The document discusses the performance of Kotlin on Android, presented by Alexander Smirnov. It explores various aspects such as Kotlin's comparative speed to Java, the critical importance of performance in UI thread operations, and details benchmarking results across different devices. The findings suggest that while Kotlin can be as fast as Java, the real focus should be on properly optimizing UI operations within the app lifecycle.

1. KOTLIN PERFOMANCE
ON ANDROID
ALEXANDER SMIRNOV
06.06.2017

2. WHOAMI
ANDROID DEVELOPER SINCE 2012
ANDROID В ЛИЦАХ (YOUTUBE – TELEGRAM)
WORKING IN SPLYT
MOSDROID

3. QUIZ: KOTLIN VS JAVA!?
1. МЕДЛЕННЕЕ
2. ОДИНАКОВО
3. БЫСТРЕЕ

4. ВСЁ ПОМЕРЯЕМ
fun measure() : Long {
val startTime = System.nanoTime()
work()
return System.nanoTime() - startTime
}
adb shell dumpsys gfxinfo %package_name%

5. QUIZ: ГДЕ ПЕРФОМАНС ВАЖЕН?
1. ОДНОЗНАЧНО ВЕЗДЕ
2. UITHREAD
3. CUSTOM VIEW + ANIMATIONS

6. VIEWS && UI THREAD

7. KOTLIN STYLE
COLLECTION API
METHOD DEFAULT PARAMETERS
DATA CLASSES
REIFIED TYPES
COROUTINES

8. class Test {
var a = 5
var b = 6
val c = B()
fun work() {
val d = a + b
val e = c.a + c.b
}
}
class B(@JvmField var a: Int = 5,
var b: Int = 6)
FIELDS

9. L0
LINENUMBER 10 L0
ALOAD 0
GETFIELD kotlin/Test.a : I
ALOAD 0
GETFIELD kotlin/Test.b : I
IADD
ISTORE 1
FIELDS var a = 5
var b = 6
val d = a + b

10. L1
LINENUMBER 11 L1
ALOAD 0
GETFIELD kotlin/Test.c : Lkotlin/B;
GETFIELD kotlin/B.a : I
ALOAD 0
GETFIELD kotlin/Test.c : Lkotlin/B;
INVOKEVIRTUAL kotlin/B.getB ()I
IADD
ISTORE 2
FIELDS val e = c.a + c.b
class B(@JvmField var a: Int = 5,
var b: Int = 6)

11. STATIC!?
companion object {
var k = 5
fun work2() : Int = 42
}

12. NOT STATIC
companion object {
var k = 5
fun work2() : Int = 42
}
val i = k + work2()
L2
LINENUMBER 21 L2
GETSTATIC kotlin/Test.Companion : Lkotlin/Test$Companion;
INVOKEVIRTUAL kotlin/Test$Companion.getK ()I
GETSTATIC kotlin/Test.Companion : Lkotlin/Test$Companion;
INVOKEVIRTUAL kotlin/Test$Companion.work2 ()I
IADD
ISTORE 3

13. NOT STATIC private static int k = 5;
public static final Test.Companion Companion =
new Test.Companion((DefaultConstructorMarker)null);
public static final class Companion {
public final int getK() { return Test.k;}
public final void setK(int var1) {
Test.k = var1;
}
public final int work2() { return 42; }
private Companion() { }
// $FF: synthetic method
public Companion(DefaultConstructorMarker
$constructor_marker) { this(); }
}

14. NOT STATIC
val i = k + work2()
companion object {
@JvmField
var k = 5
@JvmStatic
fun work2() : Int = 42
}
private static int k = 5;
public static final Test.Companion Companion =
new Test.Companion((DefaultConstructorMarker)null);
public static final class Companion {
@JvmStatic
public final int work2() { return 42; }
private Companion() {}
// $FF: synthetic method
public Companion(DefaultConstructorMarker
$constructor_marker) { this(); }
}

15. NOT STATIC
val i = k + work2()
companion object {
@JvmField
var k = 5
@JvmStatic
fun work2() : Int = 42
}
L2
LINENUMBER 21 L2
GETSTATIC kotlin/Test.k : I
GETSTATIC kotlin/Test.Companion : Lkotlin/Test$Companion;
INVOKEVIRTUAL kotlin/Test$Companion.work2 ()I
IADD
ISTORE 3

16. REAL STATIC !? object A {
fun test() = 53
}
L3
LINENUMBER 23 L3
GETSTATIC kotlin/A.INSTANCE : Lkotlin/A;
INVOKEVIRTUAL kotlin/A.test ()I
POP

17. STATIC! fun test2() = 99
L4
LINENUMBER 24 L4
INVOKESTATIC kotlin/TestKt.test2 ()I
POP

18. NULLABILITY
fun test(first: String, second: String?) : String {
second ?: return first
return "$first $second"
}

19. NULLABILITY
fun test(first: String, second: String?) : String {
second ?: return first
return "$first $second"
}
@NotNull
public final String test(@NotNull String first,
@Nullable String second) {
Intrinsics.checkParameterIsNotNull(first, "first");
return second != null ? (first + " " + second) : first;
}

