Question

这是代码

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final  WeakReference<Obj> weakReference = new WeakReference<>(new Obj());
//        just add some code here, gc "works"
//        int i = 1;
//        Log.d(TAG, "onCreate: just do something");
        triggerGc();
        if (weakReference.get() != null) {
            Log.d(TAG, "onCreate: NOT reclaimed " + weakReference.get().toString());
        } else {
            Log.d(TAG, "onCreate: reclaimed");
        }
    }

未回收弱引用的对象！但是GC确实发生了。

D/EnvTest: triggering Gc...
I/art: Starting a blocking GC Explicit
I/art: Explicit concurrent mark sweep GC freed 330(35KB) AllocSpace objects, 0(0B) LOS objects, 39% free, 4MB/7MB, paused 115us total 11.164ms
D/EnvTest: Gc triggered.
D/EnvTest: onCreate: NOT reclaimed com.example.yves.envtest.MainActivity$Obj@cd043f8

如果在triggerGc（）之前添加一些代码，例如日志记录或赋值，则该对象将按我们期望的方式回收。

这是triggerGc（）方法

    private void triggerGc() {
        Log.d(TAG, "triggering Gc...");
        Runtime.getRuntime().gc();
        Runtime.getRuntime().runFinalization();
        Log.d(TAG, "Gc triggered.");
    }

Obj在这里

   static class Obj{
        @Override
        protected void finalize() throws Throwable {
            super.finalize();
            Log.d(TAG, "finalize: ");
        }
    }

GC后，Android中的奇怪WeakReference仍然有效吗？

0 个答案: