backup

malloc/src/helpers/helpers.c

@@ -1,5 +1,6 @@
 #include "helpers.h"
 
+#include <string.h>
 #include <sys/mman.h>
 
 // Returns the smallest power of 2 greater or equal to s
@@ -55,7 +56,31 @@ void *find_free_block(struct bucket *buck)
 
 struct bucket *create_bucket(size_t min_alloc_size)
 {
+    // Round up
     size_t alloc_size = s2p(min_alloc_size);
+    // Get page
     void *page =
         mmap(NULL, alloc_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, -1, 0);
+
+    if (page == NULL)
+        return NULL;
+
+    // Init bucket
+    struct bucket *header = page;
+    header->page = page + sizeof(struct bucket);
+    header->block_size = alloc_size;
+    memset(header->free_list, 0, FREE_LIST_SIZE);
+
+    return header;
+}
+
+struct bucket *get_free_bucket(struct bucket *head, size_t size)
+{
+    while (head != NULL)
+    {
+        if (head->block_size >= size)
+            return head;
+    }
+
+    return NULL;
 }

malloc/src/helpers/helpers.h

@@ -1,18 +1,30 @@
 #ifndef HELPERS_H
 #define HELPERS_H
 
+// #define PAGE_SIZE (size_t) sysconf(_SC_PAGE_SIZE)
+#define PAGE_SIZE 4096
+#define MIN_BLOCK_SIZE 8
+#define FREE_LIST_SIZE PAGE_SIZE / MIN_BLOCK_SIZE / sizeof(unsigned char)
+
 #include <stddef.h>
 
+// Header
+// Contains all informations about the concerned bucket
 struct bucket
 {
     unsigned block_size;
-    unsigned char free_list[64]; // 4096 / MIN_BLOCK_SIZE /
+    unsigned char free_list[FREE_LIST_SIZE]; // 4096 / MIN_BLOCK_SIZE /
-                                 // sizeof(unsigned char) (in bits)
+                                             // sizeof(unsigned char)
     char *page;
+    
+    struct bucket *next;
+
+    size_t checksum;
 };
 
 size_t get_next_2power(size_t n);
 void *find_free_block(struct bucket *buck);
 struct bucket *create_bucket(size_t min_alloc_size);
+struct bucket *get_free_bucket(struct bucket *head, size_t size);
 
 #endif // ! HELPERS_H

malloc/src/malloc.c

@@ -1,9 +1,20 @@
 #include <stddef.h>
 
+#include "helpers/helpers.h"
+
+struct bucket *head = NULL;
+
 __attribute__((visibility("default"))) void *malloc(size_t size)
 {
     if (size == 0)
         return NULL;
+
+    struct bucket *buck = get_free_bucket(head, size);
+    if (buck == NULL)
+    {
+        buck = create_bucket(size);
+        return ...;
+    }
 }
 
 __attribute__((visibility("default"))) void free(void *ptr)