Is it safe to finish an android activity from a background thread?

Question

In Android, is it safe to call Activity.finish() from a background thread, or can it only called from the main thread? The documentation doesn\'t mention anything a

Answer 1

No, it is not.

The code uses at least one variable, mFinished, without synchronization. Full stop.

   public void finish() {
    if (mParent == null) {
        int resultCode;
        Intent resultData;
        synchronized (this) {
            resultCode = mResultCode;
            resultData = mResultData;
        }
        if (false) Log.v(TAG, "Finishing self: token=" + mToken);
        try {
            if (resultData != null) {
                resultData.setAllowFds(false);
            }
            if (ActivityManagerNative.getDefault()
                .finishActivity(mToken, resultCode, resultData)) {
                mFinished = true;
            }
        } catch (RemoteException e) {
            // Empty
        }
    } else {
        mParent.finishFromChild(this);
    }
}