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-rw-r--r--src/leveldb/db/skiplist_test.cc378
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diff --git a/src/leveldb/db/skiplist_test.cc b/src/leveldb/db/skiplist_test.cc
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--- a/src/leveldb/db/skiplist_test.cc
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@@ -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();
-}