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华为Harmony鸿蒙开发笔记十一：线程管理_鸿蒙线程管理demo

作者：很楠不爱3 | 2024-03-21 22:34:16

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鸿蒙线程管理demo

鸿蒙的线程是有TaskDispatcher类来分发的，TaskDispatcher有四种GlobalTaskDispatcher、ParallelTaskDispatcher、SerialTaskDispatcher、SpecTaskDispatcher。

创建对象：

  1.     private String parallelName = "parallelTaskDispatcher";
  2.     private String serialName = "serialTaskDispatcher";
  3.     private TaskDispatcher globalTaskDispatcher;//全局并发任务分发器
  4.     private TaskDispatcher parallelTaskDispatcher;//并发任务分发器
  5.     private TaskDispatcher serialTaskDispatcher;//串行任务分发器
  6.     private TaskDispatcher uiTaskDispatcher;//专有任务分发器
  7.     @Override
  8.     public void onStart(Intent intent) {
  9.         super.onStart(intent);
  10.         super.setUIContent(ResourceTable.Layout_ability_main);
  11.  
  12.         globalTaskDispatcher = getGlobalTaskDispatcher(TaskPriority.DEFAULT);
  13.         parallelTaskDispatcher = createParallelTaskDispatcher(parallelName, TaskPriority.DEFAULT);
  14.         serialTaskDispatcher = createSerialTaskDispatcher(serialName, TaskPriority.DEFAULT);
  15.         uiTaskDispatcher = getUITaskDispatcher();
  16.     }

测试同步任务代码：

  1.     private void testSyncDispatch() {
  2.         globalTaskDispatcher.syncDispatch(new Runnable() {
  3.             @Override
  4.             public void run() {
  5.                 try {
  6.                     Thread.sleep(5000);
  7.                 } catch (InterruptedException e) {
  8.                     e.printStackTrace();
  9.                 }
  10.                 HiLog.info(label, "sync task1 run");
  11.             }
  12.         });
  13.         HiLog.info(label, "after sync task1");
  14.  
  15.         parallelTaskDispatcher.syncDispatch(new Runnable() {
  16.             @Override
  17.             public void run() {
  18.                 try {
  19.                     Thread.sleep(5000);
  20.                 } catch (InterruptedException e) {
  21.                     e.printStackTrace();
  22.                 }
  23.                 HiLog.info(label, "sync task2 run");
  24.             }
  25.         });
  26.         HiLog.info(label, "after sync task2");
  27.  
  28.         serialTaskDispatcher.syncDispatch(new Runnable() {
  29.             @Override
  30.             public void run() {
  31.                 try {
  32.                     Thread.sleep(5000);
  33.                 } catch (InterruptedException e) {
  34.                     e.printStackTrace();
  35.                 }
  36.                 HiLog.info(label, "sync task3 run");
  37.             }
  38.         });
  39.         HiLog.info(label, "after sync task3");
  40.         uiTaskDispatcher.syncDispatch(new Runnable() {
  41.             @Override
  42.             public void run() {
  43.                 try {
  44.                     Thread.sleep(5000);
  45.                 } catch (InterruptedException e) {
  46.                     e.printStackTrace();
  47.                 }
  48.                 HiLog.info(label, "sync task4 run");
  49.             }
  50.         });
  51.         HiLog.info(label, "after sync task4");
  52.     }

输出日志：

  1. 01-24 09:14:31.488 4741-27498/com.example.dispatcherdemo I 00201/MY_TAG: sync task1 run
  2. 01-24 09:14:31.489 4741-4741/com.example.dispatcherdemo I 00201/MY_TAG: after sync task1
  3. 01-24 09:14:36.490 4741-27783/com.example.dispatcherdemo I 00201/MY_TAG: sync task2 run
  4. 01-24 09:14:36.491 4741-4741/com.example.dispatcherdemo I 00201/MY_TAG: after sync task2
  5. 01-24 09:14:41.492 4741-28065/com.example.dispatcherdemo I 00201/MY_TAG: sync task3 run
  6. 01-24 09:14:41.492 4741-4741/com.example.dispatcherdemo I 00201/MY_TAG: after sync task3

syncDispatch是派发同步任务，可以看出无论哪种分发器，只要使用syncDispatch来派发任务，都是同步执行的，有点协程的味道。最后一个uiTaskDispatcher没有执行是因为发生了死锁，官网说以下情况使用syncDispatch会导致死锁：

如果对syncDispatch使用不当, 将会导致死锁。如下情形可能导致死锁发生：

  • 在专有线程上，利用该专有任务分发器进行syncDispatch。
  • 在被某个串行任务分发器（dispatcher_a）派发的任务中，再次利用同一个串行任务分发器（dispatcher_a）对象派发任务。
  • 在被某个串行任务分发器（dispatcher_a）派发的任务中，经过数次派发任务，最终又利用该（dispatcher_a）串行任务分发器派发任务。例如：dispatcher_a派发的任务使用dispatcher_b进行任务的派发，在dispatcher_b派发的任务中又利用dispatcher_a进行派发任务。
  • 串行任务分发器（dispatcher_a）派发的任务中利用串行任务分发器（dispatcher_b）进行同步派发任务，同时dispatcher_b派发的任务中利用串行任务分发器（dispatcher_a）进行同步派发任务。在特定的线程执行顺序下将导致死锁

测试异步任务代码：

  1.     private void testAsyncDispatch() {
  2.         globalTaskDispatcher.asyncDispatch(new Runnable() {
  3.             @Override
  4.             public void run() {
  5.                 try {
  6.                     Thread.sleep(5000);
  7.                 } catch (InterruptedException e) {
  8.                     e.printStackTrace();
  9.                 }
  10.                 HiLog.info(label, "async task1 run");
  11.             }
  12.         });
  13.         HiLog.info(label, "after async task1");
  14.         parallelTaskDispatcher.asyncDispatch(new Runnable() {
  15.             @Override
  16.             public void run() {
  17.                 try {
  18.                     Thread.sleep(5000);
  19.                 } catch (InterruptedException e) {
  20.                     e.printStackTrace();
  21.                 }
  22.                 HiLog.info(label, "sync task2 run");
  23.             }
  24.         });
  25.         HiLog.info(label, "after sync task2");
  26.  
  27.         serialTaskDispatcher.asyncDispatch(new Runnable() {
  28.             @Override
  29.             public void run() {
  30.                 try {
  31.                     Thread.sleep(5000);
  32.                 } catch (InterruptedException e) {
  33.                     e.printStackTrace();
  34.                 }
  35.                 HiLog.info(label, "sync task3 run");
  36.             }
  37.         });
  38.         HiLog.info(label, "after sync task3");
  39.         uiTaskDispatcher.asyncDispatch(new Runnable() {
  40.             @Override
  41.             public void run() {
  42.                 try {
  43.                     Thread.sleep(5000);
  44.                 } catch (InterruptedException e) {
  45.                     e.printStackTrace();
  46.                 }
  47.                 HiLog.info(label, "sync task4 run");
  48.             }
  49.         });
  50.         HiLog.info(label, "after sync task4");
  51.     }

日志输出：

  1. 01-24 09:24:37.406 9317-9317/com.example.dispatcherdemo I 00201/MY_TAG: after async task1
  2. 01-24 09:24:37.407 9317-9317/com.example.dispatcherdemo I 00201/MY_TAG: after sync task2
  3. 01-24 09:24:37.407 9317-9317/com.example.dispatcherdemo I 00201/MY_TAG: after sync task3
  4. 01-24 09:24:37.408 9317-9317/com.example.dispatcherdemo I 00201/MY_TAG: after sync task4
  5. 01-24 09:24:42.407 9317-30393/com.example.dispatcherdemo I 00201/MY_TAG: async task1 run
  6. 01-24 09:24:42.407 9317-30394/com.example.dispatcherdemo I 00201/MY_TAG: sync task2 run
  7. 01-24 09:24:42.409 9317-9317/com.example.dispatcherdemo I 00201/MY_TAG: sync task4 run
  8. 01-24 09:24:42.409 9317-30395/com.example.dispatcherdemo I 00201/MY_TAG: sync task3 run

