Add multi-host support

Source/Engine/Networking/NetworkHost.cpp

@@ -0,0 +1,66 @@
+// Copyright (c) 2012-2021 Wojciech Figat. All rights reserved.
+
+#include "NetworkHost.h"
+
+#include "Drivers/ENetDriver.h"
+
+#include "Engine/Core/Log.h"
+#include "Engine/Core/Math/Math.h"
+#include "Engine/Platform/CPUInfo.h"
+
+void NetworkHost::Initialize(const NetworkConfig& config)
+{
+    Config = config;
+
+    ASSERT(NetworkDriver == nullptr);
+    ASSERT(Config.NetworkDriverType != NetworkTransportType::Undefined);
+    ASSERT(Config.ConnectionsLimit > 0);
+    ASSERT(Config.MessageSize > 32); // TODO: Adjust this, not sure what the lowest limit should be.
+    ASSERT(Config.MessagePoolSize > 128);
+
+    // Setup messages
+    CreateMessageBuffers();
+    MessagePool.Clear();
+
+    // Warmup message pool
+    for (uint32 messageId = Config.MessagePoolSize; messageId > 0; messageId --)
+        MessagePool.Push(messageId);
+
+    // Setup network driver
+    NetworkDriver = New<ENetDriver>();
+    NetworkDriver->Initialize(Config);
+
+    LOG(Info, "NetworkManager initialized using driver = {0}", static_cast<int>(Config.NetworkDriverType));
+}
+
+void NetworkHost::Shutdown()
+{
+    Delete(NetworkDriver);
+    DisposeMessageBuffers();
+
+    NetworkDriver = nullptr;
+}
+
+void NetworkHost::CreateMessageBuffers()
+{
+    ASSERT(MessageBuffer == nullptr);
+        
+    const uint32 pageSize = Platform::GetCPUInfo().PageSize;
+
+    // Calculate total size in bytes
+    const uint64 totalSize = static_cast<uint64>(Config.MessagePoolSize) * Config.MessageSize;
+
+    // Calculate the amount of pages that we need
+    const uint32 numPages = totalSize > pageSize ? Math::CeilToInt(totalSize / static_cast<float>(pageSize)) : 1;
+
+    MessageBuffer = static_cast<uint8*>(Platform::AllocatePages(numPages, pageSize));
+    Platform::MemorySet(MessageBuffer, 0, numPages * pageSize);
+}
+
+void NetworkHost::DisposeMessageBuffers()
+{
+    ASSERT(MessageBuffer != nullptr);
+        
+    Platform::FreePages(MessageBuffer);
+    MessageBuffer = nullptr;
+}