Diff: main.cpp

Revision:

1:21958cb07fb4

Parent:

0:65611c1179b6

Child:

2:8bab2e3d3005

--- a/main.cpp	Fri Sep 25 19:37:02 2015 +0000
+++ b/main.cpp	Sat Sep 26 21:48:56 2015 +0000
@@ -1,56 +1,60 @@
 #include "mbed.h"
 #include "TextLCD.h"
 #include "Mutex.h"
+#include "rtos.h"
+#include "Thread.h"
 using namespace rtos;
 
- 
+//Define LCD 
 TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD20x4); // rs, e, d4-d7
-DigitalOut myled(LED1); 
-Mutex forks[5];
+
+//Individual Mutex for each chopstick
+Mutex chopsticks[5];
 
-void init_mutexes(){
-    int i;
-    for(i = 0; i < 5; i++){
-        forks[i] = Mutex();
-    }
+// Eating routine
+void eat(const int* phil) {
+    // All chopsticks (0-4) are behind an individual mutex, and must be aquired from lowest to highest
+    // Each philosopher picks up the chopsticks to his left (index - 1) and right (index % 5), or waits for one
+    chopsticks[(int)phil - 1].lock();
+    chopsticks[(int)phil % 5].lock();
+    
+    //The eating period is between 1000 and 2000 ms
+    int eatPeriod = rand()%1000 + 1000;
     
+    // we locate the part of the LCD 
+    lcd.locate((int)phil,0);
+    lcd.putc((int)phil + 48);
     
+    // The thread waits while the philosopher is eating
+    Thread::wait(eatPeriod);
+    
+    //After eating, the philosopher puts down the chopsticks 
+    lcd.locate((int)phil,0);
+    lcd.printf(" ");
+    chopsticks[(int)phil - 1].unlock();
+    chopsticks[(int)phil % 5].unlock();
 }
 
-void philosophizeAndEat(){
-    // philosophize for some time (at least 5 seconds, as per point 4.)
-    wait(1);
-    lcd.printf("got to a process");
-    wait(1);
-    lcd.cls();
-    
-    // request to eat 
-    int lock_recieved = forks[0].trylock();
-    if(!lock_recieved){
-        forks[0].lock();
+// General thread behavioral routine, eating and waiting (philosophizing)
+void philosophizeAndEat(void const *args) {
+    while (true) {
+        //Decide a time between 5-10 seconds between eating requests
+        int waitPeriod = rand()%5000 + 5000;
+        
+        //Performing the eating routine
+        eat((const int*)args); 
+        
+        // wait until time elapses to eat again
+        Thread::wait(waitPeriod);
     }
-    wait(2);
-    lcd.cls();
-    forks[0].unlock();
-}
-    
-
-int main() {
-    int count_philosophers = 5;
-    
-    //initialize all mutexes for the chopsticks
-    init_mutexes();
-    lcd.printf("got to main");
-    wait(1);
-    lcd.cls();
-    
-    for(int i = 1; i < 4; i++){
-        std::thread first (philosophizeAndEat);
-        wait(1);
-        first.join();
-        lcd.printf("was termd");
-        lcd.cls();
-    }
-    
 }
 
+// setup routine, create all philosophers
+int main() {
+    // Initialize 5 philosopher threads with IDs
+    Thread t3(philosophizeAndEat, (void *)3);
+    Thread t2(philosophizeAndEat, (void *)2);
+    Thread t4(philosophizeAndEat, (void *)4);
+    Thread t5(philosophizeAndEat, (void *)5);
+    philosophizeAndEat((void *)1);
+}