Is there any way to remove this string This function is not kotlinlang #announcements

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pp.amorim

09/18/2018, 10:58 AM

Is there any way to remove this string? This function is not optional, I don't know why this is happening.

gildor

09/18/2018, 11:00 AM

Remove which string?

pp.amorim

09/18/2018, 11:01 AM

Thread.currentThread()

leosan

09/18/2018, 11:03 AM

I don’t think the

intrinsics

check is added to the final bytecode, not sure though

gildor

09/18/2018, 11:03 AM

Are we talking about LDC or about intrinsics?

intrinsics that checks for non null will be in final bytecode

Dico

09/18/2018, 11:04 AM

Kotlin uses it to provide debug info when checking that it's not null.

Why do you need to remove it?

I think there's a compiler argument that prevents the check being emitted.

gildor

09/18/2018, 11:05 AM

This compiler argument is semi-official and not recommended to use

such code will be optimized by HotSpot

pp.amorim

09/18/2018, 11:06 AM

This function runs every 10ms

gildor

09/18/2018, 11:06 AM

and?

You can remove this check by writing :

Thread.currentThread()?.isInterrupted

pp.amorim

09/18/2018, 11:08 AM

I think it's heavy to init a string every 10ms 😄, the process of this function is very light

gildor

09/18/2018, 11:08 AM

I don’t think so

pp.amorim

09/18/2018, 11:08 AM

I am working dealing with UI too

Dico

09/18/2018, 11:08 AM

it doesn't init a String at all, it's stored in a constant pool.

gildor

09/18/2018, 11:08 AM

I don’t believe that you get any measurable difference

pp.amorim

09/18/2018, 11:08 AM

hmm

Dico

09/18/2018, 11:09 AM

It depends on the JVM.

gildor

09/18/2018, 11:09 AM

this string will be cached in constant pool

pp.amorim

09/18/2018, 11:09 AM

changing the topic, why

Thread.currentThread().isInterrupted

needs to be verified?

gildor

09/18/2018, 11:09 AM

And I showed you how avoid this check

pp.amorim

09/18/2018, 11:09 AM

it's not optional

gildor

09/18/2018, 11:09 AM

First: there is no “optional” in Kotlin, there is nullable

Second: result of currentThread() has special “platform” type

Dico

09/18/2018, 11:10 AM

Because it's a platform call, Java functions can all return null and Kotlin needs to check that it doesn't when you don't expect it to.

gildor

09/18/2018, 11:10 AM

it means that it can be nulalble and non-nullable up to you, kotlin don’t know

pp.amorim

09/18/2018, 11:10 AM

I am only targeting to Android so far

Dico

09/18/2018, 11:10 AM

Love how were both explaining the same stuff simultaneously, I'll get out

Yeah, i think the check not null functions have a bigger impact on android. Don't quote me on that.

gildor

09/18/2018, 11:11 AM

so I would just ignore this bytecode, it will be optimized and you never see any performance difference

but if it’s really bothers you, just use

Thread.currentThread()?.isInterrupted == true

instead

pp.amorim

09/18/2018, 11:12 AM

no, I will try

gildor

09/18/2018, 11:13 AM

And check docs about platform types: https://kotlinlang.org/docs/reference/java-interop.html#null-safety-and-platform-types

Dico

09/18/2018, 11:13 AM

Dalvik JVM does have redundant null check elimination, if that matters.

pp.amorim

09/18/2018, 11:14 AM

@gildor worked! thank you!

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