Abstract:
A messaging processing system which includes a process control table for storing the control information of a process corresponding to access terminals connected through a public network in a form that identifiers indicating the ‘priority processing’ are added to the control information, and a scheduler that executes the process having the identifier indicating the ‘priority processing’ in preference to the other processes during the dispatching processing of the process.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a message processing system, specifically to a system that, when access terminals for accessing the messaging processing system are connected through a public network, secures a processing to the access terminals, and a method of the same. 
     In recent years, owing to the widespread use of Personal Computers (PC) and Local Area Networks (LAN), as represented by the electronic mail system, the messaging processing system using a LAN as the network path has been popularized. 
     As a typical electronic mail system with PC terminals, there are the cc: Mail from Lotus corp. and the MS mail from Microsoft corp. and the like. In these systems, using PC terminals through a LAN as access terminals, messages, namely, electronic mails are interchanged between the access terminals through a messaging server. The “cc: Mail users guide” from Lotus corp. describes the method of interchanging messages between PC terminals. 
     In the messaging processing system represented by the electronic mail system, the messaging server generates a process (a processing program to be executed) for each client access terminal before the messaging processing, and thereafter access terminals begin to communicate by a socket communication between, for example, UNIX and Windows, or Windows and Windows on the terminals. 
     In the socket communication, once a session is established with the server, the access terminal connected to the server through the LAN is able to communicate with the server whenever a data communication is needed. The details of the socket communication is described in the following published materials. 
     &lt;1&gt;“Network Programming by Winsock”: published by ASCII publishing department 
     &lt;2&gt;“Programming Winsock” written by Dumas : published by Sams 
     A normal messaging processing system makes possible message communication between PC terminals or PDA (Personal Data Assistant) terminals connected to the messaging processing system through a public line, other than message communication between the foregoing PC terminals connected through the LAN. In the prior art system, the messaging server does not distinguish a process corresponding to a message processing request received through the LAN from a process corresponding to a message processing request received through the public line, that is, the messaging server operates to process these two processes on the equal basis, and therefore, the system has the advantage that equal services are provided to users, viewing from the access terminals. 
     On the other hand, the generalization of the electronic mail system has increased the demand for requesting an access to the messaging server from any place at any time, using an access terminal represented by the PC terminal. Specially, the access through a public network becomes indispensable, where a user is on the business trip or outside the office. When a PC terminal interchanges a message with the messaging processing system through a public network, the transfer rate of the message becomes extremely lowered, compared to a case in which an access is made to the messaging processing system from a terminal connected to a LAN, and in addition the waiting time (called as the Think Time) for a message input from the PC terminal becomes elongated. As a result, there arises a problem that the service to the access terminal becomes lowered in quality, where a user employs the messaging server through the public network. Thus, the service is expected to be more than the equal level to what the terminal connected to the LAN receives. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a messaging processing system comprising a messaging server and access terminals, in which a service processing to an access terminal through a public network is executed preferentially, and a messaging processing method of the same. 
     In order to accomplish the foregoing object, the messaging processing system of the invention provides a process corresponding to an access terminal coupled through a public network with an identifier indicating the “priority processing” in a process control table, so as to execute the priority processing as for the process corresponding to the access terminal through the public network. Further, the messaging server is made to preferentially select a process having the identifier indicating the “priority processing”, when the system determines a process to be executed referring to the process control table, namely, when dispatching a process. 
     In the conventional technique, among processes waiting for message inputs from access terminals is released a process which has received no message input from the access terminals after elapsing of a specific wait time. However in the system of this invention, a dispatching processing unit redispatches the processes which have the identifier indicating the “priority processing” more frequently by a specific frequency than the other processes so that the release of the process with the above identifiers is delayed than the other processes. 
     Further, when a message is inputted in a wait state for a message input from the access terminals, a process is executed in preference to the other processes if the process has the priority processing identifier. 
     As an alternative to solve the foregoing problem, in addition to the messaging server, the messaging processing system of the invention is provided with a communication control server dedicated to communicating with access terminals through a public network, and a first process and a second process both of which correspond to the same access terminal are generated in the communication control server and the messaging server, respectively, so as to execute a socket communication between the first process and the second process. 
