From 96fcf9f5c4de862f36a69772ce997b3f17b7feeb Mon Sep 17 00:00:00 2001
From: TuDatTr <tran.tuan-dat@mailbox.org>
Date: Sun, 24 Jan 2021 21:46:07 +0100
Subject: [PATCH] Added getSizeClass

---
 Makefile |  4 ++--
 mm.c     | 67 ++++++++++++++++++++++++++++----------------------------
 2 files changed, 35 insertions(+), 36 deletions(-)

diff --git a/Makefile b/Makefile
index f9f8bed..d4ab256 100644
--- a/Makefile
+++ b/Makefile
@@ -2,8 +2,8 @@
 # Students' Makefile for the Malloc Lab
 #
 CC = gcc
-CFLAGS = -Wall -O2 -m32
-# CFLAGS = -Wall -O0 -m32 -g03 -pg
+# CFLAGS = -Wall -O2 -m32
+CFLAGS = -Wall -O0 -m32 -g03 -pg
 
 OBJS = mdriver.o mm.o memlib.o fsecs.o fcyc.o clock.o ftimer.o
 
diff --git a/mm.c b/mm.c
index e53e8c0..43711e8 100644
--- a/mm.c
+++ b/mm.c
@@ -125,10 +125,20 @@ static void add_free(void *ptr, size_t size);
 static void remove_free(void *ptr);
 static void *coalesce(void *ptr);
 static void *place(void *ptr, size_t asize);
+static int getSzClass(size_t asize);
 
 ////////////////////////////////////////////////////////////////////////////////
 /////////////////////////////// HELPER FUNCTIONS /////////////////////////////// 
 ////////////////////////////////////////////////////////////////////////////////
+static int getSzClass(size_t asize) {
+  for (size_t i = 0; i < LISTSIZE; ++i) {
+    if (asize == (1 << i)) {
+      return i;
+    }
+  }
+  return LISTSIZE-1;
+}
+
 static void *extend_heap(size_t size)
 {
   size_t asize;
@@ -149,42 +159,36 @@ static void *extend_heap(size_t size)
 }
 
 static void add_free(void *ptr, size_t size) {
-  int list = 0;
-  void *searching_ptr = ptr;
-  void *in_ptr = NULL;
-    
-  while ((list < LISTSIZE - 1) && (size > 1)) {
-    size >>= 1;
-    list++;
+  int szClass = getSzClass(size);
+  void* class_ptr = seg_list[szClass];
+  void *pre_ptr = NULL;
+
+  while ((class_ptr != NULL) && (size > GET_SIZE(HDRP(class_ptr)))) {
+    pre_ptr = class_ptr;
+    class_ptr = PRV_BLK(class_ptr);
   }
     
-  searching_ptr = seg_list[list];
-  while ((searching_ptr != NULL) && (size > GET_SIZE(HDRP(searching_ptr)))) {
-    in_ptr = searching_ptr;
-    searching_ptr = PRV_BLK(searching_ptr);
-  }
-    
-  if (searching_ptr != NULL && in_ptr != NULL) {
-    PUT_PTR(NXT_PTR(searching_ptr), ptr);
-    PUT_PTR(NXT_PTR(ptr), in_ptr);
-    PUT_PTR(PRV_PTR(ptr), searching_ptr);
-    PUT_PTR(PRV_PTR(in_ptr), ptr);
+  if (class_ptr != NULL && pre_ptr != NULL) {
+    PUT_PTR(NXT_PTR(class_ptr), ptr);
+    PUT_PTR(NXT_PTR(ptr), pre_ptr);
+    PUT_PTR(PRV_PTR(ptr), class_ptr);
+    PUT_PTR(PRV_PTR(pre_ptr), ptr);
   } 
-  else if (searching_ptr != NULL && in_ptr == NULL) {
-    PUT_PTR(PRV_PTR(ptr), searching_ptr);
-    PUT_PTR(NXT_PTR(searching_ptr), ptr);
+  else if (class_ptr != NULL && pre_ptr == NULL) {
+    PUT_PTR(PRV_PTR(ptr), class_ptr);
+    PUT_PTR(NXT_PTR(class_ptr), ptr);
     PUT_PTR(NXT_PTR(ptr), NULL);
-    seg_list[list] = ptr;
+    seg_list[szClass] = ptr;
   } 
-  else if(searching_ptr == NULL && in_ptr != NULL) {
-    PUT_PTR(NXT_PTR(ptr), in_ptr);
+  else if(class_ptr == NULL && pre_ptr != NULL) {
+    PUT_PTR(NXT_PTR(ptr), pre_ptr);
     PUT_PTR(PRV_PTR(ptr), NULL);
-    PUT_PTR(PRV_PTR(in_ptr), ptr);
+    PUT_PTR(PRV_PTR(pre_ptr), ptr);
   } 
   else {
     PUT_PTR(NXT_PTR(ptr), NULL);
     PUT_PTR(PRV_PTR(ptr), NULL);
-    seg_list[list] = ptr;
+    seg_list[szClass] = ptr;
   }
     
   return;
@@ -192,25 +196,20 @@ static void add_free(void *ptr, size_t size) {
 
 
 static void remove_free(void *ptr) {
-  int list = 0;
   size_t size = GET_SIZE(HDRP(ptr));
-    
-  while ((list < LISTSIZE - 1) && (size > 1)) {
-    size >>= 1;
-    list++;
-  }
+  int szClass = getSzClass(size);
     
   if (PRV_BLK(ptr) != NULL && NXT_BLK(ptr) != NULL) {
     PUT_PTR(NXT_PTR(PRV_BLK(ptr)), NXT_BLK(ptr));
     PUT_PTR(PRV_PTR(NXT_BLK(ptr)), PRV_BLK(ptr));
   } else if(PRV_BLK(ptr) != NULL && NXT_BLK(ptr) == NULL) {
     PUT_PTR(NXT_PTR(PRV_BLK(ptr)), NULL);
-    seg_list[list] = PRV_BLK(ptr);
+    seg_list[szClass] = PRV_BLK(ptr);
   } 
   else if(PRV_BLK(ptr) == NULL && NXT_BLK(ptr) != NULL) {
     PUT_PTR(PRV_PTR(NXT_BLK(ptr)), NULL);
   } else {
-    seg_list[list] = NULL;
+    seg_list[szClass] = NULL;
   }  
   return;
 }