Lab 5 done?

Lab5/main.c

@@ -1,36 +1,137 @@
+/* 2.1
+1. How many values can one 2-base digit take? List all of them.
+
+0, 1
+
+2. How many values can one 10-base digit take? List all of them.
+
+0, 1, 2, 3, 4, 5, 6, 7, 8, 9
+
+3. How many values can 7 bits represent? DO NOT list all of them.
+
+2^7 = 128
+
+4. Recall, look up or come up with a formula for a generic case: how many values can n m-valued bits represent?
+
+m^n, where m is the base and n is the number of bits
+
+5. If our machine is byte-addressable (i.e., each byte must have its own address), how many addresses do we need to have a table with pointers to every
+ byte in 1 Megabyte?
+
+2^20 as there are 2^20 bytes in 1 Megabyte, and each byte needs its own address
+
+6. What if our machine was bit-addressable?
+
+2^20 * 8 = 2^23, as each byte has 8 bits, and each bit needs its own address
+
+7. Consider you are using an array of pointers, each entry of which is sixty-four bits (or 8 bytes) to have a pointer to each individual byte from the
+ question 5, how much memory would this array occupy?
+
+2^20 * 8 = 2^23 bytes = 8388608 bytes, as each pointer is 8 bytes, and there are 2^20 bytes in 1 Megabyte
+
+8. Consider you are using an array of pointers, each entry of which is sixty-four bits (or 8 bytes) to have a pointer to each individual bit from the
+question 6, how much memory would this array occupy?
+
+2^23 * 8 = 2^26 bytes = 67108864 bytes, as each pointer is 8 bytes, and there are 2^23 bits in 1 Megabyte
+
+*/
+
+/* 2.2
+1. Output of program
+
+Read 4097
+Physical address is 1, logical address is 4097
+Read 100
+Physical address is 4196, logical address is 100
+Read 500
+Physical address is 4596, logical address is 500
+Read 12000
+Physical address is 7904, logical address is 12000
+Read 300
+Physical address is 8492, logical address is 300
+Read 8500
+Physical address is 4404, logical address is 8500
+Read 5000
+Physical address is 904, logical address is 5000
+Read 25300
+Physical address is 8916, logical address is 25300
+Read 4700
+Physical address is 604, logical address is 4700
+Read 13000
+Physical address is 13000, logical address is 13000
+Read 15000
+Physical address is 15000, logical address is 15000
+Read 22140
+Physical address is 18044, logical address is 22140
+Read 27000
+Physical address is 10616, logical address is 27000
+
+2. How many megabytes are required to store 2^20 integers?
+
+2^20 * 4 = 2^22 bytes = 4194304 bytes = 4 megabytes, this is assuming an int is a 32-bit integer,
+which may not be true on all architectures, but is on x86_64 machines.
+*/
+
+
 #include <stdio.h>
 #include <stdlib.h>
+
 #define OFFSETBITS 12
 // fancy way of computing 2^OFFSETBITS
 #define PAGESIZE (1 << OFFSETBITS)
 #define WORDSIZE 32
-int getPageNumber(int logicalAddress){
-	return logicalAddress / PAGESIZE ;
+#define FRAMESIZE (1 << (WORDSIZE - OFFSETBITS))
+
+int getPageNumber(int logicalAddress) {
+	return logicalAddress / PAGESIZE;
 }
 
-int getPageOffset(int logicalAddress){
-	return logicalAddress % PAGESIZE ;
-}
-int getStartingAddressOfTheFrameByIndex(int indexInFramesArray){
-	return indexInFramesArray*PAGESIZE ;
+int getPageOffset(int logicalAddress) {
+	return logicalAddress % PAGESIZE;
 }
 
-int main(int argc, char** argv){
-	/* int* frames =  malloc the recommended array here*/;
+int getStartingAddressOfTheFrameByIndex(int indexInFramesArray) {
+	return indexInFramesArray * PAGESIZE;
+}
+
+int main() {
+	//disable buffering on stdout
+	setbuf(stdout, NULL);
+
+	int* frames = malloc(sizeof(int) * FRAMESIZE);
 	int maxPreviouslyUsedFrame = 0;
 	int logicalAddress;
 	int i;
 	int hasAFrameAssignedBefore = 0;
-	int tempFrameIndex=0;
-	while(EOF != scanf("%d\n",&logicalAddress) )
-	{
-		/** reset the value of hasAFrameAssignedBefore to 0 */
-		/* for all the values from 0 to maxPreviouslyUsedFrame, check if there's a page number of the current logical address in the frame array. if it is, mark hasAFrameAssignedBefore as 1 and store the index of the frame you just found into tempFrameIndex */
+	int tempFrameIndex = 0;
+	while (EOF != scanf("%d\n", &logicalAddress)) {
+		printf("Read %i\n", logicalAddress);
+		/* reset the value of hasAFrameAssignedBefore to 0 */
+		hasAFrameAssignedBefore = 0;
+		/* for all the values from 0 to maxPreviouslyUsedFrame, check if there's a page number of the current logical address in the frame array. if it is,
+		mark hasAFrameAssignedBefore as 1 and store the index of the frame you just found into tempFrameIndex */
+		for (i = 0; i <= maxPreviouslyUsedFrame; i++) {
+			if (frames[i] == getPageNumber(logicalAddress)) {
+				hasAFrameAssignedBefore = 1;
+				tempFrameIndex = i;
+			}
+		}
 		/* After looking up through all the values from 0 to maxPreviouslyUsedFrame, if the page did not have a frame assigned before, assign the page number to the frame array
 		in the maxPreviously used frame position, store the max previously used frame into tempFrameIndex,  increment the value of the maxPreviously used frame */
-		/* now that you have the physical frame index corresponding to your page stored in tempFrameIndex, get the starting address of the frame by index and add the page offset to it and voila, you have your physical address. Print it out in the format
-		printf("Physical address is %i logical address is %i\n" ..);
-		*/
-		printf("Read %i\n",logicalAddress);
+		if(!hasAFrameAssignedBefore) {
+			frames[maxPreviouslyUsedFrame] = getPageNumber(logicalAddress);
+			tempFrameIndex = maxPreviouslyUsedFrame;
+			maxPreviouslyUsedFrame++;
+		}
+
+		/* now that you have the physical frame index corresponding to your page stored in tempFrameIndex, get the starting address of the frame by index and
+		 * add the page offset to it and voila, you have your physical address. Print it out in the format
+		 * printf("Physical address is %i logical address is %i\n" ..);
+		 */
+		int physicalAddress = getStartingAddressOfTheFrameByIndex(tempFrameIndex) + getPageOffset(logicalAddress);
+		printf("Physical address is %d, logical address is %d\n", physicalAddress, logicalAddress);
 	}
+
+	free(frames);
+	return 0;
 }