JP2715678B2 - Occupancy control method and control device for input/output device - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THEINVENTION The present invention relates to an occupancy control method and an occupancy control device for an input/output device.

[0002]

2. Description of the Related Art The environment in which a conventional input/output device occupancy control method and occupancy control device are used is shown in the block diagram of FIG. 2, which includes a plurality of host systems 8 and 9 and a plurality of input/output devices 11 and 12 that are used in common by the host systems 8 and 9.
A control device 10 for the input/output devices is located between the input/output devices 2, 13 and 14, and controls the mutual connections.

[0003] This conventional I/O device control device 10, for example, receives an occupation command for I/O device 11 output from a higher-level system 8, causes the higher-level system 8 to occupy I/O device 11, and releases the occupied I/O device 11 upon receiving a release command output from the higher-level system 8. If the higher-level system 8 receives an occupation command for I/O device 11 output from the higher-level system 9 while the higher-level system 8 is occupying the I/O device 11, it rejects the occupation command, and after the I/O device 11 is released, it notifies the higher-level system 9 that previously rejected the occupation command that the I/O device 11 has been released.

[0004]

The above-mentioned conventional I/O device exclusive control method and exclusive control device are designed to release the occupied I/O device upon receiving a release command output from a higher-level system. If the higher-level system that has exclusive use of the I/O device continues the exclusive state and leaves it as is, the I/O device will not be used by either the higher-level system that has exclusive use of it or any other higher-level system, and therefore it cannot be used effectively.

The object of the present invention is to provide an occupancy control method and occupancy control device for an I/O device which, even if occupied by a higher-level system, sends a release request to the occupying higher-level system when the I/O device has not been used for a certain period of time, thereby enabling the I/O device to be used more effectively.

[0006]

The present invention provides an exclusive control method for an input/output device, which receives an exclusive command for a specific input/output device output from a first host system among various control methods performed between a plurality of host systems and a plurality of input/output devices commonly used by the plurality of host systems, and controls the first host system to use the exclusive control command for the specific input/output device.
a first host system to occupy the specific I/O device, release the occupied specific I/O device in response to a release command output by the first host system, and when the first host system receives an occupancy command for the specific I/O device output by a second host system while occupying the specific I/O device, reject the occupancy command, and notify the second host system of the release of the specific I/O device after the release of the specific I/O device, the first host system measures the elapsed time of the occupied state of the specific I/O device occupied by the first host system, and if the occupancy is continued for a predetermined time or longer, a request for the release of the specific I/O device is made to the first host system.
It is .

The occupancy control device for an input/output device of the present invention is located between a plurality of higher-level systems and a plurality of input/output devices commonly used by the plurality of higher-level systems, and comprises an occupancy/release memory means for receiving an occupancy command and a release command for a specific I/O device outputted by a first higher-level system and storing the occupancy and release state of the specific I/O device of the first higher-level system, a command refusal means for receiving an occupancy command for the specific I/O device outputted by a second higher-level system while the first higher-level system is occupying the specific I/O device and notifying the second higher-level system that the occupancy command has been rejected, and a release report means for notifying the second higher-level system of the release of the specific I/O device when the storage state of the occupancy /release memory means for the specific I/O device has changed from occupied to released,
and a release request means for receiving the time-out signal outputted by the timing means and sending a release request signal to the first higher-level system to request the release of the specific input/output device when the time-out signal outputted by the timing means is received.

The occupancy control device for an input/output device of the present invention may be provided with a timing means which monitors the memory status of the occupancy release means, starts measuring the elapsed time when any input/output device becomes occupied, and outputs a time-out signal when a predetermined time length is exceeded, and which has a function of resetting the measurement of the elapsed time to an initial value and restarting measurement when the input/output device during which the elapsed time is being measured becomes in use.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention.

The occupancy control device for an input/output device of the present invention is located between a plurality of host systems and a plurality of input/output devices commonly used by the plurality of host systems, and comprises a main control unit 1 which receives commands from the host systems, decodes them and outputs them to each unit in the device, an occupancy/release memory unit 2 which receives occupancy commands and release commands for a specific input/output device from the host systems which are received and output by the main control unit 1, and stores the occupancy and release states of the specific input/output device of this host system, and when a host system occupies a specific input/output device and another host system outputs an occupancy command for the same specific input/output device, this occupancy command is released. a command refusal section 3 which is notified by the main control section 1 that the exclusive command has been rejected and notifies other upper systems of the refusal; a release report section 4 which is notified by the main control section 1 via the exclusive release memory section 2 that the state of the exclusive I/O device which was previously sent out and rejected has changed from exclusive to released and notifies the upper system which previously sent out the exclusive command and rejected of the release of the specific I/O device; and a timer 5 which monitors the exclusive release memory section 2 so that the upper system knows the usage state after the specific I/O device has been occupied, measures the elapsed time when an exclusive state is detected, and outputs a time-out signal when a predetermined time period has elapsed.
A release request unit 6 which, upon receiving a time-out signal output from the timer 5, sends a release request signal to the host system to request the release of a specific input/output device that is being occupied;
and a command control unit 7 which receives a command other than an occupation or release command and outputs an operation stop signal to the timer 5 if the command is for an input/output device measuring the elapsed time of a reserved state.

