【鸿蒙实战开发】基于Taskpool的多线程操作
场景描述
场景一:周期性任务处理,业务通过taskpool周期性处理业务。
场景二:延迟业务处理,业务一段时间后,通过taskpool处理业务。
场景三:串行业务处理,业务开展过程中,需要处理一系列的事务,事务处理过程中,存在先后次序。
场景四:业务的处理存在紧急优先次序,支持设置taskpool优先级处理。
场景五:ArkTS与Native协作开展业务,在ArkTS层触发业务,通过NAPI接口,传递到Native C++层,作业务管理等处理。
方案描述
场景一:周期性任务
方案:
1)定时器判断周期性事务执行。
2)Taskpool来处理任务执行。
核心代码:
▼text复制代码@Concurrent function ServiceHandle(pars: number): number { hilog.info(0x0000, 'testTag', 'start ServiceHandle:%{public}d', pars); // 业务处理过程,并将结果返回 let result = 0; return result; } let count = 0; function TimerOutHandle(pars:number) { count++; let task: taskpool.Task = new taskpool.Task(ServiceHandle, pars); hilog.info(0x0000, 'testTag', 'Timer handle count :%{public}d,pars %{public}d', count, pars); taskpool.execute(task, taskpool.Priority.HIGH).then((res: object) => { hilog.info(0x0000, 'testTag', 'ServiceHandle result :%{public}d', res); if (g_callback != null) { g_callback(count); } }); } let timerId = -1; export function TimerTest() { count = 0; let value = 88; timerId = setInterval(TimerOutHandle, 3000, value); }
定时器每3秒超时一次,进入TimerOutHandle函数处理,TimerOutHandle函数体中,通过taskpool创建异步并发任务执行业务。
运行结果:
界面上,每超时一次,会呈现运行次数:
场景二:延迟任务
方案:
1)通过setTimeout来延迟处理。
2) 通过executeDelayed来延迟处理。
核心代码:
1)setTimeout的处理如下:
▼text复制代码@Concurrent function ServiceHandle(pars: number): number { hilog.info(0x0000, 'testTag', 'start ServiceHandle:%{public}d', pars); // 业务处理过程,并将结果返回 let result = 0; return result; } let count = 0; function TimerOutHandle(pars:number) { count++; let task: taskpool.Task = new taskpool.Task(ServiceHandle, pars); hilog.info(0x0000, 'testTag', 'Timer handle count :%{public}d,pars %{public}d', count, pars); taskpool.execute(task, taskpool.Priority.HIGH).then((res: object) => { hilog.info(0x0000, 'testTag', 'ServiceHandle result :%{public}d', res); if (g_callback != null) { g_callback(count); } }); } export function OneTimerCallTest() { count = 0; if (g_callback != null) { g_callback(count); } let value = 99; hilog.info(0x0000, 'testTag', 'start setTimeout'); timerId = setTimeout(TimerOutHandle, 3000, value); }
定时器3秒超时(仅仅执行一次)后,就会进入TimerOutHandle函数处理,TimerOutHandle函数体中,通过taskpool创建异步并发任务执行业务。
2)executeDelayed来延迟
▼text复制代码@Concurrent function TaskDelayServiceHandle(pars: number): number { let t: number = Date.now(); hilog.info(0x0000, 'testTag', 'enter TaskDelayServiceHandle, timer is :%{public}d', t); // 业务处理过程,并将结果返回 let result = 0; return result; } export function TaskPoolDelayTest() { count = 0; if (g_callback != null) { g_callback(count); } let value = 100; let t: number = Date.now(); hilog.info(0x0000, 'testTag', 'taskpool start time is :%{public}d', t); let task: taskpool.Task = new taskpool.Task(TaskDelayServiceHandle, value); taskpool.executeDelayed(3000, task).then(() => { count++; let t: number = Date.now(); hilog.info(0x0000, 'testTag', 'taskpool execute success, time is :%{public}d', t); if (g_callback != null) { g_callback(count); } }).catch((e: BusinessError) => { console.error(`taskpool execute: Code: ${e.code}, message: ${e.message}`); }) }
调用executeDelayed函数3秒后,会进入TaskDelayServiceHandle函数执行,返回返回后,会进入executeDelayed后面的then的函数体中执行。
运行结果:
1)使用setTimeout运行结果
2)使用executeDelayed运行结果
场景三:串行任务
方案:
1)最简单的方案就是后面任务执行时,根据前面任务的执行结果来处理。
2)后面任务的执行,依赖另一个任务的一些处理结果后,继续执行。
核心代码:
1)通过业务逻辑的结果来处理
▼text复制代码@Concurrent function ServiceHandle1(pars: number): number { hilog.info(0x0000, 'testTag', 'start ServiceHandle1:%{public}d', pars); // 业务处理过程,并将结果返回 let result = 0; return result; } @Concurrent function ServiceHandle2(pars: number): number { hilog.info(0x0000, 'testTag', 'start ServiceHandle2:%{public}d', pars); // 业务处理过程,并将结果返回 let result = 1; return result; } export function SyncHandle() { let task1: taskpool.Task = new taskpool.Task(ServiceHandle1, 1); hilog.info(0x0000, 'testTag', 'sync handle'); taskpool.execute(task1, taskpool.Priority.HIGH).then((res1: object) => { hilog.info(0x0000, 'testTag', 'ServiceHandle result :%{public}d', res1); if (g_callback != null) { g_callback('task1 finish.'); } if ((res1 as Number) == 0) { let task2: taskpool.Task = new taskpool.Task(ServiceHandle2, 2); taskpool.execute(task2, taskpool.Priority.HIGH).then((res2: object) => { hilog.info(0x0000, 'testTag', 'ServiceHandle2 result :%{public}d', res2); if (g_callback != null) { g_callback('task2 finish.'); } }); } }); }
task1执行完毕后,根据if判断启动task2任务执行。
2)通过addDependency或SequenceRunner处理。
▼text复制代码@Concurrent function DependencyHandle(args: number): number { let t: number = Date.now(); while ((Date.now() - t) < 1000) { continue; } return args; } export function AddDependencyTest() { let task1:taskpool.Task = new taskpool.Task(DependencyHandle, 100); let task2:taskpool.Task = new taskpool.Task(DependencyHandle, 200); let task3:taskpool.Task = new taskpool.Task(DependencyHandle, 300); hilog.info(0x0000, 'testTag', 'dependency: add dependency start'); task1.addDependency(task2); task2.addDependency(task3); hilog.info(0x0000, 'testTag', 'dependency: add dependency end'); hilog.info(0x0000, 'testTag', 'dependency: start execute second'); taskpool.execute(task1).then(() => { hilog.info(0x0000, 'testTag', 'dependency: first task1 success'); if (g_callback != null) { g_callback('task1 finish.'); } }) taskpool.execute(task2).then(() => { hilog.info(0x0000, 'testTag', 'dependency: second task2 success'); if (g_callback != null) { g_callback('task2 finish.'); } }) taskpool.execute(task3).then(() => { hilog.info(0x0000, 'testTag', 'dependency: third task3 success'); if (g_callback != null) { g_callback('task3 finish.'); } }) }
task1依赖task2,task2依赖task3,上面任务执行的顺序是:task3执行完毕后再执行task2,最后执行task。
▼text复制代码@Concurrent function additionDelay(delay:number): void { let start: number = new Date().getTime(); while (new Date().getTime() - start < delay) { continue; } } @Concurrent function waitForRunner(finalString: string): string { return finalString; } export async function SeqRunnerTest() { let finalString:string = ""; let task1:taskpool.Task = new taskpool.Task(additionDelay, 3000); let task2:taskpool.Task = new taskpool.Task(additionDelay, 2000); let task3:taskpool.Task = new taskpool.Task(additionDelay, 1000); let task4:taskpool.Task = new taskpool.Task(waitForRunner, finalString); let runner:taskpool.SequenceRunner = new