     The second process is not released until the first process is released, and as to the first process, the waiting monitoring time for a message input from the access terminals is set significantly long; and thereby, the second process in the messaging server is serviced equally without being discriminated from the other processes corresponding to PC terminals connected through a LAN. As a result, the service to the access terminals connected through the public network is executed preferentially. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIG. 1 is a chart to illustrate one embodiment of a messaging processing system of the invention; 
     FIG. 2 is a flow chart to illustrate a processing procedure when the waiting time exceeds a preset time during waiting for a message input from an access terminal in a dispatching processing program (SCH); 
     FIG. 3 is a flow chart to illustrate a dispatching processing procedure of each process during a message input in the dispatching processing program (SCH); and 
     FIG. 4 is a chart to illustrate the other embodiment of the messaging processing system of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The embodiment of a messaging processing system of the invention will now be described with reference to the accompanying drawings. 
     FIG. 1 illustrates one embodiment of the messaging processing system of the invention. 
     The messaging processing system of the invention comprises two main units, that is, a messaging server  1  and a message box  2 , through which messages are interchanged. Access terminals  12   a  through  12   c , for example, access the messaging server  1  through a LAN  11 . The messaging server  1  is controlled by an operating system(OS)  3 . Access terminals  15  through  17  access the messaging server  1  through a public network  14 . A portable PC  17 , for example, accesses the public network  14  using a portable telephone  18 , and it accesses the messaging server  1  through the public network  14 . 
     When one of these terminals accesses the messaging server  1 , the messaging server  1  generates a new control table  9  or  10  for the process corresponding to the access terminal. The control table  9  is prepared to control a process corresponding to access terminals connected through the LAN, and the control table  10  is prepared to control a process corresponding to access terminals connected through the public network. Based on these control tables  9  and  10 , input messages ( 2   a ,  2   b ) from the source access terminal are stored in the message box  2 , and the messages stored in the message box  2  are transmitted to the destination access terminals. Here, a conventional PC, Workstation (WS) or PDA may be applicable as the above access terminal if communication function is equipped thereto. 
     The messaging processing system of the invention is characterized in that the messaging server  1  is provided with a storage for storing identifiers  6   b ,  7   a ,  8   a ,  10   a  or  10   b  to indicate the priority processing request, and priority processing control function  5 . 
     The storage area for the identifiers to indicate the priority processing request may be any one of the following: 
     (1) A priority (PRY) field  6   b  in the priority table (P-TBL)  6 , 
     (2) A mark bit  7   a  or  8   a  assigned to each entry inside the ready queue (RQ)  7  or the wait queue (WQ)  8 , 
     (3) An indication field of process type  10   a  in the control table  10  corresponding to each process, and 
     (4) An indication field of process priority (PRY)  10   b  in the control table  10  corresponding to each process. 
     In FIG.1, “ID”  6   a  in the priority table(P-TBL)  6  represents the process number, which is equivalent to the number of the process identifier (PID) in the control table  9 ,  10  corresponding to each process. In the same manner, the priority (“PRY”)  6   b  is equivalent to the number of the process priority (“PRY”)  10   b.    
     When any one of the access terminals  15 ˜ 17  through the public network is connected to the messaging server, the identifier to indicate that the process is a priority process is automatically stored by any one of the storage means from the foregoing (1) through (4). The setting of P=R to the process type  10   a , for example, will recognize that the process corresponds to an access terminal through the public network. 
     And, the entry in the queue  7  or  8  assigned with the mark  7   a  or  8   a  will render the process to be executed preferentially. 
     FIG. 2 illustrates a processing flow when the waiting time for a message input from an access terminal reaches the time-out in the dispatching processing program (SCH)  5  that executes the priority schedule processing, which is the feature of this invention. 
     If it is detected at the first step  21   a  that the waiting time for a message input reaches the time-out in one process, the priority schedule processing executes steps  21   b  through  21   g . The determination step  21   b  determines whether the access terminal corresponding to the time-out process that has reached the time-out is an access terminal through the public network. This determination only needs to check whether the value of the process type (P)  10   a  is P=R. However, the determination may be performed by checking the other parameters mentioned in the foregoing (1) through (4). In the determination step  21   b , if the value is P≠R for the time-out process and the priority processing is determined unnecessary, the process is released at the step  21   f.    
