JP3043881B2 - Data processing system using shared files - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data processing system comprising at least one terminal connected to a host device having a plurality of readable and writable shared files via a communication line. The present invention relates to a data processing system in which a word processor having a large storage means, a personal computer, etc., and a word processor, a personal computer, etc. which do not have such a large storage capacity are connected to a network and used.

[0002]

2. Description of the Related Art In general, a word processor is configured so that processing can be completed by itself, and when the data amount of a document or the like increases, the word processor is processed by storing it in an external storage medium such as a floppy disk. I have. However, apart from personal use, when a plurality of people try to create a new document using the same document in a company or the like, the shared document is thus dispersedly stored on a floppy disk or the like. And very inconvenient.

For this reason, a host device such as a word processor or a personal computer having a large storage capacity is prepared, and one or more terminal devices having no such large storage capacity are connected around the host device. There has been proposed a method of improving the efficiency of document processing by storing it in a host device.

[0004]

However, according to such a configuration, after reading the same shared document from different terminal devices, respectively, the same shared document is modified and then rewritten as the same document sequentially. In such a case, a document to be rewritten later is overwritten on a document to be rewritten earlier, so that there is a disadvantage that the former is erased. As a result, previously rewritten work will be wasted, and if the person who performed the previous work is unaware that it has been overwritten, this may lead to a serious problem. There is a possibility that the trust of the users will be greatly reduced.

[0005] Accordingly, the present invention solves the above-mentioned disadvantages of the prior art, and provides a system capable of performing highly reliable data processing when a plurality of readable and writable shared files are used. Is what you do.

[0006]

The present invention comprises a host device having shared file storage means for storing a plurality of shared files, and at least two terminal devices connected to the host device via a communication line. A rewritable mode in which rewriting can be performed on a shared file stored in the shared file storage means, and a rewrite inhibition mode in which rewriting of a shared file stored in the shared file storage means is prohibited. A data processing system using a shared file having a mode, wherein the host device comprises:
A first central processing unit, a shared file storage unit, and a first flag that stores, for each shared file stored in the shared file storage unit, a first flag indicating whether the file is in a readable state or in a read prohibited state. Auxiliary storage means,
The terminal device includes a second central processing unit, a file storage unit that stores the content of the shared file read from the shared file storage unit of the host device, and the content of the file storage unit stored in the shared file storage unit. A second auxiliary storage unit for storing a second flag indicating whether the shared file is in a rewritable state or a non-rewritable state, and whether the shared file is in a rewritable mode or a rewritable mode. A data processing system using a shared file having a mode designating means for designating, and when a mode in which rewriting to a shared file is possible is designated by a mode designating means of the terminal device, a second processing of the host device is performed. 1 of the central processing unit, initially set to ready read the contents of the first flag, and the second of the terminal device Central processing unit, initially sets the contents <br/> the second flag to re-write protected, the transfer request of the content <br/> the first flag of the shared file to the host device from the terminal device Once, the first central processing unit of the host device, to the terminal device Tsu line a transfer request of the content of the first flag, and transfers the contents of the corresponding first flag, then the set prohibited state reads the contents of the first flag, whereas, the second central processing unit of the terminal device whose contents are transferred to the first flag, transferred content readable state of the first flag When representing,
2 flag indicates a re-writable state, and
When the content of the first flag indicates a read prohibited state,
The second flag indicates a rewrite-inhibited state.
The contents of the second flag is set to the second auxiliary storage means, wherein the transfer request of the shared file to the host device to determine line Ukaina based on the second flag, the first central processing unit, If a transfer request is made, and forwards the transfer request, shared file to the terminal device, the second central processing unit of the terminal device stores the contents of the transferred shared file in the file storage unit, further determining whether rewriting to the second flag in <br/> based Dzu have been the shared file storage means the stored shared file.

Further according to the present invention, a mode of a terminal device is provided.
When the rewriting prohibition mode for the shared file is designated by the designation means, the second central processing of the terminal device is performed.
Management device, initially setting the second flag to re-write protected, perform a transfer request of the shared file to the host device,
The first central processing unit of the host device transfers the shared file requested to be transferred to the terminal device, the second central processing device stores the content of the transferred shared file in file storage means, It is determined whether to rewrite the shared file based on the second flag.

According to the second aspect of the present invention, a host device having shared file storage means for storing a plurality of shared files and at least two terminal devices connected to the host device via a communication line are provided. A data processing system using a shared file provided, wherein the host device comprises:
A first central processing unit, a shared file storage unit, and a first flag that stores, for each shared file stored in the shared file storage unit, a first flag indicating whether the file is in a readable state or in a read prohibited state. Auxiliary storage means,
The terminal device includes a second central processing unit, a file storage unit that stores the content of the shared file read from the shared file storage unit of the host device, and the content of the file storage unit stored in the shared file storage unit. A second auxiliary storage means for storing, in the shared file, a second flag indicating whether the file is in a rewritable state or a non-rewritable state, the data processing system using a shared file, First central processing unit of the apparatus
Is initially set to ready read the contents of the first flag, and the second central processing unit of the terminal device, the second
Initially set the contents of the flag to rewrite prohibited state,
Among from the terminal device of the first flag to the host device
When the transfer request of the contents is, the first central processing unit of the host device transfers to the terminal apparatus Tsu line a transfer request of the content of the first flag, the contents of the corresponding first flag and, then, set to disable status reads the contents of the first flag, while the second central processing unit of the terminal apparatus the content of the first flag is transferred, the transferred first
If the content of the flag indicates a readable state,
The second flag indicates a re-writable state, and
When the content of the first flag indicates a read-inhibited state,
Is set so that the second flag indicates a rewrite prohibited state.
In, the contents of the second flag is set to the second auxiliary storage means, on the basis of the second flag to determine the line or Ukaina a transfer request of the shared file to the host device, the first central processing apparatus, if a transfer request is made, and forwards the transfer request, shared file to the terminal device, the second central processing unit of the terminal device, the content of the transferred shared file in the file storage unit stored, to determine whether rewriting to the further second flag shared files stored in the shared file storage means based on the.

[0009]

In the first invention, when the mode in which rewriting to a shared file is possible is designated by the mode designation means of the terminal device, the first central processing unit of the host device reads the contents of the first flag. The terminal is initially set to the enabled state, and the second central processing unit of the terminal device initially sets the content of the second flag to the rewrite-inhibited state, and the first flag of the shared file is transmitted from the terminal device to the host device. When the transfer request is, the first central processing unit of the host device,
The transfer request of the content of the first flag to the terminal apparatus Tsu row, transfers the contents of the corresponding first flag, then set the disabled state reads the contents of the first flag, whereas,
The second central processing unit of the terminal apparatus the content of the first flag has been transferred, the contents of the first flag that is transferred can be read
When the status is indicated, the second flag is set to a re-writable state.
, And the content of the first flag is read-inhibited.
State, the second flag indicates the rewrite prohibition state.
As represented, the contents of the second flag is set to the second auxiliary storage means, based on the second flag to determine the line or Ukaina a transfer request of the shared file to the host device, a first central processing unit , if the transfer request is made, and forwards the transfer request, shared file to the terminal device, the second central processing unit of the terminal device stores the contents of the transferred shared file in the file storage means, further and based on the second flag to determine whether rewriting to the shared file stored in the shared file storage unit. Further, when the mode for prohibiting rewriting to the shared file is designated by the mode designating means of the terminal device, the second central processing unit of the terminal device:
Initially setting the second flag to the rewrite prohibition state, making a transfer request of the shared file to the host device, the first central processing unit of the host device transfers the requested shared file to the terminal device, The second central processing unit stores the content of the transferred shared file in the file storage unit, and determines whether to rewrite the shared file based on the second flag.

In the second invention, the first of the host devices
Central processing unit is initially set to ready read the contents of the first flag, and the second central processing unit of the terminal device, initially set to the contents of the second flag to re-write protected , when the first flag of the contents <br/> transfer request is from a terminal device to a host device, a first central processing unit of the host device, the terminal device Tsu line a transfer request of the content of the first flag In response, the contents of the corresponding first flag are transferred, and then
Set prohibited state reads the contents of the first flag, One
Write, second central processing unit of the terminal apparatus the content of the first flag is transferred, the contents of the first flag transferred read
When indicating the possible state, the second flag can be rewritten
In order to indicate the status, and the content of the first flag is read prohibited.
In the case of indicating the stop state, the second flag is
To represent the state, the contents of the second flag is set to the second auxiliary storage means, a transfer request of the shared file to the host device determines whether the row Ukaina based on the second flag, the first central When the transfer request is made , the processing device transfers the requested shared file to the terminal device, and the second file of the terminal device
The central processing unit, whether to store the contents of the transferred shared file in the file storage means, to rewrite further based have been <br/> shared file storage means stored shared file to a second flag To determine.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is a block diagram schematically showing a configuration of a data processing system including a host device and a plurality of terminal devices as one embodiment of the present invention.

As shown in FIG. 1, a word processor having a large storage capacity, a host device 10 such as a personal computer, a first terminal device 20 having no large storage capacity, and a second terminal having no large storage capacity. Device 30
Are connected so that data can be mutually transmitted by a communication line (or other data transmission means) 40. Although two terminal devices are provided in the example of FIG. 2, it is clear that the number of terminal devices may be any number other than two.

The host device 10 includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12 storing a program, a keyboard 13, and an LCD.
A display 14 according to (liquid crystal display) or the like, and input-output interface 15, a large amount of shared document F _1, F _2, F
_3, ..., F _n, and read and writable memory (RAM) 16 stores ..., each shared document F of the memory 16
_{1, F 2, F 3,} ..., F n, ... corresponding flag T _1,
Auxiliary storage unit 17 for storing T ₂ , T ₃ ,..., T _n ,.
And an internal bus 18 interconnecting them. These flags T ₁ , T ₂ , T ₃ ,..., T _n ,.
The corresponding shared documents F ₁ , F ₂ , F ₃ ,..., F _n ,.
In the present embodiment, it is a 1-bit signal indicating whether the state is a readable state or a read-inhibited state. The auxiliary storage unit 17 may be configured as a part of the memory 16 or may be configured by a separately provided register.

First terminal device 20 and second terminal device 3
0 denotes CPUs 21 and 31, ROMs 22 and 32 storing programs, and keyboards 23 and 33.
And a display 24 such as an LCD (liquid crystal display).
, 34, the input / output interfaces 25 and 35, and the documents transferred from the host device 10 into the documents _Ft1 and _Ft2.
And writable memory (R
AM) 26 and 36 and the document F _{t1 in the} memories 26 and 36
And storing the flag T _t1 and T _t2 of F _t2 auxiliary storage unit 2
7 and 37, internal buses 28 and 38 interconnecting them, and an external storage device 29a such as a floppy disk.
, And 39a, respectively. These flags T _t1 and T _t2 are 1-bit signals in the present embodiment that indicate whether the corresponding documents F _t1 and F _t2 are in a rewrite enabled state or a rewrite prohibited state on the host device 10 side. is there. Auxiliary storage units 27 and 37
May be constituted as a part of the memories 26 and 36, respectively, or may be constituted by separately provided registers.

The first terminal device 20 and the second terminal device 30 communicate with the shared documents F ₁ , F ₂ , F
_3, ..., F _n, accessible ... through the communication line 40, by changing the read shared document to write this by creating a re-write or or a new document to the memory 17 to the memory 17 be able to. Further, the control unit 29
And 39, the document can be transferred to and from the external storage devices 29a and 39a unique to each device.

At least one of the plurality of terminal devices may be housed in the same device as the host device 10.
In this embodiment, each terminal device is described as having one auxiliary storage unit. However, when a plurality of documents are called from the host device 10, a plurality of auxiliary storage units are provided according to the number. Can be

FIG. 1 shows a first terminal device 20 and a host device 1.
FIG. 9 is a flowchart in the case of transmitting and receiving a shared document to and from 0, and the operation of this embodiment will be described below with reference to FIG.

In this embodiment, a mode for rewriting a shared file (an operation mode on the premise of re-registration)
There are two types of calling modes: a mode in which rewriting to a shared file is not performed (an operation mode that does not assume re-registration). The operator of the terminal device 20 instructs which mode to call a shared file in. Execute.

In the initial state, all the flags T ₁ , T ₂ , T ₃ ,.
_Tn ,... Are set to “1” indicating that reading is possible, and all the flags T on the terminal devices 20 and 30 are set.
_t1 and _Tt2 are set to "0" indicating that rewriting is prohibited.

First, a mode for performing rewriting is specified.
After correcting reads the shared document F _n of the host device 10 from the terminal device 20 side will be described when performing rewriting.

