SynchronizationContext and blocking calls

Microsoft.Azure.Cosmos/src/ChangeFeedProcessor/ChangeFeedProcessorBuilder.cs

@@ -162,7 +162,7 @@ public ChangeFeedProcessorBuilder WithLeaseContainer(Container leaseContainer)
             if (this.leaseContainer != null) throw new InvalidOperationException("The builder already defined a lease container.");
             if (this.LeaseStoreManager != null) throw new InvalidOperationException("The builder already defined an in-memory lease container instance.");
 
-            this.leaseContainer = (ContainerCore)leaseContainer;
+            this.leaseContainer = (ContainerInlineCore)leaseContainer;
             return this;
         }
 

Microsoft.Azure.Cosmos/src/CosmosClient.cs

@@ -324,7 +324,7 @@ public virtual Task<AccountProperties> ReadAccountAsync()
         /// <returns>Cosmos database proxy</returns>
         public virtual Database GetDatabase(string id)
         {
-            return new DatabaseCore(this.ClientContext, id);
+            return new DatabaseInlineCore(new DatabaseCore(this.ClientContext, id));
         }
 
         /// <summary>

Microsoft.Azure.Cosmos/src/Resource/Conflict/ConflictsInlineCore.cs

@@ -0,0 +1,79 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+
+namespace Microsoft.Azure.Cosmos
+{
+    using System;
+    using System.Threading;
+    using System.Threading.Tasks;
+
+    // This class acts as a wrapper for environments that use SynchronizationContext.
+    internal sealed class ConflictsInlineCore : Conflicts
+    {
+        private readonly ConflictsCore conflicts;
+
+        internal ConflictsInlineCore(ConflictsCore conflicts)
+        {
+            if (conflicts == null)
+            {
+                throw new ArgumentNullException(nameof(conflicts));
+            }
+
+            this.conflicts = conflicts;
+        }
+
+        public override Task<ResponseMessage> DeleteAsync(
+            ConflictProperties conflict,
+            PartitionKey partitionKey,
+            CancellationToken cancellationToken = default(CancellationToken))
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.conflicts.DeleteAsync(conflict, partitionKey, cancellationToken));
+        }
+
+        public override FeedIterator GetConflictQueryStreamIterator(
+           string queryText = null,
+           string continuationToken = null,
+           QueryRequestOptions requestOptions = null)
+        {
+            return this.conflicts.GetConflictQueryStreamIterator(queryText, continuationToken, requestOptions);
+        }
+
+        public override FeedIterator<T> GetConflictQueryIterator<T>(
+            string queryText = null,
+            string continuationToken = null,
+            QueryRequestOptions requestOptions = null)
+        {
+            return this.conflicts.GetConflictQueryIterator<T>(queryText, continuationToken, requestOptions);
+        }
+
+        public override FeedIterator GetConflictQueryStreamIterator(
+            QueryDefinition queryDefinition,
+            string continuationToken = null,
+            QueryRequestOptions requestOptions = null)
+        {
+            return this.conflicts.GetConflictQueryStreamIterator(queryDefinition, continuationToken, requestOptions);
+        }
+
+        public override FeedIterator<T> GetConflictQueryIterator<T>(
+            QueryDefinition queryDefinition,
+            string continuationToken = null,
+            QueryRequestOptions requestOptions = null)
+        {
+            return this.conflicts.GetConflictQueryIterator<T>(queryDefinition, continuationToken, requestOptions);
+        }
+
+        public override Task<ItemResponse<T>> ReadCurrentAsync<T>(
+            ConflictProperties cosmosConflict,
+            PartitionKey partitionKey,
+            CancellationToken cancellationToken = default(CancellationToken))
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.conflicts.ReadCurrentAsync<T>(cosmosConflict, partitionKey, cancellationToken));
+        }
+
+        public override T ReadConflictContent<T>(ConflictProperties cosmosConflict)
+        {
+            return this.conflicts.ReadConflictContent<T>(cosmosConflict);
+        }
+    }
+}

Microsoft.Azure.Cosmos/src/Resource/Container/ContainerCore.cs

@@ -43,8 +43,8 @@ internal ContainerCore(
                 id: containerId);
 
             this.Database = database;
-            this.Conflicts = new ConflictsCore(this.ClientContext, this);
-            this.Scripts = new ScriptsCore(this, this.ClientContext);
+            this.Conflicts = new ConflictsInlineCore(new ConflictsCore(this.ClientContext, this));
+            this.Scripts = new ScriptsInlineCore(new ScriptsCore(this, this.ClientContext));
             this.cachedUriSegmentWithoutId = this.GetResourceSegmentUriWithoutId();
             this.queryClient = cosmosQueryClient ?? new CosmosQueryClientCore(this.ClientContext, this);
             this.BatchExecutor = this.InitializeBatchExecutorForContainer();

