Kotlin/Native嘗試
在官網看到Kotlin/Native已經達到1.0 Beta版於是就去嘗試了一下,結果發現坑還是挺多的。
首先Kotlin/JVM很多庫是用不了的,這個已經猜到了。官網說已經預先導入了 POSIX、 gzip、 OpenGL、 Metal、 Foundation 等很多其他的庫,然後我就嘗試了下基本的文件讀寫。和C還是有一點的差別的。如下:
fun hello(): String = "Hello, Kotlin/Native!"
fun letter() = "abcdefghigklmnopqrstuvwxyz"
fun main(args: Array<String>) {
val file = fopen("data.txt", "w")
fprintf(file, "%s", hello())
fprintf(file, "%s", "\n")
fprintf(file, "%s", letter())
fclose(file)
println("write finished")
val filer = fopen("data.txt", "r")
val buf = ByteArray(255)
// fscanf(filer, "%s", buf.pin().addressOf(0))
fgets(buf.pin().addressOf(0), 255, filer)
fclose(filer)
print(buf.stringFromUtf8())
buf.pin().unpin()
println("read finished")
system("pause")
}
運行結果如下
> Task :runProgram
write finished
Hello, Kotlin/Native!
read finished
Press any key to continue . . .
C:\BuildAgent\work\4d622a065c544371\runtime\src\main\cpp\Memory.cpp:1150: runtime assert: Memory leaks found
> Task :runProgram FAILED
令人鬱悶的是提示C:\BuildAgent\work\4d622a065c544371\runtime\src\main\cpp\Memory.cpp:1150: runtime assert: Memory leaks found
,雖然調用了buf.pin().unpin()
,但依舊提示內存泄漏,也沒有異常退出啊。
如果是改成如下方式就不會提示錯誤了:
fun hello(): String = "Hello, Kotlin/Native!"
fun letter() = "abcdefghigklmnopqrstuvwxyz"
fun main(args: Array<String>) {
val file = fopen("data.txt", "w")
fprintf(file, "%s", hello())
fprintf(file, "%s", "\n")
fprintf(file, "%s", letter())
fclose(file)
println("write finished")
val filer = fopen("data.txt", "r")
val buf = ByteArray(255)
// fscanf(filer, "%s", buf.pin().addressOf(0))
// fgets(buf.pin().addressOf(0), 255, filer)
// fclose(filer)
// print(buf.stringFromUtf8())
// buf.pin().unpin()
buf.usePinned {
fgets(it.addressOf(0), 255, filer)
fclose(filer)
print(buf.stringFromUtf8())
}
println("read finished")
system("pause")
}
結果如下:
> Task :runProgram
write finished
Hello, Kotlin/Native!
read finished
Press any key to continue . . .
BUILD SUCCESSFUL in 9s
另外吐槽下,這麼幾行代碼就要9s,是不是太慢了。
隨後又試了下開啓pthread線程,但是pthread_create
函數的第一個參數th: kotlinx.cinterop.CValuesRef<platform.posix.pthread_tVar>
,CValuesRef
類型的變量怎麼獲得一直無解,難道只能通過繼承獲得?
然後我在寫文章的時候又發現只要這樣寫就可以了???
fun main(args: Array<String>) {
pthread_create(null, null, test(), null)
}
typealias func = kotlinx.cinterop.CPointer<kotlinx.cinterop.CFunction<(kotlinx.cinterop.COpaquePointer?) -> kotlinx.cinterop.COpaquePointer?>>?
fun test(): func {
return staticCFunction<kotlinx.cinterop.COpaquePointer?, kotlinx.cinterop.COpaquePointer?> {
println("run test")
it
}
}
結果如下:
> Task :runProgram
run test
BUILD SUCCESSFUL in 8s