JPH11196151A - Server device control method therefor and recording medium recorded with server device control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable efficient non-real-time transfer by inputting and outputting data to and from a storage medium at a data rate calculated from the data transfer capacity of the server device and the data rate total of a real-time input/output control means by controlling data into and output between the storage medium and real-time terminal device and stopping the use of a synchronizing clock source. SOLUTION: In order to record and reproduce a video, it is indispensable that a VTR 111 input and output data in real time. For the purpose, a control means 106 controls the timing of input and output by using the synchronizing clock source 110. The control means 106 absorbs and adjusts differences between the transfer processing rate and input/output timing on an internal bus 103, and the input/output processing rate and input/output timing of a real-time data stream to the VTR 111 by using a buffer 104 to transfer data with a real-time VTR device 111 without any break of video data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a real-time server device for inputting and outputting real-time data such as digitized video and audio to and from a plurality of terminal devices, and a control method therefor.

[0002]

2. Description of the Related Art In recent years, the spread of digital video and audio equipment, the performance of digital data recording devices, and the cost reduction have been progressing. Along with this, development and commercialization of a real-time server device that stores digital data such as video and audio in digital form and transfers digital data such as video and audio in real time in response to requests from multiple terminal devices in accordance with the time axis Is progressing.

[0006] Digital data transfer methods include real-time transfer represented by the above-described video and audio data transfer and non-real-time transfer represented by the static data such as still image transfer. Hereinafter, these features will be described.

In the transfer of real-time data, it is necessary to transfer at a constant rate without delay or interruption in order to faithfully reproduce video and audio along a time axis. In order to realize this, a maximum bandwidth corresponding to the processing capacity is usually set in the real-time server device, and bandwidth allocation control is performed when starting a connection between the server device and the terminal device. That is, a band that can be used by each terminal device when a connection is made is set so that the total load on the server device does not exceed the maximum band set for the server device. Further, the server device performs transfer scheduling and switching for each terminal device so as not to exceed the bandwidth set in the transfer with each terminal device, and allocates processing capacity and memory and other resources of the server device. Do. As described above, the server device performs data transfer to the terminal device within the set maximum bandwidth, thereby performing a process with a margin for the processing capability of the server device, and causing a delay or interruption due to overload. Data transfer with the terminal device.

On the other hand, static still images, data files, etc.
Strict bandwidth allocation is not required for non-real-time transfer in which delay or interruption is allowed, and an algorithm for performing transfer as fast as possible with each terminal device is employed. For example, a simple flow control algorithm corresponds to this. In the flow control algorithm, the transmitting side performs data transmission with the maximum transfer capability as long as the buffer provided on the data receiving side does not overflow. Thereby, the transfer capabilities of the server device, the terminal device, and the communication medium connecting them can be matched, and the transfer capabilities can be used without waste. On the other hand, when data is transferred to a plurality of terminal devices, a delay or interruption may occur in another terminal device due to the influence of a load from one terminal device.

As described above, in real-time transfer and non-real-time transfer, transfer control is generally performed by different algorithms. However, depending on the application, there are cases where it is desired to perform real-time transfer and non-real-time transfer simultaneously using the same server device. For example, real-time video transmission is performed with a certain terminal device, and real-time video display is not performed with another terminal device, but a digital video created and edited in advance by another device or the like is registered in a real-time server device. For example. In the latter case, it is not necessary to perform real-time transfer, but rather a non-real-time transfer that can be transferred and registered as fast as possible is desirable. In such a case, it is ideal that the server device performs the non-real-time transfer to the terminal device that requests the real-time transfer, while performing the non-real-time transfer to the terminal device that requests the non-real-time transfer.

In order to meet such a demand for a mixture of real-time transfer and non-real-time transfer, and to harmonize with a non-real-time transfer algorithm so as to avoid delay or interruption of data in the real-time transfer, some conventional methods have been proposed. was there.

As a simple solution, a server device is composed of a computer, each input / output is controlled by an individual process, and real-time processing is performed without particularly arbitrating bandwidth between processes. It is conceivable that the priority of the parallel processing of the process is simply made higher than the process of performing the non-real-time processing. There are several operating systems that can provide high priority to a process that performs real-time processing, and it has been expected that resources for input and output are preferentially allocated to execute real-time processing. However, according to this method, there is not enough reliability to ensure that no data delay or interruption occurs. This is because, even though a process with a higher priority is given priority, a process with a lower priority cannot always be interrupted unconditionally. For example, if the data storage medium is a hard disk drive, it is not practical to interrupt another transfer request during the transfer of one block because a head seek or the like will occur and transfer efficiency will be significantly reduced. Therefore, the block transfer processing of the hard disk drive is processed first, and a considerable waiting time is required to switch from low priority processing to high priority processing. If the processes based on the simple priority management are sequentially executed under such restrictions, influences such as delay and interruption may occur during the execution of the real-time process.

As a first example which solves the above problems, there is a technique disclosed in Japanese Patent Application Laid-Open No. Hei 8-228200. In other words, this is a method in which the transfer to each terminal device is scheduled at a constant period that is standardized throughout the server system, real-time transfer is performed first, and the remaining time of the period is used as non-real-time data transfer.

As another second example, Japanese Patent Application Laid-Open No. 8-163
There is a technique disclosed in Japanese Patent Application Laid-Open No. 072-72. That is, the transfer is managed by time-slotted time slots, and time slots are first allocated to real-time transfer,
This is a method in which a vacant time slot not allocated to real-time transfer is used as a time slot for non-real-time data transfer.

In these methods, the non-real-time processing is executed after the processing amount required for the real-time processing is reserved in advance, so that the non-real-time processing is performed without delay or interruption to the terminal device requesting the real-time transfer. High-speed transfer is performed for a terminal device that requests transfer.

[0012]

However, on the other hand, the above-mentioned first and second conventional examples have a common drawback. According to these methods, the scheduling of data transfer is performed by one reference clock standardized in the system. For this reason, when the terminal devices are operating asynchronously with each other, it is necessary to perform scheduling in accordance with the reference clock, so that scheduling in each terminal device becomes difficult, the degree of freedom of input / output timing decreases, and It is difficult to set an appropriate reference clock for the local clock. In particular, when performing data input / output processing for various existing terminal devices,
Because the clock speed and the standard itself are also significantly different,
Procedures such as clock synchronization and stuffing for adjusting speed are complicated, and it is difficult to perform operation arbitration by taking synchronization. Further, in the first example, scheduling is performed in accordance with a unique cycle that is relatively long, so that when a transfer request occurs on the terminal device side, a delay occurs in order to synchronize with the unique cycle. There are many disadvantages when trying to build a system with a complicated terminal device.

In the first and second conventional examples described above, when this is realized by a computer program, the operations of both real-time transfer and non-real-time transfer are inevitably arbitrated by a single scheduler. Therefore, there is also a disadvantage that it is difficult to obtain a structure in which the process is divided. That is, it is difficult to separate the processes of the real-time transfer and the non-real-time transfer, the program scale is increased and the structure is complicated, and the protocol of the real-time transfer and the non-real-time transfer cannot be easily changed.

In view of the above-mentioned problems of the prior art, the present invention enables efficient processing of data transfer to terminal devices that operate asynchronously with each other. The arbitration between processes is simple, the program code is easily separated, and real-time transfer is reliably performed without delay or interruption for terminal devices that require real-time transfer. It is an object to provide a server device capable of performing real-time transfer and a control method thereof.

[0015]

In order to solve the above-mentioned problems, a real-time server device according to the present invention corresponds to a synchronous clock source and real-time input / output control means corresponding to each real-time terminal device, and a non-real-time terminal device. A clock source, a non-real-time input / output control unit, and a storage medium, wherein the real-time input / output control unit starts using the corresponding synchronous clock source at the time of data input / output to allow communication between the storage medium and the real-time terminal device. When the data input / output is completed, the use of the synchronous clock source is stopped, and the non-real-time input / output control means controls the data transfer capability of the server device and the corresponding synchronization at the time of data input / output. Data of real-time input / output control means using a clock source The data input / output to / from the storage medium and the non-real-time data input / output to / from the non-real-time terminal device are performed using the clock source at the maximum available data rate calculated from the difference from the total of the tare rates. And

With this configuration, the plurality of real-time input / output control means transfers data to terminal devices that are asynchronous with each other, eliminates data delay and interruption to the terminal device that inputs and outputs data in real time, and provides non-real-time input / output control. Means monitors the clock usage of each real-time input / output control means, detects the band currently used by each real-time input / output control means from the operating state, and limits the bandwidth so that the overall system load does not become excessive. Non-real-time input / output can be performed. In addition, a single clock source is used as a clock which serves as a rate reference for limiting the bandwidth, and this clock source does not need to be associated with the scheduling of the entire system, and thus is used when arbitrating multiple terminal devices. Synchronous processing and stuffing processing, which were conventionally required, are not required, and a clock having a stable cycle can be easily obtained. Therefore, reliable rate control can be performed without complicated processing.

In order to solve the above-mentioned problems, a real-time server device according to the present invention comprises a synchronous clock source and real-time input / output control means corresponding to each real-time terminal device, and a clock source corresponding to a non-real-time terminal device. Real-time input / output control means,
A storage medium, and a bandwidth information management unit that manages bandwidth information used for data input / output of the server device, wherein the real-time input / output control unit registers the bandwidth information in the bandwidth information management unit when data is input / output. Then, the use of the corresponding synchronous clock source is started to control data input / output between the storage medium and the real-time terminal device, and when the data input / output is completed, the band information registered in the band information management unit is deleted. Deleting, stopping the use of the synchronous clock source, the non-real-time input / output control unit performs a data rate based on a data transfer capability of the entire server device and a band rate registered in the band information management unit at the time of data input / output. The maximum available bandwidth calculated from the difference from the total is used to input and output data to and from the storage medium using the clock source. And performing the non-real-time data input and output between the non-real-time terminal device.

The band information is speed information at the time of performing data transfer, and typically means a bit transfer amount per unit time.

With this configuration, the non-real-time input / output control unit can easily and reliably acquire the band information. Therefore, it is easy to functionally separate the control means for performing real-time processing from the control means for performing non-real-time processing.

Next, the server device may use any one of synchronous clock sources used by the real-time input / output control means for inputting / outputting data as a clock source corresponding to the non-real-time terminal device. It is preferable to use

With this configuration, since the limitation is performed according to any one clock source used by the real-time input / output control means, the non-real-time input / output control means does not need to prepare an independent clock and does not need to perform band limitation. The effect is in certain cases to ensure that there is more than one available clock.

Next, the server device determines whether or not the non-real-time input / output control means has started or stopped using the corresponding synchronous clock source.
It is preferable to have a function of determining whether or not the real-time input / output control means is executing real-time data input / output.

With this configuration, the clock is always used when the real-time input / output control means actually performs data input / output, so that the operation state can be determined easily and reliably. Use of,
By adopting a method utilizing non-use, it is possible to ensure that there is little restriction between control means, and it is easy to separate control means for performing real-time processing from control means for performing non-real-time processing.

Next, the server device starts and stops using the synchronous clock source corresponding to each of the real-time input / output control means by registering and deleting each clock interrupt. When selecting a synchronous clock source used by the output control means, it is preferable to determine whether or not the synchronous clock source is used by the real-time input / output control means based on the interrupt registration status.

With this configuration, in selecting a clock source to be used by the non-real-time input / output control means, it is easier and more reliable to determine whether or not the clock source is used by the real-time input / output control means.

Next, in the control method of the server device, all or a part of the functions of the real-time input / output control means and the non-real-time input / output control means of the server device are as follows.
It is realized by a CPU process which operates in parallel and is controlled by a program step.

[0027] Further, the recording medium on which the server device control program is recorded records program steps of the server device control method.

With this configuration, each control means is controlled by each program step and operates in parallel.
By using the U process, it is possible to provide a method of controlling the server device by a computer controlled by the CPU.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing the operation of the real-time server device according to the embodiment of the present invention. Hereinafter, the configuration and operation of the embodiment will be described with reference to FIG.

The server device 101 performs input / output with respect to (n-1) VTRs 111 which are real-time terminal devices via a communication path, and at the same time, a tape data storage device 112 which is a non-real-time terminal device and other server devices 113 Also, data input / output with the control computer 114 is performed. The server device 101 includes a recording medium 102, and records video and audio data on the recording medium 102. Recording medium 102
Is a digital recording medium such as a hard disk drive accessible from a plurality of streams via the bus 103. The maximum data input / output band is set in the server device 101 in advance. The maximum bandwidth has a bandwidth equal to or greater than the sum of the maximum bandwidths allocated to each real-time terminal device, and is set so that failures due to delays and interruptions do not occur even if each real-time terminal performs data input and output up to the maximum bandwidth. It is determined by the data input / output processing capability of the recording medium 102, the transfer processing capability of the bus 103, and the like. The video / audio data on the recording medium 102 is input / output to / from the real-time terminal device 111 on the same time axis as the video-specific time axis, and is treated as a real-time data stream 116. The same video / audio data is input / output to / from the non-real-time terminal devices 112 to 114 on an arbitrary time axis irrespective of the video-specific time axis, and is treated as a non-real-time data stream 117.

