SU1580390A1 - Model of server for queueing systems - Google Patents

Abstract

The invention relates to specialized means of computing and is intended to simulate the process of servicing a quota and failure processes when servicing a quota by one multichannel servicing device. The purpose of the invention is to simplify the known model. This goal is achieved by the fact that the model contains K service channels, the element OR, the first group of elements AND, the first and second elements NOT, the first and second groups of elements OR - NOT and the second group of elements I. Each service channel of the order includes a trigger, element OR and random pulse generator. 2 Il.

Description

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The invention relates to specialized means of computing and is intended to simulate the process of servicing a quota and failure processes when servicing a quota by one multichannel servicing device.

The purpose of the invention is to simplify the model.

Figure 1 shows a diagram of the model; Fig. 2 is a diagram of the service channel of the quotation.

The model contains K service channels 1 with a start input 2, service stop 3 input, second 4 and first 5 trigger outputs and output 6, element OR 7, first group of elements AND 8, first 9, second 10 NOT elements, first 11 and the second 12 groups of elements OR NOT, the second group of elements AND 13.

The service channel of the quotation contains a trigger 14, an OR element 15, and a generator of 16 random pulses.

The device also includes the input 17 of the reception of the quota for service and the input 18 of the service termination of the quota.

The verbal description of the model operation is as follows.

In the initial state, all service channels are free and ready to receive a quotation. The application received in the model is occupied by a free service channel, which has a smaller number of free channels. When a signal arrives at the termination input, the service is terminated in the channel that has the lowest number of service users.

The model works as follows.

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In the initial state, the generators 16, the random pulses of all service channels are not triggered, and the triggers 14 are in the state in which the output 4 has a logical unit signal, and the output 5 has a logic zero signal.

At the same time, all elements of AND 8 are open by the second inputs connected to the outputs of 4 triggers of service channels, but all elements of AND 8, starting from the second, are closed by a zero signal coming to their third input from the corresponding elements OR-HE. This is due to the fact that at all inputs of the elements OR-NO 8 there is a single signal, which is also at the input of the element NOT 10. Thus, only the first service channel is ready to accept the application in the initial state.

Upon receipt of the application, it passes through the open first element AND 8, overturning the trigger of the first service channel, and starts its random pulse generator 16. In the first inputs of the OR-NOT 11 elements, the signal of the logical unit disappears, and the second And 8 element opens the third input, since the signal at the input of the element NOT 10 is also zero. The next one, which arrives before the end of the first service, ends only through the second element And 8, since all the other elements And 8 are closed. At the same time, the OR-NOT 11 elements will open in the second inputs, and the third channel AND 8 element is ready to receive a signal from the input 17, since there is a zero signal on both inputs of the first OR-NOT-11 element. Thus, the passage of a request to any service channel causes the following switchings in the model: at the second input, AND 8 of this channel is closed by a signal from output 4 of trigger 14; the zero signal from output 4 opens, on the corresponding input, the elements of the OR NOT of all channels having a number greater than the number of the occupied channel; a single signal from the output 5 of the trigger 14 opens on the corresponding input the element And 13, whose number is equal to the number of the busy channel; a single signal from the output 5 of the trigger 14 is closed on the input element NO 9

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or the corresponding inputs elements OR NOT 12.

Thus, after accepting several requests for service, for example, three, only the fourth element AND 8 is ready for reception of the request, and of elements 13 and 13 ready for the signal from input 18, only the first element 13 is ready.

After the end of the random service time of the request in the service channel, the generator 16 generates a pulse, which through the OR element 7 arrives at the model output and simultaneously through the OR element 15 overturns its trigger 14 .. At this, the AND element 8 of this channel opens, closes to the second input, all the elements OR-NOT 11, are closed by a zero potential, the element AND 13 of this channel and the elements OR-NOT 12 are opened at the corresponding input.

