Question

Android sdk允许使用以下内容自定义非ui线程的堆栈大小：

ThreadGroup group = new ThreadGroup("threadGroup");
new Thread(group, runnableObject, "YourThreadName", 20000).start();

是否可以进行类似的调用，允许我使用堆栈大小增加的AsyncTask api？

Answer 1

AsyncTask有一个ThreadFactory的私有静态对象（匿名内部类）来生成新的Thread [1]：

private static final ThreadFactory sThreadFactory = new ThreadFactory() {
    private final AtomicInteger mCount = new AtomicInteger(1);

    public Thread newThread(Runnable r) {
        return new Thread(r, "AsyncTask #" + mCount.getAndIncrement());
    }
};

正如您所看到的，newThread方法返回Thread(Runnable runnable, String threadName)而没有stackSize的任何参数。所以你无法改变它。但是，线程中的堆栈大小具有高度依赖于平台的解释。甚至可以完全忽略它[2]。

修改您可以使用自定义执行者，而不是THREAD_POOL_EXECUTOR使用AsyncTask的{{1}}。例如：

sThreadFactory

然后，您可以使用自定义执行程序：

private static final int CPU_COUNT = Runtime.getRuntime().availableProcessors();
private static final int CORE_POOL_SIZE = CPU_COUNT + 1;
private static final int MAXIMUM_POOL_SIZE = CPU_COUNT * 2 + 1;
private static final int KEEP_ALIVE = 1;

private static final ThreadFactory yourFactory = new ThreadFactory() {
    private final AtomicInteger mCount = new AtomicInteger(1);

    public Thread newThread(Runnable r) {
        ThreadGroup group = new ThreadGroup("threadGroup");
        return new Thread(group, r, "YourThreadName", 20000);
    }
};

private static final BlockingQueue<Runnable> sPoolWorkQueue =
        new LinkedBlockingQueue<Runnable>(128);

public static final Executor YOUR_CUSTOM_THREAD_POOL_EXECUTOR
        = new ThreadPoolExecutor(CORE_POOL_SIZE, MAXIMUM_POOL_SIZE, KEEP_ALIVE,
                TimeUnit.SECONDS, sPoolWorkQueue, yourFactory);

[1] https://github.com/android/platform_frameworks_base/blob/master/core/java/android/os/AsyncTask.java

[2] http://developer.android.com/reference/java/lang/Thread.html

Answer 2

所有AsyncTasks都由共享（静态）ThreadPoolExecutor和LinkedBlockingQueue在内部控制。当您在AsyncTask上调用execute时，ThreadPoolExecutor将通过在内部运行新线程或对其进行排队来执行它。因此线程堆栈大小由内部ThreadPoolExecutor控制。您无法访问它。如果要控制堆栈大小，请使用您自己的ThreadPoolExecutor。但是，正如@ yaa110所述，堆栈大小参数与平台高度相关。

增加AsyncTask堆栈大小？

2 个答案: