Next() and Seek(). For every key we encounter, we -// check that it is either expected given the initial snapshot or has -// been concurrently added since the iterator started. -class ConcurrentTest { - private: - static const uint32_t K = 4; - - static uint64_t key(Key key) { return (key >> 40); } - static uint64_t gen(Key key) { return (key >> 8) & 0xffffffffu; } - static uint64_t hash(Key key) { return key & 0xff; } - - static uint64_t HashNumbers(uint64_t k, uint64_t g) { - uint64_t data[2] = { k, g }; - return Hash(reinterpret_cast<char*>(data), sizeof(data), 0); - } - - static Key MakeKey(uint64_t k, uint64_t g) { - assert(sizeof(Key) == sizeof(uint64_t)); - assert(k <= K); // We sometimes pass K to seek to the end of the skiplist - assert(g <= 0xffffffffu); - return ((k << 40) | (g << 8) | (HashNumbers(k, g) & 0xff)); - } - - static bool IsValidKey(Key k) { - return hash(k) == (HashNumbers(key(k), gen(k)) & 0xff); - } - - static Key RandomTarget(Random* rnd) { - switch (rnd->Next() % 10) { - case 0: - // Seek to beginning - return MakeKey(0, 0); - case 1: - // Seek to end - return MakeKey(K, 0); - default: - // Seek to middle - return MakeKey(rnd->Next() % K, 0); - } - } - - // Per-key generation - struct State { - port::AtomicPointer generation[K]; - void Set(int k, intptr_t v) { - generation[k].Release_Store(reinterpret_cast<void*>(v)); - } - intptr_t Get(int k) { - return reinterpret_cast<intptr_t>(generation[k].Acquire_Load()); - } - - State() { - for (int k = 0; k < K; k++) { - Set(k, 0); - } - } - }; - - // Current state of the test - State current_; - - Arena arena_; - - // SkipList is not protected by mu_. We just use a single writer - // thread to modify it. - SkipList<Key, Comparator> list_; - - public: - ConcurrentTest() : list_(Comparator(), &arena_) { } - - // REQUIRES: External synchronization - void WriteStep(Random* rnd) { - const uint32_t k = rnd->Next() % K; - const intptr_t g = current_.Get(k) + 1; - const Key key = MakeKey(k, g); - list_.Insert(key); - current_.Set(k, g); - } - - void ReadStep(Random* rnd) { - // Remember the initial committed state of the skiplist. - State initial_state; - for (int k = 0; k < K; k++) { - initial_state.Set(k, current_.Get(k)); - } - - Key pos = RandomTarget(rnd); - SkipList<Key, Comparator>::Iterator iter(&list_); - iter.Seek(pos); - while (true) { - Key current; - if (!iter.Valid()) { - current = MakeKey(K, 0); - } else { - current = iter.key(); - ASSERT_TRUE(IsValidKey(current)) << current; - } - ASSERT_LE(pos, current) << "should not go backwards"; - - // Verify that everything in [pos,current) was not present in - // initial_state. - while (pos < current) { - ASSERT_LT(key(pos), K) << pos; - - // Note that generation 0 is never inserted, so it is ok if - // <*,0,*> is missing. - ASSERT_TRUE((gen(pos) == 0) || - (gen(pos) > initial_state.Get(key(pos))) - ) << "key: " << key(pos) - << "; gen: " << gen(pos) - << "; initgen: " - << initial_state.Get(key(pos)); - - // Advance to next key in the valid key space - if (key(pos) < key(current)) { - pos = MakeKey(key(pos) + 1, 0); - } else { - pos = MakeKey(key(pos), gen(pos) + 1); - } - } - - if (!iter.Valid()) { - break; - } - - if (rnd->Next() % 2) { - iter.Next(); - pos = MakeKey(key(pos), gen(pos) + 1); - } else { - Key new_target = RandomTarget(rnd); - if (new_target > pos) { - pos = new_target; - iter.Seek(new_target); - } - } - } - } -}; -const uint32_t ConcurrentTest::K; - -// Simple test that does single-threaded testing of the ConcurrentTest -// scaffolding. -TEST(SkipTest, ConcurrentWithoutThreads) { - ConcurrentTest test; - Random rnd(test::RandomSeed()); - for (int i = 0; i < 10000; i++) { - test.ReadStep(&rnd); - test.WriteStep(&rnd); - } -} - -class TestState { - public: - ConcurrentTest t_; - int seed_; - port::AtomicPointer quit_flag_; - - enum ReaderState { - STARTING, - RUNNING, - DONE - }; - - explicit TestState(int s) - : seed_(s), - quit_flag_(NULL), - state_(STARTING), - state_cv_(&mu_) {} - - void Wait(ReaderState s) { - mu_.Lock(); - while (state_ != s) { - state_cv_.Wait(); - } - mu_.Unlock(); - } - - void Change(ReaderState s) { - mu_.Lock(); - state_ = s; - state_cv_.Signal(); - mu_.Unlock(); - } - - private: - port::Mutex mu_; - ReaderState state_; - port::CondVar state_cv_; -}; - -static void ConcurrentReader(void* arg) { - TestState* state = reinterpret_cast<TestState*>(arg); - Random rnd(state->seed_); - int64_t reads = 0; - state->Change(TestState::RUNNING); - while (!state->quit_flag_.Acquire_Load()) { - state->t_.ReadStep(&rnd); - ++reads; - } - state->Change(TestState::DONE); -} - -static void RunConcurrent(int run) { - const int seed = test::RandomSeed() + (run * 100); - Random rnd(seed); - const int N = 1000; - const int kSize = 1000; - for (int i = 0; i < N; i++) { - if ((i % 100) == 0) { - fprintf(stderr, "Run %d of %d\n", i, N); - } - TestState state(seed + 1); - Env::Default()->Schedule(ConcurrentReader, &state); - state.Wait(TestState::RUNNING); - for (int i = 0; i < kSize; i++) { - state.t_.WriteStep(&rnd); - } - state.quit_flag_.Release_Store(&state); // Any non-NULL arg will do - state.Wait(TestState::DONE); - } -} - -TEST(SkipTest, Concurrent1) { RunConcurrent(1); } -TEST(SkipTest, Concurrent2) { RunConcurrent(2); } -TEST(SkipTest, Concurrent3) { RunConcurrent(3); } -TEST(SkipTest, Concurrent4) { RunConcurrent(4); } -TEST(SkipTest, Concurrent5) { RunConcurrent(5); } - -} // namespace leveldb - -int main(int argc, char** argv) { - return leveldb::test::RunAllTests(); -} |