[question] daemon concept

listvin commented 9 months ago

While caching compiled code is great, one of the concerns I have while trying Kotlin scripting is startup time.

What's your opinion on possibility of JVM running as daemon, ready to pickup scripts on startup? Similar in some manner to Gradle daemon.

Some properties to clarify concept:

start daemon when first script is started since system startup
- limited lifetime
- optional startup when system boots
dynamically load bytecode
one daemon per every runtime configuration
- maybe several daemons per runtime if there are more than one script running

I believe it will give performance boost by utilizing JIT out of the box.

aartiPl commented 9 months ago

Hi! This is an interesting idea. I am very curious about the real gains of daemon implementation compared to the implementation without daemon.

ybznek commented 8 months ago

Startup time of compiled (.jar) script if it is an issue it could be compiled into native code (https://www.graalvm.org/latest/reference-manual/native-image/basics/), but the binary is roughly 8MB at minimum (maybe could be adjusted more?) and compilation is slow. Task of gradle daemon is "just" compilation. Shared daemon across various scripts would require some isolation - e.g. you don't want to kill daemon if one of scripts call exit(), etc.

Initial startup time of not complied script: I've done experiment with my <1 day project similar to kscript. I do not call kotlinc, but ./gradlew and pass variables like srcDir, dependencies, .. via env. variables First start with kscript seems to be roughly 6x slower than my solution with running gradle daemon

Significant slowdown of kscript seems to be due to resolution of dependency. My solution just collect runtimeClasspath from gradle (/home/z/.gradle/caches/modules-2/files-2.1/org.jsoup/jsoup/1.16.2/5d39ff6d1b8331c376a04c50c6716afbcdfe567d/jsoup-1.16.2.jar) - and let gradle to download that.

Script:

#!/usr/bin/env /home/z/projects/kotlin/kscript2/runner/kscript2
@file:DependsOn("org.jsoup:jsoup:1.16.2")
import org.jsoup.Jsoup
println("a")
println( Jsoup.parse("<html><body id=\"b\">sth</body></html>")!!.getElementById("b")!!.text())

First run with kscript:

time kscript /home/z/projects/kotlin/kscript2/runner/src/test/resources/source/main.kts a
[kscript] Resolving org.jsoup:jsoup:1.16.2...
a
sth
kscript  a  5,37s user 0,50s system 263% cpu 2,225 total

First run with my experiment with running daemon:

time /home/z/projects/kotlin/kscript2/runner/src/test/resources/source/main.kts a
a
sth
/home/z/projects/kotlin/kscript2/runner/src/test/resources/source/main.kts a  0,86s user 0,16s system 98% cpu 1,027 total

aartiPl commented 8 months ago

Nice - 6x improvement in start-up looks very promising 👍

listvin commented 8 months ago

@ybznek thanks for actual minifyed timing sample! Can you please share your project as repo?

Shared daemon across various scripts would require some isolation - e.g. you don't want to kill daemon if one of scripts call exit(), etc.

Nice concern. Do you have more ideas of isolation cases? Regarding .exit probably auto-restarting daemon, if it exits or crashes on its own (not via ~ $ kscriptd stop-daemon), would be sufficient at least for a poc-version?

kscripting / kscript

[question] daemon concept #413