taskpool.SequenceRunner(); runner.execute(task1).then(() => { finalString += 'task1 finish.'; hilog.info(0x0000, 'testTag', 'seqrunner: task1 done.'); if (g_callback != null) { g_callback('task1 finish.'); } }); runner.execute(task2).then(() => { finalString += 'task2 finish.'; hilog.info(0x0000, 'testTag', 'seqrunner: task2 done.'); if (g_callback != null) { g_callback('task2 finish.'); } }); runner.execute(task3).then(() => { finalString += 'task3 finish.'; hilog.info(0x0000, 'testTag', 'seqrunner: task3 done.'); if (g_callback != null) { g_callback('task3 finish.'); } }); await runner.execute(task4); hilog.info(0x0000, 'testTag', 'seqrunner: task4 done, finalString is %{public}s', finalString); }
task1执行完毕后,执行task2,最后是task3执行完毕。
运行结果:
1)通过业务逻辑的结果来处理
2)通过addDependency或SequenceRunner处理
场景四:优先级任务
方案:
在taskpool.execute的参数二种设置线程的优先级,优先级分三个级别:LOW、MEDIUM(默认)、HIGH。通过设置优先级来运行taskpool任务。
核心代码:
▼text复制代码@Concurrent function ServiceHandle(pri: string): string { hilog.info(0x0000, 'testTag', 'enter ServiceHandle:%{public}s', pri); hilog.info(0x0000, 'testTag', 'end ServiceHandle:%{public}s', pri); return pri; } export function CallPriorityHanel() { let task1: taskpool.Task = new taskpool.Task(ServiceHandle, "LOW"); let task2: taskpool.Task = new taskpool.Task(ServiceHandle, "MEDIUM"); let task3: taskpool.Task = new taskpool.Task(ServiceHandle, "HIGH"); taskpool.execute(task1, taskpool.Priority.LOW).then((res: object) => { hilog.info(0x0000, 'testTag', 'task return result :%{public}s', res); }); taskpool.execute(task2, taskpool.Priority.MEDIUM).then((res: object) => { hilog.info(0x0000, 'testTag', 'task return result :%{public}s', res); }); taskpool.execute(task3, taskpool.Priority.HIGH).then((res: object) => { hilog.info(0x0000, 'testTag', 'task return result :%{public}s', res); }); }
当前的设备都是多核的,并不是说将优先级设置程HIGH,该任务就会最先调度。
运行结果:
场景五:taskpool的Napi调用
方案:C++层编译的库,在ArkTS层通过import库的方式引用后,在taskpool的回调函数中调用接口。核心代码:
▼text复制代码@Concurrent function ServiceHandle(pars: number): number { hilog.info(0x0000, 'testTag', 'start ServiceHandle:%{public}d', pars); // 业务处理过程,并将结果返回 testNapi.jsServiceHandle(88, 99); return 0; } export function CallHandle() { let task: taskpool.Task = new taskpool.Task(ServiceHandle, 1); taskpool.execute(task,).then((res: object) => { hilog.info(0x0000, 'testTag', 'printArgs result :%{public}d', res); }); } typedef struct TestData { int data; int type; } TestData; static napi_value JsServiceHandle(napi_env env, napi_callback_info info) { size_t argc = 2; napi_value args[2] = {nullptr}; napi_get_cb_info(env, info, &argc, args, nullptr, nullptr); TestData testData; napi_get_value_int32(env, args[0], &testData.data); napi_get_value_int32(env, args[1], &testData.type); OH_LOG_INFO(LOG_APP, "Native C++ Service handle:%{public}d,type:%{public}d", testData.data, testData.type); return nullptr; } EXTERN_C_START static napi_value Init(napi_env env, napi_value exports) { napi_property_descriptor desc[] = { {"jsServiceHandle", nullptr, JsServiceHandle, nullptr, nullptr, nullptr, napi_default, nullptr} }; napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc); return exports; } EXTERN_C_END
运行结果:

