ceph/src/rocksdb/test_util/mock_time_env.h

   1 // Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under both the GPLv2 (found in the
   3 //  COPYING file in the root directory) and Apache 2.0 License
   4 //  (found in the LICENSE.Apache file in the root directory).
   5
   6 #pragma once
   7
   8 #include <atomic>
   9 #include <limits>
  10
  11 #include "rocksdb/system_clock.h"
  12
  13 namespace ROCKSDB_NAMESPACE {
  14
  15 // NOTE: SpecialEnv offers most of this functionality, along with hooks
  16 // for safe DB behavior under a mock time environment, so should be used
  17 // instead of MockSystemClock for DB tests.
  18 class MockSystemClock : public SystemClockWrapper {
  19  public:
  20   explicit MockSystemClock(const std::shared_ptr<SystemClock>& base)
  21       : SystemClockWrapper(base) {}
  22
  23   static const char* kClassName() { return "MockSystemClock"; }
  24   const char* Name() const override { return kClassName(); }
  25   virtual Status GetCurrentTime(int64_t* time_sec) override {
  26     assert(time_sec != nullptr);
  27     *time_sec = static_cast<int64_t>(current_time_us_ / kMicrosInSecond);
  28     return Status::OK();
  29   }
  30
  31   virtual uint64_t NowSeconds() { return current_time_us_ / kMicrosInSecond; }
  32
  33   virtual uint64_t NowMicros() override { return current_time_us_; }
  34
  35   virtual uint64_t NowNanos() override {
  36     assert(current_time_us_ <= std::numeric_limits<uint64_t>::max() / 1000);
  37     return current_time_us_ * 1000;
  38   }
  39
  40   uint64_t RealNowMicros() { return target_->NowMicros(); }
  41
  42   void SetCurrentTime(uint64_t time_sec) {
  43     assert(time_sec < std::numeric_limits<uint64_t>::max() / kMicrosInSecond);
  44     assert(time_sec * kMicrosInSecond >= current_time_us_);
  45     current_time_us_ = time_sec * kMicrosInSecond;
  46   }
  47
  48   // It's a fake sleep that just updates the Env current time, which is similar
  49   // to `NoSleepEnv.SleepForMicroseconds()` and
  50   // `SpecialEnv.MockSleepForMicroseconds()`.
  51   // It's also similar to `set_current_time()`, which takes an absolute time in
  52   // seconds, vs. this one takes the sleep in microseconds.
  53   // Note: Not thread safe.
  54   void SleepForMicroseconds(int micros) override {
  55     assert(micros >= 0);
  56     assert(current_time_us_ + static_cast<uint64_t>(micros) >=
  57            current_time_us_);
  58     current_time_us_.fetch_add(micros);
  59   }
  60
  61   void MockSleepForSeconds(int seconds) {
  62     assert(seconds >= 0);
  63     uint64_t micros = static_cast<uint64_t>(seconds) * kMicrosInSecond;
  64     assert(current_time_us_ + micros >= current_time_us_);
  65     current_time_us_.fetch_add(micros);
  66   }
  67
  68   // TODO: this is a workaround for the different behavior on different platform
  69   // for timedwait timeout. Ideally timedwait API should be moved to env.
  70   // details: PR #7101.
  71   void InstallTimedWaitFixCallback();
  72
  73  private:
  74   std::atomic<uint64_t> current_time_us_{0};
  75   static constexpr uint64_t kMicrosInSecond = 1000U * 1000U;
  76 };
  77
  78 }  // namespace ROCKSDB_NAMESPACE