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  • mac获取方法的执行时间

    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;

    }

    将目标方法放在块语法中,可得到目标方法的执行时间

    调用方法如下

    Oc代码  收藏代码
    1. int main (void) {    
    2.     CGFloat time;    
    3.     
    4.     NSString *thing1 = @"hi";    
    5.     NSString *thing2 = @"hello there";    
    6.     
    7.     time = BNRTimeBlock(^{    
    8.             for (int i = 0; i < LOOPAGE; i++) {    
    9.                 [thing1 isEqual: thing2];    
    10.             }    
    11.         });    
    12.     printf ("isEqual: time: %f\n", time);    
    13.     
    14.     time = BNRTimeBlock(^{    
    15.             for (int i = 0; i < LOOPAGE; i++) {    
    16.                 [thing1 isEqualToString: thing2];    
    17.             }    
    18.         });    
    19.     printf ("isEqualToString: time: %f\n", time);    
    20.     
    21.     return 0;    

    引入包

    #import <mach/mach_time.h>

    例如:
    #import <mach/mach_time.h>

    uint64_t start = mach_absolute_time();

    // do stuff to be timed

    uint64_t end = mach_absolute_time();
    uint64_t elapsed = end - start;

    mach_timebase_info_data_t info;
    if (mach_timebase_info (&info) != KERN_SUCCESS) {
    printf ("mach_timebase_info failed\n");
    }

    uint64_t nanosecs = elapsed * info.numer / info.denom;
    uint64_t millisecs = nanosecs / 1000000;
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  • 原文地址:https://www.cnblogs.com/greywolf/p/2863924.html
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