add a common io handler

Author: SilenceDut

taskscheduler/src/main/java/com/silencedut/taskscheduler/TaskScheduler.java

@@ -33,6 +33,7 @@ public class TaskScheduler {
 
     private Executor mParallelExecutor ;
     private ExecutorService mTimeOutExecutor ;
+    private static Handler sIOHandler;
     private SafeSchedulerHandler mMainHandler = new SafeSchedulerHandler(Looper.getMainLooper());
 
 
@@ -70,6 +71,8 @@ private TaskScheduler() {
         mTimeOutExecutor = new ThreadPoolExecutor(0,MAXIMUM_POOL_SIZE,
                 KEEP_ALIVE,TimeUnit.SECONDS,new SynchronousQueue<Runnable>(),ThreadFactory.TIME_OUT_THREAD_FACTORY);
 
+        sIOHandler = provideHandler("IoHandler");
+
     }
 
     /**
@@ -86,6 +89,13 @@ public static Handler provideHandler(String handlerName) {
         return new SafeSchedulerHandler(handlerThread.getLooper());
     }
 
+    /**
+     * 提供一个公用的异步handler
+     */
+    public static Handler ioHandler() {
+        return sIOHandler;
+    }
+
     /**
      * 主线程周期性执行任务，默认立刻执行，之后间隔period执行，不需要时注意取消,每次执行时如果有相同的任务，默认会先取消
      * @param task 执行的任务