Patent Publication Number: US-7908364-B2

Title: Method storing socket state information in application space for improving communication efficiency of an application program

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 60/886,677, entitled “HIGH PERFORMANCE KERNEL BYPASS OBJECT STATE NOTIFICATION MECHANISM,” filed on Jan. 26, 2007, which is assigned to the current assignee hereof and are incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates generally to data communications, and more specifically to a system and method for monitoring a state of a communication socket at a data processing device. 
     BACKGROUND 
     In recent years, several applications have been developed that rely on timely and effective interactions between two or more elements of a communication network. For example, in the sphere of online gaming, hundreds or thousands of game clients executing on user machines may be interacting with a central server executing on a networked computer. With such an architecture, a game server program is frequently tasked with providing content to clients, receiving client requests, processing those requests, responding to those requests, and synchronizing those requests with the requests of other clients. One factor that can affect the server programs ability to timely respond to client requests is the speed at which the server program can be notified that it has received data from the client, and the speed with which the data can be provided to the server program. One conventional method is for the server program to periodically poll the network stack of the server operating system to determine if data has been received. However, this method can take an undesirable amount of time, resulting in an undesirable delay in the server program responding to client requests. Furthermore, the speed at which a client program can be notified that it has received data from the server, and the speed with which the data can be provided to the server program can also cause undesirable delay. Similar problems can occur in peer-to-peer networks, resulting in undesirable delays in communications between programs at computer devices in the peer-to-peer network. 
     In the gaming context, this can result in distracting events such as game freezes, stuttering, warping, etc. As such, a need exists for an improved processing system and method that manages received data. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       It will be appreciated that for simplicity and clarity of illustration, elements illustrated in the Figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements are exaggerated relative to other elements. Embodiments incorporating teachings of the present disclosure are shown and described with respect to the drawings presented herein, in which: 
         FIG. 1  is a block diagram of a particular embodiment of a network arrangement incorporating teachings of the present disclosure; 
         FIG. 2  is a block diagram of a particular embodiment of a computer device that incorporates teachings of the present disclosure; 
         FIG. 3  is a block diagram of an alternative embodiment of a computer device and a network device that incorporates teachings of the present disclosure; and 
         FIG. 4  is a block diagram of an alternative embodiment of a network device and a computer device that incorporates teachings of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments discussed below describe, in part, distributed computing solutions that manage all or part of a communicative interaction between network elements. In this context, a communicative interaction may be one or more of: intending to send information, sending information, requesting information, receiving information, or receiving a request for information. As such, a communicative interaction could be one directional, bi-directional, or multi-directional. In some circumstances, a communicative interaction could be relatively complex and involve two or more network elements. For example, a communicative interaction may be “a conversation” or series of related communications between a client and a server or computer devices in a peer-to-peer network—each network element sending and receiving information to and from the other. Whatever form the communicative interaction takes, it should be noted that the network elements involved need not take any specific form. A network element may be a node, a piece of hardware, software, firmware, middleware, some other component of a computing system, and/or some combination thereof. 
     From a high level, a system incorporating teachings of the present disclosure may include a network that monitors communications between a computer programs at different computer devices in a network, such as a client program resident on a user machine and a server program resident on a computer device remote from the user, or a program at one device in a peer-to-peer network communicating with a program at another device in the network. In the case of a server/client architecture, the server program may be part of a two-tier architecture that is deployed in a hub and spoke or centralized server configuration. The server program may also be utilized in a less centralized model. For example, the server program may be implemented as one of two or more client programs that perform server-like functionality. For purposes of discussion herein, a program communicating with another program in the network is referred to herein as a peer program, and the device executing the peer program as a peer. 
     However, the peer program is implemented, state information indicating the state of a communication socket at the computer device can be monitored and stored in application space. In an embodiment, the state of the communication socket is maintained at a network device and communicated to a device driver for the network device. The device driver can send messages to an interface program in application space, which stores the state information in dedicated application space memory. In response to a query from the peer program requesting the state of the communication socket, the interface program retrieves the state information from the dedicated memory. Because the state information and the interface program are located in application space, the number of kernel transitions required to determine the socket state is reduced, improving communication efficiency. 
     In another embodiment, the device driver for the network device can store the socket state information in memory that is shared between application space and kernel space. The interface program can then access the stored state information in the shared memory in response to a state query from the peer program. 
     In still another embodiment, the state information can be maintained at the device driver itself, rather than at the network device. The device driver can communicate the state information to the interface program via messages, or by storing the information in shared memory. 
     As indicated above, this application claims priority to U.S. Provisional Patent No. 60/886,677 filed on Jan. 26, 2007. The provisional application describes in part specific implementations of the teachings disclosed herein and is not intended to limit the scope of the claims attached below. The entirety of the provisional application is incorporated herein by reference. 
     Referring to  FIG. 1 , a block diagram of a particular embodiment of a network arrangement that includes a peer program  103  executing at a computer device  102 , a network  106  including a network device  104 , and a peer program  107  executing at a computer device  108 . The actual location of the network device  104  may be modified in other deployments. For example, the network device may be implemented at the computer device  102  as a network card, a processor dongle, a “LAN on Motherboard” processor, etc. In the embodiment of  FIG. 1 , network  106  may be a wide area network, such as the Internet, a local area network, or some other appropriate network or bus. Within arrangement  100 , computer devices  102  and  108  may be similar or different. For example, computer device  108  may be a local user computer, a laptop, a cellular telephone, a gaming console, a workstation, or some other appropriate device, and host computer device  102  may be a peer computer, a workstation, a peer of computer device  108 , or some other appropriate device. 
     In operation, the peer program  107  and the peer program  103  may communicate with each other via the network  106 , and in particular via the network device  104 . In one embodiment, the peer program  107  and peer program  103  may work together to provide a user of computer device  108  with an online experience. In operation, peer program  107  may receive content from computer device  102  and may occasionally send requests to peer program  103  in an effort to affect the content being provided or to modify data at the peer program  103 . As shown,  FIG. 1  includes only two devices executing a peer program. In practice, however, peer program  103  and computer device  102  may be providing content to many peers at or near the same time. 
     In operation, the peer program  107  may send communications or messages to the peer program  103  to update information, request that tasks be performed, and the like. For example, the peer program  103  can be an online banking application and the peer program  107  can be a web browser. The peer program  107  can send requests to the peer program  103  to view account information, conduct transactions, and the like. In response, the peer program  103  can determine if the requested tasks are authorized and, if so, execute the tasks. In another embodiment, the peer program  103  is a server game program and the peer program  107  is a peer-side game program that provides a user with an online-gaming experience. In another embodiment, the peer program  103  and the peer program  107  work together to provide a game simulation experience to two or more players at each computer device  102  and  106 . 
     To communicate with the peer program  103 , the peer program  107  sends messages via the network  106 , and in particular to the network device  104 . Each message includes information, such as address information, indicating the location of the computer device  102 . Each message also includes port information, indicating the target port of the computer device  102  with which the message is associated. 
     The network device  104  delivers messages from network to the computer device  102  via communication sockets, such a communication socket  115 . Each communication socket can be associated with one or more communication ports. In the illustrated embodiment, the communication socket  115  is associated with ports  110  and  125 . In an embodiment, each port can be associated with a different program or communication function at the computer device  102 . 
     Each communication socket of the computer device  102  is associated with socket state information indicating the state of the socket. For example, the state information can indicate whether a socket is “busy” (i.e. whether information is currently being transmitted or received at the socket) or “available” (i.e. whether the socket is available to transmit or receive information). To determine the state of a particular socket, programs at the computer device  102  can request the state information associated with that socket. This allows a program to manage communication flows. To illustrate, the peer program  103  can communicate with the peer program  107  via the socket  115 . Prior to sending a message, the peer program  103  can request the socket state of the socket  115  from the computer device  102 . If the socket state is busy, the peer program  103  can wait to send the message. If the socket state indicates the socket is available the peer program  103  can send the message. 
     In the illustrated embodiment of  FIG. 1 , the network device  104  maintains socket state information  155  for the socket  115 . In particular, because communications associated with the socket  115  flow through the network device  104 , the device is able to determine the state of the socket. For example, based on whether communications are being transmitted or received via the socket  115 , the network device updates the state information  155  to indicate whether the socket  115  is busy or available. The state information  155  can also include other state information for the socket  115 , such as an error state (e.g. whether communications over the socket have experienced an error, or there is an error associated with the socket itself), socket availability (e.g. whether the socket is available to send or receive data), data availability (e.g. whether data is available to send or be received via the socket), connected state of the socket (e.g. whether the socket is connected or disconnected, including virtually connected or disconnected, to another device for communications), a security state of the socket, including whether communications associated with the socket are encrypted, whether communications associated with the socket are or should be authenticated, and the like), firewall states (e.g. whether the socket is firewall enabled, or enabled for firewall pass through), and the like. The state information  155  can also include information associated with data communicated via the socket  115 , including, for example, bandwidth information (e.g. minimum, maximum, or average bandwidth, current bandwidth information), latency information (e.g. minimum, maximum, or average latency), round-trip time for communications, amount of data sent, amount of data received, and the like. In addition, the state information  155  can include information with respect to buffers associated with communications over the socket  115 , including buffer overflow and underflow status, amount of data waiting to be sent, amount of data waiting to be received, and the like. 
     The network device  104  can communicate the state information  155  to the computer device  102  via the device driver  105 . In an embodiment, the device driver  105  is a device driver for the network device  104 . Accordingly, the device driver  105  can control functions and settings of the network device  104 , as well as the interaction between the network device  104  and the computer device  102 . 
     In another embodiment, the socket state information  155  can be maintained at the device driver  105 . In this embodiment, the device driver  105  controls communications between programs at the computer device  102 , such as the peer program  103 , and the network device  104 . Accordingly, communications transmitted and received via the socket  115  will be controlled by the device driver  105 , allowing the driver to maintain and update the socket state information  155 . 
     In response to receiving the socket state information  155 , or in response to an update in the state information (if the state information is maintained at the device driver  105 ), the device driver  105  communicates the information to application space at the computer device  102 . This can be better understood with reference to  FIGS. 2 and 3 . 
       FIG. 2  illustrates a block diagram of a particular embodiment of a computer device  202 , corresponding to the computer device  102  of  FIG. 1 . The computer device  202  includes application space  220  and kernel space  230 . As used herein, the term kernel space refers to memory address space that is typically only accessible by the kernel of an operating system at the computer device  202 . Applications executing at the computer device  202  typically cannot access the kernel space directly, but instead must request information stored in the kernel space from the operating system kernel. Application space refers to memory address space that is accessible by applications at the computer device  202 . Applications can typically access information stored in the application space  220  more quickly than information stored in the kernel space  230 , because accesses to the application space  220  are not typically performed through the kernel. Note that both the kernel space  230  and the application space  220  can be virtual memory address spaces. 
     As illustrated, the application space  220  includes a peer program  203 , an interface program  208 , and dedicated memory  225 . The dedicated memory  255  is dedicated to the application space  220 , and is typically not accessed directly by programs executing in the kernel space  230 . The kernel space  230  includes a network stack  235  and a device driver  205 , corresponding to the device driver  105  of  FIG. 1 . 
     In operation, the network stack  235  is configured to store messages and other information received from the network  106  via the socket  215 , corresponding to the socket  115  of  FIG. 1 . As illustrated, the socket  215  includes ports  210  and  225 . In the illustrated embodiment, the port  225  is associated with the peer program  203 , while the port  210  is associated with another program (not shown). 
