#include <time.h>
time_t start1, end1, total1, ;
float s1, e1, t1;
s1 = start1 = time(NULL);
for(int i = 0; i < 1000; i++)
DrawTriangle1(memDC, BLUE);
e1 = end1 = time(NULL);
t1 = e1 - s1;
char str[100];
sprintf(str,"Flood Fill Scan = %.2f", s1);
TextOut(memDC, 10, 20, str, strlen(str));
Timing a function!
Author
This shows me the current time before and after the function giving me zero for an answer.
time(NULL);
Any other suggestions got get the time before the function is called and after, and finding the difference.
That would be because you are actually only printing the start time :)
Also, note that time() is not an accurate timing function on most systems, try gettimeofday() on *nix/mac or QueryPerformanceCounter on windows to get better timer resolution.
Also, note that time() is not an accurate timing function on most systems, try gettimeofday() on *nix/mac or QueryPerformanceCounter on windows to get better timer resolution.
You'll want to use ctime instead of time.h.
Here's what I use:
Delta now holds how long it took, in seconds. So, for half a second Delta would be 0.5f and for a second and a half it'd be 1.5f.
HTH!
Here's what I use:
unsigned long StartTime = timeGetTime();// do code hereunsigned long EndTime = timeGetTime();float Delta = (EndTime - StartTime) * 0.001f;Delta now holds how long it took, in seconds. So, for half a second Delta would be 0.5f and for a second and a half it'd be 1.5f.
HTH!
Author
gettimeofday();
Its not part of time.h, whats the #include?
Im not getting any usable respondes from google?
http://www.cplusplus.com/reference/clibrary/ctime/
"That would be because you are actually only printing the start time :)"
I should look over my post better, it was t1 before which gives me 0.
I printed start and end both give me the same number.
OOPS DIDNT NOTICE Programmer16 responds ill try that out
[Edited by - pascalosti on July 26, 2007 11:07:43 PM]
Its not part of time.h, whats the #include?
Im not getting any usable respondes from google?
http://www.cplusplus.com/reference/clibrary/ctime/
"That would be because you are actually only printing the start time :)"
I should look over my post better, it was t1 before which gives me 0.
I printed start and end both give me the same number.
OOPS DIDNT NOTICE Programmer16 responds ill try that out
[Edited by - pascalosti on July 26, 2007 11:07:43 PM]
Quote:Original post by pascalosti
gettimeofday();
Its not part of time.h, whats the #include?
Im not getting any usable respondes from google?
man gettimeofday would be more helpful than Google, I think. FWIW, on GNU/Linux systems, you need to include sys/time.h and time.h.
Author
Maybe im loosing my mind. Neither worked for me!
unsigned long StartTime1 = timeGetTime();
// thats with #include<ctime>
// and using namespace std;
Error 'timeGetTime': identifier not found
gettimeofday();
// I added every #include that i could find with "time" in it
// I could not find "FWIW" or anything that looks similar.
Error 'gettimeofday': identifier not found
unsigned long StartTime1 = timeGetTime();
// thats with #include<ctime>
// and using namespace std;
Error 'timeGetTime': identifier not found
gettimeofday();
// I added every #include that i could find with "time" in it
// I could not find "FWIW" or anything that looks similar.
Error 'gettimeofday': identifier not found
From the first hit on Google:
You are running Linux/Unix, not Windows, right?
Edit: According to the "Who's online" section, you are running Windows XP. As was previously mentioned, on Windows, you want to use QueryPerformanceCounter.
#include <sys/time.h>You are running Linux/Unix, not Windows, right?
Edit: According to the "Who's online" section, you are running Windows XP. As was previously mentioned, on Windows, you want to use QueryPerformanceCounter.
Author
I was very intimidated by this site
http://support.microsoft.com/kb/172338
this one made it easier to swallow
http://www.decompile.com/cpp/faq/windows_timer_api.htm
I think im making progress!