无论哪种分发器，只要使用了asyncDispatch分发任务，都是异步执行，既然这样，为什么还要给分发器分类呢。

先测试一下Paralle和Serial分发异步任务

  1.     private void testSerialDispatch() {
  2.         serialTaskDispatcher.asyncDispatch(new Runnable() {
  3.             @Override
  4.             public void run() {
  5.                 try {
  6.                     Thread.sleep(5000);
  7.                 } catch (InterruptedException e) {
  8.                     e.printStackTrace();
  9.                 }
  10.                 HiLog.info(label, "serialTaskDispatcher sync task1 run");
  11.             }
  12.         });
  13.         HiLog.info(label, "serialTaskDispatcher after sync task1");
  14.         serialTaskDispatcher.asyncDispatch(new Runnable() {
  15.             @Override
  16.             public void run() {
  17.                 try {
  18.                     Thread.sleep(1000);
  19.                 } catch (InterruptedException e) {
  20.                     e.printStackTrace();
  21.                 }
  22.                 HiLog.info(label, "serialTaskDispatcher sync task2 run");
  23.             }
  24.         });
  25.         HiLog.info(label, "serialTaskDispatcher after sync task2");
  26.     }
  27.  
  28.     private void testParalleDispatch() {
  29.         parallelTaskDispatcher.asyncDispatch(new Runnable() {
  30.             @Override
  31.             public void run() {
  32.                 try {
  33.                     Thread.sleep(5000);
  34.                 } catch (InterruptedException e) {
  35.                     e.printStackTrace();
  36.                 }
  37.                 HiLog.info(label, "parallelTaskDispatcher sync task1 run");
  38.             }
  39.         });
  40.         HiLog.info(label, "parallelTaskDispatcher after sync task1");
  41.         parallelTaskDispatcher.asyncDispatch(new Runnable() {
  42.             @Override
  43.             public void run() {
  44.                 try {
  45.                     Thread.sleep(1000);
  46.                 } catch (InterruptedException e) {
  47.                     e.printStackTrace();
  48.                 }
  49.                 HiLog.info(label, "parallelTaskDispatcher sync task2 run");
  50.             }
  51.         });
  52.         HiLog.info(label, "parallelTaskDispatcher after sync task2");
  53.     }

日志：

  1. 01-24 09:36:52.844 15707-15707/com.example.dispatcherdemo I 00201/MY_TAG: parallelTaskDispatcher after sync task1
  2. 01-24 09:36:52.845 15707-15707/com.example.dispatcherdemo I 00201/MY_TAG: parallelTaskDispatcher after sync task2
  3. 01-24 09:36:53.845 15707-8432/com.example.dispatcherdemo I 00201/MY_TAG: parallelTaskDispatcher sync task2 run
  4. 01-24 09:36:57.845 15707-8431/com.example.dispatcherdemo I 00201/MY_TAG: parallelTaskDispatcher sync task1 run
  5. 01-24 09:37:00.949 15707-15707/com.example.dispatcherdemo I 00201/MY_TAG: serialTaskDispatcher after sync task1
  6. 01-24 09:37:00.950 15707-15707/com.example.dispatcherdemo I 00201/MY_TAG: serialTaskDispatcher after sync task2
  7. 01-24 09:37:05.950 15707-8894/com.example.dispatcherdemo I 00201/MY_TAG: serialTaskDispatcher sync task1 run
  8. 01-24 09:37:06.951 15707-9210/com.example.dispatcherdemo I 00201/MY_TAG: serialTaskDispatcher sync task2 run

原来，使用使用syncDispatch和asyncDispatch分发任务，同步异步是针对于主线程的，而ParallelTaskDispatcher、SerialTaskDispatcher的区别是自己派发出去的任务是串行还是并行。

常规操作延时执行：

  1.     private void testDelayDispatch() {
  2.         globalTaskDispatcher.delayDispatch(new Runnable() {
  3.             @Override
  4.             public void run() {
  5.                 HiLog.info(label, "delayDispatch task1 run");
  6.             }
  7.         }, 50000);
  8.         HiLog.info(label, "after delayDispatch task1");
  9.     }

鸿蒙还可以将线程分组，将几个线程放在一个group中，并且可以添加这一组线程执行完的回调：

  1.     private void testGroupDispatch() {
  2.         // 创建任务组。
  3.         Group group = parallelTaskDispatcher.createDispatchGroup();
  4.         // 将任务1加入任务组，返回一个用于取消任务的接口。
  5.         parallelTaskDispatcher.asyncGroupDispatch(group, new Runnable(){
  6.             @Override
  7.             public void run() {
  8.                 try {
  9.                     Thread.sleep(1000);
  10.                 } catch (InterruptedException e) {
  11.                     e.printStackTrace();
  12.                 }
  13.                 HiLog.info(label, "download task1 is running");
  14.             }
  15.         });
  16.         // 将与任务1相关联的任务2加入任务组。
  17.         parallelTaskDispatcher.asyncGroupDispatch(group, new Runnable(){
  18.             @Override
  19.             public void run() {
  20.                 try {
  21.                     Thread.sleep(1000);
  22.                 } catch (InterruptedException e) {
  23.                     e.printStackTrace();
  24.                 }
  25.                 HiLog.info(label, "download task2 is running");
  26.             }
  27.         });
  28.         // 在任务组中的所有任务执行完成后执行指定任务。
  29.         parallelTaskDispatcher.groupDispatchNotify(group, new Runnable(){
  30.             @Override
  31.             public void run() {
  32.                 HiLog.info(label, "the close task is running after all tasks in the group are completed");
  33.             }
  34.         });
  35.     }

日志：

  1. 01-24 09:49:25.346 4247-8522/com.example.dispatcherdemo I 00201/MY_TAG: download task1 is running
  2. 01-24 09:49:25.348 4247-8523/com.example.dispatcherdemo I 00201/MY_TAG: download task2 is running
  3. 01-24 09:49:25.349 4247-8587/com.example.dispatcherdemo I 00201/MY_TAG: the close task is running after all tasks in the group are completed

对于分组任务还可以设置屏障任务：可以使用asyncDispatchBarrier和syncDispatchBarrier来派发异步或同步的屏障线程，这种线程必须是在Group线程执行完成后，才执行的

  1.     private void testBarrierDispatch() {
  2.         // 创建任务组。
  3.         Group group = parallelTaskDispatcher.createDispatchGroup();
  4.         // 将任务加入任务组，返回一个用于取消任务的接口。
  5.         parallelTaskDispatcher.asyncGroupDispatch(group, new Runnable(){
  6.             @Override
  7.             public void run() {
  8.                 HiLog.info(label, "parallelTaskDispatcher task1 is running");  // 1
  9.             }
  10.         });
  11.         parallelTaskDispatcher.asyncGroupDispatch(group, new Runnable(){
  12.             @Override
  13.             public void run() {
  14.                 HiLog.info(label, "parallelTaskDispatcher task2 is running");  // 2
  15.             }
  16.         });
  17.  
  18.         parallelTaskDispatcher.syncDispatchBarrier(new Runnable() {
  19.             @Override
  20.             public void run() {
  21.                 try {
  22.                     Thread.sleep(1000);
  23.                 } catch (InterruptedException e) {
  24.                     e.printStackTrace();
  25.                 }
  26.                 HiLog.info(label, "parallelTaskDispatcher barrier is running");  // 3
  27.             }
  28.         });
  29.         HiLog.info(label, "parallelTaskDispatcher after syncDispatchBarrier");  // 4
  30.  
  31.         TaskDispatcher parallelTaskDispatcher2 = createParallelTaskDispatcher("dispatcherName", TaskPriority.DEFAULT);
  32.         // 创建任务组。
  33.         Group group2 = parallelTaskDispatcher2.createDispatchGroup();
  34.         // 将任务加入任务组，返回一个用于取消任务的接口。
  35.         parallelTaskDispatcher2.asyncGroupDispatch(group2, new Runnable(){
  36.             @Override
  37.             public void run() {
  38.                 HiLog.info(label, "parallelTaskDispatcher2 task1 is running");  // 1
  39.             }
  40.         });
  41.         parallelTaskDispatcher2.asyncGroupDispatch(group2, new Runnable(){
  42.             @Override
  43.             public void run() {
  44.                 HiLog.info(label, "parallelTaskDispatcher2 task2 is running");  // 2
  45.             }
  46.         });
  47.  
  48.         parallelTaskDispatcher2.asyncDispatchBarrier(new Runnable() {
  49.             @Override
  50.             public void run() {
  51.                 try {
  52.                     Thread.sleep(1000);
  53.                 } catch (InterruptedException e) {
  54.                     e.printStackTrace();
  55.                 }
  56.                 HiLog.info(label, "parallelTaskDispatcher2 barrier is running");  // 3
  57.             }
  58.         });
  59.         HiLog.info(label, "parallelTaskDispatcher2 after asyncDispatchBarrier");  // 4
  60.     }
  61. 日志：
  62. 01-24 10:08:15.493 30657-9662/com.example.dispatcherdemo I 00201/MY_TAG: parallelTaskDispatcher task1 is running
  63. 01-24 10:08:15.493 30657-9663/com.example.dispatcherdemo I 00201/MY_TAG: parallelTaskDispatcher task2 is running
  64. 01-24 10:08:16.494 30657-9664/com.example.dispatcherdemo I 00201/MY_TAG: parallelTaskDispatcher barrier is running
  65. 01-24 10:08:16.495 30657-30657/com.example.dispatcherdemo I 00201/MY_TAG: parallelTaskDispatcher after syncDispatchBarrier
  66. 01-24 10:08:16.496 30657-9727/com.example.dispatcherdemo I 00201/MY_TAG: parallelTaskDispatcher2 task1 is running
  67. 01-24 10:08:16.496 30657-30657/com.example.dispatcherdemo I 00201/MY_TAG: parallelTaskDispatcher2 after asyncDispatchBarrier
  68. 01-24 10:08:16.496 30657-9728/com.example.dispatcherdemo I 00201/MY_TAG: parallelTaskDispatcher2 task2 is running
  69. 01-24 10:08:17.497 30657-9729/com.example.dispatcherdemo I 00201/MY_TAG: parallelTaskDispatcher2 barrier is running

