计算函数执行的时间
2020-05-21 本文已影响0人
执拗的男孩
方法1
double func_runtime(double last, char* key) {
clock_t now = clock();
printf("time:%fs \t key:%s \n", (last != 0) ? (double)(now - last) / CLOCKS_PER_SEC : 0, key);
return now;
}
double t = func_runtime(0, "");
func_runtime(t, "end");
方法2
#ifndef NonAtomicTest_Method_h
#define NonAtomicTest_Method_h
//c函数实现 返回值类型 函数名 函数参数(是一个block)
CGFloat BNRTimeBlock (void (^block)(void)) {
mach_timebase_info_data_t info;
if (mach_timebase_info(&info) != KERN_SUCCESS) return -1.0;
uint64_t start = mach_absolute_time ();
block ();
uint64_t end = mach_absolute_time ();
uint64_t elapsed = end - start;
uint64_t nanos = elapsed * info.numer / info.denom;
return (CGFloat)nanos / NSEC_PER_SEC;
} // BNRTimeBlock
#endif
CGFloat time = 0.0 ;
printf("begin:===========%lf\n",time);
time = BNRTimeBlock(^{
printf("end2:===========%lf\n",time);
});
printf("end1:===========%lf\n",time);