implement utilization calc

README.md

@@ -1,7 +1,15 @@
 Horologa
 =
 
-Determine the frame length and hyper period to be used in a static clock-driven scheduler. 
+Determine the utilization, hyper period, and frame length to be used in a static clock-driven scheduler. 
+
+## Utilization
+
+This program calculates the rate-monotonic utilization of a set of tasks.
+
+Liu & Layland (1973) proved that for a set of n period tasks with unique periods, a feasible schedule that will always meet deadlines exists if the CPU utilization is below a specific bound (depending on the number of tasks). The scheduling test for this is the following equation: 
+
+Utility = sum i = 1 to n [e_i/c_i] <= (2^(1/n) - 1)
 
 ## Hyper Period
 

cmd/horologa/main.go

@@ -37,6 +37,9 @@ func main() {
     os.Exit(horologa.Errors.FailedToDetermineHyperPeriod.Code)
   }
 
+  utilzation := horologa.DetermineUtilization(tasks)
+
   fmt.Println("Hyper Period:", hyper_period)
   fmt.Println("Frame Length:", frame_length)
+  fmt.Println("Utilization:", utilzation)
 }

internal/horologa/horologa.go

@@ -2,6 +2,7 @@ package horologa
 
 import (
 	"errors"
+  "fmt"
 )
 
 // helper function to determine the gcd
@@ -123,3 +124,17 @@ func DetermineHyperPeriod(tasks Tasks) (int, error) {
 
 	return hyper_period, nil
 }
+
+/* Utilization - this function returns 1 if the set of tasks
+completely utilize the 'processor' => utilization = 1 means 
+the schedule is optimal. 
+*/
+func DetermineUtilization(tasks Tasks) (float64) {
+  var utilization float64 = 0
+
+  for _, task := range tasks.T {
+    utilization += float64(task.ExecutionTime)/float64(task.Period)
+  }
+
+  return utilization
+}

tasks.json

@@ -1,8 +1,8 @@
 {"tasks": [
-  {"phase": 0, "period": 4, "executionTime": 2, "relativeDeadline": 4},
+  {"phase": 0, "period": 4, "executionTime": 1, "relativeDeadline": 4},
   {"phase": 0, "period": 5, "executionTime": 2, "relativeDeadline": 5},
-  {"phase": 0, "period": 20, "executionTime": 1, "relativeDeadline": 20},
-  {"phase": 0, "period": 20, "executionTime": 2, "relativeDeadline": 20}
+  {"phase": 0, "period": 20, "executionTime": 1, "relativeDeadline": 10},
+  {"phase": 0, "period": 15, "executionTime": 2, "relativeDeadline": 15}
 ]
 }