Merge #16046: util: Add type safe GetTime

fa013664ae23d0682a195b9bded85bc19c99536e util: Add type safe GetTime (MarcoFalke)

Pull request description:

  There are basically two ways to get the time in Bitcoin Core:
  * get the system time (via `GetSystemTimeInSeconds` or `GetTime{Millis,Micros}`)
  * get the mockable time (via `GetTime`)

  Both return the same type (a plain int). This can lead to (test-only) bugs such as 99464bc38e9575ff47f8e33223b252dcea2055e3.

  Fix that by deprecating `GetTime` and adding a `GetTime<>` that returns the mockable time in a non-int type. The new util function is currently unused, but new code should it where possible.

ACKs for commit fa0136:
  promag:
    utACK fa013664.

Tree-SHA512: efab9c463f079fd8fd3030c479637c7b1e8be567a881234bd0f555c8f87e518e3b43ef2466128103db8fc40295aaf24e87ad76d91f338c631246fc703477e95c

1 files changed, 21 insertions, 0 deletions

diff --git a/src/test/util_tests.cpp b/src/test/util_tests.cpp
index 51dd25ed1c..8fee66d6c3 100644
--- a/src/test/util_tests.cpp
+++ b/src/test/util_tests.cpp
@@ -1068,6 +1068,27 @@ BOOST_AUTO_TEST_CASE(gettime)
     BOOST_CHECK((GetTime() & ~0xFFFFFFFFLL) == 0);
 }
 
+BOOST_AUTO_TEST_CASE(util_time_GetTime)
+{
+    SetMockTime(111);
+    // Check that mock time does not change after a sleep
+    for (const auto& num_sleep : {0, 1}) {
+        MilliSleep(num_sleep);
+        BOOST_CHECK_EQUAL(111, GetTime()); // Deprecated time getter
+        BOOST_CHECK_EQUAL(111, GetTime<std::chrono::seconds>().count());
+        BOOST_CHECK_EQUAL(111000, GetTime<std::chrono::milliseconds>().count());
+        BOOST_CHECK_EQUAL(111000000, GetTime<std::chrono::microseconds>().count());
+    }
+
+    SetMockTime(0);
+    // Check that system time changes after a sleep
+    const auto ms_0 = GetTime<std::chrono::milliseconds>();
+    const auto us_0 = GetTime<std::chrono::microseconds>();
+    MilliSleep(1);
+    BOOST_CHECK(ms_0 < GetTime<std::chrono::milliseconds>());
+    BOOST_CHECK(us_0 < GetTime<std::chrono::microseconds>());
+}
+
 BOOST_AUTO_TEST_CASE(test_IsDigit)
 {
     BOOST_CHECK_EQUAL(IsDigit('0'), true);