Protect DI scheduler initialization from concurrent initialization (#…

…1265)
quartznet · Aug 1, 2021 · 6e989ec · 6e989ec
1 parent f376d69
commit 6e989ec
Showing 1 changed file with 19 additions and 2 deletions.
diff --git a/src/Quartz.Extensions.DependencyInjection/ServiceCollectionSchedulerFactory.cs b/src/Quartz.Extensions.DependencyInjection/ServiceCollectionSchedulerFactory.cs
@@ -21,6 +21,7 @@ internal class ServiceCollectionSchedulerFactory : StdSchedulerFactory
         private readonly IOptions<QuartzOptions> options;
         private readonly ContainerConfigurationProcessor processor;
         private bool initialized;
+        private readonly SemaphoreSlim initializationLock = new SemaphoreSlim(1, 1);
 
         public ServiceCollectionSchedulerFactory(
             IServiceProvider serviceProvider,
@@ -44,6 +45,24 @@ public override async Task<IScheduler> GetScheduler(CancellationToken cancellati
                 return scheduler;
             }
 
+            await initializationLock.WaitAsync(cancellationToken);
+            try
+            {
+                if (!initialized)
+                {
+                    await InitializeScheduler(scheduler, cancellationToken);
+                    initialized = true;
+                }
+            }
+            finally
+            {
+                initializationLock.Release();
+            }
+            return scheduler;
+        }
+
+        private async Task InitializeScheduler(IScheduler scheduler, CancellationToken cancellationToken)
+        {
             foreach (var listener in serviceProvider.GetServices<ISchedulerListener>())
             {
                 scheduler.ListenerManager.AddSchedulerListener(listener);
@@ -70,8 +89,6 @@ public override async Task<IScheduler> GetScheduler(CancellationToken cancellati
             }
 
             await processor.ScheduleJobs(scheduler, cancellationToken);
-            initialized = true;
-            return scheduler;
         }
 
         protected override T InstantiateType<T>(Type? implementationType)