private void showStack(ThreadInfo tinfo, int selectFrame) {
StackTraceListModel model = new StackTraceListModel(tinfo);
stackModel = model;
list.setModel(stackModel);
list.setSelectedIndex(selectFrame);
list.ensureIndexIsVisible(selectFrame);
}
private void setSelectedIndex(int index) {
if (index == -1) {
list.getSelectionModel().clearSelection();
} else if (list.getModel().getSize() != 0) {
list.setSelectedIndex(index);
list.ensureIndexIsVisible(index);
}
}
private void assembleAction() {
String line;
messages = new Vector();
mainFrame.resetExecWindow();
save();
assembleFailed = false;
haveAssemblyErrors = false;
if (Assembler.version()) {
while ((line = Assembler.output()) != null) {
messages.addElement(line);
}
Assembler.setPaths(baseName, sourcePath);
if (Assembler.assemble()) {
while ((line = Assembler.output()) != null) {
System.out.println(line);
messages.addElement(line);
if (line.startsWith(" [ERROR:")) {
haveAssemblyErrors = true;
}
}
messageList.setListData(messages);
messageList.ensureIndexIsVisible(0);
mainFrame.showExecWindow(baseName);
} else {
assembleFailed = true;
}
} else {
assembleFailed = true;
}
if (assembleFailed) {
String message =
String.format(
"Autocoder failed!\nVerify the correctness of autocoder path\n%s",
AssemblerOptions.assemblerPath);
System.out.println(message);
JOptionPane.showMessageDialog(this, message, "ROPE", JOptionPane.ERROR_MESSAGE);
}
}
// FUNCTION TO SIMULATE A STEP IN THE SIMULATION ON THE FRAME
public void step() {
/**
* EACH TIME THE NEXT BUTTON IS PRESSED, ALL THE STATES THAT OCURRED UPTO THE CURRENT STATE ARE
* EVALUATED. THERE IS A while STATEMENT THAT PERFORMS THIS FUNCTION AND CONTAINS A switch
* STATEMENT WITHIN IT TO EVALUATE EACH STEP AS IT OCCURS.
*/
////////////////////// INITIALIZATION ///////////////////////////////////////
// UPDATE THE STATE OF THE CACHE AND MEMORY
for (int i = 0; i < 16; i++) {
cachePanel.stringBlocks[i] = "";
cachePanel.boolBlocks[i] = false;
cachePanel.tag[i] = "";
cachePanel.boolTags[i] = false;
statusCacheEmpty[i] = true;
statusCacheLRU[i] = 0;
}
for (int i = 0; i < 8; i++) {
cachePanel.boolWords[i] = false;
memoryPanel.boolWords[i] = false;
}
for (int i = 0; i < 32; i++) memoryPanel.boolBlocks[i] = false;
// UPDATE THE BITS IN MAIN MEMORY ADDRESS
tTag.setText("");
tWord.setText("");
tTag.setBackground(new Color(205, 205, 205));
tWord.setBackground(new Color(205, 205, 205));
// UPDATE THE CACHE HITS AND MISSES FIELDS
cacheHits = 0;
cacheMisses = 0;
tCacheHits.setText(" 0");
tCacheMisses.setText(" 0");
// UPDATE THE VALUES USED FOR BRINGING MEMORY BLOCKS IN CACHE
statusLRU = 0;
memInCache = -1;
lruCacheBlock = -1;
// RESET THE VALUE OF addSel
evaluateIndex = 0;
// DISABLE ADDRESS GENERATION BUTTONS
autoGen.setEnabled(false);
selfGen.setEnabled(false);
////////////////////// END INITIALIZATION /////////////////////////////////////
// IF Next WAS CLICKED, INCREMENT moveStatus
if (nextClicked) moveStatus++;
else {
// DECREMENT moveStatus AND ENABLE NEXT SINCE IT MIGHT BE DISABLED
moveStatus--;
next.setEnabled(true);
}
// IF NO MORE back MOVES CAN BE MADE, DISABLE back BUTTON
if (moveStatus == 0) {
back.setEnabled(false);
tProgress.setText(
"You cannot go back any further."
+ "\nPlease click on \"Next\" or \"Restart\" to continue.");
tProgress.setCaretPosition(0);
// CLEAR THE SELECTED ADDRESS REFERENCE STRING
addRefStrList.clearSelection();
} else
// ENABLE back BUTTON ONCE THE FIRST MOVE IS MADE
back.setEnabled(true);
// INITIALIZE THE VARIABLE THAT KEEPS TRACK OF THE STATE WE ARE CURRENTLY EVALUATING.
int tempState = 1;
// CONTINUE TO EVALUATE EACH STATE TILL WE REACH THE CURRENT STATE
while (tempState <= moveStatus) {
switch (tempState % 6) {
case 1: // IF A NEW CYCLE IS BEGINNING, OBTAIN NEXT ADDRESS REFERENCE
// OBTAIN THE ADDRESS REFERENCE STRING
addRefStrList.setSelectedIndex(evaluateIndex);
// ENSURE THAT THE LIST SCROLLS AND SELECTED INDEX IS VISIBLE
// DUE TO REPAINTING CONSTRAINTS, ONLY DO THIS IN THE CURRENT STATE
if (tempState == moveStatus) addRefStrList.ensureIndexIsVisible(evaluateIndex);
// EVALUATE THE TAG, BLOCK AND WORD
hexAddress = (String) addRefStrList.getSelectedValue();
int intAddress = Integer.parseInt(hexAddress, 16);
binAddress = Integer.toBinaryString(intAddress);
// USING CLASS INTEGER'S parseInt FUNCTION RETURNS A BINARY STRING WITHOUT LEADING 0'S
// ENSURE THAT binAddress is 8 bits
if (binAddress.length() < 8) {
int zeroes = 8 - binAddress.length();
for (int i = 0; i < zeroes; i++) binAddress = '0' + binAddress;
}
tag = binAddress.substring(0, 5);
word = binAddress.substring(5);
// CALCULATE THE ACTUAL CACHE AND MEMORY BLOCKS AND WORDS IN QUESTION
intWordDec = Integer.parseInt(word, 2);
intBlockDecMem = Integer.parseInt(tag, 2);
// IF THIS IS THE CURRENT STATE, UPDATE THE PROGRESS FIELD
if (tempState == moveStatus) {
tProgress.setText(
"The memory address we want is obtained from the Address Reference String."
+ "\nIt is (in hexadecimal): "
+ hexAddress
+ ".");
tProgress.setCaretPosition(0);
}
break;
case 2: // EVALUATE THE BITS IN MAIN MEMORY ADDRESS AND HIGHLIGHT THEM
// IF THIS IS THE CURRENT STATE, UPDATE THE PROGRESS FIELD
if (tempState == moveStatus) {
tProgress.setText(
"The hexadecimal address "
+ hexAddress
+ " evaluates to its binary equivalent "
+ binAddress
+ "."
+ "\nHence the bits in the Main Memory Address are divided into the following fields\n"
+ tag
+ " --> Tag, "
+ word
+ " --> Word."
+ "\nThe tag bits identify the memory block, "
+ "and the word bits identify the word within the block.");
tProgress.setCaretPosition(0);
// HIGHLIGHT THE BITS IN MAIN MEMORY ADDRESS IN GREEN
tTag.setBackground(Color.green);
tWord.setBackground(Color.green);
}
tTag.setText(" " + tag);
tWord.setText(" " + word);
break;
case 3: // FIND THE CACHE BLOCK IN QUESTION AND HIGHLIGHT IT
// UNDO HIGHLIGHTS OF PREVIOUS STEP
tTag.setBackground(new Color(205, 205, 205));
tWord.setBackground(new Color(205, 205, 205));
// IF THIS IS THE CURRENT STATE, UPDATE THE PROGRESS FIELD
if (tempState == moveStatus) {
tProgress.setText(
"Every time a memory block is placed in cache, its tag field is stored with it as well."
