網路桌面遊戲之模式與系統設計

Abstract

網路桌面遊戲，如西洋棋、圍棋、橋牌、麻將等，在Internet上十分受歡迎。許多桌面遊戲擁有相同的特性，如玩家圍坐在桌子旁，使用撲克牌之類的小物體來玩遊戲。由於桌面遊戲普及性及相似性，讓我們想研究如何加速網路桌面遊戲的發展。根據桌面遊戲的相同特性，我們設計兩個模式。第一個模式允許玩家在一個虛擬的大廳中邀請朋友一起玩遊戲。第二個模式則是為桌面遊戲定義了物件、狀態、以及遊戲的動作。根據這兩個模式，我們設計並實作了了一套網路桌面遊戲發展系統。這個系統的功能包括了網路通訊功能，玩家及遊戲伺服器管理，以及專為桌面遊戲提供的圖形介面支援等等。 在實作的過程中，我們遇到了兩個會造成我們的系統服務暫停或中止的問題。第一個問題是某些對網路讀寫資料的動作可能會造成遊戲伺服器暫時停止運作。第二個問題是當緩衝區溢位 (buffer overflow) 這種錯誤發生時，會讓整個遊戲伺服器程式被破壞，無法繼續提供服務。我們深入研究了這兩個問題並在本論文中提出了我們的解決方法。我們的研究成果可以讓遊戲伺服器程式避免被上述那兩個問題干擾，而能夠正確地持續提供服務。 實際上在台灣和香港已經有數個遊戲網站採用我們的系統。近年來，這些遊戲網站已經擁有超過百萬的會員，而最高的同時上線玩遊戲人數，也屢次超過了一萬人，足以說明我們的系統的實用性及穩定性。

Online tabletop games, such as Chess, Go, Bridge, Mahjong, etc, are popular in the Internet. Many online tabletop games share the same characteristics, e.g., players play around tables using physical objects such as cards. Due to the popularity and similarity of tabletop games, we are motivated to facilitate the development of online tabletop games. We design two models for online tabletop games according to the shared characteristics. The first model allows players to invite friends to play games together in a virtual room. The second model defines game objects, game states, and playing operations for tabletop games. Based on the two models, we design and implement a system for developing online tabletop games. The functionalities of the game system include network communication, player management, game server management, and graphical support for online tabletop games. While implementing the game system practically, we encounter two issues on which the services of our system for online tabletop games are blocked or disrupted. The first issue is that some network I/O operations may block servers in our system unexpectedly for a long time. The second issue is that buffer overflow failures may crash servers in our system and therefore disrupt the services. In this dissertation we propose solutions to the two issues respectively so that our game system can support services smoothly and correctly without suffering form the two issues. In practice, our game system has been used in some commercial game sites in Taiwan and Hong-Kong. These game sites have attracted more than one million people to register as members and have supported up to 10,000 concurrent players.