feat(gsoc'24): Implemented state machine for simulator (#3781)

src/simulator/src/circuit.ts

@@ -273,6 +273,8 @@ export function changeCircuitName(name: string, id = globalScope.id) {
     circuit_list.value[index].name = name
 }
 
+type State = 'normal' | 'error'
+
 /**
  * Class representing a Scope
  * @class
@@ -305,6 +307,8 @@ export default class Scope {
     Splitter?: any[];
     SubCircuit?: any[];
     Clock?: any[];
+    states: { NORMAL: State; ERROR: State; };
+    currentState: State;
     constructor(name = 'localScope', id = undefined) {
         this.restrictedCircuitElementsUsed = []
         this.id = id || Math.floor(Math.random() * 100000000000 + 1)
@@ -340,6 +344,15 @@ export default class Scope {
             title_y: 13,
             titleEnabled: true,
         }
+
+        // Defining all the possible states of simulator
+        this.states = {
+            NORMAL: 'normal',
+            ERROR: 'error',
+        };
+
+        // Setting current state of simulator
+        this.currentState = this.states.NORMAL;
     }
 
     isVisible() {

src/simulator/src/data/undo.js

@@ -8,7 +8,7 @@ import { layoutModeGet } from '../layoutMode'
 import Scope, { scopeList } from '../circuit'
 import { loadScope } from './load'
 import { updateRestrictedElementsInScope } from '../restrictedElementDiv'
-import { forceResetNodesSet } from '../engine'
+import { errorDetectedSet, forceResetNodesSet } from '../engine';
 /**
  * Function called to generate a prompt to save an image
  * @param {Scope=} - the circuit in which we want to call undo
@@ -38,6 +38,9 @@ export default function undo(scope = globalScope) {
     tempScope.name = scope.name
     tempScope.testbenchData = scope.testbenchData
     scopeList[scope.id] = tempScope
+    if (globalScope.currentState === globalScope.states.ERROR) {
+        errorDetectedSet(false);
+    }
     globalScope = tempScope
     globalScope.ox = backupOx
     globalScope.oy = backupOy

src/simulator/src/engine.js

@@ -14,6 +14,7 @@ import { resetup } from './setup'
 import { verilogModeGet } from './Verilog2CV'
 import { renderOrder, updateOrder } from './metadata'
 import ContentionPendingData from './contention';
+import { hidetabs, visibletabs } from './listeners';
 
 /**
  * Core of the simulation and rendering algorithm.
@@ -401,53 +402,65 @@ export function updateSelectionsAndPane(scope = globalScope) {
  * @category engine
  */
 export function play(scope = globalScope, resetNodes = false) {
-    if (errorDetected) return // Don't simulate until error is fixed
-    if (loading === true) return // Don't simulate until loaded
-
-    simulationArea.simulationQueue.reset()
-    plotArea.setExecutionTime() // Waveform thing
-    resetNodeHighlights(scope);
-    // Reset Nodes if required
-    if (resetNodes || forceResetNodes) {
-        scope.reset()
-        simulationArea.simulationQueue.reset()
-        forceResetNodesSet(false)
-    }
+    try {
+        if (errorDetected) return; // Don't simulate until error is fixed
+        if (loading === true) return; // Don't simulate until loaded
+
+        simulationArea.simulationQueue.reset();
+        plotArea.setExecutionTime(); // Waveform thing
+        resetNodeHighlights(scope);
+        // Reset Nodes if required
+        if (resetNodes || forceResetNodes) {
+            scope.reset();
+            simulationArea.simulationQueue.reset();
+            forceResetNodesSet(false);
+        }
 
-    // To store set of Nodes that have shown contention but kept temporarily
+        // To store set of Nodes that have shown contention but kept temporarily
     simulationArea.contentionPending = new ContentionPendingData();
-    // add inputs to the simulation queue
-    scope.addInputs()
-    // to check if we have infinite loop in circuit
-    let stepCount = 0
-    let elem
-    while (!simulationArea.simulationQueue.isEmpty()) {
-        if (errorDetected) {
-            simulationArea.simulationQueue.reset()
-            return
-        }
-        elem = simulationArea.simulationQueue.pop()
+        // add inputs to the simulation queue
+        scope.addInputs();
+        // to check if we have infinite loop in circuit
+        let stepCount = 0;
+        let elem;
+        while (!simulationArea.simulationQueue.isEmpty()) {
+            if (errorDetected) {
+                simulationArea.simulationQueue.reset();
+                return;
+            }
+            elem = simulationArea.simulationQueue.pop();
 