+ "\nSo, to find the required memory block in cache, its tag, "
+ tag
+ " is compared to all the valid tag fields in cache.");
tProgress.setCaretPosition(0);
}
// GET THE BLOCK IN CACHE WHERE MEMORY BLOCK EXISTS, IF AT ALL
memInCache = getCacheBlock(tag);
// IF MEMORY BLOCK IS NOT IN CACHE...
if (memInCache == -1) {
if (tempState == moveStatus) {
tProgress.append(
"\n\nSince the memory block is not in cache, there is a cache miss."
+ "\nSo the block needs to be brought in from memory.");
tProgress.setCaretPosition(0);
}
// GET FIRST EMPTY CACHE BLOCK, IF AVAILABLE
emptyCacheBlock = getFirstEmptyCacheBlock();
// IF EMPTY CACHE BLOCK IS AVAILABLE, THIS IS WHERE THE MEMORY WILL BE BROUGHT SO
// DISPLAY IT
if (!(emptyCacheBlock == -1)) {
// IF THIS IS THE CURRENT STATE, UPDATE THE PROGRESS FIELD
if (tempState == moveStatus) {
tProgress.append(
"\nSince the cache has empty space, the first available block will be filled."
+ "\nSee the highlighted cache block.");
tProgress.setCaretPosition(0);
}
// HIGHLIGHT THE CACHE BLOCK IN YELLOW
cachePanel.boolBlocks[emptyCacheBlock] = true;
cachePanel.boolTags[emptyCacheBlock] = true;
// STORE THE CHANGED CACHE BLOCK INDEX IN COMMON VARIABLE
intBlockDec = emptyCacheBlock;
}
// ELSE DISPLAY THE LRU CACHE BLOCK WHICH WILL BE REPLACED
else {
// IF THIS IS THE CURRENT STATE, UPDATE THE PROGRESS FIELD
if (tempState == moveStatus) {
tProgress.append(
"\nSince the cache is full, the least recently used cache block will be replaced."
+ "\nSee the highlighted cache block.");
tProgress.setCaretPosition(0);
}
lruCacheBlock = getLRUCacheBlock();
// HIGHLIGHT THE CACHE BLOCK IN YELLOW
cachePanel.boolBlocks[lruCacheBlock] = true;
cachePanel.boolTags[lruCacheBlock] = true;
// STORE THE CHANGED CACHE BLOCK INDEX IN COMMON VARIABLE
intBlockDec = lruCacheBlock;
}
// UPDATE COUNT OF CACHE MISSES
cacheMisses++;
tCacheMisses.setText(" " + cacheMisses);
} else {
if (tempState == moveStatus) {
tProgress.append(
"\n\nSince the required memory block is in cache block "
+ memInCache
+ " there is a cache hit.");
tProgress.setCaretPosition(0);
}
// HIGHLIGHT THE CACHE BLOCK IN YELLOW
// TO CAUSE HIGHLIGHTING ON THE CACHE, WE NEED TO MODIFY IT'S STATE, i.e. IT'S DATA
// MEMBERS
cachePanel.boolBlocks[memInCache] = true;
cachePanel.boolWords[intWordDec] = true;
cachePanel.boolTags[memInCache] = true;
// STORE THE CHANGED CACHE BLOCK INDEX IN COMMON VARIABLE
intBlockDec = memInCache;
// UPDATE COUNT OF CACHE HITS
cacheHits++;
tCacheHits.setText(" " + cacheHits);
}
break;
case 4: // EVALUATE THE MEMORY BLOCK IN QUESTION AND HIGHLIGHT IT
// UNDO THE HIGHLIGHTS OF THE PREVIOUS STEP
cachePanel.boolBlocks[intBlockDec] = false;
cachePanel.boolWords[intWordDec] = false;
cachePanel.boolTags[intBlockDec] = false;
// IF THIS IS THE CURRENT STATE, UPDATE THE PROGRESS FIELD
if (tempState == moveStatus) {
tProgress.setText(
"Highlighted is the memory block in question. Since the tag bits are "
+ tag
+ ", the memory block, in decimal, is "
+ intBlockDecMem
+ ".");
tProgress.setCaretPosition(0);
}
// SET THE MEMORY STATE SO AS TO HIGHLIGHT THE REQUIRED MEMORY BLOCK
memoryPanel.boolBlocks[intBlockDecMem] = true;
// SET THE MEMORY STATE SO AS TO HIGHLIGHT THE REQUIRED WORD
memoryPanel.boolWords[intWordDec] = true;
break;
case 5: // HIGHLIGHT THE CACHE BLOCK WITH THE MEMORY BLOCK NOW IN IT
// UNDO HIGHLIGHTS OF PREVIOUS STEP
memoryPanel.boolBlocks[intBlockDecMem] = false;
memoryPanel.boolWords[intWordDec] = false;
/*
* NOW, THERE ARE 3 WAYS TO GO FROM HERE
* 1. IF THERE IS AN EMPTY CACHE BLOCK, SIMPLY BRING THE MEMORY BLOCK INTO CACHE
* 2. IF THE REQUIRED MEMORY BLOCK IS ALREADY IN CACHE, DO NOTHING
* 3. IF THE CACHE IS FULL, FIND THE LRU BLOCK AND REPLACE IT WITH THE REQUIRED MEMORY BLOCK
*/
// IF THE MEMORY BLOCK WAS NOT IN CACHE AND AN EMPTY CACHE BLOCK IS AVAILABLE
// BRING THE MEMORY BLOCK AND TAG INTO CACHE AND HIGHLIGHT CACHE BLOCK
if ((memInCache == -1) && !(emptyCacheBlock == -1)) {
// IF THIS IS THE CURRENT STATE, UPDATE THE PROGRESS FIELD
if (tempState == moveStatus) {
tProgress.setText(
"As we saw earlier, the required memory block was not in cache."
+ "\nSince there was empty space in cache, we brought the memory block into it."
+ "\nWe also stored the tag, "
+ tag
+ ", of the memory block with the cache block."
+ "\n\nRemember that the memory block could be brought into any empty cache block."
+ "\nIn our example, we are using the first available empty block.");
tProgress.setCaretPosition(0);
}
// UPDATE THE COUNTER FOR THE LRU CACHE BLOCK
statusLRU++;
statusCacheLRU[emptyCacheBlock] = statusLRU;
statusCacheEmpty[emptyCacheBlock] = false;
// UPDATE THE CACHE ARRAYS KEEPING TRACK OF MEMORY BLOCKS AND TAGS
cachePanel.stringBlocks[emptyCacheBlock] = "" + intBlockDecMem;
cachePanel.tag[emptyCacheBlock] = tag;
// HIGHLIGHT THE CACHE BLOCK IN YELLOW
cachePanel.boolBlocks[emptyCacheBlock] = true;
cachePanel.boolWords[intWordDec] = true;
cachePanel.boolTags[emptyCacheBlock] = true;
// STORE THE CHANGED CACHE BLOCK INDEX IN COMMON VARIABLE
intBlockDec = emptyCacheBlock;
} // END IF
// IF MEMORY BLOCK IS ALREADY IN CACHE THEN JUST HIGHLIGHT THE CACHE BLOCK
else if ((memInCache >= 0) && (memInCache < 16)) {
// IF THIS IS THE CURRENT STATE, UPDATE THE PROGRESS FIELD
if (tempState == moveStatus) {
tProgress.setText(
"As we saw earlier, the required memory block is already in cache.");
tProgress.setCaretPosition(0);
}
// UPDATE THE COUNTER FOR THE LRU CACHE BLOCK
statusLRU++;
statusCacheLRU[memInCache] = statusLRU;
// HIGHLIGHT THE CACHE BLOCK IN YELLOW
cachePanel.boolBlocks[memInCache] = true;
cachePanel.boolWords[intWordDec] = true;
cachePanel.boolTags[memInCache] = true;
// STORE THE CHANGED CACHE BLOCK INDEX IN COMMON VARIABLE
intBlockDec = memInCache;
} // END ELSE IF
// IF THE MEMORY BLOCK IS NOT IN CACHE AND THE CACHE IS FULL
// FIND THE LRU CACHE BLOCK AND REPLACE IT WITH THE MEMORY BLOCK, THEN HIGHLIGHT THE CACHE
// BLOCK
else {
// FIND THE LRU CACHE BLOCK
lruCacheBlock = getLRUCacheBlock();
// IF THIS IS THE CURRENT STATE, UPDATE THE PROGRESS FIELD
if (tempState == moveStatus) {
tProgress.setText(
"As we saw earlier, the cache is full."