     If the time-out process is determined as an object of the priority processing, the determination step  21   c  determines whether the wait frequency (WC) exceeds the maximum value WMAX. The maximum value WMAX can be set freely in the range from two times to ten times of the normal process which the priority processing is unnecessary. If WC exceeds WMAX, the time-out process is released at the step  21   f . If the time-out process is determined as the priority processing object and the wait frequency WC does not exceed the maximum value WMAX, the wait frequency WC is incremented by 1 at the step  21   d , and thereafter, the time-out process is registered in the wait queue (WQ)  8  at the step  21   e.    
     Owing to the foregoing control, it is possible to secure n-times waiting time compared to the waiting time for an access terminal through the general LAN and provide a preferential service, as to an access terminal through the public network, even if it exceeds a specific waiting time for a message input. 
     Next, the processing procedure when a message is inputted from an access terminal will be described. FIG. 3 illustrates the dispatching processing procedure of a process during a message input in the dispatching processing program  5  of the invention. 
     Such a process that turned into a waiting state of a message input from an access terminal is transferred to the wait queue (WQ)  8  from the ready queue (RQ)  7 . When a message is inputted from an access terminal, the process corresponding to the access terminal is transferred to the ready queue (RQ) to be ready for run, according to the following procedure. 
     First at step  22   b , the corresponding process is taken out from the wait queue (WQ)  8 , and the determination step  22   c  checks whether the corresponding process is to be treated as the object of the priority processing. Here, the discrimination as to the priority processing object is carried out on the basis of the foregoing (1) through (4). If the process is not the priority processing object, the process is put on the tail end of the ready queue (RQ)  7  at step  22   e.    
     If the process is the priority processing object, the process is inserted into the ready queue (RQ)  7  at step  22   d . At this moment, referring to the priority (PRY)  10   a  or (PRY)  6   b , the process with a larger value of the PRY, namely, the process with a higher priority is put forwarder in the ready queue (RQ)  7 . Next, the leading process in the ready queue (RQ)  7  is executed at step  22   f.    
     Thus, the priority service to access terminals through the public network can be carried out preferentially by the foregoing priority processing control according to the invention. 
     FIG. 4 illustrates the other embodiment of the messaging processing system of the invention. The difference from FIG. 1 lies in that FIG. 4 is provided with a communication control server  25  dedicated to communicating with access terminals through a public network. In FIG. 4, the components having the same functions as those mentioned in FIG. 1 are given the same symbols. The communication control server  25  is connected to the messaging server  1  through the LAN  11 , and performs the socket communication with the messaging server  1  under the control of an operating system(OS)  26 . 
     A communication program  27  in the communication control server  25  interchanges messages with the access terminals  15 ˜ 17  connected through the public network. When an access terminal is connected, a control table for a new process  28   a  or  28   b  corresponding to the access terminal is generated. The process  28   a , for example, corresponds to the access terminal  15 , and the process  28   b  corresponds to the portable PC  1  terminal  17 . At this moment, according to the well-known socket communication technique, new processes  10   d  or  10   e  corresponding to the new processes  28   a  or  28   b  is generated in the messaging server  1 . The process  10   d  is the process exited by the process  28   a  in the communication control server  25 . The process  10   e  is the process exited by the process  28   b.    
     These processes  10   d  and  10   e  in the message server  1  are processed in the same manner as the process  9  corresponding to the access terminal  12   a  connected to the LAN  11 . These processes  10   d  and  10   e  are not released, as long as the processes  28   a  and  28   b  in the communication control server  25  are not released. Therefore, as long as the access terminals:  15 ˜ 17  do not show the log-off request, the conventional problem accompanied with the electronic mail communication through the public network can be solved by employing the processing procedure (not illustrated) which does not release the processes  28   a ,  28   b  in the communication control server  25 . 
     The messaging processing system of the invention can be applied to the electronic mail system that has been widespread rapidly in recent years. Further, in case that the device  12   a  connected to the LAN  11  is a server device, the messaging processing system of the invention provides the control means that administer the relay of messages between the servers, or between the server and the client PC  15 . 
     According to the invention, since the service processing to access terminals connected through a public network can be made preferentially, if used on the business trip or from outside of the office, the messaging processing system can provide the service quality more than equal to that when used from an access terminal connected through a conventional LAN. 
     Further, the messaging processing system of the invention is provided with the relay function of messages, even while communications are being made between the servers, or between the server and the client PC; and therefore, even from an access terminal through the public network, the access terminal is able to carry out a satisfactory role as the client terminal.