backup

malloc/Makefile

@@ -1,20 +1,29 @@
 CC=gcc
 CFLAGS=-std=c99 -pedantic -Werror -Wall -Wextra -Wvla -fvisibility=hidden -fPIC
 CPPFLAGS= -D_DEFAULT_SOURCE
-LDFLAGS= -shared -Wl --no-undefined
+LDFLAGS= -shared -Wl,--no-undefined
+LDLIBS=
 
 SRCS=src/malloc.c src/helpers/helpers.c src/helpers/allocate.c
 OBJS=${SRCS:.c=.o}
+TST_OBJS = tests/test.o
 TARGET=libmalloc.so
 
 library: $(OBJS)
-	$(CC) -o $(TARGET) $^
+	$(CC) -o $(TARGET) $^ $(LDFLAGS)
 
-debug: $(OBJS) $(TST_OBJS)
+debug: CFLAGS += -g
-	$(CC) -o $(TST_TARGET) $^
+debug: $(OBJS)
+	$(CC) -o $(TARGET) $^ $(LDFLAGS)
+
+# test: LDLIBS += -lcriterion
+test: CFLAGS = -g -L. -lmalloc -fPIC -fvisibility=hidden
+test: library $(TST_OBJS)
+	$(CC) -o $(TST_TARGET) $^ $(LDLIBS)
 
 check:
+	dash tests/test-cmd.sh
 
 clean:
-	$(RM) *.o
+	$(RM) $(OBJS)
 	$(RM) $(TARGET)

malloc/src/helpers/allocate.c

@@ -4,16 +4,17 @@
 #include <sys/mman.h>
 
 #include "helpers.h"
-
+// c'est dangereux de pas s'i3lock
+// coucou
 void *allocate_block(struct bucket *biquette, int block_number)
 {
     if (block_number == -1)
         return NULL;
 
     // Update header
-    unsigned char byte_mask = 1 << ((block_number % 8) - 1);
+    unsigned char byte_mask = 1 << (8 - 1 - (block_number % 8));
     biquette->alloc_blk_cnt++;
-    biquette->free_map[block_number / 8] &= byte_mask;
+    biquette->free_map[block_number / 8] |= byte_mask;
 
     // Compute block address
     return get_block(biquette, block_number);
@@ -31,8 +32,8 @@ struct bucket *create_bucket(size_t min_alloc_size)
         alloc_size = s2p(min_alloc_size);
 
     // Get page
-    void *page =
+    void *page = mmap(NULL, alloc_size, PROT_READ | PROT_WRITE,
-        mmap(NULL, alloc_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, -1, 0);
+                      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 
     if (page == NULL)
         return NULL;
@@ -41,6 +42,7 @@ struct bucket *create_bucket(size_t min_alloc_size)
     struct bucket *header = page;
     header->block_size = alloc_size;
     header->alloc_blk_cnt = 0;
+    header->alloc_size = alloc_size;
     memset(header->free_map, 0, FREE_LIST_SIZE);
 
     return header;
@@ -51,8 +53,26 @@ void free_block(void *ptr, struct bucket **list)
     // Compute header location and block number
     struct bucket *header = get_page_begin(ptr);
 
+    // Verify that header belongs to list
+    struct bucket *elt = *list;
+    int found = 0;
+    while (elt != NULL)
+    {
+        if (elt == header)
+        {
+            found = 1;
+            break;
+        }
+        elt = elt->next;
+    }
+    if (!found)
+        return;
+
     // free in map and update size
-    int block_number; // ...
+    int block_number = get_block_number(header, ptr);
+    if (block_number == -1)
+        return;
+
     unsigned char byte_mask = 1 << ((block_number % 8) - 1);
     header->free_map[block_number / 8] &= ~byte_mask;
 
@@ -65,6 +85,6 @@ void free_block(void *ptr, struct bucket **list)
     if (header->alloc_blk_cnt == 0)
     {
         bucket_list_remove(list, header);
-        munmap(ptr, 1);
+        munmap(header, header->alloc_size);
     }
 }

malloc/src/helpers/allocate.h

@@ -1,10 +1,10 @@
 #ifndef ALLOCATE_H
 #define ALLOCATE_H
 
-#include "helpers.h"
-
 #include <stddef.h>
 
+#include "helpers.h"
+
 void *allocate_block(struct bucket *biquette, int block_number);
 struct bucket *create_bucket(size_t min_alloc_size);
 void bucket_append(struct bucket **head, struct bucket *elt);

malloc/src/helpers/helpers.c

@@ -21,7 +21,7 @@ size_t s2p(size_t s)
     // (found __builtin_clzll but not sure of what it does)
 
     // So here's the good old way
-    size_t n = 1;
+    size_t n = MIN_BLOCK_SIZE;
     while (n < s)
     {
         n <<= 1;
@@ -41,7 +41,7 @@ int find_free_block(struct bucket *buck)
         // Test byte
         for (unsigned j = 0; j < 8; j <<= 1)
         {
-            if (map_byte & bit) // Test if free
+            if (map_byte ^ bit) // Test if free
                 return i * 8 + j;
 
             bit <<= 1;
@@ -51,6 +51,7 @@ int find_free_block(struct bucket *buck)
     return -1;
 }
 
+// Computes the block address based on its position in the freemap
 void *get_block(struct bucket *biquette, int block_number)
 {
     if (block_number == -1)
@@ -60,6 +61,7 @@ void *get_block(struct bucket *biquette, int block_number)
     return data_begin + (biquette->block_size * (block_number));
 }
 
+// Gets block position in the freemap based on its address
 int get_block_number(struct bucket *biquette, void *block)
 {
     if (block == NULL || biquette == NULL)
@@ -81,17 +83,20 @@ struct bucket *get_bucket(struct bucket *head, size_t size)
     {
         if (head->block_size >= size)
             return head;
+
+        head = head->next;
     }
 
     return NULL;
 }
 
+// Computes the buckets first block address
 void *get_data_begin(struct bucket *biquette)
 {
-    // TODO alignment
     return biquette + sizeof(struct bucket);
 }
 
+// Computes the beginning address of the page containing ptr
 void *get_page_begin(void *ptr)
 {
     size_t quelenfer = ((size_t)ptr) & ~(PAGE_SIZE - 1);
@@ -99,6 +104,7 @@ void *get_page_begin(void *ptr)
     return pointeur_alacon + quelenfer;
 }
 
+// Appends a bucket address to the list pointed by head
 void bucket_list_append(struct bucket **head, struct bucket *elt)
 {
     struct bucket *list_elt = *head;

malloc/src/helpers/helpers.h

@@ -3,7 +3,7 @@
 
 // #define PAGE_SIZE sysconf(_SC_PAGE_SIZE)
 #define PAGE_SIZE 4096
-#define MIN_BLOCK_SIZE 8
+#define MIN_BLOCK_SIZE 16
 #define FREE_LIST_SIZE PAGE_SIZE / MIN_BLOCK_SIZE / sizeof(unsigned char)
 
 #include <stddef.h>
@@ -19,7 +19,10 @@ struct bucket
                                             // representation
     unsigned short alloc_blk_cnt; // Counts the number of allocated blocks
     struct bucket *next;
-    size_t checksum;
+    size_t alloc_size;
+
+    unsigned short space1; //
+    unsigned int space2; // -> Both are used to align data on 16 bytes
 };
 
 #define BUCKET_SIZE PAGE_SIZE - sizeof(struct bucket)
@@ -30,6 +33,7 @@ struct bucket *get_bucket(struct bucket *head, size_t size);
 void *get_data_begin(struct bucket *biquette);
 void *get_page_begin(void *ptr);
 void *get_block(struct bucket *biquette, int block_number);
+int get_block_number(struct bucket *biquette, void *block);
 void bucket_list_append(struct bucket **head, struct bucket *elt);
 void bucket_list_remove(struct bucket **head, struct bucket *elt);
 

malloc/src/malloc.c

@@ -18,7 +18,7 @@ __attribute__((visibility("default"))) void *malloc(size_t size)
         // Find adequate block
         int block_number = find_free_block(buck);
         if (block_number != -1)
-            return get_block(buck, block_number);
+            return allocate_block(buck, block_number);
         else
         {
             // No free space -> loop
@@ -27,8 +27,8 @@ __attribute__((visibility("default"))) void *malloc(size_t size)
     }
 
     buck = create_bucket(size);
-    bucket_append(&head, buck);
+    bucket_list_append(&head, buck);
-    return get_data_begin(buck);
+    return allocate_block(buck, 1);
 }
 
 __attribute__((visibility("default"))) void free(void *ptr)

malloc/tests/test-cmd.sh

@@ -0,0 +1,3 @@
+#!/bi/sh
+
+echo Hello world!

malloc/tests/test.c

@@ -0,0 +1,25 @@
+// #include <criterion/criterion.h>
+// #include <criterion/new/assert.h>
+
+// TestSuite(Main);
+
+// Test(Main, test1)
+// {
+//     int *i = malloc(16);
+//     cr_assert(i != NULL);
+// }
+
+#include <stdlib.h>
+
+int main(void)
+{
+    int *test = malloc(8);
+    void *tes2 = malloc(8);
+    void *tes3 = malloc(32);
+    void *tes4 = malloc(64);
+    void *tes5 = malloc(128);
+    void *tes6 = malloc(256);
+    void *tes7 = malloc(512);
+    void *tes8 = malloc(4096);
+    void *tes9 = malloc(95956);
+}