withBufferLocked
Platform and version requirements: Native (1.3) 
fun <R> withBufferLocked( block: (array: ByteArray, dataSize: Int) -> R ): R
Executes provided block under lock with the raw data buffer. Block is executed under the spinlock, and must be short.
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Licensed under the Apache License, Version 2.0.
    https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.native.concurrent/-mutable-data/with-buffer-locked.html