I'm developing a distributed database system, then mainly by the gRPC this library, and then my main is written according to gRPC paradigm, but appeared the problem, the error code is 12 said I didn't implement this function on the server side, they would like to ask you, the following is the code
Sundial_sync_server. H

 
# # ifndef SUNDIAL_GRPC_SYNC_SERVER_H 
# define SUNDIAL_GRPC_SYNC_SERVER_H 

# endif//SUNDIAL_GRPC_SYNC_SERVER_H 

# include "sundial_grpc GRPC. Pb. H" 
# include "sundial_grpc. Pb. H" 
# include & lt; Iostream> 
# include & lt; Memory> 
# include & lt; String> 
# include & lt; GRPCPP/GRPCPP. H> 
Using GRPC: : Channel; 
Using GRPC: : ServerContext; 
Using GRPC: : Status; 
Using sundial_rpc: : SundialRequest; 
Using sundial_rpc: : SundialResponse; 
Using sundial_rpc: : Sundial_GRPC_SYNC; 
# # ifndef ABC 
# define ABC 
The class SundialServiceImp final: public Sundial_GRPC_SYNC: : Service 
{
Public: 
The Status contactRemote (: : GRPC: : ServerContext * context, const: : sundial_rpc: : SundialRequest * request, : : sundial_rpc: : SundialResponse * response) override. 
Void the run (); 

}; 
# endif 

Sundial_sync_server. CPP

 # include "sundial_grpc. GRPC. Pb, h" 
# include "sundial_grpc. Pb. H" 
# include & lt; Iostream> 
# include & lt; Memory> 
# include & lt; String> 
# include & lt; GRPCPP/GRPCPP. H> 
# include "TXN. H" 
# include "global h" 
H # include "manager." 
# include "stats. H" 
# include "helper. H" 
# include "grpc_sync_server. H" 
# include "txn_table. H" 
# include & lt; GRPCPP/GRPCPP. H> 
# include & lt; GRPCPP/health_check_service_interface. H> 
# include & lt; GRPCPP/ext/proto_server_reflection_plugin. H> 
Using GRPC: : ServerContext; 
Using GRPC: : Status; 
Using sundial_rpc: : SundialRequest; 
Using sundial_rpc: : SundialResponse; 
Using sundial_rpc: : Sundial_GRPC_SYNC; 
Using GRPC: : Server; 
Using GRPC: : ServerBuilder; 
The Status SundialServiceImp: : contactRemote (: : GRPC: : ServerContext * context, const: : sundial_rpc: : SundialRequest * request, : : sundial_rpc: : SundialResponse * response) {
If (request - & gt; Request_type ()==SundialRequest: : SYS_REQ) {
Glob_manager - & gt; Receive_sync_request (); 
The response - & gt; Set_response_type (SundialResponse: : SYS_RESP); 
The return Status: : OK. 
} 
Uint64_t txn_id=request - & gt; Txn_id (); 
TxnManager * txn_man=txn_table - & gt; Get_txn (txn_id); 
//If no TxnManager exists for requesting the transaction, create one. 
If (txn_man==NULL) {
//printf (" adding ld into txn_table txnID=% \ n ", txn_id); 
Assert (request - & gt; Request_type ()==SundialRequest: : READ_REQ); 
Txn_man=new TxnManager (); 
Txn_man - & gt; Set_txn_id (txn_id); 
Txn_table - & gt; Add_txn (txn_man); 
} 
//the transaction handles the RPC call 
Txn_man - & gt; Process_remote_request (request, response); 
//if the sub - the transaction is no longer required, remove the from txn_table 
If (the response - & gt; The payload ()==SundialResponse: : RESP_ABORT 
| | response - & gt; The payload ()==SundialResponse: : PREPARED_OK_RO 
| | response - & gt; The payload ()==SundialResponse: : PREPARED_ABORT 
| | response - & gt; The payload ()==SundialResponse: : ACK) {
Txn_table - & gt; Remove_txn (txn_man); 
The delete txn_man; 
} 
The return Status: : OK. 
} 

Void SundialServiceImp: : run () {
STD: : istringstream in (ifconfig_string); 
The string line; 
Uint32_t num_nodes=0; 
String port; 
While (getline (in line)) {
If (line [0]=='#') 
continue; 
The else {
If (num_nodes==g_node_id) {
Port=line. Substr (0, the line. The length ()); 
break; 
} 
Num_nodes + +; 
} 
} 
Port. Append (sync_port); 
GRPC: : EnableDefaultHealthCheckService (true); 
GRPC: : reflection: : InitProtoReflectionServerBuilderPlugin (); 
ServerBuilder builder; 
Builder. AddListeningPort (port, GRPC: : InsecureServerCredentials ()); 
Builder. RegisterService (this); 
STD: : unique_ptr & lt; Server> Server (builder. BuildAndStart ()); 
STD: : cout & lt; <"Server listening on" & lt; Server - & gt; Wait (); 
} 

Sundial_sync_client. H

 # endif//SUNDIAL_GRPC_CLIENT_H 
# include "sundial_grpc GRPC. Pb. H" 
# include "sundial_grpc. Pb. H" 
# include & lt; Iostream> 
# include & lt; Memory> 
# include & lt; String> 
# include & lt; GRPCPP/GRPCPP. H> 
Using GRPC: : Channel; 
Using GRPC: : ClientContext; 
Using GRPC: : Status; 
Using sundial_rpc: : SundialRequest; 
Using sundial_rpc: : SundialResponse; 
Using sundial_rpc: : Sundial_GRPC_SYNC; 
//toDo: now assume we only have 2 nodes 
# # ifndef SSC 
# define SSC 
The class Sundial_Sync_Client {
Public: 
Sundial_Sync_Client (STD: : from & lt; Channel> * channel); 
The Status contactRemote (uint64_t node_id SundialRequest& Request, SundialResponse * response); 
Private: 
STD: : unique_ptr & lt; Sundial_GRPC_SYNC: : Stub> Stub_; 
}; 
# endif 

Sundial_sync_client. CPP

 
nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull