Merge pull request #14876 from VampireFlower/usbgecko

Optimize USB Gecko Emulation

2 files changed, 54 insertions, 20 deletions

diff --git a/Source/Core/Core/HW/EXI/EXI_DeviceGecko.cpp b/Source/Core/Core/HW/EXI/EXI_DeviceGecko.cpp
index 5d58f4a926..9d064582a7 100644
--- a/Source/Core/Core/HW/EXI/EXI_DeviceGecko.cpp
+++ b/Source/Core/Core/HW/EXI/EXI_DeviceGecko.cpp
@@ -99,7 +99,6 @@ bool GeckoSockServer::GetAvailableSock()
 
   if (!waiting_socks.empty())
   {
-    client = std::move(waiting_socks.front());
     if (clientThread.joinable())
     {
       client_running.Clear();
@@ -108,6 +107,9 @@ bool GeckoSockServer::GetAvailableSock()
       recv_fifo = std::deque<u8>();
       send_fifo = std::deque<u8>();
     }
+    client = std::move(waiting_socks.front());
+    client_running.Set();
+    client_connected.Set();
     clientThread = std::thread(&GeckoSockServer::ClientThread, this);
     client_count++;
     waiting_socks.pop();
@@ -119,8 +121,6 @@ bool GeckoSockServer::GetAvailableSock()
 
 void GeckoSockServer::ClientThread()
 {
-  client_running.Set();
-
   Common::SetCurrentThreadName("Gecko Client");
 
   client->setBlocking(false);
@@ -130,7 +130,7 @@ void GeckoSockServer::ClientThread()
     bool did_nothing = true;
 
     {
-      std::lock_guard lk(transfer_lock);
+      std::lock_guard lk(recv_lock);
 
       // what's an ideal buffer size?
       std::array<char, 128> buffer;
@@ -145,24 +145,35 @@ void GeckoSockServer::ClientThread()
 
         recv_fifo.insert(recv_fifo.end(), buffer.data(), buffer.data() + got);
       }
+    }  // unlock recv
+
+    {
+      std::lock_guard lk(send_lock);
 
       if (!send_fifo.empty())
       {
-        did_nothing = false;
+        std::size_t sent;
 
         std::vector<char> packet(send_fifo.begin(), send_fifo.end());
-        send_fifo.clear();
 
-        if (client->send(&packet[0], packet.size()) == sf::Socket::Status::Disconnected)
+        if (client->send(packet.data(), packet.size(), sent) == sf::Socket::Status::Disconnected)
           client_running.Clear();
+
+        if (sent)
+        {
+          did_nothing = false;
+
+          send_fifo.erase(send_fifo.begin(), send_fifo.begin() + sent);
+        }
       }
-    }  // unlock transfer
+    }  // unlock send
 
     if (did_nothing)
       Common::YieldCPU();
   }
 
   client->disconnect();
+  client_connected.Clear();
 }
 
 CEXIGecko::CEXIGecko(Core::System& system) : IEXIDevice(system)
@@ -174,7 +185,7 @@ void CEXIGecko::ImmReadWrite(u32& _uData, u32 _uSize)
   // We don't really care about _uSize
   (void)_uSize;
 
-  if (!client || client->getLocalPort() == 0)
+  if (!client_connected.IsSet())
     GetAvailableSock();
 
   switch (_uData >> 28)
@@ -195,11 +206,15 @@ void CEXIGecko::ImmReadWrite(u32& _uData, u32 _uSize)
   // |= 0x08000000 if successful
   case CMD_RECV:
   {
-    std::lock_guard lk(transfer_lock);
-    if (!recv_fifo.empty())
+    if (m_recv_buffer.empty())
+    {
+      std::lock_guard lk(recv_lock);
+      m_recv_buffer.swap(recv_fifo);
+    }
+    if (!m_recv_buffer.empty())
     {
-      _uData = 0x08000000 | (recv_fifo.front() << 16);
-      recv_fifo.pop_front();
+      _uData = 0x08000000 | (m_recv_buffer.front() << 16);
+      m_recv_buffer.pop_front();
     }
     break;
   }
@@ -208,24 +223,36 @@ void CEXIGecko::ImmReadWrite(u32& _uData, u32 _uSize)
   // |= 0x04000000 if successful
   case CMD_SEND:
   {
-    std::lock_guard lk(transfer_lock);
-    send_fifo.push_back(_uData >> 20);
-    _uData = 0x04000000;
+    std::lock_guard lk(send_lock);
+
+    if (send_fifo.size() < 1024)
+    {
+      send_fifo.push_back(_uData >> 20);
+      _uData = 0x04000000;
+    }
+    else
+    {
+      _uData = 0;
+    }
+
     break;
   }
 
   // Check if ok for Gecko -> PC, or FIFO full
   // |= 0x04000000 if FIFO is not full
   case CMD_CHK_TX:
-    _uData = 0x04000000;
+  {
+    std::lock_guard lk(send_lock);
+    _uData = send_fifo.size() < 1024 ? 0x04000000 : 0;
     break;
+  }
 
   // Check if data in FIFO for PC -> Gecko, or FIFO empty
   // |= 0x04000000 if data in recv FIFO
   case CMD_CHK_RX:
   {
-    std::lock_guard lk(transfer_lock);
-    _uData = recv_fifo.empty() ? 0 : 0x04000000;
+    std::lock_guard lk(recv_lock);
+    _uData = m_recv_buffer.empty() && recv_fifo.empty() ? 0 : 0x04000000;
     break;
   }
 
diff --git a/Source/Core/Core/HW/EXI/EXI_DeviceGecko.h b/Source/Core/Core/HW/EXI/EXI_DeviceGecko.h
index 59a8041294..8765349e5a 100644
--- a/Source/Core/Core/HW/EXI/EXI_DeviceGecko.h
+++ b/Source/Core/Core/HW/EXI/EXI_DeviceGecko.h
@@ -25,9 +25,13 @@ public:
 
   // Client for this server object
   std::unique_ptr<sf::TcpSocket> client;
+  // Set before starting the client thread; cleared after it closes the socket.
+  Common::Flag client_connected{false};
   void ClientThread();
   std::thread clientThread;
-  std::mutex transfer_lock;
+
+  std::mutex send_lock;
+  std::mutex recv_lock;
 
   std::deque<u8> send_fifo;
   std::deque<u8> recv_fifo;
@@ -65,5 +69,8 @@ private:
   };
 
   static const u32 ident = 0x04700000;
+
+  // Only accessed by the CPU thread. Refilled from recv_fifo under recv_lock
+  std::deque<u8> m_recv_buffer;
 };
 }  // namespace ExpansionInterface