Thanks all for the help
[Edited by - pascalosti on July 27, 2007 12:51:50 AM]
Author
Here is what the final looks like!!
Looks really messy
if(GetTime){ // get the high resolution counter's accuracy QueryPerformanceFrequency(&ticksPerSecond); // what time is it? QueryPerformanceCounter(&tick); // since the system was started... timeX.QuadPart = tick.QuadPart/ticksPerSecond.QuadPart; //get the number of hours Delta1 = (timeX.QuadPart * 100); GetTime = false; } DrawTriangle1(memDC, BLUE); //DrawTriangle(memDC, GREEN); if(GetTime1) { // get the high resolution counter's accuracy QueryPerformanceFrequency(&ticksPerSecond1); // what time is it? QueryPerformanceCounter(&tick1); //get the number of hours // since the system was started... timeX1.QuadPart = tick1.QuadPart/ticksPerSecond1.QuadPart; Delta2 = (timeX1.QuadPart * 100); GetTime1 = false; } total = Delta2 - Delta1;
Edit: call QueryPerformanceFrequency() only once, and handle the timer accuracy in a better, more readable way
And here's how it should look like, providing that you are using C++ and not plain C.
And it's used like this:
Which is a bit easier than your code [smile].
[Edited by - Emmanuel Deloget on July 27, 2007 9:33:03 AM]
Quote:Original post by pascalosti
Here is what the final looks like!!
Looks really messy
*** Source Snippet Removed ***
And here's how it should look like, providing that you are using C++ and not plain C.
class timer{ LARGE_INTEGER frequency; LARGE_INTEGER tick_start; LARGE_INTEGER accumulated_time; unsigned long timer_accuracy;public: static const unsigned long seconds = 1; static const unsigned long milliseconds = 1000; static const unsigned long microseconds = 1000000;public: timer(unsigned long accuracy = milliseconds) : accumulated_time() , timer_accuracy(accuracy) { QueryPerformanceFrequency(&frequency); restart(); } void restart() { QueryPerformanceCounter(&tick_start); } void reset() { accumulated_time = LARGE_INTEGER(); } // stop the timer, and update the accumulated time void stop() { LARGE_INTEGER tick_current; QueryPerformanceCounter(&tick_current); accumulated_time.QuadPart += tick_current.QuadPart - tick_start.QuadPart; } // retrieve accumulated time unsigned __int64 get_accumulated_time(unsigned long accuracy) const { return (accumulated_time.QuadPart * accuracy) / frequency.QuadPart; } unsigned __int64 get_accumulated_time() const { return get_accumulated_time(timer_accuracy); } // compute elapsed time since last restart, but do not // accumulate the time unsigned __int64 get_elapsed_while_running(unsigned long accuracy) const { LARGE_INTEGER tick_current; QueryPerformanceCounter(&tick_current); LARGE_INTEGER elapsed; elapsed.QuadPart = tick_current.QuadPart - tick_start.QuadPart; return (elapsed.QuadPart * accuracy) / frequency.QuadPart; } unsigned __int64 get_elapsed_while_running() const { return get_elapsed_while_running(timer_accuracy); }};And it's used like this:
// time with a milliseconds accuracy timer my_timer(timer::milliseconds); for (int i=0; i<1000; ++i) { std::cout << "index = " << i << std::endl; } my_timer.stop(); std::cout << "accumulated elasped time: " << my_timer.get_accumulated_time() << " ms" << std::endl; my_timer.restart(); for (int i=0; i<1000; ++i) { std::cout << "elapsed time since last restart = " << my_timer.get_elapsed_while_running(timer::microseconds); << " µs" << std::endl; } my_timer.stop(); std::cout << "accumulated elasped time: " << my_timer.get_accumulated_time() << " ms" << std::endl;Which is a bit easier than your code [smile].
[Edited by - Emmanuel Deloget on July 27, 2007 9:33:03 AM]
This topic is closed to new replies.
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