My iOS app crashes with the following error: ``` m...

# kotlin-native

[Thomas]

My iOS app crashes with the following error:

malloc: *** error for object 0x280872d78: pointer being freed was not allocated
malloc: *** set a breakpoint in malloc_error_break to debug

I am guessing I am doing something wrong with my cinterop code. How can I find the cause of the issue in my code?

[Artyom Degtyarev [JB]]

Hello! Can you share some code, please?

[Thomas]

Hi @Artyom Degtyarev [JB], I am not sure what code causes the issue. Is there a proper way to debug this?

This is some code I recently added (and am using it), could this be the issue?

import kotlinx.cinterop.CPointer
import kotlinx.cinterop.addressOf
import kotlinx.cinterop.get
import kotlinx.cinterop.usePinned
import platform.Foundation.NSData
import platform.Foundation.create
import platform.posix.uint8_tVar

fun ByteArray.toNSData(): NSData = usePinned { pinned ->
    return NSData.create(
        bytesNoCopy = pinned.addressOf(0),
        length = size.toULong()
    )
}

fun NSData.toByteArray(): ByteArray {
    @Suppress("UNCHECKED_CAST")
    val bytePtr = (bytes as CPointer<uint8_tVar>)

    return ByteArray(length.toInt()) { index ->
        bytePtr[index].toByte()
    }
}

[Thomas]

I replaced bytesNoCopy with bytes, which fixed the issue. This is probably because NSData with bytesNoCopy expects the ByteArray to be stable in memory, even after the create function. Is that right?

[svyatoslav.scherbina]

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