Brandon Hopper

README.md

@@ -1,4 +1,4 @@
-# Multi-Level Feedback Queue
+#  Multi-Level Feedback Queue
 
 ### Motivation
 After talking about one of the most popular scheduling algorithms used by operating systems to schedule processes,

src/Process.js

@@ -16,11 +16,16 @@ class Process {
     }
 
     setParentQueue(queue) {
-
+        this.queue = queue;
     }
 
     isFinished() {
-
+        if (this.blockingTimeNeeded) {
+            return false;
+        }
+        else {
+            return this.cpuTimeNeeded <= 0;
+        }
     }
 
     // If no blocking time is needed by this process, decrement the amount of 
@@ -29,7 +34,18 @@ class Process {
     // by emitting the appropriate interrupt
     // Make sure the `stateChanged` flag is toggled appropriately
     executeProcess(time) {
-
+        const { PROCESS_BLOCKED } = SchedulerInterrupt;
+        if (this.blockingTimeNeeded > 0) {
+            this.stateChanged = !this.stateChanged;
+            this.queue.emitInterrupt(this, PROCESS_BLOCKED);
+        }
+        else {
+            for (let i = time; i > 0; i--) {
+                if (--this.cpuTimeNeeded == 0) {
+                    break;
+                }
+            }
+        }
    }
 
    // If this process requires blocking time, decrement the amount of blocking
@@ -38,16 +54,27 @@ class Process {
    // top running queue by emitting the appropriate interrupt
    // Make sure the `stateChanged` flag is toggled appropriately
     executeBlockingProcess(time) {
+        for (let i = time; i > 0; i--) {
+            if (--this.blockingTimeNeeded == 0) {
+                break;
+            }
+        }
+
+        const { PROCESS_READY } = SchedulerInterrupt;
+        if (this.blockingTimeNeeded <= 0) {
+            this.stateChanged = !this.stateChanged;
+            this.queue.emitInterrupt(this, PROCESS_READY);
+	    }
 
     }
 
     // Returns this process's stateChanged property
     isStateChanged() {
-
+        return this.stateChanged;
     }
 
     get pid() {
-
+        return this._pid;
     }
 
     // Private function used for testing; DO NOT MODIFY

src/Queue.js

@@ -18,57 +18,80 @@ class Queue {
     }
 
     // Enqueues the given process. Return the enqueue'd process
-    enqueue(process) {
-
-    }
+    enqueue(process) {  
+        process.setParentQueue(this);
+        this.processes.push(process);
+        return process;
+;    }
 
     // Dequeues the next process in the queue. Return the dequeue'd process
     dequeue() {
-
+        return this.processes.shift();
     }
 
     // Return the least-recently added process without removing it from the list of processes
     peek() {
-
+        return this.processes[0];
     }
 
     isEmpty() {
-
+        return this.processes == 0;
     }
 
     getPriorityLevel() {
-
+        return this.priorityLevel;
     }
 
     getQueueType() {
-
+        return this.queueType;
     }
 
     // Manages a process's execution for the given amount of time
     // Processes that have had their states changed should not be affected
     // Once a process has received the alloted time, it needs to be dequeue'd and 
     // then handled accordingly, depending on whether it has finished executing or not
     manageTimeSlice(currentProcess, time) {
-
+        if (currentProcess.stateChanged) {
+            this.quantumClock = 0;
+            this.scheduler.handleInterrupt(this, currentProcess, SchedulerInterrupt.PROCESS_BLOCKED);
+        }
+        else if (time < this.quantum) {
+            this.quantumClock += time;
+        }
+        if (time > this.quantum) {
+            if (currentProcess.cpuTimeNeeded != 0 && currentProcess.blockingTimeNeeded === 0) {
+                this.scheduler.handleInterrupt(this, currentProcess, SchedulerInterrupt.LOWER_PRIORITY);
+                this.quantumClock = 0;
+            }
+            this.dequeue();
+        }
+        return currentProcess;
     }
 
     // Execute the next non-blocking process (assuming this is a CPU queue)
     // This method should call `manageTimeSlice` as well as execute the next running process
     doCPUWork(time) {
-
+        const proc = this.peek();
+        proc.executeProcess(time);
+        this.manageTimeSlice(proc, time);
+
     }
 
     // Execute the next blocking process (assuming this is the blocking queue)
     // This method should call `manageTimeSlice` as well as execute the next blocking process
     doBlockingWork(time) {
-
+        const proc = this.peek();
+        proc.executeBlockingProcess(time);
+        this.manageTimeSlice(proc, time);
     }
 
     // The queue's interrupt handler for notifying when a process needs to be moved to a different queue
     // Should handle PROCESS_BLOCKED and PROCESS_READY interrupts
     // The process also needs to be removed from the queue
     emitInterrupt(source, interrupt) {
-
+        const sourceIndex = this.processes.indexOf(source);
+        this.processes.splice(sourceIndex, 1);
+        this.scheduler.handleInterrupt(this, source, interrupt);
     }
 }