1 00:00:01,090 --> 00:00:02,560 Hello, welcome back. 2 00:00:02,590 --> 00:00:08,830 In this lesson, we going to see how to work with counting semaphores, I'm going to make a copy of 3 00:00:08,830 --> 00:00:12,100 our Lost Project, this number twenty here. 4 00:00:12,100 --> 00:00:17,770 I'm going to make a copy of, say, copy and then paste over here. 5 00:00:18,520 --> 00:00:20,680 And then I'll call this counting semaphores. 6 00:00:35,850 --> 00:00:38,430 When it's done, I'm going to close this old farmhouse. 7 00:00:39,620 --> 00:00:45,880 OK, so this is just a tiny bit of difference open, I may not see fall over here. 8 00:00:48,390 --> 00:00:55,590 And over here, where we created a SEMAFO, remember the projects, we made a copy of this for the SEMAFO 9 00:00:55,590 --> 00:00:57,560 Mutex, that's why we see this here. 10 00:00:57,840 --> 00:01:05,430 So if we want to create account in SEMAFO, the function to use is X semafo create counting and this 11 00:01:05,430 --> 00:01:07,080 function takes to document. 12 00:01:09,860 --> 00:01:12,200 The first argument is the total count. 13 00:01:13,580 --> 00:01:16,400 So we can say 10 and then the next argument. 14 00:01:17,310 --> 00:01:26,220 Is the initial count so you can think of this as using a bathroom or washroom analogy and the semaphores 15 00:01:26,220 --> 00:01:33,120 being the keys, so if we say we are creating account semaphore, we are saying accounting SEMAFO with 16 00:01:33,120 --> 00:01:35,820 a total count of 10, we are saying we have 10 keys. 17 00:01:36,940 --> 00:01:45,730 To, let's say, 10 separate bathrooms and initially zero of the keys is taken, so zero, so 10 is 18 00:01:45,730 --> 00:01:48,910 the total count, but in our case, our resources, a single one. 19 00:01:49,060 --> 00:01:54,080 In this experiment, we're using one zero port to print the data. 20 00:01:54,100 --> 00:02:00,720 So our number of count, total number of count is one and then initially zero. 21 00:02:00,970 --> 00:02:05,260 That is how we're going to initialize our account and SEMAFO and we leave everything the same. 22 00:02:05,380 --> 00:02:09,070 Let's build and see what we have or click here. 23 00:02:09,910 --> 00:02:10,630 Right, click. 24 00:02:11,790 --> 00:02:13,770 And built project over here. 25 00:02:15,410 --> 00:02:16,910 It's built successfully. 26 00:02:17,690 --> 00:02:18,320 Right click. 27 00:02:19,200 --> 00:02:24,570 And then I'll say run us ASTM 30 to a select number, twenty one over here. 28 00:02:25,480 --> 00:02:27,070 I say, OK, over here. 29 00:02:32,220 --> 00:02:36,630 Let's see, it's downloading, he says 97, it's done. 30 00:02:37,760 --> 00:02:40,700 OK, so this report, I'm going to open it. 31 00:02:43,440 --> 00:02:48,030 Cletis, I see real time, it's not responding. 32 00:02:49,100 --> 00:02:51,740 Going to close and open real tim. 33 00:02:54,380 --> 00:02:54,910 OK. 34 00:02:57,880 --> 00:03:00,100 OK, so the reason. 35 00:03:01,140 --> 00:03:08,490 It's not moving as this count in SEMAFO is just like the binary SEMAFO, before we use the SEMAFO, 36 00:03:08,490 --> 00:03:09,800 we first have to give it. 37 00:03:10,020 --> 00:03:13,280 We have to give the SEMAFO before the first function takes it. 38 00:03:13,740 --> 00:03:17,370 We realized that in our mutex example, we didn't have to give the SEMAFO. 39 00:03:17,370 --> 00:03:18,620 We could simply take it. 40 00:03:19,260 --> 00:03:24,540 But this time we have a single count and we have to give this. 41 00:03:27,070 --> 00:03:31,480 So before we start our scheduler, I will say eczema for give over here. 42 00:03:38,920 --> 00:03:40,180 It's pure successfully. 43 00:03:40,450 --> 00:03:41,770 I'm going to click here to run. 44 00:03:51,370 --> 00:03:54,460 It's downloaded successfully, I'm going to open our support. 45 00:03:56,540 --> 00:03:58,190 See, selectees. 46 00:04:02,520 --> 00:04:08,590 OK, as you can see, it's running when I press the push button, it becomes your right. 47 00:04:08,980 --> 00:04:09,510 OK. 48 00:04:12,960 --> 00:04:19,020 So you may wonder what is the difference between the binary semaphore and in this one, of course, 49 00:04:19,020 --> 00:04:23,610 the binary SEMAFO, like we said, there's one or zero two values. 50 00:04:24,540 --> 00:04:30,480 One key task is the haystack you or it does not, whereas this one, we can create as many clues as 51 00:04:30,480 --> 00:04:30,980 we want. 52 00:04:31,410 --> 00:04:36,050 And one other thing over here, we said this is the total number of count and this is initial count. 53 00:04:36,330 --> 00:04:44,400 If we want to give the key, if we want to give the key without using our zemi forgive here, we can 54 00:04:44,400 --> 00:04:48,960 simply set initial count to one so that we give it to the first the first task. 55 00:04:48,990 --> 00:04:50,010 So we don't need this. 56 00:04:50,190 --> 00:04:57,750 If we comment ximo give and then we said initial count to one, then our task would automatically receive 57 00:04:57,750 --> 00:04:57,960 it. 58 00:04:58,230 --> 00:05:00,750 We don't have to explicitly give from here. 59 00:05:00,960 --> 00:05:03,720 Let's see if what I'm saying is the way it works. 60 00:05:03,720 --> 00:05:04,920 I'll click over here to build. 61 00:05:10,180 --> 00:05:10,810 It's Putin. 62 00:05:12,930 --> 00:05:13,550 OK. 63 00:05:15,360 --> 00:05:16,530 Now click here to run. 64 00:05:18,730 --> 00:05:19,330 I see. 65 00:05:23,590 --> 00:05:25,960 OK, system initialization. 66 00:05:27,000 --> 00:05:27,590 AC. 67 00:05:29,220 --> 00:05:30,240 Verification. 68 00:05:31,230 --> 00:05:33,090 OK, as you can see, it's raining. 69 00:05:33,970 --> 00:05:34,720 The same way. 70 00:05:35,790 --> 00:05:42,090 OK, when I press the push button, we can see we received our data and we're not using this this we've 71 00:05:42,090 --> 00:05:45,930 commented out, but we set initial count one meaning we've given it. 72 00:05:46,530 --> 00:05:49,480 OK, so that's all there is for counting semaphores. 73 00:05:49,500 --> 00:05:50,630 I'll see you in the next lesson. 74 00:05:50,640 --> 00:05:51,390 Have a nice day.