Microsoft.Azure.Cosmos/src/Resource/Container/ContainerInlineCore.cs

@@ -0,0 +1,252 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+
+namespace Microsoft.Azure.Cosmos
+{
+    using System;
+    using System.IO;
+    using System.Linq;
+    using System.Threading;
+    using System.Threading.Tasks;
+
+    // This class acts as a wrapper for environments that use SynchronizationContext.
+    internal sealed partial class ContainerInlineCore : Container
+    {
+        private readonly ContainerCore container;
+
+        public override string Id => this.container.Id;
+
+        public override Conflicts Conflicts => this.container.Conflicts;
+
+        public override Scripts.Scripts Scripts => this.container.Scripts;
+
+        internal CosmosClientContext ClientContext => this.container.ClientContext;
+
+        internal Uri LinkUri => this.container.LinkUri;
+
+        internal ContainerInlineCore(ContainerCore container)
+        {
+            if (container == null)
+            {
+                throw new ArgumentNullException(nameof(container));
+            }
+
+            this.container = container;
+        }
+
+        public override Task<ContainerResponse> ReadContainerAsync(
+            ContainerRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.ReadContainerAsync(requestOptions, cancellationToken));
+        }
+
+        public override Task<ResponseMessage> ReadContainerStreamAsync(
+            ContainerRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.ReadContainerStreamAsync(requestOptions, cancellationToken));
+        }
+
+        public override Task<ContainerResponse> ReplaceContainerAsync(
+            ContainerProperties containerProperties,
+            ContainerRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.ReplaceContainerAsync(containerProperties, requestOptions, cancellationToken));
+        }
+
+        public override Task<ResponseMessage> ReplaceContainerStreamAsync(
+            ContainerProperties containerProperties,
+            ContainerRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.ReplaceContainerStreamAsync(containerProperties, requestOptions, cancellationToken));
+        }
+
+        public override Task<ContainerResponse> DeleteContainerAsync(
+            ContainerRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.DeleteContainerAsync(requestOptions, cancellationToken));
+        }
+
+        public override Task<ResponseMessage> DeleteContainerStreamAsync(
+            ContainerRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.DeleteContainerStreamAsync(requestOptions, cancellationToken));
+        }
+
+        public override Task<int?> ReadThroughputAsync(CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.ReadThroughputAsync(cancellationToken));
+        }
+
+        public override Task<ThroughputResponse> ReadThroughputAsync(
+            RequestOptions requestOptions,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.ReadThroughputAsync(requestOptions, cancellationToken));
+        }
+
+        public override Task<ThroughputResponse> ReplaceThroughputAsync(
+            int throughput,
+            RequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.ReplaceThroughputAsync(throughput, requestOptions, cancellationToken));
+        }
+
+        public override Task<ResponseMessage> CreateItemStreamAsync(
+            Stream streamPayload,
+            PartitionKey partitionKey,
+            ItemRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.CreateItemStreamAsync(streamPayload, partitionKey, requestOptions, cancellationToken));
+        }
+
+        public override Task<ItemResponse<T>> CreateItemAsync<T>(T item,
+            PartitionKey? partitionKey = null,
+            ItemRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.CreateItemAsync<T>(item, partitionKey, requestOptions, cancellationToken));
+        }
+
+        public override Task<ResponseMessage> ReadItemStreamAsync(
+            string id,
+            PartitionKey partitionKey,
+            ItemRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.ReadItemStreamAsync(id, partitionKey, requestOptions, cancellationToken));
+        }
+
+        public override Task<ItemResponse<T>> ReadItemAsync<T>(
+            string id,
+            PartitionKey partitionKey,
+            ItemRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.ReadItemAsync<T>(id, partitionKey, requestOptions, cancellationToken));
+        }
+
+        public override Task<ResponseMessage> UpsertItemStreamAsync(
+            Stream streamPayload,
+            PartitionKey partitionKey,
+            ItemRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.UpsertItemStreamAsync(streamPayload, partitionKey, requestOptions, cancellationToken));
+        }
+
+        public override Task<ItemResponse<T>> UpsertItemAsync<T>(
+            T item,
+            PartitionKey? partitionKey = null,
+            ItemRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.UpsertItemAsync<T>(item, partitionKey, requestOptions, cancellationToken));
