Timer.cc

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#include "Timer.hh"
#include <chrono>
#include <thread>
 
namespace openmsx::Timer {
 
uint64_t getTime()
{
        static uint64_t lastTime = 0;
 
        using namespace std::chrono;
        uint64_t now = duration_cast<microseconds>(
                steady_clock::now().time_since_epoch()).count();
 
        // Other parts of openMSX may crash if this function ever returns a
        // value that is less than a previously returned value. Hence this
        // extra check.
        // Steady_clock _should_ be monotonic. It's implemented in terms of
        // clock_gettime(CLOCK_MONOTONIC). Unfortunately in older linux
        // versions we've seen buggy implementation that once in a while did
        // return time points slightly in the past.
        if (now < lastTime) return lastTime;
        lastTime = now;
        return now;
}
 
void sleep(uint64_t us)
{
        std::this_thread::sleep_for(std::chrono::microseconds(us));
}
 
} // namespace openmsx::Timer