bug grpc: fix a rare data race in client::ReaderWriter with parallel read-write

commit_hash:1cc8c1961246741ebfd96ce094ad97160a0a58e7

Author: Anton3

grpc/include/userver/ugrpc/client/impl/async_stream_methods.hpp

@@ -150,7 +150,7 @@ bool Write(GrpcStream& stream, const Request& request, grpc::WriteOptions option
     const auto lock = state.TakeMutexIfBidirectional();
     if (state.IsFinished()) {
         // It't forbidden to work with a stream after Finish.
-        throw ugrpc::client::RpcInterruptedError{state.GetCallName(), "Write"};
+        return false;
     }
 
     UINVARIANT(IsWriteAvailable(state), "'impl::Write' called on a stream that is closed for writes");

grpc/include/userver/ugrpc/client/impl/rpc.hpp

@@ -427,6 +427,10 @@ bool BidirectionalStream<Request, Response>::Write(const Request& request) {
 
     {
         const auto lock = state_.TakeMutexIfBidirectional();
+        if (state_.IsFinished()) {
+            // It't forbidden to work with a stream after Finish.
+            return false;
+        }
         RunMiddlewarePipeline(state_, MiddlewareHooks::SendMessageHooks(request));
     }
 
@@ -445,6 +449,10 @@ void BidirectionalStream<Request, Response>::WriteAndCheck(const Request& reques
 
     {
         const auto lock = state_.TakeMutexIfBidirectional();
+        if (state_.IsFinished()) {
+            // It't forbidden to work with a stream after Finish.
+            throw ugrpc::client::RpcInterruptedError{state_.GetCallName(), "WriteAndCheck"};
+        }
         RunMiddlewarePipeline(state_, MiddlewareHooks::SendMessageHooks(request));
     }