Stage-1 Students SoCEM / Mbed OS Task615Solution-mbedos54

Solution to 6.1.5 updated for mbed os 5.4

main.cpp@2:91200df5ccd6, 2017-03-30 (annotated)

Committer:
noutram
Date:
Thu Mar 30 14:24:24 2017 +0000
Revision:
2:91200df5ccd6
Parent:
1:4fb27aea76b2 
updated for mbed 5.4

Who changed what in which revision?

UserRevisionLine numberNew contents of line
noutram 0:f916cefba2f4 1 #include "mbed.h"
noutram 0:f916cefba2f4 2
noutram 0:f916cefba2f4 3 #define RED_DONE 1
noutram 0:f916cefba2f4 4 #define YELLOW_DONE 2
noutram 0:f916cefba2f4 5
noutram 0:f916cefba2f4 6
noutram 0:f916cefba2f4 7 //Function declarations
noutram 2:91200df5ccd6 8 void countUP();
noutram 2:91200df5ccd6 9 void countDOWN();
noutram 0:f916cefba2f4 10
noutram 0:f916cefba2f4 11 //Digital outputs
noutram 0:f916cefba2f4 12 DigitalOut onBoardLED(LED1);
noutram 0:f916cefba2f4 13 DigitalOut redLED(D7);
noutram 0:f916cefba2f4 14 DigitalOut yellowLED(D6);
noutram 0:f916cefba2f4 15 DigitalOut greenLED(D5);
noutram 0:f916cefba2f4 16
noutram 0:f916cefba2f4 17 //Digital inputs
noutram 0:f916cefba2f4 18 DigitalIn onBoardSwitch(USER_BUTTON);
noutram 0:f916cefba2f4 19 DigitalIn SW1(D4);
noutram 0:f916cefba2f4 20 DigitalIn SW2(D3);
noutram 0:f916cefba2f4 21
noutram 1:4fb27aea76b2 22 //MUTEX Lock
noutram 1:4fb27aea76b2 23 Mutex *countLock;
noutram 0:f916cefba2f4 24
noutram 0:f916cefba2f4 25 //Thread ID for the Main function (CMSIS API)
noutram 0:f916cefba2f4 26 osThreadId tidMain;
noutram 0:f916cefba2f4 27
noutram 0:f916cefba2f4 28 //Stared mutable state
noutram 0:f916cefba2f4 29 volatile long long count = 0;
noutram 0:f916cefba2f4 30
noutram 0:f916cefba2f4 31 //Threads
noutram 2:91200df5ccd6 32 void countUP()
noutram 0:f916cefba2f4 33 {
noutram 0:f916cefba2f4 34 redLED = 1;
noutram 0:f916cefba2f4 35
noutram 0:f916cefba2f4 36 for (unsigned int n=0; n<10000; n++) {
noutram 1:4fb27aea76b2 37 //Take lock
noutram 1:4fb27aea76b2 38 countLock->lock();
noutram 1:4fb27aea76b2 39
noutram 1:4fb27aea76b2 40 //Critical section(s)
noutram 0:f916cefba2f4 41 count++;
noutram 0:f916cefba2f4 42 count++;
noutram 0:f916cefba2f4 43 count++;
noutram 0:f916cefba2f4 44 count++;
noutram 0:f916cefba2f4 45 count++;
noutram 0:f916cefba2f4 46 count++;
noutram 0:f916cefba2f4 47 count++;
noutram 0:f916cefba2f4 48 count++;
noutram 0:f916cefba2f4 49 count++;
noutram 0:f916cefba2f4 50 count++;
noutram 1:4fb27aea76b2 51
noutram 1:4fb27aea76b2 52 //Release lock
noutram 1:4fb27aea76b2 53 countLock->unlock();
noutram 0:f916cefba2f4 54 }
noutram 0:f916cefba2f4 55
noutram 0:f916cefba2f4 56 redLED = 0;
noutram 0:f916cefba2f4 57 osSignalSet(tidMain, RED_DONE); //Signal main thread we are done
noutram 0:f916cefba2f4 58 }
noutram 0:f916cefba2f4 59
noutram 2:91200df5ccd6 60 void countDOWN()
