clock

I want to calculate time intervals (in 1/10th of 1 second) between some events happening in my program. Thus I use clock function for these needs like follows: clock_t begin; clock_t now; clock_t diff; begin = clock(); while ( 1 ) { now = clock(); diff = now - begin; cout << diff / CLOCKS_PER_SEC << "\n"; //usleep ( 1000000 ); }; I expect the program to print 0 for 1 second, then 1 for 1 sec., then 2 for 1 sec. and so on... In fact it prints 0 for about 8 seconds, then 1 for about 8 seconds and so on... By the way, if I add usleep in order program prints only 1 time per second, it prints only

Possible Duplicate: The C clock() function just returns a zero I ran the following code to test the working of clock() function. I work on ubuntu 12.04. #include <stdio.h> #include <time.h> #include <iostream> using namespace std; double diffclock(clock_t clock1,clock_t clock2) { double diffticks=clock1-clock2; double diffms=(diffticks*10)/CLOCKS_PER_SEC; return diffms; } int main() { string name; int i; clock_t begin=clock(); cout << "Hi what is your name? "; getline(cin, name); clock_t end=clock(); cout << "Time elapsed: " << double(diffclock(end,begin)) << " ms"<< endl; return 0; } But no

I need to use a global timestamp (std::chrono::high_resolution_clock::now()) in my c++ program. I declared it in the header file Header.h: #include<chrono> using namespace std; extern auto start; I want to initialize a value in main, so in main.cpp, I did: #include"Header.h" #include<chrono> using namespace std; auto start; int main(){ start = std::chrono::high_resolution_clock::now(); } However, when compiling it, I got: error: declaration of ‘auto start’ has no initializer Can anybody tell me what I did wrong? Thanks! How is auto supposed to deduce the type of start ? You need to declare the

As could be read at: https://svn.boost.org/trac/boost/ticket/3504 a deadline_timer that timeouts periodically and which is implemented using deadline_timer::expires_at() (like the example in Boost Timer Tutorial, 3th example ) will probably fail if the system time is modified (for example, using the date command, if your operating system is Linux). Is there a simple and appropiate way of performing this operation now, using Boost? I do not want to use deadline_timer::expires_from_now() because I could verify that it is less accurate than "manually" updating the expiry time. As a temporal

http://json-time.appspot.com/time.json?tz=GMT has been broken for a while now... at least a month. This service returns the current time in jsonp, and I have a jquery plugin that uses it to determine the correct time. I'm under the assumption that this service is permanently down since it's been down for a long time and I can't find any posts by the author as to it's status. Does anyone know of a service that I can use that returns the correct time in JSON or XML? Thanks! Looks like you can set up your own: https://github.com/simonw/json-time 来源： https://stackoverflow.com/questions/7520793

The following piece of code was given to us from our instructor so we could measure some algorithms performance: #include <stdio.h> #include <unistd.h> static unsigned cyc_hi = 0, cyc_lo = 0; static void access_counter(unsigned *hi, unsigned *lo) { asm("rdtsc; movl %%edx,%0; movl %%eax,%1" : "=r" (*hi), "=r" (*lo) : /* No input */ : "%edx", "%eax"); } void start_counter() { access_counter(&cyc_hi, &cyc_lo); } double get_counter() { unsigned ncyc_hi, ncyc_lo, hi, lo, borrow; double result; access_counter(&ncyc_hi, &ncyc_lo); lo = ncyc_lo - cyc_lo; borrow = lo > ncyc_lo; hi = ncyc_hi - cyc_hi -

I am trying to create two clocks on a website that says two times on it. One from London and the other from New York. I have been able to create a clock that reads the current time on my computer but i'm not sure how to place a time zone into this. The code I have so far is: <script type="text/javascript" language="javascript"> function renderTime() { var currentTime = new Date(); var diem = "AM"; var h = currentTime.getHours(); var m = currentTime.getMinutes(); var s = currentTime.getSeconds(); if (h == 0) { h = 12 } else if (h > 12) { h = h - 12; diem = "PM"; } if (h < 10) { h = "0" + h; }