SU1288711A1 - Device for simulating process for servicing requests - Google Patents

Abstract

The invention relates to specialized computer facilities and is intended to simulate the process of servicing two flows of applications with different priorities by one device; can be used in devices simulating the operation of queuing systems. The aim of the invention is to expand the functionality of the device by reproducing the mode of relative priority in servicing multi-priority bids. The device contains an input for high priority wok, an input for low priority wok, the second and fourth elements of the prohibition, the first and second reversible counters, the first and second elements OR, the fourth and fifth elements And, the third element of the ban, the first and second elements And, the third element OR, the first element of the prohibition, the first and second triggers, the quarter element OR, the third element AND, the separation diode, the first and second switches, the first and second impulse generators with a random following interval. 1 il. (Lu 00 00

Description

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The invention relates to specialized computer aids and is intended to simulate the process of servicing two flows of orders with different priorities by one device and can be used in devices simulating the operation of queuing systems.

The purpose of the invention is to expand the functionality of the device by reproducing the mode of relative priority in servicing multi-priority orders.

The drawing shows a block diagram of the device.

The device contains input 1 for a high priority wok, input 2 for a low priority wok, the second 3 and the fourth 4 prohibition elements, the first 5 and second 6 reversible counters, the first 7 and second 8 OR elements, the fourth 9 and fifth 5 AND elements , the third element 11 of the prohibition, the first 12 and the second 13 elements AND, the third element OR 14, the first 15 elements of the prohibition, the first 16 and the second 17 triggers, the fourth element OR 18, the third element And 19, the separation diode 20, the first 21 and the second 22 switches, the first 23 and the second 24 pulse generators with a random interval followed .

The verbal model of the device is the following.

Two random flows of different priority applications are serviced by one device. When the servicing device is busy, the applications of each of the streams become, in turn, limited in length. Low priority requests are accepted for service if there is no high priority queue. -

When modeling an absolute priority in the service discipline, a high priority application interrupts service of a low priority application, is accepted for service, after which, if there is no high priority queue, low priority service is resumed.

When modeling the relative priority in the discipline of service, an application for high priority is accepted for service only after the release of the service provider.

boron no matter what. For what priority priority was served.

The service request flows at inputs 1 and 2 are random pulse sequences, the intervals between which are distributed according to certain (different or the same) laws.

The model of the servicing device is the generators 23 and 24. The law of distribution of random pulses at their outputs is the same, since they simulate the same device. The time interval from the moment of launching the generators to the appearance of a pulse at their output is random and is distributed according to the accepted law of service.

Blocks 1, 3, 5, 7, 9 and blocks 2, 4, 6, 8, 10 simulate a queue of requests of high and low priority, respectively, and its length limit

With open switches 21 and 22, the absolute priority mode for servicing a request is modeled, and with closed switches, a relative priority mode in servicing a request is modeled.

The device works as follows.

In the initial state, in the reversible counters 5 and 6 zero is written, so that prohibition elements 3, 4 and 11 are opened. Triggers 16 and 17 are set to a position where there are voltages on the corresponding inputs of elements And 12 and 13. Herewith element 15 prohibition is open at the control input. In the future, the operation of the device in all modes occurs automatically.

In the absolute priority mode (the switches 21 and 22 are open), the low priority application from input 2 through the open prohibition element 4 is fed to the summing input of counter 6. At the input of the OR 8 element, there is a voltage that, through the open of the prohibition element 11, element And 13, the element 15 of the ban, the diode 20 starts the generator 24 pulses. In doing so, the trigger 16 overturns and closes the element AND 13 at the first entrance. Low priority bids, which arrived at the moment when the servicing device is busy, are queued to increase the contents of the reversible counter. When filling the reversible counter 6 at the output of the element312

M & 10 appears a signal closing the prohibition element 4 at the control input, limiting the queue length. After the termination of the service, the signal from the output of the generator 24 reduces the queue length by one, removing it from counter 6 on the subtracting input. The trigger 16 is reset and, if there is a queue in the counter 6, then the signal from the output of the element OR 8 again starts the generator 24 and the operation of the device is repeated.

Servicing a high priority quota in the absence of a low priority quota occurs similarly with the formation of a queue and its limitation using blocks 3, 5, 7 and 9. Signal C (element OR 7 through the open element And 12 is launched into generator 23. At the same time bans control element 11 is closed at the control input, preventing a low priority from entering the service before the end of the service of all high priority bids from the queue, and trigger 17 tilts, relieving the voltage from the input of the element 12. An high priority application and a closure at the control input of the prohibition element 15. Closing the prohibition elements 11 and 15 is necessary because, in the absence of a high priority queue, the low priority application could go to the generator 24 start up, despite the fact that the high priority is still being serviced. Therefore, the prohibition element 11 is closed for the duration of the queue of high-priority applications, and the prohibition element 15 is closed for the service time of the high-priority application.

