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#region Copyright notice and license
// Copyright 2015, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#endregion
using System;
using System.Diagnostics;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Threading;
using System.Threading.Tasks;
using Grpc.Core.Internal;
using Grpc.Core.Utils;
namespace Grpc.Core.Internal
{
/// <summary>
/// Manages client side native call lifecycle.
/// </summary>
internal class AsyncCall<TRequest, TResponse> : AsyncCallBase<TRequest, TResponse>
{
Channel channel;
// Completion of a pending unary response if not null.
TaskCompletionSource<TResponse> unaryResponseTcs;
// Set after status is received. Used for both unary and streaming response calls.
ClientSideStatus? finishedStatus;
bool readObserverCompleted; // True if readObserver has already been completed.
public AsyncCall(Func<TRequest, byte[]> serializer, Func<byte[], TResponse> deserializer) : base(serializer, deserializer)
{
}
public void Initialize(Channel channel, CompletionQueueSafeHandle cq, string methodName, Timespec deadline)
{
this.channel = channel;
var call = channel.Handle.CreateCall(channel.CompletionRegistry, cq, methodName, channel.Target, deadline);
channel.Environment.DebugStats.ActiveClientCalls.Increment();
InitializeInternal(call);
}
// TODO: this method is not Async, so it shouldn't be in AsyncCall class, but
// it is reusing fair amount of code in this class, so we are leaving it here.
// TODO: for other calls, you need to call Initialize, this methods calls initialize
// on its own, so there's a usage inconsistency.
/// <summary>
/// Blocking unary request - unary response call.
/// </summary>
public TResponse UnaryCall(Channel channel, string methodName, TRequest msg, Metadata headers, DateTime deadline)
{
using (CompletionQueueSafeHandle cq = CompletionQueueSafeHandle.Create())
{
byte[] payload = UnsafeSerialize(msg);
unaryResponseTcs = new TaskCompletionSource<TResponse>();
lock (myLock)
{
Initialize(channel, cq, methodName, Timespec.FromDateTime(deadline));
started = true;
halfcloseRequested = true;
readingDone = true;
}
using (var metadataArray = MetadataArraySafeHandle.Create(headers))
{
using (var ctx = BatchContextSafeHandle.Create())
{
call.StartUnary(payload, ctx, metadataArray);
var ev = cq.Pluck(ctx.Handle);
bool success = (ev.success != 0);
try
{
HandleUnaryResponse(success, ctx);
}
catch (Exception e)
{
Console.WriteLine("Exception occured while invoking completion delegate: " + e);
}
}
}
try
{
// Once the blocking call returns, the result should be available synchronously.
return unaryResponseTcs.Task.Result;
}
catch (AggregateException ae)
{
throw ExceptionHelper.UnwrapRpcException(ae);
}
}
}
/// <summary>
/// Starts a unary request - unary response call.
/// </summary>
public Task<TResponse> UnaryCallAsync(TRequest msg, Metadata headers, DateTime deadline)
{
lock (myLock)
{
Preconditions.CheckNotNull(call);
started = true;
halfcloseRequested = true;
readingDone = true;
byte[] payload = UnsafeSerialize(msg);
unaryResponseTcs = new TaskCompletionSource<TResponse>();
using (var metadataArray = MetadataArraySafeHandle.Create(headers))
{
call.StartUnary(payload, HandleUnaryResponse, metadataArray);
}
return unaryResponseTcs.Task;
}
}
/// <summary>
/// Starts a streamed request - unary response call.
/// Use StartSendMessage and StartSendCloseFromClient to stream requests.
/// </summary>
public Task<TResponse> ClientStreamingCallAsync(Metadata headers, DateTime deadline)
{
lock (myLock)
{
Preconditions.CheckNotNull(call);
started = true;
readingDone = true;
unaryResponseTcs = new TaskCompletionSource<TResponse>();
using (var metadataArray = MetadataArraySafeHandle.Create(headers))
{
call.StartClientStreaming(HandleUnaryResponse, metadataArray);
}
return unaryResponseTcs.Task;
}
}
/// <summary>
/// Starts a unary request - streamed response call.
/// </summary>
public void StartServerStreamingCall(TRequest msg, Metadata headers, DateTime deadline)
{
lock (myLock)
{
Preconditions.CheckNotNull(call);
started = true;
halfcloseRequested = true;
halfclosed = true; // halfclose not confirmed yet, but it will be once finishedHandler is called.
byte[] payload = UnsafeSerialize(msg);
using (var metadataArray = MetadataArraySafeHandle.Create(headers))
{
call.StartServerStreaming(payload, HandleFinished, metadataArray);
}
}
}
/// <summary>
/// Starts a streaming request - streaming response call.
