Working?

Assignment7/code/main.c

@@ -9,19 +9,129 @@ int framesSize;
 unsigned int pageFault=0;
 unsigned int pageHits = 0;
 unsigned int pagesSwapped = 0;
+int time = 0;
+
+
+
+typedef struct frameEntry{
+	unsigned int pageNumber;
+	int lastUsed;
+	bool dirty;
+} frameEntry;
+
+frameEntry* frames;
+
+int getPageOffsetAddress(unsigned long logicalAddress){
+	// Last 12 bits of logical address
+	// Page size is 4096 bytes, and we bitwise AND with 4095 (111111111111) to get the last 12 bits
+	return logicalAddress & (PAGESIZE-1);
+}
+
+int getPageNumber(unsigned long logicalAddress){
+	// First 20 bits of logical address
+	// Bitwise shift right 12 bits to get the first 20 bits, as the last 12 bits are discarded
+	return logicalAddress >> OFFSETBITS;
+
+}
 
 void printPhysicalAddress(int frameID, unsigned long logicalAddress){
- //   printf("%lu -> %i\n",logicalAddress,frameID*PAGESIZE+getPageOffsetAddress(logicalAddress));
+	printf("%lu -> %i\n",logicalAddress,frameID*PAGESIZE+getPageOffsetAddress(logicalAddress));
 }
 
 double computeFormula(){
-    // TODO work on that
-    return 0.0f;
+	// probabilityOfNoPageFault ∗ 10 + probabilityOfMajorPageFaultWithOneCopy ∗ 1000 + probabilityOfMajorPageFaultWithTwoCopyOperations ∗ 3000
+	double probabilityOfNoPageFault = 1 - (double)pageFault/(pageFault+pageHits);
+	double probabilityOfMajorPageFaultWithOneCopy = (double)pageFault/(pageFault+pageHits)*(1-(double)pagesSwapped/pageFault);
+	double probabilityOfMajorPageFaultWithTwoCopyOperations = (double)pageFault/(pageFault+pageHits)*(double)pagesSwapped/pageFault;
+	return probabilityOfNoPageFault*10 + probabilityOfMajorPageFaultWithOneCopy*1000 + probabilityOfMajorPageFaultWithTwoCopyOperations*3000;
+}
+
+// Int so we can return the index of the frame if it is in the frames array
+int isInFrames(int pageNumber){
+	for (int i = 0; i < framesSize; i++){
+		if (frames[i].pageNumber == pageNumber){
+			return i;
+		}
+	}
+	return -1;
+}
+
+int swapOut(){
+	// Find the least recently used frame
+	int leastRecentlyUsed = 0x7FFFFFFF;
+	int leastRecentlyUsedIndex = -1;
+	for (int i = 0; i < framesSize; i++){
+		if (frames[i].lastUsed < leastRecentlyUsed){
+			leastRecentlyUsed = frames[i].lastUsed;
+			leastRecentlyUsedIndex = i;
+		}
+	}
+	// Swap out is implied, so we increment pageSwapped
+	if (frames[leastRecentlyUsedIndex].dirty) {
+		pagesSwapped++;
+	}
+
+	return leastRecentlyUsedIndex;
+}
+
+int swapIn(int pageNumber){
+	// Find the first empty frame
+	for (int i = 0; i < framesSize; i++){
+		if (frames[i].pageNumber == -1){
+			pageFault++;
+			frames[i].pageNumber = pageNumber;
+			return i;
+		}
+	}
+	// If no empty frames, swap out a frame
+	int frameID = swapOut();
+	frames[frameID].pageNumber = pageNumber;
+	pageFault++;
+	return frameID;
+}
+
+
+
+void readFromAddress(unsigned long logicalAddress){
+	unsigned int pageNumber = getPageNumber(logicalAddress);
+	int frameID = isInFrames(pageNumber);
+	if (isInFrames(pageNumber) == -1){
+		frameID = swapIn(pageNumber);
+	}
+	else{
+		pageHits++;
+	}
+	frames[frameID].lastUsed = time;
+	printPhysicalAddress(frameID,logicalAddress);
+}
+
+void writeToAddress(unsigned long logicalAddress){
+	unsigned int pageNumber = getPageNumber(logicalAddress);
+	int frameID = isInFrames(pageNumber);
+	if (isInFrames(pageNumber) == -1){
+		frameID = swapIn(pageNumber);
+	}
+	else{
+		pageHits++;
+	}
+	frames[frameID].dirty = true;
+	frames[frameID].lastUsed = time;
+	printPhysicalAddress(frameID,logicalAddress);
 }
 
 
 int main(int argc, char** argv){
+	//Disable printf buffering
+	setbuf(stdout, NULL);
+
     framesSize = atoi(argv[1]);
+	frames = calloc(framesSize,sizeof(frameEntry));
+	// Initialize frames to -1, so we can check if a frame is empty
+	for (int i = 0; i < framesSize; i++){
+		frames[i].pageNumber = -1;
+		frames[i].lastUsed = -1;
+		frames[i].dirty = false;
+	}
     unsigned long logicalAddress;
     char operation;
     printf("Logical addresses -> Physical addresses:\n");
@@ -29,12 +139,13 @@ int main(int argc, char** argv){
     {
         if (operation == 'r')
         {
-            // readFromAddress(logicalAddress);
+            readFromAddress(logicalAddress);
         }
         else
         {
-            // writeToAddress(logicalAddress);
+            writeToAddress(logicalAddress);
         }
+		time++;
     }
 
     printf("\nStats:\nmajor page faults = %u\npage hits = %u\npages swapped out = %u\nEffective Access Time = %.3lf\n",pageFault,pageHits,pagesSwapped, computeFormula());