For example, service three channels 1 is in service, the fourth channel is ready to receive the request, since the fourth element AND 8 is open at the control inputs, open at the control input and the element 13 of the first service channel of the request. Let the second channel now be free. Then the element AND 8 of the second service channel opens and the second channel is again ready to receive the application, since it has the smallest number of free channels and all channels, starting from the third, are closed with zero potential coming from the corresponding channels OR-NOT 11, and elements And 13 is ready to skip the signal from input 18 again only the first element And 13.

When a signal appears at the input 18, indicating the need to discontinue the application, it passes through the And 13 element, the one of the occupied channels, which has the lowest number. Let this be the first element of AND 13, then the signal from its output stops the generator 16 of the first channel 1 of the service, and through the element OR 15, the trigger 14 transfers to the initial state. In this case, a signal from the generator 16 is not received at the model output.

Rollover trigger 14 causes the first element to close.

And 13 is a zero signal from output 5 of the first channel and opening through the second inputs of all elements OR NOT 12 elements AND 13, starting from the third and also opening through the element 9 of the second element AND 13, which is ready to skip the signal from input 18. If This signal arrives before the end of service for the second channel, then the third element AND 13 is prepared in the same way. If the second channel also ends the service of the application, only the third element 13 is open to the control inputs, i.e. corresponding to the channel, occupied by the service, with a lower number.

the input of the second element AND the second corpse - Similarly, the model works and in the other 20 output of the element OR NOT the first group (j 1, K-2) is connected to the third input of the (j + 2) -th element AND of the first group, output j- The ro element of the OR-NOT of the second group is connected to the second input of the (j + 2) -th element AND of the second group, characterized in that, in order to simplify the model, the first output of the trigger of the 1st quotation service channel (1 1, K - 1) connected to the 1st inputs of all the elements of the OR-NOT of the second group, the first output of the M-channel trigger is about-. "Serving the reel (M 2, K) is connected to the third input of the M-th element

These are the combinations of the number of channels occupied and the number of service discontinuities.

Claims (1)

Invention Formula The model of the servicing device for queuing systems, containing two groups of elements AND K elements AND in each group, two elements NOT, two groups of elements OR — NOT K-2 elements OR — NO in each group, element OR, K service channels wok, each of which contains a random pulse generator, an OR element and a trigger, in each service channel of the request, the output of the random pulse generator is connected to the first input of the OR element, the output of which is connected to the first trigger input, the outputs of the random pulse generators connected respectively to the inputs of the element OR of the model, the output of which is the output of the model, the output of the 1st element AND of the first group (i 1, K) is connected to the trigger input of the random pulse generator and the second input of the trigger of the 1st service channel, output 1 element of element II of the second group is connected to the stop input of the random pulse generator and the second input of the element OR of the 1st service channel quota, the input input for the model service is connected to the first inputs of the elements AND of the first group, the termination input. the model is connected to the first inputs of AND gates of the second group, the first channel of the first flip-flop output service applications are coupled to a second input of the first AND gate group and the second input of the first NOT element, whose output is connected to a second the input of the second element AND the second corpse of the 20 output element OR NOT-per5 0 the howling group (j 1, K-2) is connected to the third input of the (j + 2) -th element AND of the first group, the output of the j-ro element OR-NOT of the second group is connected to the second input of the (j + 2) -th element AND the second groups, characterized in that, in order to simplify the model, the first output of the trigger of the 1st service channel of the application (1 1, K - 1) is connected to the 1st inputs of all OR-NOT elements of the second group, the first output of the M trigger go channel about-. "Serving the reel (M 2, K) is connected to the third input of the M-th element 5 And the second group, the second output of the K-th trigger of the service channel; the quota is connected to the second input of the K-th element AND of the first group; the second trigger output of the first service channel 0 for wok is connected to the input of the second the element NOT, the output of which is connected to the third input of the second element AND of the first group, and the second output of the trigger of the 1st service channel 5 the call is connected to the 1st inputs of all the elements OR NOT the first group. JL i and K wha th j U / g.2