feat: partially implemented malloc and free

hw3/Makefile

@@ -17,7 +17,7 @@ INC := -I $(INCD)
 
 CFLAGS := -Wall -Werror -Wno-unused-function -MMD
 COLORF := -DCOLOR
-DFLAGS := -g -DDEBUG -DCOLOR
+DFLAGS := -g -DDEBUG -DCOLOR -DWEAK_MAGIC
 PRINT_STAMENTS := -DERROR -DSUCCESS -DWARN -DINFO
 
 STD := -std=c99

hw3/include/sfmm.h

@@ -315,8 +315,12 @@ void *sf_mem_grow();
  */
 sf_header sf_magic();
 
+//#define MAGIC (sf_magic())
+#ifndef WEAK_MAGIC 
 #define MAGIC (sf_magic()) 
-
+#else 
+#define MAGIC ((sf_header)0x0) 
+#endif 
 /*
  * Set the "magic number" used to obfuscate header and footer contents.
  * Setting the magic number to zero essentially turns off obfuscation, which will

hw3/src/main.c

@@ -2,13 +2,17 @@
 #include "sfmm.h"
 
 int main(int argc, char const *argv[]) {
+    sf_set_magic(0x0);
     double* ptr = sf_malloc(sizeof(double));
 
-    *ptr = 320320320e-320;
+    *ptr = 114514;
 
     printf("%f\n", *ptr);
 
     sf_free(ptr);
 
+    sf_show_heap();
+    sf_show_free_lists();
+
     return EXIT_SUCCESS;
 }

hw3/src/sfmm.c

@@ -7,28 +7,347 @@
 #include <string.h>
 #include "debug.h"
 #include "sfmm.h"
+#include "errno.h"
 
-void *sf_malloc(sf_size_t size) {
+static sf_size_t min = 32;
+static sf_block *pro;
+static sf_block *epi;
+static sf_size_t in_qklst = 0x00000001;
+static sf_size_t prv_alloc = 0x00000002;
+static sf_size_t alloc = 0x00000004;
+
+int sf_initialize();
+void set_header(sf_block *block, sf_header value);
+void set_entire_header(sf_block *block, sf_size_t paylod_size, sf_size_t block_size,
+                       sf_size_t is_alloc, sf_size_t is_prv_alloc, sf_size_t is_in_qklst);
+void set_payload_size(sf_block *block, sf_size_t payload_size);
+void set_block_size(sf_block *block, sf_size_t block_size);
+void set_alloc(sf_block *block, sf_size_t is_alloc);
+void set_prv_alloc(sf_block *block, sf_size_t is_prv_allc);
+void set_in_qklst(sf_block *block, sf_size_t is_qklst);
+sf_size_t get_payload_size(sf_header header);
+sf_size_t get_block_size(sf_header header);
+sf_size_t get_alloc(sf_header header);
+sf_size_t get_prv_alloc(sf_header header);
+sf_size_t get_in_qklst(sf_header header);
+void put_block(sf_block *block);
+sf_size_t get_min_size(sf_size_t size);
+sf_size_t get_index(sf_size_t size);
+sf_size_t get_size_of_index(sf_size_t index);
+sf_block *split_block(sf_block *block, size_t size);
+void valid_pointer(sf_block *pp);
+void release_block(sf_block *block);
+
+void *sf_malloc(sf_size_t size)
+{
+    if (size == 0)
+        return NULL;
+
+    if (sf_mem_start() == sf_mem_end())
+        if (sf_initialize())
+            return NULL;
+
+    sf_size_t min_size = get_min_size(size);
+
+    sf_size_t index = (min_size - 32) / 16;
+    if (index < 10)
+        if (sf_quick_lists[index].length > 0)
+        {
+            sf_block *block = sf_quick_lists[index].first;
+            sf_quick_lists[index].length -= 1;
+            sf_quick_lists[index].first = block->body.links.next;
+            return block;
+        }
+
+    index = get_index(min_size);
+
+    for (size_t i = index; i < NUM_FREE_LISTS; i++)
+    {
+        sf_block *header = &sf_free_list_heads[i];
+        sf_block *ptr = header->body.links.next;
+        if (i == index)
+        {
+            while (ptr != header)
+            {
+                if (get_block_size(ptr->header) >= min_size)
+                {
+                    set_entire_header(ptr, size, get_block_size(ptr->header), 1, 0, 0);
+                    return ptr->body.payload;
+                }
+            }
+        }
+        else
+        {
+            while (ptr != header)
+            {
+                if (get_block_size(ptr->header) - min_size > get_size_of_index(i))
+                {
+                    sf_block *block = split_block(ptr, min_size);
+                    sf_size_t block_size = get_block_size(block->header);
+                    set_entire_header(block, size, block_size, 1, 0, 0);
+                    sf_show_block(block);
+                    sf_show_block(ptr);
+                    return block->body.payload;
+                }
+            }
+        }
+    }
+
+    // TO BE IMPLEMENTED
+    return NULL;
+}
+
+void sf_free(void *pp)
+{
+    sf_block *block = (sf_block *)(intptr_t)(pp - 2 * sizeof(sf_header));
+    valid_pointer(block);
+
+    sf_size_t index = (get_block_size(block->header) - 32) / 16;
+    if (index < 10)
+    {
+        set_entire_header(block, 0, get_block_size(block->header), 1, get_prv_alloc(block->header), 1);
+        if (sf_quick_lists[index].length >= 5)
+        {
+            sf_block *ptr = sf_quick_lists[index].first;
+            while (ptr != NULL)
+            {
+                sf_block *tmp = ptr;
+                ptr = ptr->body.links.next;
+                release_block(tmp);
+            }
+            sf_quick_lists[index].length = 0;
+            sf_quick_lists->first = NULL;
+        }
+        block->body.links.next = sf_quick_lists[index].first;
+        sf_quick_lists[index].length += 1;
+        sf_quick_lists[index].first = block;
+        return;
+    }
+    release_block(block);
+}
+
+void *sf_realloc(void *pp, sf_size_t rsize)
+{
     // TO BE IMPLEMENTED
     abort();
 }
 
-void sf_free(void *pp) {
+double sf_internal_fragmentation()
+{
     // TO BE IMPLEMENTED
     abort();
 }
 
-void *sf_realloc(void *pp, sf_size_t rsize) {
+double sf_peak_utilization()
+{
     // TO BE IMPLEMENTED
     abort();
 }
 
-double sf_internal_fragmentation() {
+int sf_initialize()
-    // TO BE IMPLEMENTED
+{
-    abort();
+    if (sf_mem_grow() == NULL)
+    {
+        sf_errno = ENOMEM;
+        return 1;
+    }
+    pro = (sf_block *)sf_mem_start();
+    set_entire_header(pro, 0, 32, 1, 0, 0);
+    epi = (sf_block *)((intptr_t)sf_mem_end() - 2 * sizeof(sf_header));
+    set_entire_header(epi, 0, 0, 1, 1, 0);
+    for (size_t i = 0; i < NUM_FREE_LISTS; i++)
+    {
+        sf_free_list_heads[i].body.links.prev = &sf_free_list_heads[i];
+        sf_free_list_heads[i].body.links.next = &sf_free_list_heads[i];
+    }
+    for (size_t i = 0; i < NUM_QUICK_LISTS; i++)
+    {
+        sf_quick_lists[i].length = 0;
+        sf_quick_lists[i].first = NULL;
+    }
+    sf_block *block = (sf_block *)((intptr_t)sf_mem_start() + 4 * sizeof(sf_header));
+    sf_size_t size = PAGE_SZ - 6 * sizeof(sf_header);
+    set_entire_header(block, 0, size, 0, 1, 0);
+    put_block(block);
+    return 0;
 }
 
-double sf_peak_utilization() {
+sf_size_t get_min_size(sf_size_t size)
-    // TO BE IMPLEMENTED
+{
-    abort();
+    if (size <= 16)
+        return min;
+    else
+        return size % 16 == 0 ? size + 16 : (size + 32) - (size % 16);
+}
+
+void set_header(sf_block *block, sf_header value)
+{
+    block->header = value;
+    if (get_alloc(block->header) == 0)
+    {
+        sf_block *next = (sf_block *)((intptr_t)block + get_block_size(block->header));
+        next->prev_footer = block->header;
+    }
+}
+
+void set_entire_header(sf_block *block, sf_size_t paylod_size, sf_size_t block_size,
+                       sf_size_t is_alloc, sf_size_t is_prv_alloc, sf_size_t is_in_qklst)
+{
+    set_payload_size(block, paylod_size);
+    set_block_size(block, block_size);
+    set_alloc(block, is_alloc);
+    set_prv_alloc(block, is_prv_alloc);
+    set_in_qklst(block, is_in_qklst);
+}
+
+void set_payload_size(sf_block *block, sf_size_t payload_size)
+{
+    sf_header value = (block->header & 0x00000000FFFFFFFF) | (uint64_t)payload_size << 32;
+    set_header(block, value);
+}
+
+void set_block_size(sf_block *block, sf_size_t block_size)
+{
+    sf_header value = (block->header & 0xFFFFFFFF0000000F) | (uint64_t)block_size;
+    set_header(block, value);
+}
+
+void set_alloc(sf_block *block, sf_size_t is_alloc)
+{
+    sf_header value = block->header;
+    if (is_alloc)
+    {
+        value |= alloc;
+    }
+    else
+    {
+        value &= ~alloc;
+    }
+    set_header(block, value);
+}
+
+void set_prv_alloc(sf_block *block, sf_size_t is_prv_allc)
+{
+    sf_header value = block->header;
+    if (is_prv_allc)
+    {
+        value |= prv_alloc;
+    }
+    else
+    {
+        value &= ~prv_alloc;
+    }
+    set_header(block, value);
+}
+
+void set_in_qklst(sf_block *block, sf_size_t is_in_qklst)
+{
+    sf_header value = block->header;
+    if (is_in_qklst)
+    {
+        value |= in_qklst;
+    }
+    else
+    {
+        value &= ~in_qklst;
+    }
+    set_header(block, value);
+}
+
+sf_size_t get_payload_size(sf_header header)
+{
+    return ((uint64_t)header & 0xFFFFFFFF00000000) >> 32;
+}
+
+sf_size_t get_block_size(sf_header header)
+{
+    return ((uint64_t)header & 0x00000000FFFFFFF0);
+}
+
+sf_size_t get_alloc(sf_header header)
+{
+    return ((uint64_t)header & alloc) ? 1 : 0;
+}
+
+sf_size_t get_prv_alloc(sf_header header)
+{
+    return ((uint64_t)header & prv_alloc) ? 1 : 0;
+}
+
+sf_size_t get_in_qklst(sf_header header)
+{
+    return ((uint64_t)header & in_qklst) ? 1 : 0;
+}
+
+void put_block(sf_block *block)
+{
+    sf_size_t index = get_index(get_block_size(block->header));
+    sf_block *header = &sf_free_list_heads[index];
+    block->body.links.prev = header;
+    block->body.links.next = header->body.links.next;
+    header->body.links.next->body.links.prev = block;
+    header->body.links.next = block;
+}
+
+sf_size_t get_index(sf_size_t size)
+{
+    size /= 32;
+    size_t index = 0;
+    for (; index < (NUM_FREE_LISTS - 1); index++, size /= 2)
+        if (size == 1)
+            break;
+    return index;
+}
+
+sf_size_t get_size_of_index(sf_size_t index)
+{
+    return 16 << index;
+}
+
+sf_block *split_block(sf_block *block, size_t size)
+{
+    size_t original_size = get_block_size(block->header);
+    size_t new_size = original_size - size;
+    set_block_size(block, new_size);
+    sf_block *ptr = (sf_block *)((intptr_t)block + get_block_size(block->header));
+    set_entire_header(ptr, 0, size, 0, 0, 0);
+    ptr->prev_footer = block->header;
+    return ptr;
+}
+
+void valid_pointer(sf_block *pp)
+{
+    if (pp == NULL || (intptr_t)pp % 16 != 0)
+        abort();
+    // pp->header ^= sf_magic();
+    if (get_block_size(pp->header) < 32 || get_block_size(pp->header) % 16 != 0)
+        abort();
+    if ((intptr_t)&pp->header < ((intptr_t)&pro->header + 32) || (intptr_t)&pp->header > ((intptr_t)&epi->header - 8))
+        abort();
+    if (get_alloc(pp->header) == 0 || (get_prv_alloc(pp->header) == 0 && get_alloc(pp->prev_footer) != 0))
+        abort();
+    return;
+}
+
+void release_block(sf_block *block)
+{
+    sf_block *next = (sf_block *)((intptr_t)block + get_block_size(block->header));
+    sf_block *prev = (sf_block *)((intptr_t)block - get_block_size(block->prev_footer));
+    sf_size_t total_size = get_block_size(block->header);
+    if (get_alloc(next->header) == 0)
+    {
+        next->body.links.prev->body.links.next = next->body.links.next;
+        next->body.links.next->body.links.prev = next->body.links.prev;
+        total_size += get_block_size(next->header);
+    }
+    if (get_alloc(block->prev_footer) == 0)
+    {
+        prev->body.links.prev->body.links.next = prev->body.links.next;
+        prev->body.links.next->body.links.prev = prev->body.links.prev;
+        total_size += get_block_size(prev->header);
+        block = prev;
+    }
+    set_entire_header(block, 0, total_size, 0, get_prv_alloc(block->header), 0);
+    put_block(block);
+    return;
 }