都是原始类型的垃圾收集在Android的？ [英] Are primitive types garbage collected in Android?

问题描述

我知道这可能是一个愚蠢的问题，但我的背景是更多的C ++和管理自己的记忆。

I know this may be a dumb question, but my background is more in c++ and managing my own memory.

我目前砍伐的每一个配置，我可以从我的游戏，试图减少垃圾收集的频率和感知的滞后，所以对于每个变量，我创建的是一个对象（字符串和矩形一例如）我要确保我的手之前创建它在我的构造函数，而不是建立在简单的10个临时变量 行功能...（我希望是有道理的）

I am currently cutting down every single allocation that I can from one of my games to try and reduce the frequency of garbage collection and perceived "lag", so for every variable that I create that is an Object (String and Rect for example) I am making sure that I create it before hand in my constructor and not create temporary variables in simple 10 line functions... (I hope that makes sense)

反正我是工作，虽然今晚多一些，我意识到，我可能是完全错误的关于我的垃圾收集和原始类型（int，布尔型，浮点型）是我在10号线函数来创建这些原始类型变量的假设被调用20 次，第二次增加垃圾收集我的问题？

Anyways I was working though it some more tonight and I realized that I may be completely wrong about my assumption on garbage collection and primitive types (int, boolean, float) are these primitive type variables that I create in a 10 line function that gets called 20 times a second adding to my problem of garbage collection?

所以，一年前每几秒钟我就看到logcat的消息像

So a year ago every few seconds I would see a message in logcat like

GC释放4010对象/在484064字节   101ms

GC freed 4010 objects / 484064 bytes in 101ms

现在我看到消息每隔15-90秒左右...

Now I see that message every 15-90 seconds or so...

因此​​，要改写我的问题：是否原始类型（整型，浮点，布尔，等等）看到这条消息时，包括

So to rephrase my question: Are primitive types (int, float, boolean, etc) included when seeing this message?

推荐答案

基本类型不是对象，所以他们不会造成任何垃圾收集。但是，你必须要非常小心，因为由于拳击基本类型很容易成为一个对象没有你明确地这样做。

Primitive types are not objects, so they do not cause any garbage collection. However, you do have to be very careful because due to boxing a primitive type can easily become an object without you explicitly doing so.

例如，如果你想要一个HashMap＆LT;>整数键，您将使用HashMap中。注意，因为整数是不是一个对象，它不能在一个容器中使用。 Integer是一种原始的一个int对象版本。当你写code这样的，一个Integer对象将自动为你创建：

For example, if you want a HashMap<> of integer keys, you would use HashMap. Note that because "int" is not an object, it can't be used in a container. Integer is an object version of a primitive int. When you write code like this, an Integer object will automatically be created for you:

HashMap<Integer, Object> map = new HashMap<Integer, Object>();
int someNum = 12345;    // no object created.
map.put(someNum, null); // Integer object created.

需要注意的是同样的事情会发生，如果你不使用泛型，但更隐蔽：

Note that the exact same thing will happen if you don't use generics, but even more hidden:

HashMap map = new HashMap();
int someNum = 12345;    // no object created.
map.put(someNum, null); // Integer object created.

有关这种特殊情况下，可以使用Android的SparseArray类，这是基本整数键的容器。

For this particular situation, you can use Android's SparseArray class, which is a container of primitive integer keys.

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