好吧,我创建了一个具有许多功能的作业调度程序;但是我真的很想使用 .Net 4.5 Async/Await 功能来等待作业完成执行。
-代码
调度程序.cs
public abstract class Scheduler
{
#region Fields && Properties
private readonly List<Job> _jobs = new List<Job>();
private readonly Random _rand = new Random();
private Job _currentlyExecutingJob;
private Thread _workingThread;
public bool? Parallel { get; private set; }
public DateTimeOffset NextExecutionTime { get; private set; }
public string ID { get; set; }
public abstract Task JobTrigger(Job job);
public abstract void UnobservedException(Exception exception, Job job);
#endregion
#region Ctor
protected Scheduler(bool parallel) { Parallel = parallel; }
#endregion
#region Fluent
public Scheduler Start()
{
if (Equals(_workingThread, null)) {
_workingThread = new Thread(ReviewJobs);
_workingThread.Start();
}
return this;
}
public Scheduler Stop()
{
if (!Equals(_workingThread, null)) {
_workingThread.Abort();
_workingThread = null;
}
return this;
}
#endregion
#region Events
private void ReviewJobs()
{
while (!Equals(_workingThread, null)) {
IEnumerable<Job> jobsToExecute = from job in _jobs
where job.NextExecutionTime <= DateTimeOffset.Now
orderby job.Priority
select job;
if (!jobsToExecute.Any()) {
Thread.Sleep(100);
continue;
}
try {
foreach (Job job in jobsToExecute) {
Job o = _currentlyExecutingJob = job;
if (Parallel != null && (bool)Parallel) {
JobTrigger(o);
} else {
JobTrigger(o).Wait();
}
if (!o.Repeat)
_jobs.Remove(o);
else if (o.Interval != null)
o.NextExecutionTime = DateTimeOffset.Now.Add((TimeSpan)(o.RandomizeExecution
? TimeSpan.FromSeconds(_rand.Next((int)((TimeSpan)o.Interval).TotalSeconds, ((int)((TimeSpan)o.Interval).TotalSeconds + 30)))
: o.Interval));
}
} catch (Exception exception) {
UnobservedException(exception, _currentlyExecutingJob);
} finally {
NextExecutionTime = (from job in _jobs
where job.NextExecutionTime <= DateTimeOffset.Now
orderby job.Priority
select job.NextExecutionTime).FirstOrDefault();
}
}
}
#endregion
#region Helper Methods
public Job GetJob(string id) { return _jobs.Find(job => job.ID == id); }
public Job GetJob(Job job) { return _jobs.Find(x => x == job); }
public IEnumerable<Job> GetAllJobs() { return _jobs; }
public void AddJob(Job job, bool overwrite = false)
{
Job existingJob = GetJob(job);
if (null != existingJob) {
if (overwrite) {
_jobs.RemoveAll(jobs => jobs == existingJob);
_jobs.Add(job);
} else {
_jobs.Add(job);
}
} else {
_jobs.Add(job);
}
}
public bool RemoveJob(string id)
{
Job existingJob = GetJob(id);
if (null != existingJob) {
return _jobs.Remove(existingJob);
}
return false;
}
public bool RemoveJob(Job job)
{
Job existingJob = GetJob(job);
if (null != existingJob) {
return _jobs.Remove(existingJob);
}
return false;
}
public void RemoveAllJobs() { _jobs.RemoveRange(0, _jobs.Count); }
#endregion
}
作业.cs
public class Job
{
public string ID { get; set; }
public TimeSpan Interval { get; private set; }
public DateTimeOffset NextExecutionTime { get; set; }
public int Priority { get; set; }
public bool Repeat { get; private set; }
public bool RandomizeExecution { get; set; }
public object Data { get; set; }
#region Fluent
public Job RunOnceAt(DateTimeOffset executionTime)
{
NextExecutionTime = executionTime;
Repeat = false;
return this;
}
public Job RepeatFrom(DateTimeOffset executionTime, TimeSpan interval)
{
NextExecutionTime = executionTime;
Interval = interval;
Repeat = true;
return this;
}
#endregion
}
-用法
public class SchedulerUsage : Scheduler
{
public SchedulerUsage(bool parallel) : base(parallel) {
}
public override async Task JobTrigger(Job job)
{
switch (job.ID) {
//Handle Jobs
}
}
public override void UnobservedException(Exception exception, Job job)
{
//Handle Exceptions
}
/// <summary>
/// Example of adding job
/// </summary>
public void ExampleUsage()
{
Job job = new Job
{
ID = "ID",
Data = "ATTACH SOME DATA"
}.RunOnceAt(DateTimeOffset.Now.AddSeconds(7));
//Add the job... [HERE IS WHAT I WANT TO ACHIVE]
/*await*/base.AddJob(job);
//Start the scheduler...
base.Start();
}
}
问题:在我上面的实现中,如何使用 async/await 来等待作业的执行。
注意:如果我的问题看起来有点复杂,我很抱歉,但这对我来说非常必要,所以请耐心等待。