diff options
Diffstat (limited to 'absl/base/internal/cycleclock.cc')
| -rw-r--r-- | absl/base/internal/cycleclock.cc | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/absl/base/internal/cycleclock.cc b/absl/base/internal/cycleclock.cc index a742df0..9eb13b8 100644 --- a/absl/base/internal/cycleclock.cc +++ b/absl/base/internal/cycleclock.cc @@ -22,6 +22,7 @@ #include "absl/base/internal/cycleclock.h" +#include <atomic> #include <chrono> // NOLINT(build/c++11) #include "absl/base/internal/unscaledcycleclock.h" @@ -52,17 +53,26 @@ static constexpr int32_t kShift = 2; #endif static constexpr double kFrequencyScale = 1.0 / (1 << kShift); +static std::atomic<CycleClockSourceFunc> cycle_clock_source; } // namespace int64_t CycleClock::Now() { - return base_internal::UnscaledCycleClock::Now() >> kShift; + auto fn = cycle_clock_source.load(std::memory_order_relaxed); + if (fn == nullptr) { + return base_internal::UnscaledCycleClock::Now() >> kShift; + } + return fn() >> kShift; } double CycleClock::Frequency() { return kFrequencyScale * base_internal::UnscaledCycleClock::Frequency(); } +void CycleClockSource::Register(CycleClockSourceFunc source) { + cycle_clock_source.store(source, std::memory_order_relaxed); +} + #else int64_t CycleClock::Now() { |