noutram 0:f916cefba2f4 61 {
noutram 0:f916cefba2f4 62 yellowLED = 1;
noutram 0:f916cefba2f4 63
noutram 0:f916cefba2f4 64 for (unsigned int n=0; n<10000; n++) {
noutram 1:4fb27aea76b2 65 //Take lock
noutram 1:4fb27aea76b2 66 countLock->lock();
noutram 1:4fb27aea76b2 67
noutram 1:4fb27aea76b2 68 //Critical section(s)
noutram 0:f916cefba2f4 69 count--;
noutram 0:f916cefba2f4 70 count--;
noutram 0:f916cefba2f4 71 count--;
noutram 0:f916cefba2f4 72 count--;
noutram 0:f916cefba2f4 73 count--;
noutram 0:f916cefba2f4 74 count--;
noutram 0:f916cefba2f4 75 count--;
noutram 0:f916cefba2f4 76 count--;
noutram 0:f916cefba2f4 77 count--;
noutram 1:4fb27aea76b2 78 count--;
noutram 1:4fb27aea76b2 79
noutram 1:4fb27aea76b2 80 //Release lock
noutram 1:4fb27aea76b2 81 countLock->unlock();
noutram 0:f916cefba2f4 82 }
noutram 0:f916cefba2f4 83
noutram 0:f916cefba2f4 84 osSignalSet(tidMain, YELLOW_DONE); //Signal main thread we are done
noutram 0:f916cefba2f4 85 yellowLED = 0;
noutram 0:f916cefba2f4 86 }
noutram 0:f916cefba2f4 87
noutram 0:f916cefba2f4 88
noutram 0:f916cefba2f4 89 //Main thread
noutram 0:f916cefba2f4 90 int main() {
noutram 2:91200df5ccd6 91 Thread t1;
noutram 2:91200df5ccd6 92 Thread t2;
noutram 2:91200df5ccd6 93
noutram 0:f916cefba2f4 94 redLED = 0;
noutram 0:f916cefba2f4 95 yellowLED = 0;
noutram 0:f916cefba2f4 96 greenLED = 1;
noutram 0:f916cefba2f4 97
noutram 0:f916cefba2f4 98 //Main thread ID
noutram 0:f916cefba2f4 99 tidMain = Thread::gettid();
noutram 0:f916cefba2f4 100
noutram 1:4fb27aea76b2 101 //Create lock
noutram 1:4fb27aea76b2 102 countLock = new Mutex();
noutram 1:4fb27aea76b2 103
noutram 0:f916cefba2f4 104 //Press the switch to run concurrently
noutram 0:f916cefba2f4 105 if (onBoardSwitch == 1) {
noutram 0:f916cefba2f4 106 printf("Running sequntially\n");
noutram 2:91200df5ccd6 107 countUP();
noutram 2:91200df5ccd6 108 countDOWN();
noutram 0:f916cefba2f4 109 } else {
noutram 0:f916cefba2f4 110 printf("Running concurrently\n");
noutram 2:91200df5ccd6 111 t1.start(countUP);
noutram 2:91200df5ccd6 112 t2.start(countDOWN);
noutram 0:f916cefba2f4 113
noutram 0:f916cefba2f4 114 //Wait for the ALL_ON signal
noutram 0:f916cefba2f4 115 Thread::signal_wait(RED_DONE,osWaitForever);
noutram 0:f916cefba2f4 116 Thread::signal_wait(YELLOW_DONE,osWaitForever);
noutram 0:f916cefba2f4 117 }
noutram 0:f916cefba2f4 118
noutram 0:f916cefba2f4 119 printf("Final result = %lld\n", count);
noutram 0:f916cefba2f4 120 if (count == 0) {
noutram 0:f916cefba2f4 121 greenLED = 0;
noutram 0:f916cefba2f4 122 }
noutram 1:4fb27aea76b2 123
noutram 1:4fb27aea76b2 124 //Tidy
noutram 1:4fb27aea76b2 125 delete countLock;
noutram 1:4fb27aea76b2 126
noutram 0:f916cefba2f4 127 while(true);
noutram 0:f916cefba2f4 128 }