+        }
+
+        public override Task<ResponseMessage> ReplaceItemStreamAsync(
+            Stream streamPayload,
+            string id,
+            PartitionKey partitionKey,
+            ItemRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.ReplaceItemStreamAsync(streamPayload, id, partitionKey, requestOptions, cancellationToken));
+        }
+
+        public override Task<ItemResponse<T>> ReplaceItemAsync<T>(
+            T item,
+            string id,
+            PartitionKey? partitionKey = null,
+            ItemRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.ReplaceItemAsync<T>(item, id, partitionKey, requestOptions, cancellationToken));
+        }
+
+        public override Task<ResponseMessage> DeleteItemStreamAsync(
+            string id,
+            PartitionKey partitionKey,
+            ItemRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.DeleteItemStreamAsync(id, partitionKey, requestOptions, cancellationToken));
+        }
+
+        public override Task<ItemResponse<T>> DeleteItemAsync<T>(
+            string id,
+            PartitionKey partitionKey,
+            ItemRequestOptions requestOptions = null,
+            CancellationToken cancellationToken = default)
+        {
+            return TaskHelper.RunInlineIfNeededAsync(() => this.container.DeleteItemAsync<T>(id, partitionKey, requestOptions, cancellationToken));
+        }
+
+        public override FeedIterator GetItemQueryStreamIterator(
+            QueryDefinition queryDefinition,
+            string continuationToken = null,
+            QueryRequestOptions requestOptions = null)
+        {
+            return this.container.GetItemQueryStreamIterator(queryDefinition, continuationToken, requestOptions);
+        }
+
+        public override FeedIterator<T> GetItemQueryIterator<T>(
+            QueryDefinition queryDefinition,
+            string continuationToken = null,
+            QueryRequestOptions requestOptions = null)
+        {
+            return this.container.GetItemQueryIterator<T>(queryDefinition, continuationToken, requestOptions);
+        }
+
+        public override FeedIterator GetItemQueryStreamIterator(string queryText = null,
+            string continuationToken = null,
+            QueryRequestOptions requestOptions = null)
+        {
+            return this.container.GetItemQueryStreamIterator(queryText, continuationToken, requestOptions);
+        }
+
+        public override FeedIterator<T> GetItemQueryIterator<T>(
+            string queryText = null,
+            string continuationToken = null,
+            QueryRequestOptions requestOptions = null)
+        {
+            return this.container.GetItemQueryIterator<T>(queryText, continuationToken, requestOptions);
+        }
+
+        public override IOrderedQueryable<T> GetItemLinqQueryable<T>(bool allowSynchronousQueryExecution = false,
+            string continuationToken = null,
+            QueryRequestOptions requestOptions = null)
+        {
+            return this.container.GetItemLinqQueryable<T>(allowSynchronousQueryExecution, continuationToken, requestOptions);
+        }
+
+        public override ChangeFeedProcessorBuilder GetChangeFeedProcessorBuilder<T>(
+            string processorName,
+            ChangesHandler<T> onChangesDelegate)
+        {
+            return this.container.GetChangeFeedProcessorBuilder<T>(processorName, onChangesDelegate);
+        }
+
+        public override ChangeFeedProcessorBuilder GetChangeFeedEstimatorBuilder(string processorName,
+            ChangesEstimationHandler estimationDelegate,
+            TimeSpan? estimationPeriod = null)
+        {
+            return this.container.GetChangeFeedEstimatorBuilder(processorName, estimationDelegate, estimationPeriod);
+        }
+
+        public override TransactionalBatch CreateTransactionalBatch(PartitionKey partitionKey)
+        {
+            return this.container.CreateTransactionalBatch(partitionKey);
+        }
+
+        public static implicit operator ContainerCore(ContainerInlineCore containerInlineCore) => containerInlineCore.container;
+    }
+}

Microsoft.Azure.Cosmos/src/Resource/Database/DatabaseCore.cs

@@ -262,10 +262,10 @@ public override Container GetContainer(string id)
                 throw new ArgumentNullException(nameof(id));
             }
 
-            return new ContainerCore(
+            return new ContainerInlineCore(new ContainerCore(
                     this.ClientContext,
                     this,
-                    id);
+                    id));
         }
 
         public override Task<ResponseMessage> CreateContainerStreamAsync(
@@ -315,10 +315,10 @@ public override User GetUser(string id)
                 throw new ArgumentNullException(nameof(id));
             }
 
-            return new UserCore(
+            return new UserInlineCore(new UserCore(
                     this.ClientContext,
                     this,
-                    id);
+                    id));
         }
 
         public Task<ResponseMessage> CreateUserStreamAsync(