JPH0287746A - Computer communication method - Google Patents

Abstract

PURPOSE: To eliminate restriction by means of a device whose end point is controlled in a system by connecting communication devices in multiple directions through a connector, sending information from one source device to plural destination devices and sending it from the plural source devices to a single destination device. CONSTITUTION: The connector 26 constituted of a memory 10 and a controller 11 is arranged in the computer communication system. The plural devices 12 or programs 15 are connected to the memory 10 through data lines 16 and they are connected to the controller 11 by control lines 17. Communication between the programs 15 is executed from the device 12 through the connector 26 and the controller 11 controls the direction of the communication. Then, the controller 11 generates a mapping table for connecting the requested devices 12 and 13 and the program 15. Then, data is transferred to the destination communication device through the connector 26 in accordance with the generated mapping table.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of communicating from a digital data source to a destination by means of a computer arrangement.

(Description of the Prior Art) Computers are essential not only for data storage and retrieval but also for complex mathematical processing. Computers, however, do not have the generalized ability to communicate between multiple user devices through them.

Even when users are connected to a single computer with multiple time sharing, this computer is essentially a communication system from a single source to a single destination. Data to a program where one user processes the data.

and store the results in an identifiable storage area. The original user or other users can individually recall the stored results if they know the storage area.

The main type of communication between computers is electronic mail (Email).
email). As the name suggests, electronic mail is a system similar to a post office. A document is created by the sender, addressed, and stored in the 1delta child mail system in association with the addressee. When the destination user logs on to the system, he or she is notified that the document has arrived and can read it. Replies to the first document are sent and accepted in the same manner. Electronic mail requires the sender to properly address each document;
This communication does not occur in real time.

The UNIXR operating system uses “pipes”
Pip has a function called ``Pip'', which allows communication between computer programs to become widespread.
e allows the output of one program to be sent as input to another program. The ptpe consists primarily of storage buffers, and this arrangement is known to the source and destination programs, and is also a synchronizer that schedules reading and writing of the buffers. The source stores data in a buffer at a known location, and the destination allows the program to read the stored information from the buffer at a known location. With a pipe, both the source and destination must know the location of the intermediate buffer and perform data transfer to and from it. Another feature of the UNIX operating system called "Tea" allows intermediate results of piped operations to be sent to multiple named files. Tee allows information to have multiple destinations, but the destinations are only named files that can later be read by direct access.

In existing computer communication devices, connections between data sources and destinations are controlled by assigning destination information to all communications. To maintain such a connection, the source and destination,
and requires excellent ability from the operator who handles it. A problem posed by such endpoint control methods is that these systems are inflexible. For example, both cannot connect bidirectionally, and while connected, the source and destination cannot be changed. What is needed here is a computer communication technology that reduces the burden of connections from sources and destinations and provides flexibility through central control.

SUMMARY OF THE INVENTION The above problems are solved by the present invention. The present invention is a general-purpose computer communication device that enables communication between multiple communication devices. The term device or communication device refers not only to hardware such as terminals, printers and disk drives, but also to software such as processes, programs and routines. Intercommunication is performed by a computer, which includes a storage area, a write control program for writing data to a call control program for connection, and a read control program for reading data from the storage area.

A connection is initiated in response to a connection request that identifies the source and destination devices to the communication network. For example, such a request may be made by one device participating in the communication. The call control program responds to this request by creating a mapping table that determines the interconnections between the source and destination communication devices and the destination.

A communication device that has communication data issues a write request.

The write request is received by a write control program that stores data in a storage area.

The write control program reads the mapping table to identify destination communication devices for the stored data and constructs a structure of connections between the stored data and each identified destination. The binding structure consists of a pointer to each destination communication device, which pointer identifies a binding list of stored data sources. The newly stored data is a combined squirrel! • remains in the linked list until it is read to the destination device.

When a communication device wants to receive or receive data, it issues a read request. The read control program responds to read requests by reading the pointer of the communication device issuing the read request to insert the linked list. The first data in the binding list is then read and sent to the requesting communication device.

Some communication devices function more efficiently if they issue read requests only when data for them has been stored. In an embodiment, the selected devices are sent an abort signal if data is stored for them. A read request is issued by the selected device in response to this interrupt signal. To effectuate the transmission of a suspend signal, the exemplary mapping table includes a suspend state variable for each communication device. The suspend status variable determines whether a suspend signal should be sent. When data is stored in the storage area, the write control program checks the suspend status variables of the destination communication devices and sends a suspend signal to each destination device whose suspend status variables indicate that a suspend signal should be sent. send.

Mapping tables and binding structures also make it easy to add and remove devices from a communication network. A destination device is added by placing its identity in the mapping table data structure of the device from which it will receive data. To remove the device,
Just erase that identity from all data structures. Since the data structure is read to form a combined structure on each write operation, a change in the data structure is triggered by the first data write after the change.
Add or remove devices.

Embodiments of the present invention eliminate the limitations of conventional systems with endpoint controlled placement. For example, devices are communicatively coupled in both directions through connectors, and information is
from one source device to multiple destination devices, and from multiple source devices to a single destination device.

(Explanation of Examples) FIG. 1 is a representative example of a system implementing the present invention.

In FIG. 1, a connector 26 consisting of a memory lO and a controller 11 is illustrated. multiple devices 12
15 are connected to the memory 10 via a data line IB, and are also connected to the controller 11 via a control line 17.

Communication between devices 12 to 15 is performed via connector 26. The direction of communication is controlled by controller ll. First, the controller 11 connects the control line 1
For example, the request signal is received from the device 12 via the device 7, and communication is established between the specific devices. For example, a user of terminal device 12 requests communication between devices 12 and 13 and program 15. With this request, devices 12, 13, and 15 can both receive data from, and send data to, the other.

Controller 11 is the requested device 12.1
In order to connect 3 and 15, the request is met by creating a mapping table (FIG. 7) of the requested communication. The mapping table is utilized by the connector to define the source and destination of data flow through the connector and to perform the connection between devices 12.13 and 15;
As a result, each device can utilize this connection with little or no knowledge of the actual nature of the connection.

When a device 13 wishes to send data, it makes a write call to the controller 11 via the control line 17 and supplies the data to be written. Controller 11 stores data in memory 10 and uses a mapping table to form a structural connection between the stored data and each device 12 and 15 that receives the data. The mapping table determines the name of the destination (reader) of the stored data. Devices 12 and 15 issue read calls to read the stored data. The controller 11 responds to the reading role by locating and sending the stored data to the requested device using the coupling structure. Overhead for data storage and control of its delivery to the reader is provided by connector 26.

Adding or removing devices to the bond is accomplished through the cooperation of the connector and the device. For example, device (terminal)
If the user 13 wants to store all the data on the device 13 on the disk 14, the user sends a request signal ≦ to the controller 11 indicating that he wants all the data to be sent from the device 13 to the disk 14. . Controller 11 then modifies the pine pink table to indicate that disk 14 is the newly added destination for all data stored on the connector by device 13. After changing the mapping table, all data written to the connector by device 13 is coupled to disk device 14 for reading.

When viewed in conjunction with the flowchart of FIG. 3, FIG. 2 illustrates the various software components of the present invention and how they work together to form connections. In FIG. 2, a - group routine 20 represents the connector function of the controller 11, and the connector memory 21 represents the connector function of the controller 11.
represents a part of the memory 10 connected to the connector. For example, a connection begins when communication control routine 27 receives a request signal from a communication device, such as device 12 (block 30 of FIG. 3). The connection request specifies that terminal 12, terminal 13 and program 15 participate in this communication and the read/write capabilities of these devices during the communication. In this example, all three devices can send and receive data. Communication control/routine 2
7 responds to the request by forming an active device for each device specified in the connection request (Figure 3, block 32).

An active device follows a certain interface provided by connector 26 5 and can issue write calls when sending data from the device to the connector, and can issue read calls when sending data from the connector to the device. To form an active device, communication control routine 27 commits one process to reading and writing to the device and sending and receiving data to and from connector 26. An active device process is pre-arranged for the particular type of device to which it is committed. In FIG. 2, the active devices of devices 12.13 and 15 are represented by the numbers 22.23 and 25, respectively. After the active devices are formed, they are coupled to connectors 26. Also, in response to a connection request, the communication control routine forms a data structure of the type shown in FIG. 4 for each active device (FIG. 3, block 34).
). The active device data structures collectively create a mapping table of bindings.

FIG. 4 shows an active device data structure 40 and some of the coupling structures used in this embodiment. State input 41 to data structure 40 determines the read and write capabilities of the associated active device. Destination count input (DEST-
CNT) 4B indicates the number of devices for reading data written to the connector by associated active devices. The next input 47,48 determines the destination device that will read the data written to the connector by the associated active device. In accordance with this example, two destination manpowers are shown in FIG. The total number of inputs for a destination is the maximum number of active devices attached to the connector. Data structure column 43 represents data structure values for active device 22 in this example. state manpower 4
1 represents both reading and writing (R/W). Destination count 46 represents two destinations, destination count 47 and 48.
specifies data structures associated with active devices 23 and 25. Each data structure 40 further includes a pointer force 45, which is used to locate data to be read by the associated active device, as described below.

The information stored in data structure 40 collectively forms a mapping table for the connection and determines the characteristics of communication between devices within the connection. Connector routines 20 refer to mapping tables (data structures) to control communications through the connector, thereby taking over such duties for active devices. Furthermore, the mapping table can be modified so that the connection status can be easily changed. Data is stored on the connector by write routine 28.

A flow diagram of this situation is shown in FIG. When data is written to a connector by, for example, active device 22, the data is first stored in a buffer that is part of the active device process and a write call is issued by the active device. The write call specifies the active device 22 issuing the instruction and the placement of the buffer. Write routine 28 accepts the write call (Figure 5, block 71) and responds by locating space in connector memory 21 (block 72). The write routine moves the data in the buffer from the active device to allocated memory (block 73).

The write routine 28 also creates a reference block 55 (FIG. 4) for each block of data stored in the connector.
(Figure 5, block 74).

The reference block 55 includes a data φ pointer 56, a data length value 57, and a reference count 58. Data pointer 56 points to newly written data 60, and data length value 57 represents the amount of data stored.

Reference count 58 represents the number of named destinations and will be discussed below. Write routine 28 then forms a combined structure by linking data 60 and reference block 55 with all destination active devices that will receive or take the data block (Figure 5, block 75). Coupling to multiple destination devices is represented by arrow 59 and pointer 50.

For example, the coupling structure between data blocks 60 and data structures is shown in FIG. Pointer 45 of data structure 40 points to pointer block 49, which includes pointer 50 to reference block 55 associated with data 60. The pointer block 49 is connected to the next pointer block 54 by a pointer 51. Pointer block 54 is associated with the last (last written) data block 61 and contains a pointer value 53 representing the end of the pointer link (END).

Write routine 28 associates each destination with the stored data in the following manner. ;-For the writing device, set each destination to the destination value 47 or 4 in the data structure 40.
8 etc., - access the pointer 45 of each destination data structure and follow the read link to the END; - create a new pointer block linked to the previous END for the new data block; - access the pointer 45 of each destination data structure; Link a pointer block to a reference block for newly written data.

This operation writes each block of newly written data to
At the end of the data link list for each device to which data is destined.

A reference block (eg, 55) and its associated data block 60 are linked with multiple data structures when data is sent from a single source to multiple destinations.

The number of destinations for a given data block (eg 60) is stored in the reference count 58 of the reference block 55 pointing to the data block.

An active device issues a read call when it wants to receive data from a connector.

The read call identifies the read device and locates the active device buffers that store the data.

The flowchart of FIG. 6 represents the actions taken by read routine 29 in response to a read call. Connector read routine 29 (Figure 6, block 80) responds to read calls by accessing the data structure of the active device that issued the read call (Figure 6, block 81). Pointer 45 of this data structure
is used to identify the data block most directly bound to data structure 40, e.g. 60. The link formed on the connector when data is written ensures that this is the "oldest" data block. The block specified by data length 57, e.g. 60, has been read in its entirety by the active device (Figure 6, block 82).
In some cases, the read routine 29 unlinks the data block (FIG. 6, block 83) and causes the pointer 45 to point to the next pointer block, such as 54. Read routine 29 may also decrement the reference count stored at input 58 of reference block 55 (Figure 6, block 84). The reference count is
It is then checked whether the number has decreased to O (block 85).

When the reference count reaches zero, all named destinations have read their associated data blocks, and read routine 29 deallocates memory for the data blocks and reference blocks for further use (block 86).
).

Pointer blocks 49 and 54 are linked together to create a read order for active devices for each destination device unit. Data war blocks 60 and 61,
The reference blocks 50 and 62 connected thereto are stored once for each block of data stored in the connector.

Multi-destination active device data structures are
It may point to a block, e.g. 60, via a reference block, e.g. 55, connected to that data block. The linked list created by pointer blocks 49 and 54 points to data from multiple data sources.

For example, data from device 13 is stored in data block 60, and data from device 1 sent later
The coupling structure shown in FIG. 4 represents the coupling structure for device 12 when data from 5 is stored in data block 61. After creating the connection structure of FIG. 4, successive read calls from device 12 will result in a data transfer from device 13 in data block 60, followed by a data transfer from device 1 in data block Bl.
5 results in data transfer from.

This embodiment includes a simple structure for adding and removing devices from connections. A device is added to the call in response to a request to the communication control routine 27 from an existing active device (FIG. 2).

Communication control routine 27 activates the requested device and forms the data structure as described above. The new data structure contains as a destination any of the specified other active devices connected to the connector. A new active device is also added as a destination to the existing data structure that is to be its data source. After forming the new active device data structure, any data written to the connector is coupled to the new active device for reading, as described above. An active device can be removed by erasing it from the mapping structure. This removal involves erasing the data structure of the active device being removed and removing each reference (
data).

All of the active device receivers mentioned above issued read calls when they wanted to read information. This can lead to wasted time on the processor. This is because the destination active device may be attempting to read when there is actually no data available for reading. The write routine 28 of this embodiment can send an interrupt signal to a destination active device when data has already arrived at the destination active device. First, each active device's data structure 40 (FIG. 4) includes a suspend state variable 44 (INT 5TATUS), which can be set to either send a suspend signal or not. moreover,
Data arrival force 42 is stored in a data structure and defines the type of interrupt message to be sent. The write routine 28 checks the suspend status variable 44 of the destination device to which the written data block is linked (
FIG. 5, block 77). When the suspend status variable indicates that a suspend signal should be sent, write routine 28 sends a suspend signal in the format defined by data arrival command 42 (FIG. 5, block 77). The destination active device then reads the information in response to the interrupt signal.

The foregoing depiction concerned the exchange of data between devices. The data used herein includes information generated by electronic whiteboards, graphic terminals, audio digitization equipment, etc., as well as information generated by computer terminals and disk storage devices.

In the embodiments described above, a connector is a collection of data structures and routines that can be referred to as active devices. However, connectors can be implemented using other types of software, such as processes.

Also, all devices connected to the connector in this embodiment form a single communication. Connectors can also be used for multiple independent communications. For example, the first pair of terminals is
Through the connector, communications can be made with the second pair of terminals simultaneously through the connectors without any data exchange.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention; Fig. 2 is a diagram showing the software configuration of the embodiment; Fig. 3 is a flowchart showing the start of communication; Fig. 4 is a diagram for defining a connection. Figures 5 and 6 are flow diagrams illustrating data communication through the device of Figure 1; Figure 7 is a diagram illustrating the mapping table used in the example. be. 11...Controller 12, 13...Device 14...Disk 15...Program 16...Data line 17...Control line 22.23.25...Active device FIG, 1 Applicant : American Telephone &FIG,
2 FIG. FIG. FIG.

Claims (6)

[Claims] (1) establishing a mapping table that identifies a source communication device of a plurality of communication devices and a plurality of destination communication devices of communication devices that receive data from the source communication device; storing data from the device; in response to the storing step, forming a connection structure connecting the data and a destination communication device from the mapping table, regardless of the content of the data; A method of computer communication comprising the step of, in response, transferring said data to said destination communication device. (2) the forming step reads a mapping table to determine each destination communication device for data stored in the source communication device; and each destination communication device determined in the step of reading the mapping table; 2. The computer communication method according to claim 1, further comprising the step of associating data stored in the data storage step. 3. The computer communications method of claim 2, wherein the associating step comprises storing a pointer to the data stored in the data storage step for each destination communication device determined in the mapping table reading step. (4) the enacting step stores a data structure for the communication device that determines a destination communication device; and the forming step determines each destination communication device of the data stored in the source communication device. 2. The computer communication method of claim 1, further comprising the steps of: reading a data structure of the source communication device; and combining the data stored in the data storage step with each communication device determined in the data structure reading step. 5. The computer communication method of claim 1, further comprising the step of: (5) sending an interrupt signal to one of the destination communication devices in response to the data storage step. (6) each data structure includes a suspended state variable, and in response to the data storage step, accessing the suspended state variable of the data structure of the destination communication device identified in the data structure reading step; 5. The method of claim 4, further comprising the step of sending a suspend signal to the destination communication device identified in the data structure reading step when the suspend status variable indicates that a suspend signal is to be sent. Computer communication methods.