1 00:00:01,160 --> 00:00:02,150 Hello, welcome back. 2 00:00:02,360 --> 00:00:11,060 In this lesson, we go in to see how to work with semaphores using our Simms's outer space and going 3 00:00:11,070 --> 00:00:13,250 to make a copy of the last projects over here. 4 00:00:18,130 --> 00:00:20,890 My computer and I responded just a moment. 5 00:00:25,660 --> 00:00:33,580 OK, I'm going to right click, copy and paste over here, I call this 42. 6 00:00:38,160 --> 00:00:38,970 I call this. 7 00:00:42,460 --> 00:00:43,630 Over semaphores. 8 00:00:50,580 --> 00:00:51,180 Like this. 9 00:00:53,070 --> 00:00:58,770 OK, so we're going to expand this and open our mind to see fall over here. 10 00:01:03,920 --> 00:01:12,530 And this a copy of our last project in the last project we created, The Time is OK, and also in this 11 00:01:12,530 --> 00:01:13,760 project we have. 12 00:01:15,620 --> 00:01:19,610 We have four tasks and they all have different priorities. 13 00:01:20,440 --> 00:01:22,740 We can send them back to normal priority. 14 00:01:22,790 --> 00:01:27,310 We can either let them or have the same priority or keep this. 15 00:01:27,320 --> 00:01:33,320 But I'm going to set all of them to priority normal because we wanted to run a different experiment 16 00:01:33,320 --> 00:01:34,820 when we changed our priorities. 17 00:01:35,150 --> 00:01:40,810 So we have four tasks of the same priority and we have two timers. 18 00:01:41,210 --> 00:01:42,250 We don't need a timers. 19 00:01:42,260 --> 00:01:43,820 We can keep it without cleaning it. 20 00:01:44,340 --> 00:01:48,190 OK, so we are here to find out how to deal with semaphores. 21 00:01:48,710 --> 00:01:56,970 So semaphores, we have to go to our documentation to see what apps we have available for us. 22 00:01:57,650 --> 00:01:58,940 OK, I'll come over here. 23 00:02:00,540 --> 00:02:04,440 And then there is semaphores punishment here, click this dropdown. 24 00:02:08,510 --> 00:02:09,620 And over here. 25 00:02:11,680 --> 00:02:16,960 Let's see the SEMAFO Hassan attributes just like the task, so let's find out what his attributes looks 26 00:02:16,960 --> 00:02:17,260 like. 27 00:02:19,340 --> 00:02:20,420 So this attributes. 28 00:02:21,460 --> 00:02:26,890 The name of the SEMAFO attributes bit memory control block the size provided. 29 00:02:27,250 --> 00:02:29,820 OK, so we just going to give our SEMAFO and name. 30 00:02:29,860 --> 00:02:32,050 We're not going to assign the other attributes. 31 00:02:32,590 --> 00:02:37,240 OK, so now let's see this function or SEMAFO new see. 32 00:02:39,330 --> 00:02:40,800 So 074 new. 33 00:02:41,970 --> 00:02:49,230 This function creates an initializes a SEMAFO object, so this is what we would use to create our semaphore, 34 00:02:49,770 --> 00:02:52,520 and this function, as we can see, takes three arguments. 35 00:02:52,890 --> 00:02:56,010 The first argument is the maximum count of the SEMAFO. 36 00:02:57,100 --> 00:03:01,300 And then the second argument is the initial count, and the third argument is the attributes. 37 00:03:02,920 --> 00:03:10,870 The attribute structure, so from here, we know we are creating a account in semaphore, right, so 38 00:03:10,900 --> 00:03:17,290 there is maximum initial count and then the SEMAFO attribute, such as the name and the other stuff 39 00:03:17,290 --> 00:03:18,710 kept in the attribute structure. 40 00:03:19,240 --> 00:03:28,030 OK, and then of course, after that we would have our SEMAFO or SEMAFO receive and some of our acquire 41 00:03:28,360 --> 00:03:36,460 and then the other functions gets count, delete, SEMAFO gets the name of SEMAFO, etc. So we know 42 00:03:36,460 --> 00:03:36,990 what to do. 43 00:03:37,240 --> 00:03:42,520 So we have to declare an attribute, just like our tasks here have attributes. 44 00:03:43,720 --> 00:03:47,820 The SEMAFO has its own attributes and the attribute structure has its own members. 45 00:03:48,190 --> 00:03:53,350 But what are we going to do here is just create we're going to create a simple attribute. 46 00:03:53,380 --> 00:03:54,510 This will have just a name. 47 00:03:54,940 --> 00:03:56,020 So come up here. 48 00:03:56,470 --> 00:04:02,260 I'll have this attribute SEMAFO attributes I could have created inside of me and function. 49 00:04:02,260 --> 00:04:04,150 It is fine, but I'm creating it here. 50 00:04:04,750 --> 00:04:12,880 OK, and we given this the name you are SEMAFO and then we're going to declare a Hando or a SEMAFO idee. 51 00:04:13,210 --> 00:04:22,470 So Hindoos that we had in the native free Arktos APIs are called IDRs in the Simms's Arktos space. 