1 00:00:00,790 --> 00:00:01,940 Hello, welcome back. 2 00:00:02,380 --> 00:00:08,920 In this lesson, we going to experiment with different configurations of our shetler have created a 3 00:00:08,920 --> 00:00:12,940 new project here called 32 Deshler Preemption Only. 4 00:00:13,240 --> 00:00:20,110 And what we're going to do over here is disable the time slicing option in our scheduler such that our 5 00:00:20,110 --> 00:00:25,480 scheduler has just preemption and we want to observe the effect that would have on our program. 6 00:00:25,900 --> 00:00:27,250 So this is the project. 7 00:00:27,410 --> 00:00:28,080 It's empty. 8 00:00:28,090 --> 00:00:29,800 There is no school here. 9 00:00:31,180 --> 00:00:38,410 We are going to go to our free ARTUS configurator, followed by opening the include fuda here and if 10 00:00:38,410 --> 00:00:42,190 we are to US configurator and then we'll check what we currently have. 11 00:00:43,800 --> 00:00:47,790 Currently, our schedule has configures preemptions set to one. 12 00:00:48,760 --> 00:00:55,750 And then config use less lead time slicing what a time slices here. 13 00:00:56,910 --> 00:01:00,180 We can simply surge control F and then. 14 00:01:01,080 --> 00:01:03,600 We can say slice, we can search the words slice. 15 00:01:06,300 --> 00:01:09,170 OK, time slicing, it's not written here. 16 00:01:10,620 --> 00:01:11,220 Let's see. 17 00:01:13,870 --> 00:01:17,560 Perhaps slicing, yes, lyson is the word rather than slice. 18 00:01:20,960 --> 00:01:28,870 OK, slicing the snow here, so we have config use preemption this year, if we want to have our shetler 19 00:01:28,970 --> 00:01:33,320 with time slicing, we can define time slicing here, OK? 20 00:01:35,540 --> 00:01:41,510 So what I'm going to do is I'm going to define configures time slicing and then I'll set it to zero 21 00:01:41,660 --> 00:01:42,810 and then we see something. 22 00:01:43,970 --> 00:01:47,270 OK, so over here, close to config use preemption. 23 00:01:47,450 --> 00:01:50,180 I'm going to have a new define over here. 24 00:01:52,260 --> 00:01:56,570 I see defined config use time slicing, and this is zero. 25 00:01:58,510 --> 00:02:08,320 OK, right, so this is our main road to see far less, I did a number of a number of tasks and run 26 00:02:08,320 --> 00:02:09,030 the experiment. 27 00:02:09,340 --> 00:02:11,830 So we're going to have less, say, four tasks. 28 00:02:12,820 --> 00:02:17,440 Each task would have its own profiler, the task profile that we created. 29 00:02:17,830 --> 00:02:25,090 So I'm going to come over here and define the profile this or come over here and then the profiler. 30 00:02:25,090 --> 00:02:28,390 We're simply using TYPEDEF to create a new name for this. 31 00:02:28,570 --> 00:02:32,800 You intended to underscore T word and we defined an orange task profile. 32 00:02:32,800 --> 00:02:34,930 I read the task profile are green and blue. 33 00:02:35,590 --> 00:02:39,730 OK, so once this is done, we going to create four tasks. 34 00:02:40,480 --> 00:02:45,610 We're going to have one for orange alert controller, red ality controller blue and the controller and 35 00:02:45,610 --> 00:02:46,630 green the controller. 36 00:02:46,630 --> 00:02:50,950 We're going to have one task for each controller such that we end up with this. 37 00:02:51,250 --> 00:02:52,150 We've done this before. 38 00:02:52,180 --> 00:02:55,280 This is the same as our first task creation project. 39 00:02:55,840 --> 00:02:56,260 So. 40 00:02:57,890 --> 00:02:58,730 What do we have here? 41 00:02:58,760 --> 00:02:59,420 We have. 42 00:03:00,530 --> 00:03:06,650 Task create the name of this task, task function will be orange, the controller, it has a priority 43 00:03:06,650 --> 00:03:07,120 of one. 44 00:03:07,640 --> 00:03:08,600 We have this one. 45 00:03:08,630 --> 00:03:11,650 The name of this task function will be the controller. 