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digitalmars.D.learn - Better than "Clock.currStdTime()/10000000"

reply berni <berni example.com> writes:
I need to measure time elapsed in seconds, like this:

 auto start = Clock.currStdTime();
 // some stuff
 auto stop = Clock.currStdTime();
 auto duration = (stop-start)/10000000;
This works, but I wonder if there is something better that using the magic constant 10000000. I read about 10.secs giving the duration of 10 seconds, but I don't understand how to adapt this to my case. I've read the documentation of core.time, std.datetime (and the Introduction to this package) but I can't make head or tail of it. PS: It's not about benchmarking. I'd like to show the user the time elapsed.
Feb 15
next sibling parent reply drug <drug2004 bk.ru> writes:
15.02.2017 16:19, berni пишет:
 I need to measure time elapsed in seconds, like this:

 auto start = Clock.currStdTime();
 // some stuff
 auto stop = Clock.currStdTime();
 auto duration = (stop-start)/10000000;
This works, but I wonder if there is something better that using the magic constant 10000000. I read about 10.secs giving the duration of 10 seconds, but I don't understand how to adapt this to my case. I've read the documentation of core.time, std.datetime (and the Introduction to this package) but I can't make head or tail of it. PS: It's not about benchmarking. I'd like to show the user the time elapsed.
doesn't it work for you? ``` void main() { import std.datetime, core.thread, std.stdio; MonoTime before = MonoTime.currTime; Thread.sleep(dur!"msecs"(1000)); MonoTime after = MonoTime.currTime; Duration timeElapsed = after - before; writeln(timeElapsed); } ``` I get: "1 sec, 26 μs, and 4 hnsecs"
Feb 15
parent reply Jonathan M Davis via Digitalmars-d-learn writes:
On Wednesday, February 15, 2017 16:27:34 drug via Digitalmars-d-learn wrote:
 15.02.2017 16:19, berni пишет:
 I need to measure time elapsed in seconds, like this:
 auto start = Clock.currStdTime();
 // some stuff
 auto stop = Clock.currStdTime();
 auto duration = (stop-start)/10000000;
This works, but I wonder if there is something better that using the magic constant 10000000. I read about 10.secs giving the duration of 10 seconds, but I don't understand how to adapt this to my case. I've read the documentation of core.time, std.datetime (and the Introduction to this package) but I can't make head or tail of it. PS: It's not about benchmarking. I'd like to show the user the time elapsed.
doesn't it work for you? ``` void main() { import std.datetime, core.thread, std.stdio; MonoTime before = MonoTime.currTime; Thread.sleep(dur!"msecs"(1000)); MonoTime after = MonoTime.currTime; Duration timeElapsed = after - before; writeln(timeElapsed); } ``` I get: "1 sec, 26 μs, and 4 hnsecs"
This is the correct way to do it. Using SysTime for timing things is wrong, because it's not a monotonic clock. So, it could be changed - even going backwards - while you're doing the timing. MonoTime, on the other hand, uses the system's monotonic clock and is therefore guaranteed to move forward at a fixed rate. - Jonathan M Davis
Feb 15
parent berni <berni example.com> writes:
On Wednesday, 15 February 2017 at 15:58:41 UTC, Jonathan M Davis 
wrote:
 [...]
      MonoTime before = MonoTime.currTime;
      Thread.sleep(dur!"msecs"(1000));
      MonoTime after = MonoTime.currTime;
      Duration timeElapsed = after - before;

      writeln(timeElapsed);
 }
 ```
 I get: "1 sec, 26 μs, and 4 hnsecs"
This is the correct way to do it. [...]
Oh, thanks for noting this. As I finally needed the seconds as an int (or long) I had to use timeElapsed.total!"seconds" which I would not have found out without Seb's posting. :-)
Feb 15
prev sibling parent Seb <seb wilzba.ch> writes:
On Wednesday, 15 February 2017 at 13:19:57 UTC, berni wrote:
 I need to measure time elapsed in seconds, like this:

 auto start = Clock.currStdTime();
 // some stuff
 auto stop = Clock.currStdTime();
 auto duration = (stop-start)/10000000;
This works, but I wonder if there is something better that using the magic constant 10000000. I read about 10.secs giving the duration of 10 seconds, but I don't understand how to adapt this to my case. I've read the documentation of core.time, std.datetime (and the Introduction to this package) but I can't make head or tail of it. PS: It's not about benchmarking. I'd like to show the user the time elapsed.
How about something like this: import std.stdio; void main() { import core.thread, core.time; import std.conv, std.datetime; auto start = Clock.currTime; Thread.sleep(500.msecs); auto diff = Clock.currTime - start; diff.writeln; // Duration (diff.total!"msecs").writeln; (to!("msecs", long) (diff.to!TickDuration)).writeln; (to!("msecs", double)(diff. to!TickDuration)).writeln; } Note that TickDuration is deprecated.
Feb 15