https://github.com/ufechner7/timers.jl
Timers for Julia
https://github.com/ufechner7/timers.jl
Last synced: 3 months ago
JSON representation
Timers for Julia
- Host: GitHub
- URL: https://github.com/ufechner7/timers.jl
- Owner: ufechner7
- License: mit
- Created: 2022-04-10T18:27:09.000Z (about 3 years ago)
- Default Branch: main
- Last Pushed: 2023-01-13T13:30:40.000Z (over 2 years ago)
- Last Synced: 2025-02-22T12:04:57.213Z (4 months ago)
- Language: Julia
- Size: 21.5 KB
- Stars: 11
- Watchers: 3
- Forks: 2
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Timers
The package provides the following functions:
## Functions
```tic()```
Starts a timer
```toc(prn=true)```
Print the time in seconds since tic() was called. To suppress the printed output
use `toc(false)`.
Returns the time since the timer was started in seconds.
```sleep_ms(time_ms)```
Sleeps for the given number of milli-seconds. Accuracy on Linux better than 100 nanoseconds +-0.2%, but only if the system is not fully loaded. On Linux for delays larger than 10ms sleep() is used, on Windows for delays larger than 16 ms.
```wait_until(finish_ns; always_sleep=false)```
Sleeps until the given time [ns] is reached. Example:
```julia
dt = 0.05
start = time_ns()
for i in 1:100
# do some work
wait_until(start + i*dt*1e9)
end
```
The section "```# do some work```" is executed exactly every 50ms as long as executing this section takes less than 50ms.
The additional parameter always_sleep can be set to true if you want to ensure that the sleep function
is always called for at least 1 ms. This is useful if you need to ensure that cooperative multitasking
works even for the price to miss the deadline.
## Test results
Comparison of the desired and actual sleep time for the functions sleep() and sleep_ms():
OS: Ubuntu 18.04 with a i7-7700K CPU and the standard kernel version 5.4.0-87-generic.
```julia
julia> include("test/bench.jl")
7-element BenchmarkTools.BenchmarkGroup:
tags: ["sleep_ms"]
"100µs" => TrialEstimate(100.152 μs)
"200µs" => TrialEstimate(200.108 μs)
"5ms" => TrialEstimate(5.000 ms)
"1ms" => TrialEstimate(1.000 ms)
"10ms" => TrialEstimate(10.001 ms)
"500µs" => TrialEstimate(500.093 μs)
"2ms" => TrialEstimate(2.000 ms)
4-element BenchmarkTools.BenchmarkGroup:
tags: ["sleep"]
"20ms" => TrialEstimate(21.267 ms)
"5ms" => TrialEstimate(6.255 ms)
"1ms" => TrialEstimate(2.219 ms)
"10ms" => TrialEstimate(11.215 ms)
"2ms" => TrialEstimate(3.199 ms)
```
This are the mean values. The error of the sleep_ms function is below 0.1% +- 100ns. The error of the default sleep() function of Julia on Linux is between 1ms and 2ms, for the set values of 1ms to 10ms this is an error of 13% to 62%.
On Windows the error is between 10ms and 20ms.