46 00:03:11,870 --> 00:03:13,640 It's a priority of two. 47 00:03:14,390 --> 00:03:15,560 We have this other one. 48 00:03:15,710 --> 00:03:17,400 The name of it will be Red Alert. 49 00:03:17,420 --> 00:03:22,380 The controller is got a priority of two as well, and then green the controller. 50 00:03:22,670 --> 00:03:24,800 So in summary, we have four tasks. 51 00:03:25,010 --> 00:03:29,720 Two of them have a priority of two and two of them have a priority of one. 52 00:03:29,960 --> 00:03:32,980 So we have two of them with a higher priority than the others. 53 00:03:33,620 --> 00:03:42,860 So what are we going to do basically is just place each task profiler and each of the task functions. 54 00:03:44,120 --> 00:03:49,160 So I come down here and then I'll create a task function for blue controller task. 55 00:03:49,550 --> 00:03:56,300 All I'm doing is incrementing the blue task profile in incrementing the global variable. 56 00:03:56,780 --> 00:04:01,550 I'm going to do exactly the same thing for the other tasks. 57 00:04:02,390 --> 00:04:07,580 I'll do it for Red and then I'll do it for orange. 58 00:04:10,140 --> 00:04:13,980 Over here, and then I'll do it for green. 59 00:04:15,680 --> 00:04:21,050 OK, so each task is performing a simple task, which is increment a global variable. 60 00:04:21,440 --> 00:04:28,820 OK, and we know that we have blue and red with the highest priority. 61 00:04:29,430 --> 00:04:34,660 OK, so now what we have to do is take the task functions and declare them at the top. 62 00:04:35,480 --> 00:04:39,350 So I'll declare the task functions at the top over here. 63 00:04:40,070 --> 00:04:43,040 So we have our blue, red, orange, green. 64 00:04:44,480 --> 00:04:48,970 OK, so back to our three Arktos config dots each file. 65 00:04:49,010 --> 00:04:53,510 Our scheduler says we are using preemption by no time slicing. 66 00:04:53,850 --> 00:05:00,590 OK, what we would expect without understanding how the scheduler works, what we would expect is that 67 00:05:01,190 --> 00:05:09,170 OK, since we have two tasks here with the same priority, then these two tasks should be the only ones 68 00:05:09,170 --> 00:05:09,590 running. 69 00:05:10,940 --> 00:05:15,890 Unless they go to sleep or they get blocked before the lower priority tasks should run. 70 00:05:16,120 --> 00:05:16,610 Correct. 71 00:05:17,640 --> 00:05:18,810 OK, I heard you. 72 00:05:19,350 --> 00:05:21,440 So let's see what we get with this. 73 00:05:22,440 --> 00:05:23,730 I'll click over here to build. 74 00:05:28,400 --> 00:05:29,150 It's bugden. 75 00:05:30,920 --> 00:05:35,990 OK, so we've got our you at we can delete the Ewart's. 76 00:05:37,680 --> 00:05:38,900 Oh, goodness. 77 00:05:40,410 --> 00:05:48,440 You out in the system clock, I cleaned the prototypes, so we simply have to bring them over here. 78 00:05:51,530 --> 00:05:57,710 As this clock as well as Jhpiego system clocked in A to function Prototyp. 79 00:05:59,040 --> 00:06:03,270 No, I just copied System Clock, so I copied the one for you at. 80 00:06:09,860 --> 00:06:11,870 And then I'll copy the one for you. 81 00:06:18,550 --> 00:06:25,720 And in fact, what I'm going to do is we don't need we don't need a new article because of the letter. 82 00:06:25,720 --> 00:06:30,330 The other instance I would need to put it about, because we don't need you out for this experiment. 83 00:06:30,700 --> 00:06:33,570 I'm simply going to delete you at function. 84 00:06:34,260 --> 00:06:38,170 OK, so if that is deleted, then we need not call you to over here. 85 00:06:38,770 --> 00:06:41,020 We need not call you at as simple as that. 86 00:06:41,080 --> 00:06:41,470 OK. 87 00:06:42,740 --> 00:06:47,810 Dispute over here, we're going to run the experiment, just observing the debug for you, I'll click 88 00:06:47,810 --> 00:06:48,410 here to build. 89 00:06:52,390 --> 00:06:53,980 OK, it's built successfully. 90 00:06:54,920 --> 00:07:02,710 All right, click over here, I'll go to debuggers ASTM 30 to select the current project. 