JPH0713778A - Device and method for process communication control - Google Patents

Abstract

PURPOSE:To establish interface with flexibility higher than the signal function of UNIX between a device driver and an application program without modifying the kernel of UNIX by adding a virtual device driver between the device driver and the kernel in a system of UNIX. CONSTITUTION:The application program 10 provided with plural processes, and the virtual device driver 80 provided between the processes of the device driver 70 and the application program 10 and equipped with a first counter corresponding to each process and a second counter corresponding to each device driver 70 are provided. The process is executed in such a way that a value in the first counter is set, and the device driver 70 increases the count of the second counter when receiving interruption from a device, and the virtual device driver 80 reports the coincidence of the value of the second counter with that of the first counter to the application program 10 when the coincidence is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an application program operating on a UNIX system, and to this UNIX.
The present invention relates to a process communication control device and method with a device driver that controls an input / output device connected to an X system.

[0002]

2. Description of the Related Art FIG. 1 is a block diagram for explaining a conventional process communication control system. The application program 10 and the plurality of device drivers 20 are UN
It is connected through the kernel 30 of IX. Each device driver 20 controls the hardware (input / output device) 40 connected to it. Further, the application program 10 includes a plurality of processes.

Here, the communication between each device driver 20 and the process in the application program 10 is as follows.
Generally, the method is as follows.

(1) This is performed by utilizing the signal function of UNIX.

(2) Kernel 30 of UNIX system
Is modified to add a special control function.

[0006]

However, the conventional method described above has the following disadvantages.

(1) In the above method (1), the use of signals is limited, and the types of communication that can be used are limited.

(2) In the method of (2) above, UNIX
Every time the version is updated, the kernel has to be modified, and a huge amount of work is required.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a highly versatile process communication control apparatus and method for notifying an application program of an event from hardware. .

[0010]

In order to solve the above problems, the present invention provides a plurality of processes in a computer system having an operating system having a multitasking function and a device driver operating on the operating system. A first counter that is provided between the application program and the device driver and each process of the application program and that corresponds to each process, and a second counter that corresponds to each device driver.
A virtual device driver having a counter of
The process sets a value in the first counter,
The device driver increments the second counter when receiving an interrupt from a device, and the virtual device driver notifies the application program when the value of the second counter matches the value of the first counter. It is characterized by notifying.

[0011]

According to the present invention, in the UNIX system, a virtual device driver having a counter is added between the device driver and the kernel, and the device driver and the application program communicate with each other through the counter value. Therefore, an interface more versatile than the UNIX signal function can be established between the device driver and the application program without modifying the UNIX kernel.

[0012]

EXAMPLES Next, examples of the present invention will be described in detail.

FIG. 2 is a block diagram showing the configuration of a control system for an incinerator to which the present invention is applied.

In the figure, a temperature sensor 52 and a pressure sensor 54 are attached to the incinerator 50 to monitor the temperature and pressure of the incinerator 50. When the temperature abnormality (high temperature, low temperature) occurs in the incinerator 50, the contact of the temperature sensor 52 is turned on, and when the pressure abnormality (high pressure, low pressure) is generated, the contact of the pressure sensor 54 is turned on. These outputs are sent to computer 66 via DI boards 62 and 64 of controller 60. The computer 66 controls the patrol light 69 to blink via the DO board 68.

FIG. 3 is a block diagram showing the software configuration of this control system. The hardware 40 is specifically the DI boards 62 and 64 and the DO board 68, and is controlled by the device driver 70.

The device driver 70 is software that has a one-to-one correspondence with each piece of hardware 40 and issues an instruction to each piece of hardware to control its operation. When an interrupt is generated from the hardware 40, the interrupt routine of the kernel 30 receives control and notifies the virtual device driver 80 of the control. For this reason, the device driver 70 has a form in which the interface unit 72 with the virtual device driver 80 is added to the device driver 20 of FIG.

The virtual device driver 80 is newly provided in the present invention and has a table structure shown in FIG. That is, each hardware 40 has a device management table 82, and each device management table 8
2 is connected to N process management tables 84 corresponding to N processes in the application program 10. Each device management table 82
Is a device number of a device to be managed, a pointer to the process management table 84, and two base counters 8
6, 87 and so on. Virtual device driver 80
Increments either the base counter 86 or 87 according to the type of interrupt from the corresponding device.

Each process management table 84 includes a process number of each process, a pointer to the next process management table, a pointer to the process structure 90, and two process counters 88 and 89. The process counters 88 and 89 are writable by the process corresponding to this process management table. Therefore, the process has counters 88, 89 for this process.
Can be set to any value. Process structure 9
0 corresponds to the header of each process and has a signal flag for the user. When this flag is turned on, the processing routine registered by this process can be started at the time of process switching of this process.
The virtual device driver 80 is the UNIX kernel 30.
Through the application program 10.

FIG. 5 is a diagram showing the mutual relationship among the device driver 70, the virtual device driver 80, and the application program 10.

At system initialization, the device driver 70 requests the virtual device driver 80 to secure the device management table 82 (step S).
1). In response to this request, the virtual device driver 80 secures the device management table 82 (step S).
2). Next, the device driver 70 requests the virtual device driver 80 to set the device management table 82 (step S3). In response to this request, the virtual device driver 80 responds to the device management table 82.
Is set (step S4). Thus, the table structure in the virtual device driver 80 is set at the time of system initialization. However, at this stage, the contents of the process management table 84 are written and the process management table 8
4 is not connected to the device management table 82.

Next, during system operation, step S5
-The operation of S15 is performed.

First, in steps S5-S6, a counter communication interface between the device driver 70 and the application program 10 is established. That is, in step S5, the application program 10 requests the virtual device driver 80 to establish a counter communication interface between the device driver 70 and the application program 10. As a result, the virtual device driver 80 writes necessary data in the process management table 84, creates these tables 84, and connects to the device management table 82 (step S6). However, at this stage, writing to the process counters 88 and 89 is not performed.

When the counter communication interface with the device driver 70 is established, the application program 10 requests the virtual device driver 80 to register a process executed based on the counter value in step S8. Specifically, the virtual device driver 80 is requested to specify the value of the process counter 88 or 89 of this process and write it in the counter. This counter value is determined according to the processing executed by the process. For example, in order to activate the abnormal handling process in the application program 10 when the temperature abnormality is detected five times, the process counter 88 in the process management table of the abnormal handling process is set to 5. Further, the application program 10 specifies to the virtual device driver 80 whether this process performs synchronous processing or asynchronous processing. This designation is necessary in step S12 described below.

The virtual device driver 80 receiving the request from the application program 10 operates in step S9.
In, the counter value designated by the application program 10 is set in the process counter 88 (or 89) of the process management table 84 of the corresponding process. In this way, the application program 10 is in a state of being able to receive the notification from the virtual device driver 80.

The device driver 70 is the hardware 4
Every time an interrupt from 0 occurs, the virtual device driver 80 is notified (step S10). Upon receiving this notification, the virtual device driver 80 increments the counter value of the base counter 86 (or 87) of the device management table 82 (step S11).

Next, in step S12, the virtual device driver 80 compares the counter value of the base counter 86 with the counter value of the process counter 88,
If both counters have the same value, the following processing is performed. That is, when the requesting process is performing synchronous processing, the process in sleep is activated,
If the request process is performing asynchronous processing, the process structure 9 connected to this process management table
Set the user signal flag of 0 to on. The application program 10 is a virtual device driver 8
Upon receiving the notification from 0, the process registered in step S8 is executed (step S13). That is, in the case of synchronous processing, the started process moves from the waiting state to the program execution state. On the other hand, in the case of asynchronous processing, it is detected that the user signal flag is turned on, and predetermined processing is executed. When the processing of the application program 10 ends (step S14),
An end notification is sent to the virtual device driver 80. The virtual device driver 80 erases all the process management tables 84 (step S15) and ends the process.

FIG. 6 is a flowchart showing the operation when such a process communication control system is applied to the control of the incinerator of FIG.

In step S21, the above step S
In the same manner as in 8, the process (abnormality process) that executes the process when the temperature abnormality of the incinerator occurs is registered. Similarly, in step S22, a process for executing the process when the pressure abnormality of the incinerator occurs is registered. In this state, the temperature and pressure of the incinerator are continuously monitored (steps S23 and S25), and if a temperature abnormality or pressure abnormality occurs (steps S24 and S26), the patrol light 69 is turned on. This process
It is performed as already described with reference to FIG. In this case, the type of counter used (counter 88
, Or 89) or by changing the count value to be set, it is possible to perform flexible control.

In the above-mentioned embodiment, the number of base counters and process counters is two, but by increasing these numbers, more events from the device can be dealt with. Further, not only the control of the incinerator but also any system built on UNIX can be applied.

[0030]

As described above, according to the present invention,
On a UNIX system, simply add a virtual device driver between the device driver and the kernel, without modifying the UNIX kernel.
An interface that is more versatile than the signal function of the above can be established between the device driver and the application program.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining a conventional process communication control method.

FIG. 2 is a block diagram showing a configuration of a control system for an incinerator to which the present invention is applied.

3 is a block diagram showing a software configuration of the control system shown in FIG.

FIG. 4 is a block diagram showing a table structure in the virtual device driver of FIG.

5 is a diagram showing a mutual relation of operations of a device driver 70, a virtual device driver 80, and an application program 10. FIG.

FIG. 6 is a flowchart showing an operation when the process communication control method according to the present invention is applied to control of the incinerator of FIG.

[Explanation of symbols]

10 Application Program 20 Device Driver 30 Kernel 40 Hardware 50 Incinerator 52 Temperature Sensor 54 Pressure Sensor 60 Control System 62, 64 DI Board 66 Computer 68 DO Board 69 Patlite 70 Device Driver 72 Interface between Device Driver and Virtual Device Driver 80 Virtual device driver 82 Device management table 84 Process management table 86 Base counter 1 87 Base counter 2 88 Process counter 1 89 Process counter 2 90 Process structure

Claims (2)

[Claims] 1. A computer system having an operating system having a multitasking function and a device driver operating thereon, comprising: an application program having a plurality of processes; and a device driver and each process of the application program. A virtual device driver having a first counter corresponding to each of the processes and a second counter corresponding to each of the device drivers, wherein the process has a value stored in the first counter. Set
The device driver increments the second counter when receiving an interrupt from a device, and the virtual device driver notifies the application program when the value of the second counter matches the value of the first counter. A process communication control device characterized by notifying. 2. A computer system having an operating system having a multitasking function, a device driver operating on the operating system, and an application program having a plurality of processes, wherein the process stores a value in a first counter. The step of setting, the step of incrementing a second counter when the device driver receives an interrupt from a device, and the step of incrementing the second counter when the value of the second counter matches the value of the first counter. And a step of notifying an application program.