From 5ea65b6b0c686d9537c92e0fd240620ad3cc7996 Mon Sep 17 00:00:00 2001
From: Alex Kotov <kotovalexarian@gmail.com>
Date: Sun, 27 Nov 2022 19:31:56 +0400
Subject: [PATCH] Fix free list (#113)

---
 src/free_list.c        |   3 +-
 tests/test_free_list.c | 121 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 122 insertions(+), 2 deletions(-)

diff --git a/src/free_list.c b/src/free_list.c
index 170dae85..988901c5 100644
--- a/src/free_list.c
+++ b/src/free_list.c
@@ -187,8 +187,6 @@ void *KernAux_FreeList_malloc(void *const malloc, size_t size)
     if (node) {
         // Can we split the block?
         if (node->size - size >= MIN_SPLIT_SIZE) {
-            node->size = NODE_HEADER_SIZE + size;
-
             KernAux_FreeList_Node new_node =
                 (KernAux_FreeList_Node)(((uintptr_t)&node->block) + size);
 
@@ -200,6 +198,7 @@ void *KernAux_FreeList_malloc(void *const malloc, size_t size)
 
             new_node->orig_ptr = new_node;
             new_node->size = node->size - size - NODE_HEADER_SIZE;
+            node->size = NODE_HEADER_SIZE + size;
             KernAux_FreeList_insert(free_list, new_node, node, node->next);
         }
 
diff --git a/tests/test_free_list.c b/tests/test_free_list.c
index b3450814..4fe60dfd 100644
--- a/tests/test_free_list.c
+++ b/tests/test_free_list.c
@@ -9,10 +9,13 @@
 #include <assert.h>
 #include <stddef.h>
 #include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 static void test_default();
 static void test_cross_zone_defrag();
+static void test_hello_and_mrb_state();
 
 static void test_calloc();
 static void test_calloc_nomem();
@@ -26,6 +29,7 @@ static void test_realloc_increase();
 static void test_realloc_decrease();
 
 static size_t nodes_count(KernAux_FreeList free_list);
+static void print_nodes(KernAux_FreeList free_list);
 
 static const char *const hello = "Hello, World!";
 
@@ -33,6 +37,7 @@ void test_main()
 {
     test_default();
     test_cross_zone_defrag();
+    test_hello_and_mrb_state();
 
     test_calloc();
     test_calloc_nomem();
@@ -59,6 +64,29 @@ size_t nodes_count(const KernAux_FreeList free_list)
     return nodes_count;
 }
 
+void print_nodes(const KernAux_FreeList free_list)
+{
+    printf("\n\n\n");
+    printf("========================================\n");
+    printf("free_list:       %p\n", (void*)free_list);
+    printf("free_list->head: %p\n", (void*)free_list->head);
+    for (
+        KernAux_FreeList_Node item_node = free_list->head;
+        item_node;
+        item_node = item_node->next
+    ) {
+        printf("----------------------------------------\n");
+        printf("item_node:           %p\n",  (void*)item_node);
+        printf("item_node->orig_ptr: %p\n",  (void*)item_node->orig_ptr);
+        printf("item_node->next:     %p\n",  (void*)item_node->next);
+        printf("item_node->prev:     %p\n",  (void*)item_node->prev);
+        printf("&item_node->block:   %p\n",  (void*)&item_node->block);
+        printf("item_node->size:     %lu\n", (unsigned long)item_node->size);
+    }
+    printf("========================================\n");
+    printf("\n\n\n");
+}
+
 void test_default()
 {
     char memory_block[1000];
@@ -111,6 +139,99 @@ void test_cross_zone_defrag()
     assert(nodes_count(&free_list) == 1);
 }
 
+void test_hello_and_mrb_state()
+{
+    char *const zone = malloc(1024 * 128); // 128 KiB
+    assert(zone);
+
+    struct KernAux_FreeList free_list = KernAux_FreeList_create(NULL);
+    printf("KernAux_FreeList_create(NULL) = %p\n", (void*)&free_list);
+    print_nodes(&free_list);
+
+    KernAux_FreeList_add_zone(&free_list, zone, 1024 * 128);
+    printf(
+        "KernAux_FreeList_add_zone(&free_list, zone = %p, 1024 * 128 = %i)\n",
+        (void*)zone,
+        1024 * 128
+    );
+    print_nodes(&free_list);
+
+    {
+        char *const str = KernAux_Malloc_malloc(&free_list.malloc, 100);
+        printf(
+            "KernAux_Malloc_malloc(&free_list.malloc, 100) = %p\n",
+            (void*)str
+        );
+        print_nodes(&free_list);
+
+        assert(str);
+
+        KernAux_Malloc_free(&free_list.malloc, str);
+        printf(
+            "KernAux_Malloc_free(&free_list.malloc, str = %p)\n",
+            (void*)str
+        );
+        print_nodes(&free_list);
+    }
+
+    {
+        char *const str =
+            KernAux_Malloc_realloc(&free_list.malloc, NULL, 100);
+        printf(
+            "KernAux_Malloc_realloc(&free_list.malloc, NULL, 100) = %p\n",
+            (void*)str
+        );
+        print_nodes(&free_list);
+
+        assert(str);
+
+        KernAux_Malloc_free(&free_list.malloc, str);
+        printf(
+            "KernAux_Malloc_free(&free_list.malloc, str = %p)\n",
+            (void*)str
+        );
+        print_nodes(&free_list);
+    }
+
+    {
+        char *const mrb = KernAux_Malloc_malloc(&free_list.malloc, 6356);
+        printf(
+            "KernAux_Malloc_malloc(&free_list.malloc, 6356) = %p\n",
+            (void*)mrb
+        );
+        print_nodes(&free_list);
+
+        assert(mrb);
+
+        KernAux_Malloc_free(&free_list.malloc, mrb);
+        printf(
+            "KernAux_Malloc_free(&free_list.malloc, mrb = %p)\n",
+            (void*)mrb
+        );
+        print_nodes(&free_list);
+    }
+
+    {
+        char *const mrb = KernAux_Malloc_realloc(&free_list.malloc, NULL, 6356);
+        printf(
+            "KernAux_Malloc_realloc(&free_list.malloc, NULL, 6356) = %p\n",
+            (void*)mrb
+        );
+        print_nodes(&free_list);
+
+        assert(mrb);
+
+        KernAux_Malloc_free(&free_list.malloc, mrb);
+        printf(
+            "KernAux_Malloc_free(&free_list.malloc, mrb = %p)\n",
+            (void*)mrb
+        );
+        print_nodes(&free_list);
+    }
+
+    free(zone);
+}
+
 void test_calloc()
 {
     char zone[1000];