After the end of high-priority service, the signal from the output of generator 23 reduces the queue in the reversible counter 3 and sets the trigger 17 to the initial state, open elements And 12 and prohibition 15, If there is a queue in the counter 5, the signal from the output of the element OR 7 restarts generator 23 and the operation of the device is repeated.

If there are no high-priority queues, then the service is received for a low priority.

Application of high priority, received at the time of service applications

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low priority from input 1 through prohibition element 3, reversible counter 5, element OR 7 and element 12 triggers generator 23, triggers trigger 17, closing element 12 and element 15 of prohibition on service time of high priority, and sets generator 24 the initial state, imitating the interruption of the service. low priority applications. After the signal appears at the output of generator 23, the contents of counter 5 decrease by one, the trigger 17 is reset to the initial state simultaneously the signal from the output of generator 23 through the first input from trigger 16 opens element I, and the generator 24 is started, simulating repeated maintenance of a low priority application . It is served by generator 24 if it is not in the queue for high priority wok.

After the end of the service of all high priority requests and after them of low priority requests, the circuit returns to its initial state. In relative priority mode (switches 21 and 22 are closed), if the first to receive a high-priority application, then its service is no different from the service in the previous mode.

Servicing a low priority wok, if not a high priority wok, is similar to the previous mode.

The difference between the operation of the device in this mode and the absolute priority mode is the following.

When entering into service, first a low priority application, and before the end of its service, a high priority application, this high priority application is not accepted for service until the end of the service, a low priority application. This is ensured by the fact that the signal from you-. the stroke of the first prohibition element 15 simultaneously tilts the trigger 17 through the second switch, removing the voltage from the input element I 12 and thereby preventing the receipt of a high priority application to the service device - generator 23, until the end of the service of the low priority application.

After the end of its service, the signal from the output of the generator 24 one 5128

temporarily through the first switch 21 causes the trigger 17 to its original position.

Thus, the device allows you to simulate the service of high priority priority, low priority priority service, low priority priority service interruption.

when receiving a high priority malware with an absolute priority of service and the resumption of service of an interrupted low priority application, also the organization of service

NIN of multi-priority orders with relative priority in service. In addition, the device simulates a limited queue for both nq-current orders.

Claims (1)

Invention Formula A device for simulating the process of servicing a claim containing the first element I, the output of which is connected to the start input of the first pulse generator with a random following interval, the output of which is the output of the device serviced by the high priority of the device, the second element AND whose output through the serially connected first element the interdiction and separation diode is connected to the start input of the second pulse generator with a random following interval, the output of which is the output served by low priority of the device and connected to the first input of the first trigger, the first output of which is connected to the first input of the second element, the second output of the first trigger is connected to the first input of the third element, and the second input of which is connected to the output of the first pulse generator; following interval, and the output of the third element And is connected to the start input of the second pulse generator with a random interval following, the installation input of which is connected to the output of the first element And, the first output of the second the trigger is connected to the first input of the first element, and the second output of the second trigger is connected to the control input of the first prohibition element, the output of which is connected to the second input of the first trigger, the first and 0 0 5 0 5 0 5 sixteen second reversible counters, first, second and third elements OR, fourth. The first and fifth elements AND, characterized in that, in order to expand the functionality of the device by reproducing the relative priority mode in servicing different priority applications, it additionally contains a fourth OR element, two switches and three prohibition elements, the information input of the second prohibition element is an input for the high priority device, ,, and the output of the second prohibition element is connected to the summing input of the first reversible counter, the bit outputs of which are connected respectively, to the inputs of the fourth element AND, the output of which is connected to the control Input of the second prohibition element and the inputs of the first OR element, the output of which is connected to the second input of the first AND element and the control input of the third prohibition element, whose output is connected to the second input of the second, AND element , but. the information input of the third prohibition element is connected to the output of the second OR element, whose inputs and inputs of the fifth AND element are connected respectively to the bit outputs of the second reversible counter, subtracting the 1x input - which is connected to the output of the second pulse generator with a random interval, and the summing input is connected with the output of the fourth prohibition element, the control input of which is connected to the output of the fifth element AND, and the information input is the input of the device low priority, the output of the first The first pulse generator with a random interval of the next is connected to the subtractive input of the first reversible counter and the first input of the third OR element, the second input of which through the first switch is connected to the output of the second pulse generator with a random interval of the next, the output of the first AND element, the second input of which is connected via the second switch to the output of the first prohibition element, and the outputs of the third and fourth elements OR are connected respectively to the first th and second inputs of the second trigger