/// Use StartSendMessage and StartSendCloseFromClient to stream requests.
/// </summary>
public void StartDuplexStreamingCall(Metadata headers, DateTime deadline)
{
lock (myLock)
{
Preconditions.CheckNotNull(call);
started = true;
using (var metadataArray = MetadataArraySafeHandle.Create(headers))
{
call.StartDuplexStreaming(HandleFinished, metadataArray);
}
}
}
/// <summary>
/// Sends a streaming request. Only one pending send action is allowed at any given time.
/// completionDelegate is called when the operation finishes.
/// </summary>
public void StartSendMessage(TRequest msg, AsyncCompletionDelegate<object> completionDelegate)
{
StartSendMessageInternal(msg, completionDelegate);
}
/// <summary>
/// Receives a streaming response. Only one pending read action is allowed at any given time.
/// completionDelegate is called when the operation finishes.
/// </summary>
public void StartReadMessage(AsyncCompletionDelegate<TResponse> completionDelegate)
{
StartReadMessageInternal(completionDelegate);
}
/// <summary>
/// Sends halfclose, indicating client is done with streaming requests.
/// Only one pending send action is allowed at any given time.
/// completionDelegate is called when the operation finishes.
/// </summary>
public void StartSendCloseFromClient(AsyncCompletionDelegate<object> completionDelegate)
{
lock (myLock)
{
Preconditions.CheckNotNull(completionDelegate, "Completion delegate cannot be null");
CheckSendingAllowed();
call.StartSendCloseFromClient(HandleHalfclosed);
halfcloseRequested = true;
sendCompletionDelegate = completionDelegate;
}
}
/// <summary>
/// Gets the resulting status if the call has already finished.
/// Throws InvalidOperationException otherwise.
/// </summary>
public Status GetStatus()
{
lock (myLock)
{
Preconditions.CheckState(finishedStatus.HasValue, "Status can only be accessed once the call has finished.");
return finishedStatus.Value.Status;
}
}
/// <summary>
/// Gets the trailing metadata if the call has already finished.
/// Throws InvalidOperationException otherwise.
/// </summary>
public Metadata GetTrailers()
{
lock (myLock)
{
Preconditions.CheckState(finishedStatus.HasValue, "Trailers can only be accessed once the call has finished.");
return finishedStatus.Value.Trailers;
}
}
/// <summary>
/// On client-side, we only fire readCompletionDelegate once all messages have been read
/// and status has been received.
/// </summary>
protected override void ProcessLastRead(AsyncCompletionDelegate<TResponse> completionDelegate)
{
if (completionDelegate != null && readingDone && finishedStatus.HasValue)
{
bool shouldComplete;
lock (myLock)
{
shouldComplete = !readObserverCompleted;
readObserverCompleted = true;
}
if (shouldComplete)
{
var status = finishedStatus.Value.Status;
if (status.StatusCode != StatusCode.OK)
{
FireCompletion(completionDelegate, default(TResponse), new RpcException(status));
}
else
{
FireCompletion(completionDelegate, default(TResponse), null);
}
}
}
}
protected override void OnReleaseResources()
{
channel.Environment.DebugStats.ActiveClientCalls.Decrement();
}
/// <summary>
/// Handler for unary response completion.
/// </summary>
private void HandleUnaryResponse(bool success, BatchContextSafeHandle ctx)
{
var fullStatus = ctx.GetReceivedStatusOnClient();
lock (myLock)
{
finished = true;
finishedStatus = fullStatus;
halfclosed = true;
ReleaseResourcesIfPossible();
}
if (!success)
{
unaryResponseTcs.SetException(new RpcException(new Status(StatusCode.Internal, "Internal error occured.")));
return;
}
var status = fullStatus.Status;
if (status.StatusCode != StatusCode.OK)
{
unaryResponseTcs.SetException(new RpcException(status));
return;
}
// TODO: handle deserialization error
TResponse msg;
TryDeserialize(ctx.GetReceivedMessage(), out msg);
unaryResponseTcs.SetResult(msg);
}
/// <summary>
/// Handles receive status completion for calls with streaming response.
/// </summary>
private void HandleFinished(bool success, BatchContextSafeHandle ctx)
{
var fullStatus = ctx.GetReceivedStatusOnClient();
AsyncCompletionDelegate<TResponse> origReadCompletionDelegate = null;
lock (myLock)
{
finished = true;
finishedStatus = fullStatus;
origReadCompletionDelegate = readCompletionDelegate;
ReleaseResourcesIfPossible();
}
ProcessLastRead(origReadCompletionDelegate);
}
}
}
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