First, the data input / output operation in real time will be described. Since the VTR 111 records and reproduces video in real time, it is essential to input and output data in real time. For this reason, the control means 106 controls the input / output timing using the synchronous clock source 110. The control unit 106 uses the buffer 104 to absorb and adjust the difference between the transfer processing speed and input / output timing on the internal bus 103 and the input / output processing speed and input / output timing of the real-time data stream to / from the VTR 111 to adjust the video data. The data transfer process with the real-time VTR device 111 is performed without interruption.

The server apparatus 101 detects a clock rate unique to each VTR of a previously connected real-time terminal apparatus, and sets the detected clock rates to the synchronous clock sources 1 to n-1.
Here, each of the control means 1 to n-1 uses the set synchronous clock source 1 to n-1 and the control means n uses one clock arbitrarily selected from the synchronous clock sources 1 to n-1. Thus, the server device controls input and output by n control units that operate asynchronously with each other.

Now, of the n-1 VTRs 111, the VT
Assume that R1 records digital data output from the server device on a tape. The synchronous clock source 1 in the server apparatus 101 generates a clock which is a reference of the real time data stream 116 for the VTR 1, and the control means 1 receives a periodic interrupt generated by the clock source 1 and And use it as a time reference to maintain the transfer rate,
Real-time data stream 116 for VTR1
Generate and transfer In the VTR 1, the built-in VTR specific clock 1 is synchronized with the clock source 1, and the VTR 1 receives the real-time data stream 116 and performs recording on the tape.

Next, it is assumed that VTRn-1 is reproducing a tape. Many VTR devices, except for products used for broadcasting stations and business editing applications, do not have a function to perform playback in synchronization with an externally supplied clock from the viewpoint of cost. It will be performed based on the standard. For this reason, a synchronous clock source n-1 in the server apparatus 101 set in advance so as to synchronize with the VTR built-in clock source n-1 of the VTR n-1 is used. The control means n-1 is a synchronous clock source n-1
And generates and transfers a real-time data stream 116 for the VTRn-1 by using the periodic interrupt generated by VTRn-1 as a time reference for maintaining the real-time property and bit rate of the data stream.

As shown in the present embodiment, the present invention does not require the synchronization for unifying the entire special system, so that the existing equipment which does not have the function of synchronizing with the externally supplied clock as described above can be used. There is an advantage that it can be used as a terminal device without special modification.

Next, real-time input / output control means 1 to n-
The operation 1 will be described with reference to the flowchart of FIG. Naturally, according to the program based on this flowchart, the control means can be realized as a process on the CPU.

Now, VTRm which is a real-time terminal
(VTRm is a VTR of VTR1 to VTRn-1)
Performs data transfer with the server apparatus 101.
In the transfer process, a control unit m (the control unit m is a certain control unit among the control units 1 to n-1) is assigned. Before starting the data input / output, the control means m
It is determined whether there is a usable band. That is,
The total of the bandwidths already registered by the other control means 1 to n-1 and the total of the bandwidths to be registered by the control means m are calculated, and the result and the maximum bandwidth preset for the server apparatus 101 are calculated. If it does not exceed, it is determined that it can be used. This registration management is performed by providing a memory area for registration management in a memory connected to the bus 103, for example. If the result of determination is that there is no usable band, data input / output is not performed. In this case, it is preferable to report to the control computer 114 of the server device and the VTRm that the transfer process is busy. Next, if there is a usable band, the band information of the data input / output used by the control unit m is registered, and the clock source m specific to the control unit m (the clock source m is the clock source of the VTRm) (Previously set to be synchronized).

When the use of the interrupt is started, until the data input / output is completed, the bandwidth of the input / output is limited to the registered band or less using the interrupt, and the recording medium 102 is used.
And data transfer between the VTRm. When the data input / output is completed, the use of the interrupt of the unique clock source m is stopped, and the data input / output band information registered by the control unit m is deleted.

Next, a non-real-time data input / output operation will be described. In FIG. 1, a tape data storage device 112, another server device 113, a control computer 1
Reference numerals 14 denote devices for inputting and outputting data in a non-real time manner. These devices are used to retrieve stored images, register coded images, transfer images at high speed for editing and browsing, etc., regardless of real time. Perform output. For these terminal devices, the control means n (107) controls input / output timing.

The control means n according to the present embodiment is constituted by sub-control means n0 and n1 to n3. Here, the connected non-real-time devices are 112 to 11
The sub-control means corresponding to three of four will be described as n1 to n3, but the number of connected devices and the number of sub-control means are merely examples and are not limited to three.

An important point in the configuration of the control means n is that it has two types of sub-control means n0 and n1 to n3, and the sub-control means n0 coordinates with the process of another real-time terminal device. To perform data input / output to / from the storage medium 102,
According to 1 to n3, it is possible to perform a high-speed data transfer process with a non-real-time terminal device as much as possible. As a result, real-time data transfer with the real-time terminal device can be reliably performed, and high-speed data transfer with the non-real-time terminal device can be realized while considering the data input / output processing efficiency of the entire system.

The sub-control means n0 controls the data transfer between the recording medium 102 and the buffer 105,
n3 is the buffer 105 and each of the terminal devices 112-1.
14 is controlled. It is assumed that the buffer 105 can perform input / output independently in a FIFO configuration. Therefore, the control means n0 and the control means n1 to n3 can perform transfer independently of each other. According to the configuration of the control means n as described above, since each of the sub-control means n1 to n3 can operate independently, a control means which does not perform the conventional band management can be used as it is for n1 to n3. , Each of which can employ a different algorithm or protocol, can be operated flexibly, and is particularly suitable for non-real-time high-speed transfer. Each of the control units n1 to n3 performs input / output between the buffer 105 and each non-real-time terminal device according to any general transfer algorithm such as conventional flow control. These operations are well-known data transfer means, and a description thereof will be omitted.

Next, a description will be given of the control means n0 for executing data input / output with the storage medium 102 by limiting the bandwidth in the non-real-time input / output control means n.

The operation of the control means n0 will be described with reference to the flowchart of FIG. The control means n0 performs real-time input / output control means 1 to n-
It is determined whether or not 1 uses an interrupt. If the result of the determination is that no interrupt has been used, data is transferred between the recording medium 102 and the buffer 105 at the maximum allowed speed. Thereby, the full capacity of the server device can be utilized to the maximum. As a result of the interrupt use determination, if the interrupt is used by the other control means 1 to n-1, first, the control means n0 calculates a usable bandwidth. The bandwidth usable by the control unit n0 is calculated by subtracting the total bandwidth already registered by the control units 1 to n-1 from the maximum bandwidth set in the server apparatus 101 in advance.

Next, an arbitrary one of the synchronous clock sources 1 to n-1 in which the interrupt is used is selected, and the interrupt is shared so that the interrupt is used by the control means n0. Instead of selecting multiple clocks here or combining clocks from multiple clock sources,
The reason for choosing any one of the clocks already in use is that there is a great advantage in that sharing with the clock of another process can reduce the processing complexity rather than adopting a completely independent clock. Because there is. It is not always necessary to share the clock source with the clock source of another process, and the control means n may use an individual clock source n. In this case, in particular, even if the first to (n-1) th clock sources can be changed depending on the convenience of the terminal device, it is possible to obtain a clock having a stable cycle since the clock for non-real-time transfer is not affected. it can.

When the sharing of the interrupt is completed, the control means n uses the interrupt to calculate the input / output band (the sum of the three bands corresponding to each of the non-real-time terminal devices 112 to 114) calculated in the previous step. The data transfer is performed between the recording medium 102 and the buffer 105 while restricting the bandwidth to a value less than or equal to the minimum bandwidth. Here, the control means n0 performs data input / output with the recording medium 102 by adjusting so as not to collide with the process of the control means using the shared interrupt. Note that the control means n0 returns to the first step and performs the updating process every time the state of the interrupt changes, such as an increase or decrease in the number of terminal devices that perform real-time data input / output.

The connection stream 116 between the server device and the terminal device shown as a stream in FIG. 1 indicates a data flow having logically consistent continuity, and a physical communication line is connected. Not a representation.
In other words, even when the server device and the terminal device are individually connected by a communication line, the server device and the terminal device are physically connected by a network that shares one communication line, and a plurality of real-time The effect of the present invention is the same even in a configuration in which a server device and a terminal device are connected by a non-real-time stream.

As described above, each control means of the real-time system can notify the other control means of the current operation state through the use of an interrupt. Since the use of interrupts is a basic operation for generating a time reference based on hardware, there are few errors as an index of the operation status, and the bandwidth information can be updated reliably by registering the bandwidth information at the same time It is. The non-real-time control means can appropriately grasp the current operation status of the other control means by using the interrupt.