+ "\nSo we picked the least recently used cache block, "
+ lruCacheBlock
+ ", and replaced it with the required memory block.");
tProgress.setCaretPosition(0);
}
// UPDATE THE COUNTER FOR THE LRU CACHE BLOCK
statusLRU++;
statusCacheLRU[lruCacheBlock] = statusLRU;
statusCacheEmpty[lruCacheBlock] = false; // redundant stmt
// UPDATE THE CACHE ARRAYS KEEPING TRACK OF MEMORY BLOCKS AND TAGS
cachePanel.stringBlocks[lruCacheBlock] = "" + intBlockDecMem;
cachePanel.tag[lruCacheBlock] = tag;
// HIGHLIGHT THE CACHE BLOCK IN YELLOW
cachePanel.boolBlocks[lruCacheBlock] = true;
cachePanel.boolWords[intWordDec] = true;
cachePanel.boolTags[lruCacheBlock] = true;
// STORE THE CHANGED CACHE BLOCK INDEX IN COMMON VARIABLE
intBlockDec = lruCacheBlock;
} // END ELSE
break;
case 0: // LAST STEP IN CYCLE - CLEANUP STEP!
// UNDO HIGHLIGHTS OF PREVIOUS STEP
cachePanel.boolBlocks[intBlockDec] = false;
cachePanel.boolWords[intWordDec] = false;
cachePanel.boolTags[intBlockDec] = false;
tTag.setText("");
tWord.setText("");
tTag.setBackground(new Color(205, 205, 205));
tWord.setBackground(new Color(205, 205, 205));
// CLEAR THE SELECTED ADDRESS REFERENCE STRING
addRefStrList.clearSelection();
// INCREMENT THE INDEX SO AS TO POINT TO THE NEXT ADDRESS REFERENCE STRING
evaluateIndex++;
// IF THE LAST ADDRESS REFERENCE STRING HAS BEEN REACHED, DO THE APPROPRIATE
if (evaluateIndex == listData.size()) {
if (tempState == moveStatus) {
tProgress.setText(
"This completes the runthrough."
+ "\nPlease click on \"Restart\", generate the Address Reference String "
+ "OR click \"Quit\" to finish.");
tProgress.setCaretPosition(0);
}
next.setEnabled(false);
// ENABLE ADDRESS GENERATION BUTTONS
autoGen.setEnabled(true);
selfGen.setEnabled(true);
reStarted = false;
}
// ELSE AN ACCESS CYCLE HAS BEEN COMPLETED SO SHOW THE APPROPRIATE MESSAGE IN THE PROGRESS
// FIELD
else {
if (tempState == moveStatus) {
tProgress.setText("This completes an access cycle.");
tProgress.setCaretPosition(0);
}
// CLEAR THE SELECTION IN THE ADDRESS REFERENCE STRING
addRefStrList.clearSelection();
}
break;
default:
JOptionPane.showMessageDialog(null, "Uh Oh, there's a problem in switch-case!");
} // END switch
tempState++;
} // END while
// CALL THE REPAINT METHOD
repaint();
} // END FUNCTION step