SU1451716A1 - Device for modeling mass service priority systems - Google Patents

Abstract

The invention relates to specialized computer aids and is intended to simulate the service process for r SEM in priority orientation-oriented queuing systems. The purpose of the invention is to expand the functionality of the device by simulating the process of probabilistic orientation of the serving device to service applications with different priorities. The goal is achieved by introducing elements of prohibition into the device, OR, and probablity. foot switch The device simulates the operation of queuing systems of two streams of different priority orders by one servicing device with failures in service reception, if the servicing device is occupied with orientation or servicing the application of the same or higher priority at the moment of receipt of the application. Orientation of the servicing device to servicing the applications of different priority begins immediately after termination of the service of the previous application, and it is most likely that orientation is to servicing the backward flow, the probability of which is maximum. A request that arrives at the moment when the servicing device is oriented towards servicing the flow of this flow is sent immediately to the servicing. The application that arrives during the orientation period of the servicing device for servicing the same flow is accepted for servicing immediately after the end of orientation. The application that arrives during the period when the servicing device is not occupied, but is oriented or oriented towards servicing the application of another flow, begins the reorientation of the servicing device. 3 il. S (L 4 ate about

Description

The invention relates to specialized, 3jdpoBaHHbtM means of computing technology and is intended to simulate the process of servicing applications in priority orientation-oriented queuing systems.

The aim of the invention is to expand the functionality of the device by simulating the process of probabilistic orientation of the serving instrument to service applications with different priorities.

Fig, 1 shows a block diagram of the device; Fig. 2 is a block diagram of a unit for forming time intervals corresponding to the length of orientation of the serving device for servicing the application; Fig. 3 is a diagram of a probability switch (switch),

The device contains the first 1 and third 2 elements And, the sixth 3 and third 4 elements of UTA, the second 5 5th 6, the sixth 7, the fourth 8, the seventh 9 and the eighth 10 elements And, the first 11, three 12 and the third 13 triggers, first 14 and the second 15 elements of the ban, a quarter of 16; F 5 17, the first 18 and second 19 OR elements, the first 20 and second 21 random pulse generators, a probability switch (switch) 22, the second 23 and the first; 24 blocks for the formation of time intervals corresponding to the duration of the orientation of the servicing device for servicing the application. .

Each of blocks 23 and 24 contains a generator of 25 random pulses and a trigger 26 and is designed to simulate a random time interval from the moment of starting the generator 25 .. until the appearance of a pulse at its output, which will continue to be valid. the orientation of the servicing device, the servicing of the low (block 23) and high (block 24) priorities, in the general case. the duration, the orientations for each of the flows are different, and are determined by the distribution of random pulses, the output of the generator 25. Odi from the outputs, the block orientation1 1 and pulse,. another way out is potential. A high potential. Sets up with a pulse of the generator 25 by setting the trigger 26 to the appropriate state.

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. The installation inputs Y. and „are intended respectively for disrupting the work, running the generator 25 and transferring the trigger 26 to the state at. which has a zero signal at the potential output of the orientation block. ...

f Generators 20 and 21 random pulses simulate the operation of the same service device. Therefore, their simultaneous work is prohibited.

In block 24, only one installation input Y, j is used.

The accuracy switch (switch) 22 contains a generator of 27 clock pulses, delay element 28, trigger 29, elements AND 30, 30, and element OR 31, Switch 22 absorbs random signals, probability P, and P, the appearance of which at any time interval may be .; pre-installed, and P and P / j form a complete group of incompatible events (P, + Pj 1).

This is done as follows. Let the period of the pulse sequence of the generator 27 is equal to T, and T, T - the magnitude of the delay of the pulse element 28 delay. Then for any period of time the probability of receiving a signal at the input of the first element I 30 is equal to Р T, / T, and on the second element I 30 j P (,} - 1 - (t, / T), Changing is the value of T, you can obtain the required probabilities of the occurrence of signals at the switch outputs.

The probability switch is intended to simulate the process of adapting the orientation of the instrument to the probabilistic characteristics of the flow of a quotation.

The essence of adaptation is as follows. If the probabilities of occurrence at the inputs of low priority (P,) and high priority (P2 1-P), then after the service is finished with the next request with probability P, the orientation of the serving device to service the low priority application begins, and with probability P, to service a high priority application.

Verbal model of work, the device is as follows.

