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Sato Shun
Tapple, inc.
Kotlin Nativeͷfrozenͱ
ฒߦॲཧʹ͍ͭͯ
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લఏࣝ
• ଟগͷKotlinͷࣝ
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࣍
• ͦͦͷฒߦॲཧͷ͍͠ॴ
• Kotlin NativeͰͲͷΑ͏ʹͯ͠ɺ͜ͷ՝Λղܾ͔ͨ͠
• Kotlin Nativeͷฒߦॲཧ
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ฒߦॲཧͷ͍͠ॴ
• mutableͳΠϯελϯεΛෳεϨου͔Βૢ࡞͢Δ࣌
• synchronizedɺmutexͳͲͷϩοΫΛ͏
• AtomicܥͷAPIΛ͏
• બࢶଟ͘ɺదʹॻ͘͜ͱ͍͠
• ·ͨόά͕ى͖ͨ࣌ʹ࠶ݱੑ͕͘ɺݪҼͷಛఆ͕ࠔ
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ฒߦॲཧͷ͍͠ॴ
• ͦ͜ͰKotlin NativeʢiOSଆʣͰɺmutableͳঢ়ଶͷΠϯελϯεʹର͠
ͯɺͱ͋Δ੍Λઃ͚Δ͜ͱͰղܾΛࢦͨ͠
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shared XOR mutable੍
• ฒߦॲཧͰ͕ग़Δɺshared ͔ͭ mutableͳঢ়ଶΛڐՄ͠ͳ͍ͱ͍͏੍
• RustͳͲͰΘΕ͍ͯΔ੍ʢΒ͍͠ʣ
• ͜ͷ੍Λຬͨͨ͢ΊʹɺKotlin NativeͰ frozenঢ়ଶ Λಋೖͨ͠
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frozenঢ়ଶ?
• ͦͷΠϯελϯε͕immutableͰ͋Δ͜ͱΛอূ͢Δ
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frozenঢ়ଶ?
• ͦͷΠϯελϯε͕immutableͰ͋Δ͜ͱΛอূ͢Δ
/**
* Freezes object subgraph reachable from this object. Frozen objects can be freely
* shared between threads/workers.
*
* @throws FreezingException if freezing is not possible
* @return the object itself
* @see ensureNeverFrozen
*/
public fun T.freeze(): T
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frozenঢ়ଶ?
• ͦͷΠϯελϯε͕immutableͰ͋Δ͜ͱΛอূ͢Δ
• freezeͨ͠ΠϯελϯεΛมߋ͠Α͏ͱ͢ΔͱɺΫϥογϡ͢Δ
• ଞͷεϨουͱ҆શʹڞ༗͢Δ͜ͱ͕ग़དྷΔ
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frozenঢ়ଶ?
• ͦͷΠϯελϯε͕immutableͰ͋Δ͜ͱΛอূ͢Δ
• freezeͨ͠ΠϯελϯεΛมߋ͠Α͏ͱ͢ΔͱɺΫϥογϡ͢Δ
• ଞͷεϨουͱ҆શʹڞ༗͢Δ͜ͱ͕ग़དྷΔ
/**
* Checks if given object is null or frozen or permanent (i.e. instantiated at compile-time).
*
* @return true if given object is null or frozen or permanent
*/
public val Any
?.
isFrozen
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frozenঢ়ଶ?
• ͦͷΠϯελϯε͕immutableͰ͋Δ͜ͱΛอূ͢Δ
• freezeͨ͠ΠϯελϯεΛมߋ͠Α͏ͱ͢ΔͱɺΫϥογϡ͢Δ
• ଞͷεϨουͱ҆શʹڞ༗͢Δ͜ͱ͕ग़དྷΔ
• unfreezeଘࡏ͠ͳ͍
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val sample = Sample(3)
sample.i
+ +
sample.freeze()
sample.i
+ +
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val sample = Sample(3)
sample.i
+ +
sample.freeze()
sample.i
+ +
Uncaught Kotlin exception: kotlin.native.concurrent.InvalidMutabilityException
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KMMͷfrozenͷ
• JVM(Android)ͱNative(iOS)Ͱڍಈ͕ҟͳΔ
• JVMʹfrozenঢ়ଶͱ͍͏֓೦ͳ͍
• AndroidͰಈ͘ɺ͔͠͠iOSͰΫϥογϡ͢ΔɻΈ͍ͨͳ͜ͱ͕ى͜
ΔՄೳੑ͕͋Δ
• ·ͨɺKotlin NativeͰfreezeΛ໌ࣔతʹݺͳͯ͘ɺ҉తʹfreeze͠
ͯ͠·͏ύλʔϯ͕͋Δ
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҉తͳfreeze
• objectɺcompanion objectͳͲɺࣗಈͰfreeze͢Δ༷ʹͳ͍ͬͯΔ
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object DefaultGlobalState {
private var i = 5
fun countUp() {
i
++
}
}
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object DefaultGlobalState {
private var i = 5
fun countUp() {
i
++
}
}
Uncaught Kotlin exception: kotlin.native.concurrent.InvalidMutabilityException
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@ThreadLocal
object DefaultGlobalState {
private var i = 5
fun countUp() {
i
++
}
}
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͜͜·Ͱͷ·ͱΊ
• shared XOR mutableΛຬͨͨ͢Ίʹfrozen͕ಋೖ͞Εͨ
• frozenঢ়ଶʹ͢Δ͜ͱͰɺimmutableͳঢ়ଶΛදݱͰ͖Δ
• ͜ΕฒྻॲཧΛ҆શʹѻ͏͜ͱ͕ग़དྷΔ
• ͔͠͠ɺ҉తͳfrozenͳͲͰɺiOS͚ͩಈ͔ͳ͍Մೳੑ͕͋Δ
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Kotlin Nativeͷฒߦॲཧ
• ϨϕϧAPIͱͯ͠ɺWorkerΫϥε͕༻ҙ͞Ε͍ͯΔ
• JavaͰ͍͏ͱ͜ΖͷThreadΫϥε
• Kotlin NativeͰɺجຊతʹεϨου͕มΘΔ߹ɺfrozenঢ়ଶʹͯ͠
immutableʹ͢Δඞཁ͕͋Δ