91 00:07:04,830 --> 00:07:06,420 I've seen OK over here. 92 00:07:11,660 --> 00:07:13,700 It's opening click to switch. 93 00:07:17,890 --> 00:07:25,300 And I'll come to our live expressions window, I'll clear everything over here, Live Expression's. 94 00:07:26,820 --> 00:07:33,950 I see remove oh, and I'm going to add all of our task, this stuff with orange. 95 00:07:36,730 --> 00:07:38,770 I'll start with and then I'll go on to read. 96 00:07:41,600 --> 00:07:42,530 And then green. 97 00:07:47,760 --> 00:07:48,540 And then blue. 98 00:07:51,990 --> 00:07:54,600 OK, let's run and see a click here to run. 99 00:07:56,030 --> 00:08:03,250 OK, so perhaps we've not started our search to see, OK, the scheduler is not started, so let's start 100 00:08:03,260 --> 00:08:06,580 a scheduler and see what we get with this configuration. 101 00:08:07,070 --> 00:08:11,240 So we call X task scheduler over here, click to build. 102 00:08:15,780 --> 00:08:18,570 It's built successfully, like to go to the bug for you here. 103 00:08:23,810 --> 00:08:24,730 Like switch. 104 00:08:25,920 --> 00:08:26,580 Over here. 105 00:08:28,420 --> 00:08:29,680 So a quick run. 106 00:08:31,080 --> 00:08:33,600 And we have just a blue task running. 107 00:08:35,480 --> 00:08:41,420 OK, so let's see, we have blue and red having the same. 108 00:08:42,470 --> 00:08:49,700 Priority, but because we said time slicing is zero, because we've disabled homeslice in the time is 109 00:08:49,700 --> 00:08:51,950 not shared between the two high priority task. 110 00:08:53,310 --> 00:09:00,120 Only this task is running on less blue, goes to sleep or less blue is blocked before red will have 111 00:09:00,120 --> 00:09:01,000 time to run. 112 00:09:01,830 --> 00:09:06,930 So just to show you what I mean, we're going to set time slice into one. 113 00:09:06,930 --> 00:09:11,910 In effect, we're going to enable time slicing and then we'll see what effect that would have. 114 00:09:12,430 --> 00:09:20,250 So I'll come over here to a free config file and then time in here, I'm going to set it to one less 115 00:09:20,270 --> 00:09:20,550 exit. 116 00:09:20,550 --> 00:09:20,910 This. 117 00:09:23,550 --> 00:09:24,660 OK, let's build. 118 00:09:30,550 --> 00:09:31,270 It's viewed in. 119 00:09:36,070 --> 00:09:38,200 And then we click here to go to The View. 120 00:09:44,380 --> 00:09:44,950 Switch. 121 00:09:48,990 --> 00:09:49,710 It's Lodin. 122 00:09:51,760 --> 00:09:52,870 We click here to run. 123 00:09:53,970 --> 00:09:58,830 You know, as you can see, we have red and blue run, and of course, these are the two tasks with 124 00:09:58,830 --> 00:10:02,840 a higher priority compared to the rest, because we've enabled time slicing. 125 00:10:03,060 --> 00:10:08,010 Now the time is shared between the two high priority tasks in the system. 126 00:10:08,430 --> 00:10:15,120 OK, so the question becomes, how come when we disable a tiny slice in blue was the one running, why 127 00:10:15,120 --> 00:10:20,460 wasn't red selected since they have the same priority over here as a first come, first serve because 128 00:10:20,460 --> 00:10:21,720 Blue was created first? 129 00:10:22,140 --> 00:10:27,300 That is why Blue was the only one running when time slicing was disabled. 130 00:10:28,170 --> 00:10:30,210 Because blue was created before red. 131 00:10:30,570 --> 00:10:37,620 OK, so this is the effect that time slicing offers to us and of course we know why the other low priority 132 00:10:37,620 --> 00:10:38,780 tasks aren't running. 133 00:10:39,600 --> 00:10:44,280 These ones have to go to sleep before any time will be offered to. 134 00:10:44,280 --> 00:10:46,360 These was the lower priority tasks. 135 00:10:47,160 --> 00:10:49,020 So that's all there is for this lesson. 136 00:10:49,050 --> 00:10:49,930 I'll see you later. 137 00:10:49,980 --> 00:10:50,750 Have a nice day.