20. var a = 5
var b = 6
var bOption : Int? = 6
PRIMITIVES
private int a = 5;
private int b = 6;
@Nullable
private Integer bOption = Integer.valueOf(6);

21. AUTOBOXING
val a: String? = null
var b = a?.isBlank() == true

22. AUTOBOXING
val a: String? = null
var b = a?.isBlank() == true
if (a != null && a.isBlank()) true else false

23. AUTOBOXING
val a: String? = null
var b = a?.isBlank() == true
String a = (String)null;
boolean b = Intrinsics.areEqual(a != null ?
Boolean.valueOf(StringsKt.isBlank((CharSequence)a)) : null,
Boolean.valueOf(true));
if (a != null && a.isBlank()) true else false

24. LOOPS
list.forEach {
work(it * 2)
}

25. LOOPS
inline fun <reified T> List<T>.foreach(crossinline action: (T)
-> Unit): Unit {
val size = size
var i = 0
while (i < size) {
action(get(i))
i++
}
} list.foreach {
work(it * 2)
}

26. RANGES
inline fun <reified T> List<T>.foreach(crossinline action: (T)
-> Unit): Unit {
val size = size
for(i in 0..size) {
work(i * 2)
}
}

27. INTRINSICS

28. INTRINSICS
class Test {
fun concat(first: String, second: String) =
"$first $second"
}

29. INTRINSICS
public final class Test {
@NotNull
public final String concat(@NotNull String first,
@NotNull String second) {
Intrinsics.checkParameterIsNotNull(first, "first");
Intrinsics.checkParameterIsNotNull(second, "second");
return first + " " + second;
}
}

30. INTRINSICS
public final class Test {
@NotNull
public final String concat(@NotNull String first,
@NotNull String second) {
return first + " " + second;
}
}
kotlinc -Xno-call-assertions -Xno-param-assertions Test.kt

31. REDEX
ИНЛАЙНИТ, НО НЕ ВСЁ
ДЕЛАЕТ ДРУГИЕ ОПТИМИЗАЦИИ – 7% К ВЕСУ APK
РЕШЕНИЕ ОТ FACEBOOK

32. BENCHMARKS
PARTICLES DRAWABLE
BY YAROSLAV MYTKALYK (DOCTOROR)
4 DIFFERENT PHONES
DUMPSYS GFXINFO + MANY BENCHMARKING
HTTPS://GITHUB.COM/SMRED

33. 0
3,75
7,5
11,25
15
Java Kotlin Kotlin+
Min Median Mean
BENCHMARKS
1.2 ГГЦ – 1 ГБ ОЗУ
4.4.2 – 480X854
HUAWEI Y54 I-U02

34. BENCHMARKS
1.2 ГГЦ – 1 ГБ ОЗУ
4.4.2 – 480X854
HUAWEI Y54 I-U02
JAVA KOTLIN KOTLIN+
Min 9,82 9,64 9,24
Median 13,667 13,98 13,58
Mean 14,375 14,875 14,524

35. BENCHMARKS
1.3 ГГЦ – 1 ГБ ОЗУ
4.4.2 – 960X540
ONN K7 SUNNY
JAVA KOTLIN KOTLIN+
Min 9,73 10,01 9,75
Median 13,31 13,58 13,31
Mean 13,549 13,847 13,625

36. BENCHMARKS
2.1 ГГЦ + 1.5 ГГЦ – 3 ГБ ОЗУ
7.0 – 2560X1440
SAMSUNG GALAXY S6
JAVA KOTLIN KOTLIN+
Min 13,62 13 13,12
Median 24,155 24,675 23,53
Mean 23,924 25,567 23,753

37. BENCHMARKS
2.15 ГГЦ + 1.6 ГГЦ– 4 ГБ ОЗУ
7.1.2 – 1920X1080
GOOGLE PIXEL
JAVA KOTLIN KOTLIN+
Min 7,56 7,37 7,3
Median 12,96 12,89 12,9
Mean 13,579 13,624 13,553

38. ИТОГО
БЫСТРОДЕЙСТВИЕ ВАЖНО ТОЛЬКО НА UI ПОТОКЕ
ОЧЕНЬ КРИТИЧНО ТОЛЬКО В ONMEASURE - ONLAYOUT - ONDRAW
ПРАКТИЧЕСКИ ВСЕГДА МОЖНО НАПИСАТЬ С ИДЕНТИЧНОЙ СКОРОСТЬ
РАБОТЫ
ПРЕЖДЕВРЕМЕННЫЕ ОПТИМИЗАЦИИ ЗЛО

39. ENJOY
alexander.smirnov@splyt.com
@_smred
@smred