By using such a notification method using an interrupt, it is possible to configure server device control means that operate reliably in cooperation with each other, although they are asynchronous operations. According to the configuration of the present invention, for example, even when the control units operating in parallel with each other are distributedly processed by a plurality of CPUs, communication between the CPUs is not required for adjusting the bandwidth. High operation becomes possible. The real-time control means 106
Even when the number of operations is not determined, the control means 107 can control the band of the whole system so as not to exceed the maximum band by detecting the interrupt.
Extremely flexible for configuration changes. Further, since the control means n does not use individual interrupts, there is an effect that the interrupt resources in the server device can be saved.

[0051]

The real-time server device according to the method of the present invention is suitable for data transfer to terminal devices that are asynchronous with each other, arbitration between program codes for real-time data transfer and non-real-time data transfer is simple, and the programs are separated. It is easy to change the program configuration, and it is possible to reliably perform real-time transfer without delay or interruption for terminal devices that require real-time transfer, and efficiently for terminal devices that require non-real-time transfer. Non-real-time high-speed transfer can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a server device according to an embodiment of the present invention.

FIG. 2 is a flowchart of processing by a real-time input / output control unit of the server device according to the embodiment of the present invention;

FIG. 3 is a flowchart of processing by a non-real-time input / output control unit of the server device according to the embodiment of the present invention;

[Explanation of symbols]

 Reference Signs List 101 server device 102 recording medium 103 bus 104, 105 buffer 106 control means 1 to n-1 107 control means n 108 sub control means n0 109 sub control means n1 to n3 110 synchronous clock source 111 VTR 112 tape data storage device 113 other Server device 114 Control computer 115 Interrupt 116 Real-time data stream 117 Non-real-time data stream

Claims (7)

[Claims] 1. An input / output unit for inputting / outputting data in real time
Alternatively, a server device capable of performing data input / output with respect to a plurality of real-time terminal devices and one or a plurality of non-real-time terminal devices which perform non-real-time data input / output, each corresponding to the real-time terminal device A synchronous clock source and real-time input / output control means, a clock source corresponding to the non-real-time terminal device, a non-real-time input / output control means, and a storage medium, wherein the real-time input / output control means Control the data input / output between the storage medium and the real-time terminal device, stop the use of the synchronous clock source when the data input / output is completed, and execute the non-real-time input / output control. Means for transferring data of the server device at the time of data input / output. A data input to and from the storage medium is performed using the clock source at a maximum available data rate calculated from a difference between a capacity and a total data rate of the real-time input / output control means using the corresponding synchronous clock source. A server device for performing output and non-real-time data input / output with the non-real-time terminal device. 2. Input / output of data in real time
Alternatively, a server device capable of performing data input / output with respect to a plurality of real-time terminal devices and one or a plurality of non-real-time terminal devices which perform non-real-time data input / output, each corresponding to the real-time terminal device A synchronous clock source and a real-time input / output control unit, a clock source corresponding to the non-real-time terminal device, a non-real-time input / output control unit, a storage medium, and a band for managing band information used for data input / output of the server device An information management unit, wherein the real-time input / output control unit registers band information in the band information management unit at the time of data input / output, starts using the corresponding synchronous clock source, and Controls data input / output between terminal devices, and when data input / output is completed, Remove the band information registered in the frequency information management unit, to stop using the synchronous clock source,
The non-real-time input / output control means, at the time of data input / output, uses the maximum available bandwidth calculated from the difference between the data transfer capacity of the entire server device and the total data rate based on the bandwidth information registered in the bandwidth information management unit. A data input / output with the storage medium and a non-real-time data input / output with the non-real-time terminal device using the clock source. 3. A clock source corresponding to the non-real-time terminal device, wherein any one of synchronous clock sources used by a real-time input / output control unit performing data input / output is used. Or the server device according to 2. 4. The non-real-time input / output control means,
3. The apparatus according to claim 1, further comprising a function of determining whether the real-time input / output control unit is executing real-time data input / output based on whether the use of the corresponding synchronous clock source has been started or stopped. 4. The server device according to the above. 5. The use of the synchronous clock source corresponding to each of the real-time input / output control means is started and stopped by registering and deleting each clock interrupt, and is used by the non-real-time input / output control means. 4. The server device according to claim 3, wherein, upon selecting a synchronous clock source, whether or not the synchronous clock source is used by the real-time input / output control unit is determined based on a registration status of the interrupt. 6. A server device according to claim 1, wherein all or a part of the functions of said real-time input / output control means and said non-real-time input / output control means are provided.
A method for controlling a server device, which is realized by a CPU process that operates in parallel and is controlled by a program step. 7. A storage medium on which the program steps according to claim 6 are recorded.