commit

will fix myfree function later

mymalloc.c

@@ -0,0 +1,143 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "mymalloc.h"
+
+struct mm_block_def
+{
+    struct mm_block_def *next;
+    struct mm_block_def *prev;
+    int size;
+    unsigned char *buffer;
+    int isFree; // 1: free, 0: allocated
+};
+
+unsigned char malloc_size[MAX_MALLOC_SIZE];
+static struct mm_block_def *head = NULL;
+
+void initmyMalloc()
+{
+    head = (struct mm_block_def*)malloc_size; 
+    if (head == NULL) {
+        return;
+    }
+    head->prev = NULL;
+    head->next = NULL;
+    head->size = sizeof(malloc_size) - sizeof(struct mm_block_def);
+    head->buffer = (unsigned char *)(head + sizeof(struct mm_block_def)); 
+    head->isFree = 1;
+}
+
+void *mymalloc(int size)
+{ 
+    if (size <= 0) {
+        return NULL;
+    }
+
+    struct mm_block_def *current = head;
+    while(current != NULL && current->size <= size){
+        current = current->next;
+    }
+    if(current == NULL){
+        return NULL; 
+    }
+
+    //bos alani bol
+    if(current->size >= size + sizeof(struct mm_block_def)){ 
+        struct mm_block_def *newBlock = (struct mm_block_def *)(current->buffer + size);
+        newBlock->buffer = current->buffer + size + sizeof(struct mm_block_def); 
+		newBlock->size = current->size - size - sizeof(struct mm_block_def);
+		newBlock->prev = current->prev;
+		newBlock->next = current->next;
+        newBlock->isFree = 1;
+
+		current->size = size;
+        current->isFree = 0;
+
+		if(current == head){
+			head = newBlock;
+		}
+		else if(current->prev!= NULL){
+			current->prev->next = newBlock;
+		}
+		if(current->next != NULL){
+			current->next->prev = newBlock;
+		}
+
+		current->next = newBlock;
+	}
+
+	return current;
+}
+
+
+void myfree(void *buffer)
+{
+    if (buffer == NULL) {
+        return;
+    }
+
+    struct mm_block_def *block = (struct mm_block_def *)buffer;
+    block->buffer = (unsigned char *)buffer + sizeof(struct mm_block_def);
+    block->isFree = 1;
+
+    struct mm_block_def *current = head;
+    while (current != NULL && current->buffer <= block->buffer) {
+        current = current->next;
+    }
+
+    //buffer degerlerinde sorun var
+    //solda bos blok varsa mergele 
+    if (current != NULL && current->prev != NULL && current->prev->buffer + current->prev->size + sizeof(struct mm_block_def) == block->buffer) { //current boş değil ve current head değil ve önceki boş blok merge edilebilir
+        current->prev->size += block->size + sizeof(struct mm_block_def);
+        current->prev->next = block->next;
+    }
+
+    //sagda bos blok varsa mergele
+    if (current != NULL && block->buffer + block->size + sizeof(struct mm_block_def) == current->buffer) { //current boş değil ve sonraki boş blok merge edilebilir
+        block->size += current->size + sizeof(struct mm_block_def);
+        block->next = current->next;
+    }
+
+    block->next = head;
+    block->prev = NULL;
+    head = block;
+}
+
+void printmyMallocFreeList() {
+    struct mm_block_def *current = head;
+    while (current != NULL) {
+        if (current->isFree) {
+            printf("block: %p\tsize: %d\n", current, current->size);
+            current = current->next;
+        }   
+    }
+    printf("---------------\n");
+}
+
+int main()
+{
+    initmyMalloc();
+	//head değerlerini printle
+    printf("head:\t%x\n", head);
+    printf("head->size:\t%d\n", head->size);
+    printf("head->next:\t%x\n", head->next);
+    printf("head->prev:\t%x\n", head->prev);
+    printf("head->buffer:\t%x\n", head->buffer);
+    printf("-------------------------------\n");
+
+	char *a = mymalloc(200);
+	printmyMallocFreeList();
+    myfree(a);
+    printmyMallocFreeList();
+	char *c = mymalloc(50);
+	mymalloc(80);
+	char *b = mymalloc(20);
+	printmyMallocFreeList();
+	myfree(b);
+    mymalloc(800);
+    mymalloc(300);
+    myfree(c);
+	printmyMallocFreeList();
+
+    return 0;
+}

mymalloc.h

@@ -0,0 +1,8 @@
+#ifndef MYMALLOC_H
+#define MYMALLOC_H
+#define MAX_MALLOC_SIZE (1024*1024*16)
+void initmyMalloc();
+void *mymalloc(int size); 
+void myfree(void *buffer);
+void printmyMallocFreeList();
+#endif