linux 获取时间

第一种

//需要包含#include <chrono>
int64_t CurrentTimeMillis()
{
    int64_t timems = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
    return timems;
}
int64_t start_time = CurrentTimeMillis();
int64_t current_time = CurrentTimeMillis();
int64_t duration = current_time - start_time;
printf("start_time:%ld current_time:%ld\n",start_time,current_time);

第二种

//需要包含#include <chrono>
#include <iostream>
#include <chrono>
using namespace std;
using std::chrono::high_resolution_clock;
using std::chrono::milliseconds;

 high_resolution_clock::time_point start = chrono::high_resolution_clock::now();
 high_resolution_clock::time_point endTime = high_resolution_clock::now();
 milliseconds timeInterval = std::chrono::duration_cast<milliseconds>(endTime - beginTime);
 cout << "Running Time：" << timeInterval.count()  << "ms" << endl;