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val worker = Worker.start()
worker.execute(TransferMode.SAFE, { … }) {
…
}
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val worker = Worker.start()
worker.execute(TransferMode.SAFE, { … }) {
…
}
public fun execute(
mode: TransferMode,
producer: ()
->
T1,
@VolatileLambda job: (T1)
-
>
T2
): Future
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data class Sample(var i: Int)
val sample = Sample(1)
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data class Sample(var i: Int)
val sample = Sample(1)
worker.execute(TransferMode.SAFE, { sample }) {
println(it)
}
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data class Sample(var i: Int)
val sample = Sample(1)
worker.execute(TransferMode.SAFE, { sample }) {
println(it)
}
Uncaught Kotlin exception: kotlin.IllegalStateException: Illegal transfer state
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data class Sample(var i: Int)
val sample = Sample(1)
worker.execute(TransferMode.SAFE, { sample.freeze() }) {
println(it)
}
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data class Sample(var i: Int)
val sample = Sample(1)
val sample2 = Sample(2)
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data class Sample(var i: Int)
val sample = Sample(1)
val sample2 = Sample(2)
worker.execute(TransferMode.SAFE, { sample.freeze() }) {
println(it)
}
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data class Sample(var i: Int)
val sample = Sample(1)
val sample2 = Sample(2)
fun background(block: ()
->
Unit) {
worker.execute(TransferMode.SAFE, { block.freeze() }) {
it()
}
}
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data class Sample(var i: Int)
val sample = Sample(1)
val sample2 = Sample(2)
background {
println(sample)
println(sample2)
}
fun background(block: ()
->
Unit) {
worker.execute(TransferMode.SAFE, { block.freeze() }) {
it()
}
}
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data class Sample(var i: Int)
val sample = Sample(1)
val sample2 = Sample(2)
background {
println(sample)
println(sample2)
}
fun background(block: ()
->
Unit) {
worker.execute(TransferMode.SAFE, { block.freeze() }) {
it()
}
}
sampleɺsample2ຊମΛfreeze͍ͯ͠ͳ͍
εϨου͕มΘΔ߹ɺfreeze͠ͳ͍ͱ͍͚ͳ͍ͷͰ?
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data class Sample(var i: Int)
val sample = Sample(1)
val sample2 = Sample(2)
background {
println(sample)
println(sample2)
}
fun background(block: ()
->
Unit) {
worker.execute(TransferMode.SAFE, { block.freeze() }) {
it()
}
}
sampleɺsample2ຊମΛfreeze͍ͯ͠ͳ͍
εϨου͕มΘΔ߹ɺfreeze͠ͳ͍ͱ͍͚ͳ͍ͷͰ?
ϥϜμຊମΛfreeze͢Δͱɺ
ͦͷϥϜμ͕ࢀর͍ͯ͠Δม࿈తʹfreeze͞ΕΔ
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Kotlin Nativeͷฒߦॲཧͷ·ͱΊ
• Kotlin NativeʹWorkerͱ͍͏ϨϕϧAPI͕༻ҙ͞Ε͍ͯΔ
• εϨουؒΛލ͙ͱ͖ɺfreeze͢Δඞཁ͕͋Δ
• ͋ΔΠϯελϯεΛfreeze͢Δͱɺࢀর͞Ε͍ͯΔΠϯελϯε࿈త
ʹfreeze͢Δ
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͓·͚: Coroutineʹ͍ͭͯ
• ࣮ࡍͷ։ൃͰɺCoroutineͳͲͷߴϨϕϧͳAPIΛ͏͜ͱ͕ଟ͍
• ݱঢ়ɺKotlin Nativeʹ͓͚ΔCoroutineʮ୯ҰεϨουʹͷΈରԠͨ͠௨
ৗόʔδϣϯʯͱʮෳεϨουʹରԠͨ͠όʔδϣϯʯ͕͋Δ
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val sample = Sample("1")
println(sample.isFrozen)
withContext(Dispatchers.Default) {
println(sample.isFrozen)
}
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val sample = Sample("1")
println(sample.isFrozen)
withContext(Dispatchers.Default) {
println(sample.isFrozen)
}
୯ҰεϨουόʔδϣϯͷCoroutineͷ߹ɺisFrozenfalseɺ
ෳεϨουόʔδϣϯͷCoroutineͷ߹ɺisFrozentrue
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͝ਗ਼ௌ͋Γ͕ͱ͏͍͟͝·ͨ͠