主线程本身被对象阻塞。等待？

Question

我的布局有表面视图。有时当我的应用程序从后台切换到前台时，我会得到ANR。我认为原因是主线程被lock方法阻塞了。

最重要的部分是：

Answer 1

http://androidxref.com/4.4.2_r2/xref/libcore/libdvm/src/main/java/java/lang/thread.java

 public void parkFor(long nanos) {
    VMThread vmt = vmThread;

    if (vmt == null) {
        // Running threads should always have an associated vmThread.
        throw new AssertionError();
    }
    synchronized (vmt) {
        switch (parkState) {
            case ParkState.PREEMPTIVELY_UNPARKED: {
                parkState = ParkState.UNPARKED;
                break;
            }
            case ParkState.UNPARKED: {
                long millis = nanos / NANOS_PER_MILLI;
                nanos %= NANOS_PER_MILLI;

                parkState = ParkState.PARKED;
                try {
                    vmt.wait(millis, (int) nanos);//<==//here  , maybe it's a normal stack.
                } catch (InterruptedException ex) {
                    interrupt();
                } finally {
                //..................
                }