In step S1 of FIG.
0 requests the host device 10 to transfer the contents of the auxiliary storage unit 17 corresponding to the shared document F _n to be read, that is, the contents of the flag T _n . Thereby, on the host device 10 side,
The contents of the flag T _n are copied to the flag T ₀ (T _n →
T ₀ ), and further changes the flag T _n to “0” (0 → T _n , step S2). Then, in step S3, it transfers the contents of the flag T ₀ to the terminal device 20.

The terminal device 20 receives the contents of the flag T ₀ and stores it in the auxiliary storage unit 27 as the flag T _t1 (step S 4). Next, in step S5,
It is determined whether or not the content of the flag _Tt1 is "0". When T _t1 = 0, the shared document _Fn is prohibited from being read, so that the calling is not permitted and the process ends. T _t1
For = 1, proceeds from a readable to step S6, requests the transfer of the shared document F _n to the host device 10. As a result, the shared document F is displayed on the host device 10 side.
_n is transferred to the terminal device 20 (step S7).

[0024] In the terminal device 20 side receives the document F _n, and stores it as a document F _t1 to the memory 26 (step S8). Next, in step S9, the document _Ft1 is corrected, changed, printed, and the like. In the next step S10,
The operator of the terminal device 20 operates the keyboard 23 to give an instruction to rewrite the changed document _Ft1 .

In step S11, the flag T_t1Is
It is determined whether it is "0". T _t1If = 0, the sentence
Book F_t1Is not allowed to be registered because rewriting is prohibited.
The process ends. T_t1If = 1, it is rewritable
If so, the process proceeds to step S12, where the flag T_t1And Document F
_t1Is transferred to the host device 10. host
On the device 10 side, the corresponding flag T_nAnd shared document F_n
Is prepared (step S13). And the end
The terminal device 20 sets the flag T in step S14._t1And sentence
Book F_t1To the host device 10, while the host device 10
On the side, the sent flag T_t1And Document F_t1Receive
Flag T_nAnd shared document F_nMemory 16 and
Each is stored in the auxiliary storage unit 17 (step S15).
This is the end of the process.

Next, a mode in which rewriting is not performed is specified, and the shared document F _{n of the} host device 10 is sent from the terminal device 20 side.
Will be described.

In this case, first, the flag T _t1 of the terminal device 20 is set to “0” in step S16, and then the processing in steps S6 to S10 is executed. Since T _t1 = 0, this processing is performed in step S11. finish.

According to the present embodiment, if the mode for rewriting is specified, the contents of the flag T _n corresponding to the shared document F _n to be read with the host device 10 side is "1" (which is always "1" in the initial state), changing it from "1" to "0", and the content "1" in front of the flag T _n is the flag T _t1 for reading operation of the terminal device 20 as it is Moved. In other words, the flag T
_t1 (which is always “0” in the initial state) is changed from “0” to “1”. The content of the flag T _n corresponding to the shared document F _n in the host device 10 side is allowed read is "1", reading in the case of "0" is not allowed. If the content of the flag T _t1 on the terminal device 20 side is “1”, it is permitted to re-register the modified document F _t1 with the same name as the document F _n in the host device 10,
In the case of "0", re-registration with the same name is not permitted.

[0029] If the mode is not performed rewriting is specified, the contents of the flag T _n corresponding to the shared document F _n to be read with the host device 10 side is maintained intact, also flag T _t1 of the terminal device 20 Is set to “0”. Further, it is determined whether or not T _t1 = 0, and the shared document F is determined.
_{If n} is prohibited from being read, the process is terminated as a call refusal, that is, the process of step S5 is not performed. Thus even "0" the content of the flag T _n is a read prohibited corresponding to shared document F _n, in this mode it is possible to read out the shared document F _n.

According to the present embodiment, when a call is made from a plurality of terminal devices in a mode in which the same shared document is rewritten, the terminal device that first makes the call (for example, if this is the terminal device 20). Do) flag T
Only _t1 becomes "1", and other terminals, for example, the flag _Tt2 of the terminal 30 all become "0", so that only the terminal 20 can be called. In this way, it is clear whether or not the shared document can be changed at the time of calling the shared document, and unnecessary work is prevented.