取消任务：Revocable是取消一个异步任务的接口。异步任务包括通过 asyncDispatch、delayDispatch、asyncGroupDispatch 派发的任务。如果任务已经在执行中或执行完成，则会返回取消失败。

  1.     private void testRevocableDispatch() {
  2.         Revocable revocable = parallelTaskDispatcher.delayDispatch(new Runnable() {
  3.             @Override
  4.             public void run() {
  5.                 HiLog.info(label, "delay dispatch");
  6.             }
  7.         }, 1000);
  8.         boolean revoked = revocable.revoke();
  9.         HiLog.info(label, "%{public}b", revoked);
  10.     }
  11. 日志：
  12. 01-24 09:53:45.649 7590-7590/com.example.dispatcherdemo I 00201/MY_TAG: true

执行多次任务：对指定任务执行多次，使用applyDispatch配合CountDownLatch使用，可以让线程重复执行指定次数：

  1.     final int total = 10;
  2.     final CountDownLatch latch = new CountDownLatch(total);
  3.     final ArrayList<Long> indexList = new ArrayList<>(total);
  4.     private void testApplyDispatch() {
  5.         // 执行任务 total 次
  6.         globalTaskDispatcher.applyDispatch((index) -> {
  7.             indexList.add(index);
  8.             HiLog.info(label, "applyDispatch index="+index);
  9.             latch.countDown();
  10.         }, total);
  11.  
  12.         // 设置任务超时
  13.         try {
  14.             latch.await();
  15.         } catch (InterruptedException exception) {
  16.             HiLog.info(label, "latch exception");
  17.         }
  18.         HiLog.info(label, "list size matches, %{public}b", (total == indexList.size()));
  19.     }
  20. 日志：
  21. 01-24 10:16:31.939 29071-7870/com.example.dispatcherdemo I 00201/MY_TAG: applyDispatch index=0
  22. 01-24 10:16:31.940 29071-7871/com.example.dispatcherdemo I 00201/MY_TAG: applyDispatch index=1
  23. 01-24 10:16:31.940 29071-7873/com.example.dispatcherdemo I 00201/MY_TAG: applyDispatch index=3
  24. 01-24 10:16:31.941 29071-7874/com.example.dispatcherdemo I 00201/MY_TAG: applyDispatch index=4
  25. 01-24 10:16:31.941 29071-7875/com.example.dispatcherdemo I 00201/MY_TAG: applyDispatch index=5
  26. 01-24 10:16:31.941 29071-7872/com.example.dispatcherdemo I 00201/MY_TAG: applyDispatch index=2
  27. 01-24 10:16:31.942 29071-7877/com.example.dispatcherdemo I 00201/MY_TAG: applyDispatch index=7
  28. 01-24 10:16:31.943 29071-7878/com.example.dispatcherdemo I 00201/MY_TAG: applyDispatch index=8
  29. 01-24 10:16:31.943 29071-7879/com.example.dispatcherdemo I 00201/MY_TAG: applyDispatch index=9
  30. 01-24 10:16:31.943 29071-7876/com.example.dispatcherdemo I 00201/MY_TAG: applyDispatch index=6
  31. 01-24 10:16:31.943 29071-29071/com.example.dispatcherdemo I 00201/MY_TAG: list size matches, true

Demo:https://download.csdn.net/download/y280903468/14926982

 

 

 

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