     The network stack  235  is accessed by the kernel in response to requests from applications executing at the computer device  202 . The kernel can determine if the network stack stores data for the requesting application and, if so, provide the data. Because the kernel typically executes a number of tasks in addition to accessing the network stack  235 , accessing the network stack typically takes more time than an access to data stored in the application space  220 . 
     The device driver  205  receives socket state information from the network device  104  based on the socket state information  155 . In response to receiving the state information, the device driver  105  sends a message to the interface program  208 . In an embodiment, the message includes the socket state information. In response to receiving the message, the interface program  208  stores the socket state information  255  in the dedicated memory  225 . 
     To determine the state of the socket  215 , the peer program  203  can send a state query to the interface program  208 . In response, rather than requesting the state information from the kernel space  230  as in conventional systems, the interface program accesses the stored socket state information  255 . This allows the interface program  208  to more quickly access the state information, improving communication efficiency. The interface program  208  provides the socket state information  255  to the peer program  203 , which manages communication based on the information. Thus, if the socket state information  255  indicates that the socket  215  is available, the peer program  203  can send a message via the socket. In contrast, if the socket state information  255  indicates the socket is busy, the peer program  203  can perform tasks other than sending a message until the socket is available. 
     Referring to  FIG. 3 , a block diagram of a particular embodiment of a computer device  302 , corresponding to the computer device  102  of  FIG. 1 , is illustrated. The computer device  302  includes application space  320 , which includes an interface program  308  and a peer program  303 . The computer device  302  also includes kernel space  330 , which includes a device driver  305  and a network stack  335 . Further, the computer device  302  includes a communication socket  315 , including communication ports  310  and  325 . In addition, the computer device  302  includes shared memory  345 . The shared memory  345  is memory space that can be accessed by applications executing in application space  320  and functions executing in kernel space  330 . Accordingly, the shared memory  330  can be a portion of virtual memory that is addressable by functions executing in kernel space  330  and applications executing in application space  320 . 
     In operation, the device driver  305  receives information from the network device  104  indicating the state of the socket  215 . In response the device driver  305  stores socket state information  355  in the shared memory  330 . The socket state information  355  indicates the state of the socket  215 , such as whether the socket is available or busy. 
     To determine the state of the socket  315 , the peer program  303  can send a state query to the interface program  308 . In response, the interface program  308  accesses the socket state information  355  stored in the shared memory  330 . This allows the interface program  308  to access the state information  355  more quickly than accessing the information through the kernel space  330 , improving communication efficiency. The interface program  308  provides the socket state information  355  to the peer program  303 , which manages communication based on the information. Thus, if the socket state information  355  indicates that the socket  315  is available, the peer program  303  can send a message via the socket. In contrast, if the socket state information  355  indicates the socket is busy, the peer program  303  can perform tasks other than sending a message until the socket is available. 
     Referring to  FIG. 4 , a block diagram of a particular embodiment of a computer device  402 , corresponding to the network device  102 , is illustrated. The computer device  402  includes a processor  470  and a memory  460 . The memory  460  is accessible to the processor  470 . The processor  470  can be a microprocessor, microcontroller, and the like. The memory  460  is a computer readable medium that can be volatile memory, such as random access memory (RAM), or non-volatile memory, such as a hard disk or flash memory. 
     The memory  560  stores an interface program  408 , a device driver  405 , and an operating system  407 . The interface program  408 , the device driver  405 , and the operating system  407  include instructions to manipulate the processor  470  in order to implement one or more of the methods described herein. Other programs, such as applications, can also be stored in the memory  460  to manipulate the processor in order to implement the described methods. It will be appreciated that the network device  104  could be configured similarly to the computer device  402 , including a memory to store one or more programs to manipulate a processor to implement one or more of the methods described herein. 
     The above disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments that fall within the true spirit and scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.