x

test/core/resource_quota/periodic_update_test.cc

@@ -78,7 +78,35 @@ TEST(PeriodicUpdateTest, SimpleTest) {
   }
 }
 
-TEST(PeriodicUpdate, ThreadTest) {
+TEST(PeriodicUpdateTest, NoSpin) {
+  // Ensure that we do not poll the time every update... even initially
+  class NowCounter : public Timestamp::ScopedSource {
+   public:
+    Timestamp Now() override {
+      ++n_;
+      return previous()->Now();
+    }
+
+    int now_calls() const { return n_; }
+
+   private:
+    int n_ = 0;
+  };
+  NowCounter counter;
+  PeriodicUpdate upd(Duration::Seconds(5));
+  while (!upd.Tick([](Duration d) { EXPECT_GE(d, Duration::Seconds(5)); })) {
+  }
+  const int initial_now_calls = counter.now_calls();
+  EXPECT_GT(initial_now_calls, 2);
+  EXPECT_LT(initial_now_calls, 100);
+  while (!upd.Tick([](Duration d) { EXPECT_GE(d, Duration::Seconds(5)); })) {
+  }
+  const int second_round_calls = counter.now_calls() - initial_now_calls;
+  EXPECT_GE(second_round_calls, 1);
+  EXPECT_LE(second_round_calls, initial_now_calls);
+}
+
+TEST(PeriodicUpdateTest, ThreadTest) {
   std::unique_ptr<PeriodicUpdate> upd;
   std::atomic<int> count(0);
   Timestamp start;