Re: Simple timing

[Kagamin via Digitalmars-d-learn]

On Monday, 17 November 2014 at 16:38:45 UTC, Rene Zwanenburg 
wrote:
Clock.currTime uses a high performance timer, 
QueryPerformanceCounter on Windows for example, so you 
shouldn't have to worry about timer accuracy.


You probably mistake it for StopWatch, clock is not timer.

Simple timing

[Paul via Digitalmars-d-learn]

I'm trying to write a program that involves simple timing; I like 
to be able to execute some function at a point no sooner than, 
say, 3500 milliseconds from now so I need to read the current 
'system time' in ticks and calculate the required point in the 
future using ticks per sec. In other languages I've done 
something like this (pseudo code).


now = currentTime;
target = now + 3500

do something
..
until currentTime  target
execute function


I'm completely new to D and find the help pages on this subject 
very confusing (or at least a bit too detailed for a beginner!). 
Can anyone point me to a simple example or tell me how to go 
about this?


Many thanks

Paul

Re: Simple timing

[Adam D. Ruppe via Digitalmars-d-learn]

The easiest way isn't to read the clock at all and instead just 
put your program to sleep for a while:


void main() {
import std.stdio;
import core.thread;
writeln(started);
Thread.sleep(3500.msecs);
writeln(ended);
}

Re: Simple timing

[Rene Zwanenburg via Digitalmars-d-learn]

On Monday, 17 November 2014 at 16:24:10 UTC, Paul wrote:
I'm trying to write a program that involves simple timing; I 
like to be able to execute some function at a point no sooner 
than, say, 3500 milliseconds from now so I need to read the 
current 'system time' in ticks and calculate the required point 
in the future using ticks per sec. In other languages I've done 
something like this (pseudo code).


now = currentTime;
target = now + 3500

do something
..
until currentTime  target
execute function


I'm completely new to D and find the help pages on this subject 
very confusing (or at least a bit too detailed for a 
beginner!). Can anyone point me to a simple example or tell me 
how to go about this?


Many thanks

Paul


You can get the current 'system time' from std.datetime using 
Clock.currTime.


Subtracting one SysTime from another results in a 'Duration', 
which you can then compare to your target duration:


var startTime = Clock.currTime;

doSomething();

while(Clock.currTime - startTime  3500.msecs)
{
  executeFunction();
}

Clock.currTime uses a high performance timer, 
QueryPerformanceCounter on Windows for example, so you shouldn't 
have to worry about timer accuracy.

Re: Simple timing [solved]

[Paul via Digitalmars-d-learn]

Thank you both, I'm sure that answers my question.

Paul

On Monday, 17 November 2014 at 16:38:45 UTC, Rene Zwanenburg 
wrote:

On Monday, 17 November 2014 at 16:24:10 UTC, Paul wrote:
I'm trying to write a program that involves simple timing; I 
like to be able to execute some function at a point no sooner 
than, say, 3500 milliseconds from now so I need to read the 
current 'system time' in ticks and calculate the required 
point in the future using ticks per sec. In other languages 
I've done something like this (pseudo code).


now = currentTime;
target = now + 3500

do something
..
until currentTime  target
execute function


I'm completely new to D and find the help pages on this 
subject very confusing (or at least a bit too detailed for a 
beginner!). Can anyone point me to a simple example or tell me 
how to go about this?


Many thanks

Paul


You can get the current 'system time' from std.datetime using 
Clock.currTime.


Subtracting one SysTime from another results in a 'Duration', 
which you can then compare to your target duration:


var startTime = Clock.currTime;

doSomething();

while(Clock.currTime - startTime  3500.msecs)
{
  executeFunction();
}

Clock.currTime uses a high performance timer, 
QueryPerformanceCounter on Windows for example, so you 
shouldn't have to worry about timer accuracy.