aos/common/util/phased_loop_test.cc

#include "aos/common/util/phased_loop.h"

#include "gtest/gtest.h"

#include "aos/testing/test_logging.h"

namespace aos {
namespace time {
namespace testing {

using ::std::chrono::milliseconds;

class PhasedLoopTest : public ::testing::Test {
 protected:
  PhasedLoopTest() { ::aos::testing::EnableTestLogging(); }
};

typedef PhasedLoopTest PhasedLoopDeathTest;

monotonic_clock::time_point InMs(int ms) {
  return monotonic_clock::time_point(::std::chrono::milliseconds(ms));
}

TEST_F(PhasedLoopTest, Reset) {
  {
    PhasedLoop loop(milliseconds(100), milliseconds(0));

    loop.Reset(monotonic_clock::epoch());
    EXPECT_EQ(InMs(0), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(monotonic_clock::epoch()));
    EXPECT_EQ(InMs(100), loop.sleep_time());

    loop.Reset(InMs(99));
    EXPECT_EQ(InMs(0), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(InMs(99)));
    EXPECT_EQ(InMs(100), loop.sleep_time());

    loop.Reset(InMs(100));
    EXPECT_EQ(InMs(100), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(InMs(199)));
    EXPECT_EQ(InMs(200), loop.sleep_time());

    loop.Reset(InMs(101));
    EXPECT_EQ(InMs(100), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(InMs(101)));
    EXPECT_EQ(InMs(200), loop.sleep_time());
  }
  {
    PhasedLoop loop(milliseconds(100), milliseconds(1));
    loop.Reset(monotonic_clock::epoch());
    EXPECT_EQ(InMs(-99), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(monotonic_clock::epoch()));
    EXPECT_EQ(InMs(1), loop.sleep_time());
  }
  {
    PhasedLoop loop(milliseconds(100), milliseconds(99));

    loop.Reset(monotonic_clock::epoch());
    EXPECT_EQ(InMs(-1), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(monotonic_clock::epoch()));
    EXPECT_EQ(InMs(99), loop.sleep_time());

    loop.Reset(InMs(98));
    EXPECT_EQ(InMs(-1), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(InMs(98)));
    EXPECT_EQ(InMs(99), loop.sleep_time());

    loop.Reset(InMs(99));
    EXPECT_EQ(InMs(99), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(InMs(99)));
    EXPECT_EQ(InMs(199), loop.sleep_time());

    loop.Reset(InMs(100));
    EXPECT_EQ(InMs(99), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(InMs(100)));
    EXPECT_EQ(InMs(199), loop.sleep_time());
  }
}

TEST_F(PhasedLoopTest, Iterate) {
  {
    PhasedLoop loop(milliseconds(100), milliseconds(99));
    loop.Reset(monotonic_clock::epoch());
    EXPECT_EQ(1, loop.Iterate(monotonic_clock::epoch()));
    EXPECT_EQ(InMs(99), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(InMs(100)));
    EXPECT_EQ(InMs(199), loop.sleep_time());
    EXPECT_EQ(0, loop.Iterate(InMs(100)));
    EXPECT_EQ(InMs(199), loop.sleep_time());
    EXPECT_EQ(0, loop.Iterate(InMs(101)));
    EXPECT_EQ(InMs(199), loop.sleep_time());
    EXPECT_EQ(0, loop.Iterate(InMs(198)));
    EXPECT_EQ(InMs(199), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(InMs(199)));
    EXPECT_EQ(InMs(299), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(InMs(300)));
    EXPECT_EQ(InMs(399), loop.sleep_time());
    EXPECT_EQ(3, loop.Iterate(InMs(600)));
    EXPECT_EQ(InMs(699), loop.sleep_time());
  }
  {
    PhasedLoop loop(milliseconds(100), milliseconds(1));
    loop.Reset(monotonic_clock::epoch());
    EXPECT_EQ(1, loop.Iterate(monotonic_clock::epoch()));
    EXPECT_EQ(InMs(1), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(InMs(100)));
    EXPECT_EQ(InMs(101), loop.sleep_time());
    EXPECT_EQ(0, loop.Iterate(InMs(100)));
    EXPECT_EQ(InMs(101), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(InMs(103)));
    EXPECT_EQ(InMs(201), loop.sleep_time());
    EXPECT_EQ(0, loop.Iterate(InMs(198)));
    EXPECT_EQ(InMs(201), loop.sleep_time());
    EXPECT_EQ(0, loop.Iterate(InMs(200)));
    EXPECT_EQ(InMs(201), loop.sleep_time());
    EXPECT_EQ(1, loop.Iterate(InMs(201)));
    EXPECT_EQ(InMs(301), loop.sleep_time());
    EXPECT_EQ(3, loop.Iterate(InMs(600)));
    EXPECT_EQ(InMs(601), loop.sleep_time());
  }
}

// Makes sure that everything works correctly when crossing zero.
// This seems like a rare case at first, but starting from zero needs to
// work, which means negatives should too.
TEST_F(PhasedLoopTest, CrossingZero) {
  PhasedLoop loop(milliseconds(100), milliseconds(1));
  loop.Reset(InMs(-1000));
  EXPECT_EQ(InMs(-1099), loop.sleep_time());
  EXPECT_EQ(9, loop.Iterate(InMs(-250)));
  EXPECT_EQ(InMs(-199), loop.sleep_time());
  EXPECT_EQ(1, loop.Iterate(InMs(-199)));
  EXPECT_EQ(InMs(-99), loop.sleep_time());
  EXPECT_EQ(1, loop.Iterate(InMs(-90)));
  EXPECT_EQ(InMs(1), loop.sleep_time());
  EXPECT_EQ(0, loop.Iterate(InMs(0)));
  EXPECT_EQ(InMs(1), loop.sleep_time());
  EXPECT_EQ(1, loop.Iterate(InMs(1)));
  EXPECT_EQ(InMs(101), loop.sleep_time());

  EXPECT_EQ(0, loop.Iterate(InMs(2)));
  EXPECT_EQ(InMs(101), loop.sleep_time());

  EXPECT_EQ(-2, loop.Iterate(InMs(-101)));
  EXPECT_EQ(InMs(-99), loop.sleep_time());
  EXPECT_EQ(1, loop.Iterate(InMs(-99)));
  EXPECT_EQ(InMs(1), loop.sleep_time());

  EXPECT_EQ(0, loop.Iterate(InMs(-99)));
  EXPECT_EQ(InMs(1), loop.sleep_time());
}

// Tests that passing invalid values to the constructor dies correctly.
TEST_F(PhasedLoopDeathTest, InvalidValues) {
  EXPECT_DEATH(PhasedLoop(milliseconds(1), milliseconds(2)),
               ".*offset<interval.*");
  EXPECT_DEATH(PhasedLoop(milliseconds(1), milliseconds(1)),
               ".*offset<interval.*");
  EXPECT_DEATH(PhasedLoop(milliseconds(1), milliseconds(-1)),
               ".*offset>=monotonic_clock::duration\\(0\\).*");
  EXPECT_DEATH(PhasedLoop(milliseconds(0), milliseconds(0)),
               ".*interval>monotonic_clock::duration\\(0\\).*");
}

}  // namespace testing
}  // namespace time
}  // namespace aos