# room\_broadcast

## room\_broadcast Sample

### Overview

The room\_broadcast sample is a demonstration program utilizing the Room and P2P features of the Diarkis server. It allows two users to connect to the same Room, conduct relay communication via the Room, then establish a P2P connection for direct communication.\
The room\_broadcast sample showcases the following features:

* Room creation
* Joining a Room
* Sending messages to Room members
* Initiating P2P
* Sending and receiving messages via P2P

### Starting the Server in Your Local Environment

Execute the tutorial to start the server used in the sample and launch the Diarkis server in your local environment.

[1. Launch Diarkis Server in Local Environment](/en/getting-started/tutorial/setup-local-server.md)

## Explanation of the room\_broadcast Sample

1. Initialize the Diarkis runtime and Diarkis Module and connect to the Diarkis server.\
   For more details, refer to [Overall Flow for Using Diarkis Module](/en/diarkis-client/diarkis-module.md#diarkis-module-usage-overview).
2. Initialize the necessary functions. Since this sample uses the Room and P2P modules, initialize those functions using the Diarkis Module.

   ```
   // diarkis =  Diarkis::DiarkisAllocShared<DiarkisInterface>(uid); 
   ...
   // Setup P2P module
   diarkis->SetupP2P();

   // Setup Room module
   diarkis->SetupRoom(false);

   ```
3. Join a Room using RandomJoin. `DiarkisRoomBase::RandomJoinRoom()` will join an existing Room if available, or create a new one if not. After sending a request to the server via `DiarkisRoomBase::RandomJoinRoom()`, check the status with `DiarkisRoomBase::IsJoin()` until the Room join is complete.

   ```cpp
   diarkis->RandomJoinRoom(10, 60, 0, true);

   // Wait for DiarkisRoomBase::OnRoomJoin
   while (diarkis->GetRoomBase()->IsJoin() == false) {
       std::this_thread::sleep_for(std::chrono::milliseconds(30));
   }
   ```
4. Wait until the expected number of participants join the Room.\
   In this sample, wait until 2 users join the same Room. You can request the list of members in the Room by calling `DiarkisRoomBase::SendGetMemberIDs()`. The results can be obtained with `DiarkisRoomBase::GetRoomMembers()`.

   ```cpp
   while (1)
   {
       Diarkis::StdVector<Diarkis::StdString> members;

       diarkis->GetRoomBase()->SendGetMemberIDs();
       diarkis->GetRoomBase()->GetRoomMembers(members);

       if (members.size() == NumPeer)
       {
           break;
       }
       std::this_thread::sleep_for(std::chrono::milliseconds(2000));
   }
   ```
5. Use Room Broadcast to send a message to all users in the Room.

   ```cpp
   diarkis->GetRoomBase()->SendBroadcastToRoom(buff, bReliable);
   ```
6. The Room owner executes `DiarkisRoomBase::SendStartP2PSync()` to notify the server of the initiation of P2P connections and to retrieve a list of address connections for participants in the Room.

   ```cpp
   if (Diarkis::StdString(uid.c_str()) == diarkis->GetRoomBase()->GetOwnerUID())
   {
       // Retrieve address list of each member's connection
       diarkis->GetRoomBase()->SendStartP2PSync();
   }
   ```
7. When the Room owner executes `DiarkisRoomBase::SendStartP2PSync()`, P2P connection information is notified to all users in the Room via `DiarkisRoomBase::OnStartP2PSync()`, triggering the start of hole punching.
8. Upon successful hole punching, communication via P2P begins.

   ```cpp
   diarkis->GetP2PBase()->SendBroadcast(buff, RudpType::UNRELIABLE_UNORDERED);
   ```
9. Execute `DiarkisRoomBase::SendLeaveRoom()` to request to leave the Room from the server. In this sample, wait until leaving the Room is complete using `DiarkisRoomBase::IsLeave()`.

   ```cpp
   // Leave the Room
   diarkis->SendLeaveRoom();

   // Wait for DiarkisRoomBase::OnRoomLeave
   while (diarkis->GetRoomBase()->IsLeave() == false) {
       std::this_thread::sleep_for(std::chrono::milliseconds(30));
   }
   ```
10. Termination\
    For more details, refer to [Overall Flow for Using Diarkis Module](/en/diarkis-client/diarkis-module.md#diarkis-module-usage-overview).

## Notes

* To successfully achieve P2P hole punching, the clients must be in the same Room and exchange addresses.
* Please prepare multiple clients and execute them simultaneously to verify operation.


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