FIG. 3 is a flow chart in the case of transmitting and receiving a shared document between the first terminal device 20 and the host device 10 according to another embodiment of the present invention. The configuration of the data processing system is exactly the same as in the above-described embodiment.

In the present embodiment, processing is performed so that only the first called document can be re-registered.

In the initial state, all the flags T ₁ , T ₂ , T ₃ ,.
T _n, ... is set to "1" is set to represent that all of the flag T _t1 and T _t2 of the terminal device 20 and 30 side are re-write inhibit "0".

[0034] After correcting reads the shared document F _n of the host device 10 from the terminal device 20 side will be described when performing rewriting.

In step S21 of FIG. 3, the terminal device 20 requests the host device 10 to transfer the contents of the auxiliary storage unit 17 corresponding to the shared document F _n to be read, that is, the contents of the flag T _n . Thus, the host device 10 side, and copies the contents of the flag T _n to the flag T ₀ (T _n → T
₀ ), and further changes the flag _Tn to “0” (0
→ T _n , step S22). Then, in step S23, to transfer the contents of the flag T ₀ to the terminal device 20.

[0036] In the terminal device 20 side receives the contents of this flag T _0, is stored as a flag T _t1 to the auxiliary storage unit 27 (step S24). Then at step S25, it requests the transfer of the shared document F _n to the host device 10.
Thus, the host device 10 transfers the shared document _Fn to the terminal device 20 (Step S26).

[0037] In the terminal device 20 side receives the document F _n, and stores it as a document F _t1 to the memory 26 (step S27). Next, in step S28, this document F
_t1 modifications, changes, performs printing, in the next step S29, the operator of the terminal apparatus 20 performs rewriting instruction document F _t1 after change by operating the keyboard 23.

In step S30, it is determined whether the content of the flag _Tt1 is "0". If T _t1 = 0, the document F _t1 is prohibited from being rewritten, so that registration is not possible and the process ends. If T _t1 = 1, rewriting is possible, and the process proceeds to step S31, where the flag T _t1 and the document F
Request that _t1 be transferred to the host device 10. On the host device 10 side, the corresponding flag T _n and the shared document F _n
Is prepared (step S32). Then, the terminal device 20 transfers the flag _Tt1 and the document _Ft1 to the host device 10 in step S33, while the host device 10
On the side, respectively stored in the memory 16 and the auxiliary storage unit 17 the flag T _t1 and documents F _t1 sent as receive flag T _n and shared document F _n (step S34).
This is the end of the process.

[0039] According to this embodiment, the flag corresponding to the shared document F _n to be read with the host device 10 side T
_If the content of _n is "1" (it is always "1" in the initial state), it is changed from "1" to "0", and the flag _Tt1 of the terminal device 20 is set to the value before the read operation is performed. Flag T
The content “1” of _n is moved as it is. In other words, the flag T _t1 (which is always “0” in the initial state) is changed from “0” to “1”. Also, the shared document F to be read
If the content of the flag T _n corresponding to the _n is "0", which was kept at "0", and the content of the flag T _n "0" it is directly transferred to the flag T _t1 of the terminal device 20. In other words, the flag T _t1 (always “0” in the initial state)
Remains at “0”. If the content of the flag T _t1 is “1” on the terminal device 20 side, the modified document F _t1 is added.
Is re-registered in the host device 10 with the same name as the document F _n, and if “0”, re-registration with the same name is not permitted.

As a result, when a plurality of terminal devices make a call for the same shared document, only the flag _{Tt1 of} the terminal device that first makes the call (for example, this is the terminal device 20) is set to "1". , And the flags of the other terminal devices that have made the second and subsequent calls, for example, the flag _Tt2 of the terminal device 30, all become "0", so that only the terminal device 20 can be re-registered.

As described above, re-registration can be performed only from the terminal device that first makes a call, so that highly reliable data processing can be performed.

[0042]

As described in detail above, according to the first aspect of the present invention, the host device includes the first central processing unit,
A shared file storage unit, and a first auxiliary storage unit that stores, for each shared file stored in the shared file storage unit, a first flag that indicates whether the file is in a readable state or a read prohibited state, The terminal device includes a second central processing unit, a file storage unit that stores the content of the shared file read from the shared file storage unit of the host device, and a shared storage device that stores the content of the file storage unit in the shared file storage unit. A second auxiliary storage unit that stores a second flag indicating whether the file is in a rewritable state or a rewritable prohibited state, and designates a rewritable mode for the shared file or a rewritable mode. A data processing system that uses a shared file provided with a mode designating means for the terminal device. When rewritable mode to yl is designated, the first central processing unit of the host device, initially set to ready read the contents of the first flag, and the second central processing unit of the terminal device the contents of the second flag is initially set to re-write disable state, when the transfer request of the first flag of the shared file to the host device from the terminal device is the first central processing unit of the host device,
The transfer request of the content of the first flag to the terminal apparatus Tsu row, transfers the contents of the corresponding first flag, then set the disabled state reads the contents of the first flag, whereas,
The second central processing unit of the terminal apparatus the content of the first flag has been transferred, the contents of the first flag that is transferred can be read
When the status is indicated, the second flag is set to a re-writable state.
, And the content of the first flag is read-inhibited.
State, the second flag indicates the rewrite prohibition state.
As represented, the contents of the second flag is set to the second auxiliary storage means, based on the second flag to determine the line or Ukaina a transfer request of the shared file to the host device, a first central processing unit , if the transfer request is made, and forwards the transfer request, shared file to the terminal device, the second central processing unit of the terminal device stores the contents of the transferred shared file in the file storage means, further and based on the second flag to determine whether rewriting to the shared file stored in the shared file storage unit.

Further, according to the second aspect of the present invention, the host device can read the first central processing unit, the shared file storage unit, and the shared file stored in the shared file storage unit in a readable state. A first central storage unit for storing a first flag indicating whether the terminal is in a read-inhibited state or not, and a terminal device comprising: a second central processing unit; and a shared file read from the shared file storage unit of the host device. And a second flag indicating whether the contents of the file storage means are in a rewritable state or a rewrite prohibited state in the shared file stored in the shared file storage means. to a second auxiliary storage means and the data processing system utilizing a shared file with a first central processing unit of the host device, read the contents of the first flag Initially set out possible state,
In addition, the second central processing unit of the terminal device includes the second flag in the second flag .
Description initially set to re-write inhibit state, from the terminal device when the transfer request of the content of the first flag to the host device is a first central processing unit of the host device, the first flag
The contents terminal device Tsu rows transfer request, transfers the contents of the corresponding first flag, then set the disabled state reads the contents of the first flag, whereas, in the first flag
The second central processing unit of the terminal device capacity is transferred, if the contents of the first flag transferred represents a readable state
In order for the second flag to indicate the re-writable state,
Also, when the content of the first flag indicates a read prohibited state,
Corresponds to the second flag so that the second flag indicates the rewrite prohibition state.
2 is set in the second auxiliary storage means,
Based on the flag to determine the line or Ukaina a transfer request of the shared file to the host device, a first central processing unit transfers needed
Request, the shared file requested to be transferred is transferred to the terminal device, and the second central processing unit of the terminal device
Storing the contents of the transferred shared file in the file storage means, for determining whether rewriting in further based have been shared file storage means stored shared file on the second flag.

Therefore, when using a plurality of readable and writable shared files, highly reliable data processing can be performed.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an operation of a data processing system including a host device and a plurality of terminal devices as one embodiment of the present invention.

FIG. 2 is a block diagram schematically showing a configuration in the system of FIG. 1;

FIG. 3 is a flowchart illustrating an operation of a data processing system including a host device and a plurality of terminal devices as another embodiment of the present invention.

[Explanation of symbols]

 10 Host device 11, 21, 31 CPU 12, 22, 32 ROM 13, 23, 33 Keyboard 14, 24, 34 Display 15, 25, 35 Interface 16, 26, 36 Memory 17, 27, 37 Auxiliary storage unit 18, 28 , 38 Internal bus 20, 30 Terminal device 29, 39 External storage device controller 40 Communication line

Continuation of the front page (56) References JP-A-3-185558 (JP, A) JP-A-3-161858 (JP, A) JP-A-3-129565 (JP, A) JP-A-3-9443 (JP) JP-A-3-67551 (JP, A) JP-A-2-257250 (JP, A) JP-A-63-157250 (JP, A) JP-A-63-156257 (JP, A) JP-A-63-156257 63-113644 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G06F 15/16-15/177 G06F 17/21-17/24 G06F 12/00 G06F 13/00 G06F 15 / 00

Claims (3)

(57) [Claims] 1. A host device having shared file storage means for storing a plurality of shared files, and at least two terminal devices connected to the host device via a communication line, wherein the host device is provided with a shared file storage means. A shared file having two modes: a rewritable mode capable of rewriting a shared file that has been rewritten, and a rewrite prohibition mode in which rewriting of a shared file stored in a shared file storage unit is prohibited. In a data processing system, a host device is in a readable state or a read-inhibited state for each of a first central processing unit, a shared file storage unit, and a shared file stored in the shared file storage unit. First auxiliary storage means for storing a first flag indicating whether the first central processing unit has a second central processing unit; File storage means for storing the contents of the shared file read from the shared file storage means of the remote device, and whether or not the contents of the file storage means can be rewritten to the shared file stored in the shared file storage means. A shared file comprising: a second auxiliary storage unit for storing a second flag indicating whether the file is in a write-protected state; The first central processing unit of the host device changes the content of the first flag when a mode in which rewriting to a shared file is possible is designated by the mode designation means of the terminal device. initially set in the read enable state, and the second central processing unit of the terminal device, re-write the contents of the second flag Initially set to look inhibition state, the transfer request of the content of the first flag to the host device from the terminal device is the first central processing unit of the host device, the contents of the first flag respect of the transfer request terminal apparatus Tsu rows, transfer the contents of the corresponding first flag, then set the disabled state reads the contents of the first flag, while the contents of the first flag the second central processing unit of the transferred terminal device, transferred content Readable the first flag
The second flag can be rewritten
And the contents of the first flag are read
When the second flag is rewritten,
The content of the second flag is set in the second auxiliary storage means so as to indicate the loading prohibition state, and based on the second flag,
Line a transfer request of the shared file to the host device Ukainaka
And the first central processing unit determines that the transfer request has been made.
If it forwards the transfer request, shared file to the terminal device, the second central processing unit of the terminal device,
Storing the contents of the transferred shared file in the file storage means, and determining whether to re-write in the shared file storage means the stored shared files have further based on the second flag A data processing system that uses shared files. 2. When a mode for prohibiting rewriting to a shared file is specified by a mode specifying means of the terminal device, a second central processing unit of the terminal device sets a second flag to a rewriting prohibition state in an initial state. , The shared file transfer request is sent to the host device, the first central processing unit of the host device transfers the requested shared file to the terminal device, and the second central processing device transfers the shared file to the terminal device. The data processing using a shared file according to claim 1, wherein the content of the shared file is stored in a file storage unit, and whether to rewrite the shared file is determined based on the second flag. system. 3. Data processing using a shared file comprising a host device having shared file storage means for storing a plurality of shared files, and at least two terminal devices connected to the host device via a communication line. In the system, the host device determines whether each of the first central processing unit, the shared file storage unit, and the shared file stored in the shared file storage unit is in a readable state or a read prohibited state. A first central storage device for storing a first flag representing the first flag, and a file storage device for storing contents of the shared file read from the shared file storage device of the host device. Rewriting the contents of the file storage means to the shared file stored in the shared file storage means, A data processing system utilizing a shared file and a second auxiliary storage means for storing a second flag indicating whether a disabled state, the first central processing unit of the host device, the first flag
Initially set state reads the contents, and the second central processing unit of the terminal device, initially sets the contents of the second flag to re-write protected, from the terminal device
Wherein the host transfer request of the content of the first flag device is, the first central processing unit of the host device, to the terminal device Tsu line a transfer request of the content of the first flag, the corresponding Then, the content of the first flag is transferred, and then the content of the first flag is set to the reading prohibited state, while the second central processing unit of the terminal device to which the content of the first flag is transferred is : The contents of the transferred first flag can be read.
The second flag can be rewritten
And the contents of the first flag are read
When the second flag is rewritten,
The content of the second flag is set in the second auxiliary storage means so as to indicate the loading prohibition state, and based on the second flag,
Line a transfer request of the shared file to the host device Ukainaka
And the first central processing unit determines that the transfer request has been made.
If it forwards the transfer request, shared file to the terminal device, the second central processing unit of the terminal device,
Storing the contents of the transferred shared file in the file storage means, and determining whether to re-write in the shared file storage means the stored shared files have further based on the second flag A data processing system that uses shared files.