52 00:04:22,840 --> 00:04:26,860 So we create an idea for some of what we're going to call this UAT. 53 00:04:26,860 --> 00:04:27,910 Same idea. 54 00:04:28,780 --> 00:04:39,460 Once that is done, we going to create our SEMAFO, we're going to create a SEMAFO of a maximum count 55 00:04:39,460 --> 00:04:45,130 of one and we're going to set initial count to one as well so that our first task will be to know the 56 00:04:45,130 --> 00:04:46,620 SEMAFO would have access to it. 57 00:04:46,990 --> 00:04:49,750 So I'm going to come down here before we start the scheduler. 58 00:04:50,110 --> 00:04:51,370 We create our SEMAFO. 59 00:04:52,670 --> 00:04:59,990 And well, criticism for the handle of the SEMAFO is going to be retained and stored in our new outswim 60 00:04:59,990 --> 00:05:04,520 ID or the idea of the SEMAFO to use the language of Simms's Arktos. 61 00:05:04,880 --> 00:05:07,460 The ID is going to be retained and we're going to start it over here. 62 00:05:08,000 --> 00:05:14,930 OK, so then we're going to use this SEMAFO to print something to our UAT. 63 00:05:16,790 --> 00:05:17,240 So. 64 00:05:18,650 --> 00:05:20,810 So far, our experiment has been. 65 00:05:21,870 --> 00:05:23,490 You know, incrementing our. 66 00:05:26,360 --> 00:05:28,530 Our task profile is with this delay. 67 00:05:28,550 --> 00:05:33,980 I'm going to delete all of our pseudo delay from each and every function, so I delete this first one, 68 00:05:34,670 --> 00:05:36,080 delete this second one. 69 00:05:37,190 --> 00:05:38,510 Delete this third one. 70 00:05:40,430 --> 00:05:42,730 And then there should be a last one to leave this one. 71 00:05:43,480 --> 00:05:50,320 OK, so each task is simply going to take the SEMAFO and imprint's to the serial port and then release 72 00:05:50,320 --> 00:05:50,970 the SEMAFO. 73 00:05:51,580 --> 00:05:58,120 So just like we did in our native apps, I'm going to say, oh, SEMAFO acquire. 74 00:05:58,780 --> 00:06:00,460 And this takes two arguments. 75 00:06:00,580 --> 00:06:06,700 The idea of the semaphore you wish to acquire and then the weeks time we saying wait forever. 76 00:06:06,730 --> 00:06:10,480 So we all get stuck here until we are able to acquire the SEMAFO. 77 00:06:10,900 --> 00:06:17,350 Once we do that, we're going to print this blue task to the new art and we're going to release the 78 00:06:17,350 --> 00:06:21,220 SEMAFO so that the next task will have access to it. 79 00:06:21,700 --> 00:06:26,730 And the next one, which is read is going to acquire the SEMAFO as well. 80 00:06:27,520 --> 00:06:30,460 And then it will do the same thing after red. 81 00:06:31,330 --> 00:06:37,510 Then Orange would acquire the semaphore and we can let Orange and the others we can. 82 00:06:39,960 --> 00:06:44,340 We can pass it around, but let's experiment, we just these two tasks. 83 00:06:45,270 --> 00:06:45,870 OK. 84 00:06:49,470 --> 00:06:51,880 Let's see, what else are we missing? 85 00:06:52,260 --> 00:06:55,530 We are looking good, so I'm going to click here to build. 86 00:07:02,710 --> 00:07:04,990 OK, so because we deleted our. 87 00:07:06,060 --> 00:07:12,780 For int, because we deleted our four inch equals zero less than seven thousand, the delay, who gets 88 00:07:12,800 --> 00:07:15,500 in a warning of having this unused variable here? 89 00:07:15,510 --> 00:07:20,280 I'm going to delete each and every one of them of deleted the one in orange. 90 00:07:20,280 --> 00:07:21,650 I've deleted the one in green. 91 00:07:22,110 --> 00:07:25,260 I'll do that for blue and red. 92 00:07:25,500 --> 00:07:28,680 I'll delete this one here and see. 93 00:07:29,740 --> 00:07:31,760 I would like to read over here as well. 94 00:07:32,260 --> 00:07:35,380 And now let's do it again, click over here to build. 95 00:07:40,150 --> 00:07:41,420 It's built successfully. 96 00:07:42,710 --> 00:07:44,170 All right, click over here. 97 00:07:45,680 --> 00:07:51,370 And then I said, bug us a STEM 32 application also like this over here. 98 00:07:54,040 --> 00:07:55,240 And then I'll say, OK. 99 00:08:01,030 --> 00:08:01,810 It's open in. 100 00:08:03,370 --> 00:08:04,180 Quick to switch. 101 00:08:08,420 --> 00:08:10,250 And then I'm going to open real to. 102 00:08:19,120 --> 00:08:21,790 OK, this is real time from the last time we used it. 103 00:08:21,820 --> 00:08:29,320 I'm going to clear this, going to minimize this and I'm going to click play over here so we can see 104 00:08:29,920 --> 00:08:31,130 how our system is working. 105 00:08:31,940 --> 00:08:38,560 OK, so as you can see, red, blue, red, blue, red, blue, blue. 106 00:08:38,860 --> 00:08:39,960 We already know this. 107 00:08:40,360 --> 00:08:45,850 So now we know how to achieve this using the CMS artist API. 108 00:08:46,570 --> 00:08:48,250 OK, so that's all there is. 109 00:08:48,880 --> 00:08:50,200 And I've seen the next lesson. 110 00:08:50,260 --> 00:08:51,100 Have a nice day.