1*7c3d14c8STreehugger Robot #include <mach/mach_time.h> 2*7c3d14c8STreehugger Robot #include <stdint.h> 3*7c3d14c8STreehugger Robot #include <stdlib.h> 4*7c3d14c8STreehugger Robot intervalInCycles(uint64_t startTime,uint64_t endTime)5*7c3d14c8STreehugger Robotdouble intervalInCycles( uint64_t startTime, uint64_t endTime ) 6*7c3d14c8STreehugger Robot { 7*7c3d14c8STreehugger Robot uint64_t rawTime = endTime - startTime; 8*7c3d14c8STreehugger Robot static double conversion = 0.0; 9*7c3d14c8STreehugger Robot 10*7c3d14c8STreehugger Robot if( 0.0 == conversion ) 11*7c3d14c8STreehugger Robot { 12*7c3d14c8STreehugger Robot mach_timebase_info_data_t info; 13*7c3d14c8STreehugger Robot kern_return_t err = mach_timebase_info( &info ); 14*7c3d14c8STreehugger Robot if( 0 != err ) 15*7c3d14c8STreehugger Robot return 0; 16*7c3d14c8STreehugger Robot 17*7c3d14c8STreehugger Robot uint64_t freq = 0; 18*7c3d14c8STreehugger Robot size_t freqSize = sizeof( freq ); 19*7c3d14c8STreehugger Robot int err2 = sysctlbyname( "hw.cpufrequency", &freq, &freqSize, NULL, 0L ); 20*7c3d14c8STreehugger Robot if( 0 != err2 ) 21*7c3d14c8STreehugger Robot return 0; 22*7c3d14c8STreehugger Robot 23*7c3d14c8STreehugger Robot conversion = (double) freq * (1e-9 * (double) info.numer / (double) info.denom); 24*7c3d14c8STreehugger Robot } 25*7c3d14c8STreehugger Robot 26*7c3d14c8STreehugger Robot return (double) rawTime * conversion; 27*7c3d14c8STreehugger Robot } 28*7c3d14c8STreehugger Robot 29