1. Introduction
The timer is implemented through several class libraries in C++ and C#, and the timer is used to count the time allowed by the program. In actual use, the millisecond timer is sufficient.
2. Millisecond timer
#include<ctime>
class Timer_milisecode{//
public:
Timer_milisecode(){
tbegin=clock();
tend=clock();
}
void begin(){
tbegin=clock();
}
void end(){
tend=clock();
}
double spent(){
return double(tend-tbegin)/CLOCKS_PER_SEC*1000;
}
double getCurrentTime(){
return double(clock());
}
private:
// const int clock_per_second=CLOCKS_PER_SEC;
clock_t tbegin,tend;
};The header file is #include<ctime>, detailed explanation
There is a clock_t type (long) under ctime, and a corresponding function clock(), whose return value is clock_t type, and there is a constant CLOCKS_PER_SEC, which represents the number of ticks per second. In theory, clock() should be Hit every millisecond. When calculating the time interval, subtract the two clock_t numbers, and then correct them to get the number of milliseconds.
3. Microsecond timer
#include<Windows.h>
class Timer_microseconds{
public:
Timer_microseconds(){
QueryPerformanceFrequency(&tc);
}
void begin(){
QueryPerformanceCounter(&t1);
}
void end(){
QueryPerformanceCounter(&t2);
}
double spent(){
return (double(t2.QuadPart-t1.QuadPart)*1000000.0)/tc.QuadPart;
}
private:
LARGE_INTEGER t1,t2,tc;
};The header file is #include<windows.h>
Similar to above. The first is to define three LARGE_INTEGER variables. There are two functions QueryPerformanceFrequency(), which queries the poor frequency per second, and QueryPerformanceCounter(), which is a counter. Then here, theoretically, the value of tc.QuadPart is 10_000_000 per second, that is, 10 will be counted every microsecond. This is more accurate.
4. Microsecond counter
#include<chrono>
class Timer_chrono{
public:
Timer_chrono(){
}
void begin(){
start=std::chrono::high_resolution_clock::now();
}
void end(){
spentTime=std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::high_resolution_clock::now()-start).count();
}
double spent(){
return (double)spentTime;
}
private:
std::chrono::time_point<std::chrono::high_resolution_clock> start;
long long spentTime;
};You need to use the header file <chrono>, which is like the above.
5. C# timer
class Timer
{
private DateTime dt;
private TimeSpan tSpen;
public Timer()
{
dt= DateTime.Now;
}
public void begin()
{
dt= DateTime.Now;
}
public void end()
{
tSpen=DateTime.Now-dt;
}
public double spent()
{
return tSpen.TotalMilliseconds;
}
}In fact, C# should not need any timers, just the DateTime and TimeSpan classes. The highest precision is milliseconds.
6. Get the current time in C++
time_t tm0;
time(&tm0);
std::cout<<tm0<<endl;
cout<<ctime(&tm0)<<endl;The output is Mon Mar 20 23:29:15 2023. ctime is to format the seconds into a string
tm ttm= *localtime(&tm0);
cout<<ttm.tm_year<<"\t"<<ttm.tm_mon<<"\t"<<ttm.tm_mday<<endl;struct tm, output the year and time since 1900.