Next, the operation will be described.

The main control unit 1 receives and decodes a command from a higher-level system. If the command is an occupancy command or a release command, it is sent to the occupancy/release memory unit 2, and if it is another command, it is sent to the command control unit 7.
The release report unit 4 stores the release of the occupation of each I/O device, and when the state of an occupying I/O device for which an occupation command was previously sent and rejected changes from occupied to released, it receives an instruction from the main control unit 1 and passes the processing to the release report unit 4. The release report unit 4 notifies the higher-level system for which an occupation command was previously sent and rejected of the release of the specific I/O device. If the command is an occupation command for an I/O device that is already occupied by an occupation command, the main control unit 1, upon learning of this,
The process is passed to the command refusal unit 3, and this fact is stored.
The command rejection unit 3 reports to the host system rejecting the command that the command has been rejected because the I/O device desired to be occupied is already occupied. The timer 5 monitors the exclusive release memory unit 2, and when it detects an occupied state, it measures the elapsed time, and when a predetermined time period is exceeded, it outputs a time-out signal.
Of course, if the I/O device being measured is released during this measurement period, the timer 5 stops measuring.
When the time-out signal output from the timer 5 is received, a release request signal is sent to the host system to request the release of the specific input/output device that is being occupied.

[0014] When the command received by the main control unit 1 is a command other than occupation or release, the command control unit 7 receives this command, and when this command is for an I/O device that is measuring the elapsed time in a reserved state, it can output an operation stop signal to the timer 5. Even when the timer 5 receives this operation stop signal, it normally ignores it and continues measuring, but it is also possible to add a function and configure it so that it resets the measurement of the elapsed time to the initial value and starts measuring again.

[0015]

As explained above, the present invention provides a conventional input/output device control device with a timing means which monitors the usage state of an input/output device after the host system has occupied it, and when it detects a reserved state, measures the elapsed time and outputs a time-out signal when a predetermined time length is exceeded, and a release request means which, upon receiving the time-out signal output by the timing means, sends a release request signal to the host system requesting the release of the I/O device. This has the effect of making it possible to effectively utilize the I/O devices, whereby an I/O device that has been occupied by a host system but not used for a certain period of time can make a release request to the occupying host system and be released.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a block diagram showing an environment in which a conventional input/output device occupancy control method and occupancy control device are used.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 Main control unit 2 Exclusive release memory unit 3 Command refusal unit 4 Release report unit 5 Timer 6 Release request unit 7 Command control unit

Claims (3)

(57) [Claims] [Claim 1] Among various control methods performed between a plurality of host systems and a plurality of input/output devices commonly used by the plurality of host systems, a first host system outputs an occupancy command for a specific input/output device, and the first host system outputs an occupancy command for a specific input/output device.
2. An input/output device monopoly control method for causing a first higher-level system to occupy the specific I/O device, releasing the occupied specific I/O device in response to a release command output by the first higher-level system, and if the first higher-level system receives an occupation command for the specific I/O device output by a second higher-level system while the first higher-level system is occupying the specific I/O device, rejecting the occupation command, and notifying the second higher-level system of the release of the specific I/O device after the release of the specific I/O device, the method comprising the steps of : measuring an elapsed time of an occupation state of the specific I/O device occupied by the first higher-level system; and if the occupation continues for a predetermined time or longer, making a request to the first higher-level system to release the specific I/O device. 2. An occupancy/release storage means for receiving an occupancy command and a release command for a specific I/O device output by a first higher-level system and storing an occupancy and release state of the specific I/O device of the first higher-level system, and for detecting that an occupancy command for the specific I/O device output by a second higher-level system is received while the first higher-level system is occupying the specific I/O device and that the occupancy command is rejected, the occupancy/release storage means for detecting that the specific I/O device is occupying the specific I/O device and ...
and a release reporting means for notifying the second host system of the release of the specific I/O device when the storage state of the occupancy/release storage means for the specific I/O device has changed from occupied to released.
an occupancy control device comprising: a timing means for detecting by monitoring an occupancy release memory means, measuring the elapsed time, and outputting a time-out signal when a predetermined time length is exceeded; and a release request means for sending a release request signal to the first higher-level system to request the release of the specific I/O device upon receiving the time-out signal output by the timing means. [Claim 3] An occupancy control device for an input/output device as described in claim 2, characterized in that the timing means monitors the memory status of the occupancy release means, and when any input/output device becomes occupied, begins measuring the elapsed time and outputs a time-out signal when a predetermined time length is exceeded, and is further provided with a function of resetting the measurement of the elapsed time to an initial value and restarting measurement when the input/output device during which the elapsed time is being measured becomes in use.