Two streams of quotes with different absolute priorities arrive at

3 -14 one serving device. Requests of the same priority for admission to service fail when the device is busy. High priority applications in the event that the device is busy servicing low priority applications terminate the service of low priority applications that leave the system.

Orientation of the servicing device to the servicing of the application of different priority is generally different and begins after the termination of the service of the previous application. With probability P, the servicing device is oriented to service a low priority application and with probability 7 to service a high priority application.

A request that arrives at the moment, the time when the servicing device is oriented towards the maintenance of the application for this flow, goes directly to the service. The application that arrives during the orientation period of the servicing device to the same flow is started after the termination of the orientation process started before the arrival of the application. The application that arrives at a time when the servicing device is not occupied, but is oriented or oriented towards servicing the application of another flow, begins reorientation of the servicing device.

The device works as follows.

The initial position of the elements: the generators 25 are not running; generator 27 operates from the moment of voltage supply; the triggers 11, 12 are in positions where the And 3, 4 elements are opened along the corresponding inputs and the And 9, 10 elements are closed; on

trigger output .13 - zero potential, | which terminates the elements And 6, 7; at the output of the trigger 26 - zero potential; prohibition elements 14, 15 are open at the control input.

Consider the main modes of operation of the device.

Orientation of the service device and maintenance of the lowest priority.

For low priority, the open element AND 1 passes; the overturns are trigger 11, which closes AND 1 and opens And 9,

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passes through the open element 14 of the ban and the element OR 17 and starts the block 23.

After a random orientation time, the generator 25 of the block 23 generates a pulse, which through the open element AND 9 comes through the element OR 18 to start the generator 20 and simultaneously triggers the trigger 26 of the block 23. A single signal appears at the output of the trigger 26, but it does not pass through the element AND 6, since this element is closed by the zero potential from trigger 13. At the same time, the pulse from the output of the element OR 18 returns the trigger 26 of block 23 to its initial state, at which a single potential is removed from the input of the element 6.

I After a time corresponding to the random service duration of the application, a signal appears at the output of the generator 20, which arrives at the output of the serviced applications of low priority and interrogates the probability switch 22. With a probability P, a signal appears lane exit 5

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And 30, and with probability P, at the output of the second element And 30j switch 22.

Let the signal appear at the output of the first element AND 30. This signal through the element 16 sets the initial state trisper 11, which opens the element 1 and closes the element 9, confirms the initial state of the trigger 12, starts the block 23 through the element OR 17 (generator 25) and overturns the trigger 13, which, prior to the end of the simulation process, now opens elements 6, 7 through the corresponding inputs. The process of pre-orientation of the servicing device towards servicing the low priority order begins.

If a low priority application comes before the end of the orientation process, then it passes through the open. element AND 1, the open element 14 of the prohibition, element OR 17 and confirms the operating state of the generator 25 of block 23. Simultaneously, the trigger 11 closes the element AND 1 and prepares a circuit for passing a signal to start the generator 20, opening element AND 9. The process of servicing the application ( generator 20 start up

immediately after the end of the orientation process and the generation of a pulse by the generator 25 of the block 23, Thus, the duration of stay of the application in the system is reduced (the service speed increases) due to the preliminary orientation of the serving device.

If the servicing device orientation is completed before the low priority application to the device input, then the output signal of the generator 23 overturns the trigger 26, which closes with a single signal from the output of element And 6 prohibition element 14 and opens element And 5, the signal from the output of generator 25 This doesn’t pass to the start of the generator 20, since the AND 9 element is closed by the trigger 1 K

When a low priority application arrives at the input of the device after the orientation is completed, it passes through the open element AND 5 and the element OR 18 immediately to the start of the generator 20 and from the output of the element OR 18 reset the trigger 26 of the block 23, and the prohibition element 14 opens and element 5 is closed. At the end of the service, the probabilistic switch 22 is again polled.

When the signal appears at the first output of the switch 22, the orientation of the device to service the low priority application begins again. When a signal appears at the second output of the probabilistic switch 22 through the elements of OR 16, prohibition 15, OR 3, block 24 is set in and the servicing device starts to service the high priority requests,

With the start of orientation, generator 25 of block 24 starts, after the end of orientation, trigger 26 of block 24 overturns, prohibition element 15 closes and element 8 opens, however, the signal from generator 25 output of block 24 to start generator -21 does not pass, because element 10 closed low potential with trigger output 42

If the process, orientation to service of a high priority application or after its termination, enters the device as a low priority, then it will open

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element I 1, prohibition element 14 starts the generator 25 of block 23, and the orientation of the device to its maintenance begins. At the same time, the signal from the output of the element And 1 is fed to the installation inputs of the block 24 and the generator 25 and the trigger 26 of the block 24, as well as the elements 7, 8 and the prohibition element 15, reset to the initial state.

Orientation of the servicing device and servicing of high priority orders.

If, after switching on the device, it passes the high priority first, then the operation of the device is similar to the work on orientation and maintenance. Low priority, only instead of AND 1, trigger 11, prohibition elements 14, OR 17, block 23, AND 6 elements , 5, 9, generator 20, work similarly as an AND 2 element, trigger 12, prohibition elements 15, OR 3, block 24, elements I. 7, 8, 10, generator 21, After the completion of service of a high priority application, the probability switch 22 when polling, it sends a signal 0 to one of its outputs. When a signal appears at the second output, the device starts to orient itself for servicing a high priority application.

If a high priority application arrives before the device is orientated to service a high priority application or after it is completed, the operation of the device is similar to the work when a low priority application arrives

Servicing a high priority application at the moment of servicing a servicing device orienting it to servicing a low priority application or servicing it,

In this case, the application from the output of the element And 2 overturns the trigger 12, which closes the element And 14, opens the element And 10, at the same time the signal from the output of the element And 2 sets to its initial state either the block 23 or the generator 20. The low priority received previously, the high priority application is reset to block 24, if it has not been in the initial state before. Therefore, the application of high priority from the output of the element And 2 passes through

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the open element 15 of the ban on the launch of block 24. In the future, the operation of the device is similar to the maintenance of the first high priority application.

Indicators of the process of servicing applications with different priorities are determined by measuring the characteristics of the input and output streams and the number of responses of individual units of the device.

Claims (1)

Invention Formula. Eni .: A device for simulating priority queuing systems containing eight AND elements, three flip-flops, two time interval forming units corresponding to the orientation time of the serving device for servicing applications, two random impulse generators, three OR elements, the first input of the first AND element is input for the low priority of the device., the second input of the first element I is connected to the first input of the first trigger, the output of the first element I is connected to the first input of the second element This And, the first input of the third element And is the input of the high priority applications, the second input of the third element And is connected to the first output of the second trigger, the outputs of the first and second random pulse generators are outputs of the served applications of the low and high priorities of the device, the outputs of the second and the fourth And elements are connected to the first inputs of the first and the second elements. OR, respectively, characterized in that, in order to expand the functionality of the device by simulating a probabilistic process orientation of the device to service a claim with different priorities, it additionally contains two prohibition elements, the fourth, five and sixth OR elements and a probability switch, with the output of the first AND element connected to the first input of the third element OR, the first reset input of the first the unit of formation of time intervals, corresponding to the length of orientation of the servicing device for servicing the application, and the information input of the first element Q 15 jo 25, 35 45 50 55 prohibition, the control input of which is connected to the second input of the second element AND and the output of the fifth element AND, the first input of which and the first input of the sixth element AND are connected to the output of the third trigger, the input of which is connected to the output of the fourth element OR and the first inputs of the first and second triggers , the second inputs of the first and second triggers are connected respectively to the outputs of the first and second elements And, the second output of the first trigger is connected to the first input of the seventh element And, the second input of which is connected to the pulse output in the first block of formation of time intervals, corresponding to the duration of orientation of the servicing device to servicing the charge, the potential output of which is connected to the second input of the fifth element AND, the output of the seventh element AND is connected to the second input of the first element OR, the output of which is connected to the start input of the first random generator pulses, the start input of the second block of formation of time intervals corresponding to the duration of the orientation of the servant. device for servicing the request, connected to the output of the fifth element OR, the first input of stopping the second block of forming time intervals corresponding to the duration of orientation of the serving device for servicing the request, and the output of stopping the first random pulse generator connected to the output of the third element AND the first input of the fourth And element and information, the input of the second element of the prohibition, the output of the first, element OR is connected to the second stop input of the second block of formation of time intervals, corresponding to the service duration; the device for servicing the demand; the control input of the second prohibition element is connected to the output of the sixth AND element and the second input of the fourth AND element, and the output of the second prohibition element is connected to the first input of the sixth OR element, the output of which is connected to the trigger input the first block of formation of time intervals corresponding to the duration of the orientation of the servicing device to the servicing of the application, potenIt  r PP 28 22