-        elem.resolve()
+            elem.resolve();
 
-        stepCount++
-        if (stepCount > 1000000) {
-            // Cyclic or infinite Circuit Detection
-            showError(
-                'Simulation Stack limit exceeded: maybe due to cyclic paths or contention'
-            )
-            forceResetNodesSet(true)
-        }
-    }
-    // Check for Contentions
-    if (simulationArea.contentionPending.size() > 0) {
-        for (const [ourNode, theirNode] of simulationArea.contentionPending.nodes()) {
-            ourNode.highlighted = true;
-            theirNode.highlighted = true;
+            stepCount++;
+            if (stepCount > 1000000) { // Cyclic or infinite Circuit Detection
+                showError('Simulation Stack limit exceeded: maybe due to cyclic paths or contention');
+                forceResetNodesSet(true);
+            }
         }
+        // Check for Contentions
+        if (simulationArea.contentionPending.size() > 0) {
+            for (const [ourNode, theirNode] of simulationArea.contentionPending.nodes()) {
+                ourNode.highlighted = true;
+                theirNode.highlighted = true;
+            }
 
-        forceResetNodesSet(true);
+            forceResetNodesSet(true);
         showError('Contention Error: One or more bus contentions in the circuit (check highlighted nodes)');
+        }
+
+        // change the state of simulator to normal
+        if (globalScope.currentState === globalScope.states.ERROR) {
+            globalScope.currentState = globalScope.states.NORMAL;
+        }
+        visibletabs();
+    } catch (error) {
+        // change the state of simulator to error
+        if (globalScope.currentState === globalScope.states.NORMAL) {
+            globalScope.currentState = globalScope.states.ERROR;
+            hidetabs();
+        }
+        showError('The simulator is in an error state. Now, you can only delete or undo components until the simulator returns to the normal state');
     }
 }
 

src/simulator/src/listeners.js

@@ -41,6 +41,38 @@ import { setupTimingListeners } from './plotArea'
 var unit = 10
 var listenToSimulator = true
 
+function setPanelVisibility(visibility, display) {
+    if (window.screen.width < 1000) {
+        $('#touchMenu').toggle(visibility === 'visible');
+        $('#smallNavbarMenu-btn').toggle(visibility === 'visible');
+    }
+    else {
+        const classes = ['draggable-panel', 'nav-dropdown', 'logixButton'];
+        classes.forEach((className) => {
+            $(`.${className}`).each((index, element) => {
+                if (className === 'logixButton') {
+                    $(element).toggle(visibility === 'visible');
+                    $(element).parent().toggle(visibility === 'visible');
+                } else {
+                    $(element).css('visibility', visibility);
+                }
+            });
+        });
+    }
+    var contextMenuItems = $("#contextMenu li:nth-child(1), #contextMenu li:nth-child(2), #contextMenu li:nth-child(3), #contextMenu li:nth-child(6), #contextMenu li:nth-child(7), #contextMenu li:nth-child(8)");
+    contextMenuItems.css("display", display);
+}
+
+// Function to hide tabs when simulator goes into error state
+export function hidetabs() {
+    setPanelVisibility('hidden', 'none');
+}
+
+// Function to visible tabs when simulator returns back to normal state
+export function visibletabs() {
+    setPanelVisibility('visible', 'block');
+}
+
 export default function startListeners() {
     $(document).on('keyup', (e) => {
         if (e.key === 'Escape') exitFullView()

src/simulator/src/ux.js

@@ -7,7 +7,8 @@ import { layoutModeGet } from './layoutMode'
 import {
     scheduleUpdate,
     wireToBeCheckedSet,
-    updateCanvasSet
+    updateCanvasSet,
+    errorDetectedSet
 } from './engine'
 import { simulationArea } from './simulationArea'
 import logixFunction from './data'
@@ -289,6 +290,10 @@ export function deleteSelected() {
     updateCanvasSet(true)
     scheduleUpdate()
     updateRestrictedElementsInScope()
+
+    if (globalScope.currentState === globalScope.states.ERROR) {
+        errorDetectedSet(false);
+    }
 }
 
 /**