- uint32_t expected,
- const std::chrono::time_point<Clock, Duration>& absTime,
- uint32_t waitMask = -1) {
- using std::chrono::duration_cast;
- using std::chrono::nanoseconds;
- using std::chrono::seconds;
- using std::chrono::steady_clock;
- using std::chrono::system_clock;
- using std::chrono::time_point;
-
- static_assert(
- (std::is_same<Clock, system_clock>::value ||
- std::is_same<Clock, steady_clock>::value),
- "futexWaitUntil only knows std::chrono::{system_clock,steady_clock}");
- assert((std::is_same<Clock, system_clock>::value) || Clock::is_steady);
-
- // We launder the clock type via a std::chrono::duration so that we
- // can compile both the true and false branch. Tricky case is when
- // steady_clock has a higher precision than system_clock (Xcode 6,
- // for example), for which time_point<system_clock> construction
- // refuses to do an implicit duration conversion. (duration is
- // happy to implicitly convert its denominator causing overflow, but
- // refuses conversion that might cause truncation.) We use explicit
- // duration_cast to work around this. Truncation does not actually
- // occur (unless Duration != Clock::duration) because the missing
- // implicit conversion is in the untaken branch.
- Duration absTimeDuration = absTime.time_since_epoch();
- if (std::is_same<Clock, system_clock>::value) {
- time_point<system_clock> absSystemTime(
- duration_cast<system_clock::duration>(absTimeDuration));
- return futexWaitImpl(expected, &absSystemTime, nullptr, waitMask);
- } else {
- time_point<steady_clock> absSteadyTime(
- duration_cast<steady_clock::duration>(absTimeDuration));
- return futexWaitImpl(expected, nullptr, &absSteadyTime, waitMask);
- }
+ uint32_t expected,
+ std::chrono::time_point<Clock, Duration> const& deadline,
+ uint32_t waitMask = -1) {
+ using Target = typename std::conditional<
+ Clock::is_steady,
+ std::chrono::steady_clock,
+ std::chrono::system_clock>::type;
+ auto const converted = time_point_conv<Target>(deadline);
+ return futexWaitImpl(expected, converted, waitMask);