Alexander Udalov
99b38ccb74
Using `ReflectionProperties.lazy` is incorrect because it allows several threads to observe different resulting values if they're computing it simultaneously (unlike `lazy(PUBLICATION)`, which always returns the value that "won the race"). In the case of property delegates, for example, if we're invoking `isAccessible = true` and then `getDelegate()` concurrently, it might happen that when some thread invokes `getDelegate()`, it gets the underlying Field object which was written by another thread and which has not yet been made accessible, leading to IllegalPropertyDelegateAccessException. #KT-27585 Fixed
40 lines
993 B
Kotlin
Vendored
40 lines
993 B
Kotlin
Vendored
import java.util.concurrent.atomic.AtomicInteger
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import java.util.concurrent.atomic.AtomicReference
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import java.util.concurrent.CyclicBarrier
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import kotlin.concurrent.thread
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import kotlin.reflect.jvm.*
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const val N_THREADS = 50
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class Delegate {
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operator fun getValue(x: Any?, y: Any?): String = "OK"
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operator fun setValue(x: Any?, y: Any?, z: String) {}
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}
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var property by Delegate()
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fun main() {
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val reference = ::property
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val gate = CyclicBarrier(N_THREADS + 1)
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var fail = AtomicReference<Throwable?>(null)
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var finished = AtomicInteger(0)
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for (i in 0 until N_THREADS) {
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thread {
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gate.await()
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reference.isAccessible = true
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try {
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reference.getDelegate()!!
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} catch (e: Throwable) {
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fail.set(e)
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}
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finished.incrementAndGet()
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}
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}
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gate.await()
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while (finished.get() != N_THREADS) Thread.sleep(25L)
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fail.get()?.let { throw it }
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}
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