#is there c's clock() in zig?

1 messages · Page 1 of 1 (latest)

crystal birch
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https://www.tutorialspoint.com/c_standard_library/c_function_clock.htm

Need it for a Lua implementation of os.clock()

os.clock ()
Returns an approximation of the amount in seconds of CPU time used by the program.
C library - clock() function

C library - clock() function - The C library clock() function returns the number of clock ticks elapsed since the program was launched. To get the number of seconds used by the CPU, we will need to divide by CLOCKS_PER_SEC. On a 32-bit system where CLOCKS_PER_SEC equals 1000000, this function will return the same value approximat

#

can be posix/linux-specific. if it works on all systems would be great. here is example of the function in lua

# 
-- test.lua
print(os.clock())

output

0.00086
crystal birch
#

I found an alternative, at the start of the program I do a std.time.milliTimestamp() and store the value in a internal field in a vm, and whenever I call os.clock() I just do the now - time I saved. Maybe there are better alternatives?

thorny comet
#

std.time.Timer

crystal birch
#

not that kind of alternative

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more like, an alternative where I dont have to add C and store the time I started my program

thorny comet
#

If you want intervals from start of program, there is no alternative

true fox
crystal birch
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that's what I'm already doing

#

The problem is solved

tawny tulip
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Timer and milliTimestamp track wall clock time, not CPU time

#

on linux you need clock_gettime with CLOCK_PROCESS_CPUTIME_ID
on windows you need GetProcessTimes
on macos/bsd/etc you can call libc clock

crystal birch
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  1. im not adding libc
  2. im not adding windows
  3. im probably not messing with linux api
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so wall clock time is awesome

tawny tulip
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awesome sure, but the function is strictly implemented incorrectly if you give wall clock time