Updated AutomaticDataMigrations to take advantage of the DistributedLockService.

src/Orchard.Tests/Stubs/StubDistributedLock.cs

@@ -17,6 +17,7 @@ namespace Orchard.Tests.Stubs {
 
         public void Dispose() {
             IsDisposed = true;
+            IsAcquired = false;
         }
     }
 }

src/Orchard.Tests/Tasks/DistributedLockServiceTests.cs

@@ -14,6 +14,7 @@ namespace Orchard.Tests.Tasks {
         private DistributedLockService _distributedLockService;
 
         protected override void Register(ContainerBuilder builder) {
+            builder.RegisterType<StubWorkContextAccessor>().As<IWorkContextAccessor>();
             builder.RegisterType<StubMachineNameProvider>().As<IMachineNameProvider>();
             builder.RegisterType<StubDistributedLock>().As<IDistributedLock>();
             builder.RegisterType<DistributedLockService>().AsSelf();
@@ -24,6 +25,7 @@ namespace Orchard.Tests.Tasks {
             _distributedLockService = container.Resolve<DistributedLockService>();
         }
 
+
         [Test]
         public void AcquiringLockSucceeds() {
             IDistributedLock @lock;

src/Orchard.Web/Modules/Orchard.Setup/SetupMode.cs

@@ -29,6 +29,7 @@ using Orchard.Mvc.ViewEngines.ThemeAwareness;
 using Orchard.Recipes.Services;
 using Orchard.Settings;
 using Orchard.Tasks;
+using Orchard.Tasks.Locking;
 using Orchard.Themes;
 using Orchard.UI.Notify;
 using Orchard.UI.PageClass;

src/Orchard/Data/Migration/AutomaticDataMigrations.cs

@@ -3,6 +3,7 @@ using System.Linq;
 using Orchard.Environment;
 using Orchard.Environment.Features;
 using Orchard.Logging;
+using Orchard.Tasks.Locking;
 
 namespace Orchard.Data.Migration {
     /// <summary>
@@ -11,13 +12,16 @@ namespace Orchard.Data.Migration {
     public class AutomaticDataMigrations : IOrchardShellEvents {
         private readonly IDataMigrationManager _dataMigrationManager;
         private readonly IFeatureManager _featureManager;
+        private readonly IDistributedLockService _distributedLockService;
 
         public AutomaticDataMigrations(
             IDataMigrationManager dataMigrationManager,
-            IFeatureManager featureManager
+            IFeatureManager featureManager,
-            ) {
+            IDistributedLockService distributedLockService) {
+
             _dataMigrationManager = dataMigrationManager;
             _featureManager = featureManager;
+            _distributedLockService = distributedLockService;
 
             Logger = NullLogger.Instance;
         }
@@ -25,24 +29,28 @@ namespace Orchard.Data.Migration {
         public ILogger Logger { get; set; } 
 
         public void Activated() {
+            IDistributedLock @lock;
+            if (_distributedLockService.TryAcquireLock(GetType().FullName, TimeSpan.FromMinutes(30), TimeSpan.FromMilliseconds(250), out @lock)) {
+                using (@lock) {
+                    // Let's make sure that the basic set of features is enabled.  If there are any that are not enabled, then let's enable them first.
+                    var theseFeaturesShouldAlwaysBeActive = new[] {
+                        "Common", "Containers", "Contents", "Dashboard", "Feeds", "Navigation", "Scheduling", "Settings", "Shapes", "Title"
+                    };
 
-            // Let's make sure that the basic set of features is enabled.  If there are any that are not enabled, then let's enable them first.
+                    var enabledFeatures = _featureManager.GetEnabledFeatures().Select(f => f.Id).ToList();
-            var theseFeaturesShouldAlwaysBeActive = new[] {
+                    var featuresToEnable = theseFeaturesShouldAlwaysBeActive.Where(shouldBeActive => !enabledFeatures.Contains(shouldBeActive)).ToList();
-                "Common", "Containers", "Contents", "Dashboard", "Feeds", "Navigation", "Scheduling", "Settings", "Shapes", "Title"
+                    if (featuresToEnable.Any()) {
-            };
+                        _featureManager.EnableFeatures(featuresToEnable, true);
+                    }
 
-            var enabledFeatures = _featureManager.GetEnabledFeatures().Select(f => f.Id).ToList();
+                    foreach (var feature in _dataMigrationManager.GetFeaturesThatNeedUpdate()) {
-            var featuresToEnable = theseFeaturesShouldAlwaysBeActive.Where(shouldBeActive => !enabledFeatures.Contains(shouldBeActive)).ToList();
+                        try {
-            if (featuresToEnable.Any()) {
+                            _dataMigrationManager.Update(feature);
-                _featureManager.EnableFeatures(featuresToEnable, true);
+                        }
-            }
+                        catch (Exception e) {
-
+                            Logger.Error("Could not run migrations automatically on " + feature, e);
-            foreach (var feature in _dataMigrationManager.GetFeaturesThatNeedUpdate()) {
+                        }
-                try {
+                    }
-                    _dataMigrationManager.Update(feature);
-                }
-                catch (Exception e) {
-                    Logger.Error("Could not run migrations automatically on " + feature, e);
                 }
             }
         }

src/Orchard/Tasks/Locking/DefaultLock.cs

@@ -1,14 +1,31 @@
 using System;
 
 namespace Orchard.Tasks.Locking {
+
     public class DefaultLock : IDistributedLock {
+        private readonly IStaticLockSemaphore _semaphore;
+
+        public DefaultLock(IStaticLockSemaphore semaphore) {
+            _semaphore = semaphore;
+        }
 
         public bool TryAcquire(string name, TimeSpan maxLifetime) {
-            return true;
+            if (_semaphore.IsAcquired)
+                return false;
+
+            return _semaphore.IsAcquired = true;
         }
 
         public void Dispose() {
-            // Noop.
+            _semaphore.IsAcquired = false;
+        }
+
+        public interface IStaticLockSemaphore : ISingletonDependency {
+            bool IsAcquired { get; set; }
+        }
+
+        public class StaticLockSemaphore : IStaticLockSemaphore {
+            public bool IsAcquired { get; set; }
         }
     }
 }