Add a buddy allocator

build.sh

@@ -2,4 +2,4 @@
 CFLAGS=${CFLAGS:-"-fsanitize=address -ggdb"}
 CC=${CC:-gcc}
 set -x
-${CC} -DDEBUG -pipe  -Wall -Wextra -Wno-unused-parameter -Wno-unused-variable -std=gnu2x $CFLAGS src/*c
+${CC} -DDEBUG -pipe  -Wall -Wextra -Wno-unused-parameter -Wno-unused-variable -std=gnu2x $CFLAGS src/*c src/base/*c

src/base/arena.c

@@ -1,5 +1,5 @@
 #include "arena.h"
-#include "base_core.h"
+#include "core.h"
 #include "platform.h"
 
 
@@ -144,8 +144,6 @@ void arena_trim(Arena *arena)
     U32 aligned_pos = RoundUpToMultiple(block->first_free, arena->commit_size);
     if (aligned_pos < block->committed_end) {
         void *trim_start = &block->base[aligned_pos];
-        // Note(nos): Should we unpoision ?
-        //ASAN_UNPOISON_MEMORY_REGION(trim_start, block->committed_end);
         memory_decommit(trim_start, block->committed_end - aligned_pos);
         block->committed_end = aligned_pos;
     }

src/base/arena.h

@@ -1,11 +1,11 @@
 #pragma once
-#include "base_core.h"
+#include "core.h"
 
 
 typedef U32 ArenaFlags;
 typedef struct ArenaOptions ArenaOptions;
 enum {
-    ArenaFlag_NoDecommit = 1, // operations which shrinks the arena does not decommit memory.
+    ArenaFlag_NoDecommit = (1 << 0), // operations which shrinks the arena does not decommit memory.
                               // (arena_trim() can still decommit when called explicitly)
 };
 struct ArenaOptions {
@@ -80,7 +80,8 @@ static INLINE void *arena_allocator_func(Allocator *allocator, AllocOperation op
         case Alloc_Op_Aligned:
             return arena_push(allocator->data, size, align);
 
-        case Alloc_Op_Free: // can't free from  an marena
+        case Alloc_Op_Free: // can't free from  an arena
+            NotImplemented;
             return NULL;
 
         case Alloc_Op_Free_All:

src/base/core.h

@@ -24,6 +24,8 @@ typedef uint8_t     U8;
 typedef uint16_t    U16;
 typedef uint32_t    U32;
 typedef uint64_t    U64;
+typedef uintptr_t   UMM;
+typedef intptr_t    IMM;
 typedef float       F32;
 typedef double      F64;
 #if defined(__FLT128_MANT_DIG__)

src/base/lalloc.c

@@ -0,0 +1,174 @@
+#include "lalloc.h"
+
+#define BLOCK_ALIGNMENT sizeof(LBlockHeader)
+#define BLOCK_SPLIT_MIN_SIZE BLOCK_ALIGNMENT
+#define NULL_BLOCK (0xffffffff)
+#define BLOCK_FREE ((U32)1)
+
+static inline void lblock_set_free(LBlockHeader *block)
+{
+    block->size_and_flags |= BLOCK_FREE;
+}
+
+static inline void lblock_set_used(LBlockHeader *block)
+{
+    block->size_and_flags &= ~BLOCK_FREE;
+}
+
+static inline void lblock_set_size(LBlockHeader *block, U32 size)
+{
+    U32 flags = block->size_and_flags & BLOCK_FREE;
+    Assert((size & BLOCK_FREE) == 0);
+    block->size_and_flags = size | flags;
+}
+
+U32 lblock_size(const LBlockHeader *block)
+{
+    return block->size_and_flags & ~BLOCK_FREE;
+}
+
+int lblock_is_free(const LBlockHeader *block)
+{
+    return (block->size_and_flags & BLOCK_FREE) != 0;
+}
+
+LBlockHeader *lblock_from_offset(const LAlloc *allocator, U32 offset)
+{
+    if (offset == NULL_BLOCK) {
+        return NULL;
+    }
+
+    return (LBlockHeader *)((UMM)allocator->base + offset);
+}
+
+static inline U32 lbh_offset(LAlloc *allocator, LBlockHeader *block)
+{
+    if (block == NULL) {
+        return NULL_BLOCK;
+    }
+
+    return (U32)((uintptr_t)block - (uintptr_t)allocator->base);
+}
+
+static void lmaybe_split_block(LAlloc *allocator, LBlockHeader *block, U32 size)
+{
+    // this function assumes size is already aligned
+
+    U32 bsize = lblock_size(block);
+    if (size > U32_Max - (sizeof(LBlockHeader) + BLOCK_SPLIT_MIN_SIZE)) {
+        return; // size is so large that size + header + min would overflow U32 anyway
+    }
+    if (bsize < size + sizeof(LBlockHeader) + BLOCK_SPLIT_MIN_SIZE) {
+        return; // no gain from splitting this block
+    }
+
+    U8 *base = (U8 *)block;
+    LBlockHeader *new_block = (LBlockHeader *)(base + size + sizeof(LBlockHeader) );
+
+    U32 new_size = bsize - size - sizeof(LBlockHeader);
+
+    lblock_set_size(block, size);
+    lblock_set_used(block);
+    lblock_set_size(new_block, new_size);
+    lblock_set_free(new_block);
+    new_block->next = block->next;
+    new_block->prev = lbh_offset(allocator, block);
+
+    LBlockHeader *next = lblock_from_offset(allocator, new_block->next);
+    if (next) {
+        next->prev = lbh_offset(allocator, new_block);
+    }
+
+    block->next = lbh_offset(allocator, new_block);
+}
+
+static void lmerge_with_next(LAlloc *allocator, LBlockHeader *block)
+{
+    LBlockHeader *next = lblock_from_offset(allocator, block->next);
+    if (next == NULL || !lblock_is_free(next)) {
+        return;
+    }
+
+    // block and next are both existing blocks within the same backing store, whose
+    // total size is asserted in lalloc_init to be < 0xfffffff0, so this can't overflow
+    // unless allocator state is already corrupted.
+    Assert(lblock_size(block) <= U32_Max - sizeof(LBlockHeader) - lblock_size(next));
+    U32 new_size = lblock_size(block) + sizeof(LBlockHeader) + lblock_size(next);
+
+    lblock_set_size(block, new_size);
+    block->next = next->next;
+    LBlockHeader *nextnext = lblock_from_offset(allocator, next->next);
+    if (nextnext) nextnext->prev = lbh_offset(allocator, block);
+    // note - caller have to adjust next_alloc on return
+}
+
+void lalloc_init(LAlloc *allocator, void *backing_store, U32 size)
+{
+    // backing store must be aligned, otherwise  all alignment guarantees are lies
+
+    Assert(IsAlignedTo((UMM)backing_store, BLOCK_ALIGNMENT));
+    Assert(size >= sizeof(LBlockHeader));
+    Assert(size < 0xfffffff0);
+
+    allocator->base = backing_store;
+    allocator->size = size;
+
+    LBlockHeader *first = backing_store;
+    // We need to keep size aligned to at least 2 as we reuse the LSB for the FREE flag
+    U32 usable = AlignDown(size, 2) - sizeof(LBlockHeader);
+    lblock_set_free(first);
+    lblock_set_size(first, usable);
+    first->next = NULL_BLOCK;
+    first->prev = NULL_BLOCK;
+
+    allocator->next_alloc = first;
+}
+
+void *lalloc(LAlloc *allocator, U32 size)
+{
+    if (size > U32_Max - (BLOCK_ALIGNMENT - 1)) { // -1 so AlignUp below doesn't overflow
+        return NULL;
+    }
+    size = AlignUp(size, BLOCK_ALIGNMENT);
+
+    LBlockHeader *start = allocator->next_alloc ? allocator->next_alloc : (LBlockHeader *)allocator->base;
+    LBlockHeader *curr = start;
+
+    do {
+        if (lblock_is_free(curr) && lblock_size(curr) >= size) {
+            lmaybe_split_block(allocator, curr, size);
+            lblock_set_used(curr);
+            LBlockHeader *next = lblock_from_offset(allocator, curr->next);
+            allocator->next_alloc = next ? next : (LBlockHeader *)allocator->base;
+            return (U8 *)curr + sizeof(LBlockHeader);
+        }
+        LBlockHeader *next = lblock_from_offset(allocator, curr->next);
+        curr = next ? next : (LBlockHeader *)allocator->base;
+    } while (curr != start);
+
+    return NULL;
+}
+
+void lfree(LAlloc *allocator, void *ptr)
+{
+    if (ptr == NULL) {
+        return;
+    }
+
+    LBlockHeader *block = (LBlockHeader *)((U8 *)ptr - sizeof(LBlockHeader));
+
+    Assert((U8 *)block >= allocator->base && (U8 *)ptr < allocator->base + allocator->size);
+    // double free detection
+    Assert(!lblock_is_free(block));
+
+    lblock_set_free(block);
+    lmerge_with_next(allocator, block);
+
+    LBlockHeader *prev = lblock_from_offset(allocator, block->prev);
+    if (prev != NULL && lblock_is_free(prev)) {
+        lmerge_with_next(allocator, prev);
+        allocator->next_alloc = prev;
+    } else {
+        allocator->next_alloc = block;
+    }
+}

src/base/lalloc.h

@@ -0,0 +1,41 @@
+#pragma once
+#include "core.h"
+
+// Internal header added in front of each allocation
+typedef struct LBlockHeader LBlockHeader;
+struct LBlockHeader {
+    U32 next;            // offset from base
+    U32 prev;            // offset from base
+    U32 size_and_flags;  // size | free_bit
+    // Padding to ensure we always return 16 byte aligned pointers.
+    uint8_t pad[4];
+};
+_Static_assert(sizeof(LBlockHeader) == 16, "sizeof(BlockHeader) is not 16");
+
+/**
+ * General purpose allocator from a pre-defined backing store
+ * - Allocated pointers are aligned to 16 bytes.
+ * - Backing buffer must be aligned to 16 bytes
+ * - 4Gb - 16 is max for the allocator backing buffer.
+ * - Allocation of > 0 bytes returns a size aligned up to 16 bytes
+ * - Allocation of 0 bytes returns a valid pointer with 0 usable space
+ * The allocator maintains a doubly linked list of blocks,
+ * when blocks are free'd, adjacent blocks are merged to keep.
+ * This is also known as a buddy allocator
+ * fragmentation to a minimum
+ */
+typedef struct LAlloc LAlloc;
+struct LAlloc {
+    uint8_t *base;              // backing store
+    U32 size;                   // total size
+    LBlockHeader *next_alloc;   // start of free block search
+};
+
+void lalloc_init(LAlloc *allocator, void *backing_store, U32 size);
+
+void *lalloc(LAlloc *allocator, U32 size);
+void lfree(LAlloc *allocator, void *ptr);
+
+LBlockHeader *lblock_from_offset(const LAlloc *allocator, U32 offset);
+U32 lblock_size(const LBlockHeader *block);
+int lblock_is_free(const LBlockHeader *block);

src/base/marena.h

@@ -1,5 +1,5 @@
 #pragma once
-#include "base_core.h"
+#include "core.h"
 
 // Mini Arena for arena allocations from a supplied buffer
 
@@ -102,13 +102,15 @@ static INLINE void *marena_allocator_func(Allocator *allocator, AllocOperation o
             return marena_push_aligned(allocator->data, size, align);
 
         case Alloc_Op_Free: // can't free/Free_all from  an marena
+            NotImplemented;
             return NULL;
 
         case Alloc_Op_Free_All:
+            marena_reset(allocator->data);
             return NULL;
     }
 
-    Assert(false);
+    ShouldNotHappen;
 }
 
 static INLINE Allocator marena_allocator(MArena *arena)

src/base/platform.c

@@ -1,4 +1,4 @@
-#include "base_core.h"
+#include "core.h"
 #include "platform.h"
 #include <stdlib.h>
 #include <stdio.h>
@@ -30,7 +30,7 @@ static void *platform_allocator_func(Allocator *allocator, AllocOperation operat
         case Alloc_Op_Aligned:
             return aligned_alloc(size, align);
 
-        case Alloc_Op_Free: // can't free/Free_all from  an marena
+        case Alloc_Op_Free:
             free(memory);
             return NULL;
 
@@ -73,7 +73,7 @@ void *memory_allocate_and_commit(size_t size)
 void memory_free(void *mem, size_t size)
 {
     TRACEF("        memory_free     size=%7zu mem=%p\n", size, mem);
-    Assert(IsPageAligned((uintptr_t)mem));
+    Assert(IsPageAligned((UMM)mem));
     Assert(IsPageAligned(size));
     int rc = munmap(mem, size);
 
@@ -93,7 +93,7 @@ void *memory_reserve(size_t size)
 
 void memory_commit(void *mem, size_t size)
 {
-    Assert(IsPageAligned((uintptr_t)mem));
+    Assert(IsPageAligned((UMM)mem));
     Assert(IsPageAligned(size));
     TRACEF("memory_commit   size=%7zu mem=%p\n", size, mem);
 
@@ -107,7 +107,7 @@ void memory_commit(void *mem, size_t size)
 void memory_decommit(void *mem, size_t size)
 {
     TRACEF("memory_decommit size=%7zu mem=%p\n", size, mem);
-    Assert(IsPageAligned((uintptr_t)mem));
+    Assert(IsPageAligned((UMM)mem));
     Assert(IsPageAligned(size));
     int rc;
     rc = mprotect(mem, size, PROT_NONE);

src/base/platform.h

@@ -1,6 +1,6 @@
 #pragma once
 #include <stdlib.h>
-#include "base_core.h"
+#include "core.h"
 
 void *platform_malloc(size_t size);
 void platform_free(void *mem);

src/base/pool.c

@@ -0,0 +1,63 @@
+#include "pool.h"
+
+APool *apool_create_ex(Allocator *allocator, const APoolCreateOptions *options)
+{
+    Assert(IsPow2(options->element_align));
+    Assert(options->n_reserved > 0 || options->flags & APoolFlag_AutoGrow);
+    U32 element_align = options->element_align;
+    if (element_align < alignof(APoolElement)) {
+        element_align = alignof(APoolElement);
+    }
+    U32 element_size = AlignUp(options->element_size, options->element_align);
+    APool *pool = allocator_push_type(allocator, APool);
+    Assert(pool != NULL);
+    pool->element_align= element_align;
+    pool->element_size = element_size;
+    pool->allocator    = allocator;
+    pool->n_elements   = 0;
+    pool->n_free       = 0;
+    pool->free_list    = NULL;
+    pool->flags        = options->flags;
+
+    if (options->n_reserved != 0) {
+        Assert(options->n_reserved <= U32_Max / element_size );
+        U32 total_size = options->n_reserved * element_size;
+        U8 *start = allocator_push(allocator, total_size, element_align);
+        for (U32 i = 0; i < total_size; i += element_size) {
+            APoolElement *element = (APoolElement *)&start[i];
+            element->next = pool->free_list;
+            pool->free_list = element;
+            pool->n_elements++;
+        }
+        pool->n_free = pool->n_elements;
+    }
+
+    return pool;
+}
+
+void *apool_alloc(APool *pool)
+{
+    APoolElement *element = pool->free_list;
+    if (element != NULL) {
+        pool->free_list = element->next;
+        pool->n_free--;
+    } else if((pool->flags & APoolFlag_AutoGrow) != 0) {
+        element = allocator_push(pool->allocator, pool->element_size, pool->element_align);
+        if (element != NULL) {
+            pool->n_elements++;
+        }
+    }
+
+    return element;
+}
+
+void apool_free(APool *pool, void *ptr)
+{
+    if (ptr != NULL) {
+        APoolElement *element = (APoolElement *)ptr;
+        element->next = pool->free_list;
+        pool->free_list = element;
+        pool->n_free++;
+
+    }
+}

src/base/pool.h

@@ -0,0 +1,43 @@
+#pragma once
+#include "core.h"
+
+enum {
+    APoolFlag_AutoGrow = (1 << 0)
+};
+typedef U32 APoolFlags;
+typedef union APoolElement APoolElement;
+union APoolElement {
+    APoolElement *next;       // offset from start to next free block (when not allocated)
+};
+
+typedef struct APool APool;
+struct APool {
+    APoolElement *free_list;  // free list
+    Allocator *allocator;
+    APoolFlags flags;
+    U32 element_size;         // aligned size of each element
+    U32 element_align;        // alignment
+    U32 n_elements;           // total elements in the pool
+    U32 n_free;               // number of free elements
+};
+typedef struct APoolCreateOptions APoolCreateOptions;
+struct APoolCreateOptions {
+    U32 element_size;         // aligned size of each element
+    U32 element_align;        // alignment of elements
+    U32 n_reserved;           // number of elements reserved
+    APoolFlags flags;
+
+};
+#define apool_create(arena, n_reserved, type) \
+        apool_create_ex(arena, &(APoolCreateOptions){sizeof(type), alignof(type), n_reserved, 0})
+APool *apool_create_ex(Allocator *allocator, const APoolCreateOptions *options);
+void *apool_alloc(APool *pool);
+INLINE void *apool_allocz(APool *pool)
+{
+    void *ptr = apool_alloc(pool);
+    if (ptr != NULL) {
+        MemoryZero(ptr, pool->element_size);
+    }
+    return ptr;
+}
+void apool_free(APool *pool, void *element);

src/base/string.h

@@ -1,5 +1,5 @@
 #pragma once
-#include "base_core.h"
+#include "core.h"
 
 typedef struct Str Str;
 struct Str {

src/main.c

@@ -1,9 +1,10 @@
-#include "base_core.h"
-#include "arena.h"
-#include "mini_arena.h"
-#include "platform.h"
-#include "pool.h"
-#include "string.h"
+#include "base/core.h"
+#include "base/arena.h"
+#include "base/marena.h"
+#include "base/platform.h"
+#include "base/pool.h"
+#include "base/string.h"
+#include "base/lalloc.h"
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -26,7 +27,7 @@ void arena_dump(const Arena *arena)
 }
 static void arena_test_1(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
     ArenaOptions arena_params = {};
     U32 arena_size = MB(1) + MemoryBlock_Header_Size;
     U32 commit_size = KB(8);
@@ -53,7 +54,7 @@ static void arena_test_1(void)
 
 static void arena_test_2(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     ArenaOptions arena_params = {};
     U32 arena_size = MB(3) + MemoryBlock_Header_Size;
@@ -106,7 +107,7 @@ static void arena_test_2(void)
 
 static void arena_test_3(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     ArenaOptions arena_params = {};
     U32 arena_size = KB(97) + MemoryBlock_Header_Size;
@@ -134,7 +135,7 @@ static void arena_test_3(void)
 // gap was not accounted for. After the fix this should allocate a larger block.
 static void arena_test_4(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     U32 page_size = platform_page_size();
     ArenaOptions arena_params = {};
@@ -151,14 +152,14 @@ static void arena_test_4(void)
     U32 push_size  = block_size - MemoryBlock_Header_Size;
 
     void *ptr = arena_push(&arena, push_size, page_size);
-    Assert(IsAlignedTo((uintptr_t)ptr, page_size));
+    Assert(IsAlignedTo((UMM)ptr, page_size));
     MemoryZero(ptr, push_size);
     printf("test_4: allocated %u bytes page-aligned at %p\n", push_size, ptr);
     arena_dump(&arena);
 
     // A second page-aligned push to make sure the cursor math still holds.
     ptr = arena_push(&arena, page_size, page_size);
-    Assert(IsAlignedTo((uintptr_t)ptr, page_size));
+    Assert(IsAlignedTo((UMM)ptr, page_size));
     MemoryZero(ptr, page_size);
     printf("test_4: allocated %u bytes page-aligned at %p\n", page_size, ptr);
 
@@ -167,7 +168,7 @@ static void arena_test_4(void)
 
 static void arena_test_allocator_interface(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     U32 page_size = platform_page_size();
     ArenaOptions arena_params = {};
@@ -185,14 +186,14 @@ static void arena_test_allocator_interface(void)
     U32 push_size  = block_size - MemoryBlock_Header_Size;
 
     void *ptr = allocator_push(&allocator, push_size, page_size);
-    Assert(IsAlignedTo((uintptr_t)ptr, page_size));
+    Assert(IsAlignedTo((UMM)ptr, page_size));
     MemoryZero(ptr, push_size);
     printf("test_4: allocated %u bytes page-aligned at %p\n", push_size, ptr);
     arena_dump(&arena);
 
     // A second page-aligned push to make sure the cursor math still holds.
     ptr = allocator_push(&allocator, page_size, page_size);
-    Assert(IsAlignedTo((uintptr_t)ptr, page_size));
+    Assert(IsAlignedTo((UMM)ptr, page_size));
     MemoryZero(ptr, page_size);
     printf("test_4: allocated %u bytes page-aligned at %p\n", page_size, ptr);
 
@@ -203,7 +204,7 @@ static void arena_test_allocator_interface(void)
 
 static void arena_test_decommit(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     U32 page_size = platform_page_size();
     ArenaOptions arena_params = {};
@@ -230,7 +231,7 @@ static void arena_test_decommit(void)
 
 void miniarena_test1(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     #define  arena_size  4096
     MARENA_DEFINE(arena, arena_size, 8);
@@ -269,12 +270,18 @@ struct PoolTest{
 
 void apool_test(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     Arena arena;
     arena_init(&arena, &ArenaOptions_Default);
     Allocator allocator = arena_allocator(&arena);
-    APool *pool = apool_create_ex(&allocator, 16, sizeof(PoolTest), alignof(PoolTest));
+    APoolCreateOptions opts = {
+        .n_reserved= 16,
+        .element_size  = sizeof(PoolTest),
+        .element_align = alignof(PoolTest),
+        .flags = 0
+    };
+    APool *pool = apool_create_ex(&allocator, &opts);
     PoolTest *list = NULL;
     for (U32 i = 0; i < U32_Max; i++) {
         PoolTest *pt = apool_alloc(pool);
@@ -297,6 +304,7 @@ void apool_test(void)
         printf("Pooltest freeing %u\n",p->n);
         apool_free(pool, p);
     }
+    printf("Pooltest total: %u free %u\n", pool->n_elements, pool->n_free);
     list = NULL;
     for (U32 i = 0; i < U32_Max; i++) {
         PoolTest *pt = apool_alloc(pool);
@@ -316,13 +324,13 @@ void apool_test(void)
 
 void apool_test_miniarena(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     MArena arena;
     U8 data[4096];
     marena_init(&arena, data, sizeof data);
     Allocator allocator = marena_allocator(&arena);
-    APool *pool = apool_create_ex(&allocator, 16, sizeof(PoolTest), alignof(PoolTest));
+    APool *pool = apool_create(&allocator, 16, PoolTest);
     PoolTest *list = NULL;
     for (U32 i = 0; i < U32_Max; i++) {
         PoolTest *pt = apool_alloc(pool);
@@ -358,19 +366,26 @@ void apool_test_miniarena(void)
     for (PoolTest *p = list; p; p = p->next){
         printf("Pooltest %u\n",p->n);
     }
+    printf("Pooltest total: %u free %u\n", pool->n_elements, pool->n_free);
+
     allocator_free_all(&allocator);
 }
 
 
 void apool_test_autogrow(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     Arena arena;
     arena_init(&arena, &ArenaOptions_Default);
     Allocator allocator = arena_allocator(&arena);
-
-    APool *pool = apool_create(&allocator, APOOL_AUTOGROW, PoolTest);
+    APoolCreateOptions opts = {
+        .n_reserved = 0,
+        .element_size  = sizeof(PoolTest),
+        .element_align = alignof(PoolTest),
+        .flags = APoolFlag_AutoGrow
+    };
+    APool *pool = apool_create_ex(&allocator, &opts);
     PoolTest *list = NULL;
     for (U32 i = 0; i < 4; i++) {
         PoolTest *pt = apool_alloc(pool);
@@ -384,6 +399,7 @@ void apool_test_autogrow(void)
     for (PoolTest *p = list; p; p = p->next){
         printf("Pooltest %u\n",p->n);
     }
+    printf("Pooltest total: %u free %u\n", pool->n_elements, pool->n_free);
 
     PoolTest *next;
     U32 count = 0;
@@ -406,6 +422,7 @@ void apool_test_autogrow(void)
     for (PoolTest *p = list; p; p = p->next){
         printf("Pooltest %u\n",p->n);
     }
+    printf("Pooltest total: %u free %u\n", pool->n_elements, pool->n_free);
 
     allocator_free_all(&allocator);
     arena_free(&arena);
@@ -414,7 +431,7 @@ void apool_test_autogrow(void)
 
 void string_test_1(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     Str str1 = S("Hello");
     printf("str1: %.*s len %d\n", str1.len, str1.str, str1.len);
@@ -431,7 +448,7 @@ void string_test_1(void)
 
 void string_split_test_1(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     Str str1 = S("|a:bb|ccc|");
     Str sep = S("|:");
@@ -445,7 +462,7 @@ void string_split_test_1(void)
 }
 void string_test_misc(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     Str str1 = S("Hello World");
     bool prefix1 = str_starts_with(str1, S("He"));
@@ -484,7 +501,7 @@ void string_test_misc(void)
 }
 void string_test_join(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
     Arena arena;
     arena_init(&arena, &ArenaOptions_Default);
     Allocator allocator = arena_allocator(&arena);
@@ -515,7 +532,7 @@ void print_runes(Str str)
 
 void string_test_utf8(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     Str str1 = S("Test 1ø2 ☺");
 
@@ -539,7 +556,7 @@ void string_test_utf8(void)
 
 void string_test_hex(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     MArena arena;
     U8 data[4096];
@@ -577,7 +594,7 @@ struct StrSList {
 
 void string_test_slist(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     Str str1 = S("one");
     Str str2 = S("two");
@@ -625,7 +642,7 @@ struct StrDList {
 
 void string_test_dlist(void)
 {
-    TRACEF("\n");
+    TRACEF("\n\n");
 
     Str str1 = S("one");
     Str str2 = S("two");
@@ -673,6 +690,49 @@ void string_test_dlist(void)
 
 }
 
+void debug_lalloc(const LAlloc *allocator)
+{
+    puts("--debug start--");
+    for (LBlockHeader *b = (LBlockHeader *)allocator->base; b; b = lblock_from_offset(allocator, b->next)) {
+        printf("Block size %u free %d prev %u next %u \n", lblock_size(b), lblock_is_free(b), b->prev, b->next);
+    }
+    puts("--debug end--");
+}
+
+static void lalloc_test_basic(void)
+{
+    printf("bh size %zu\n", sizeof(LBlockHeader));
+#define SZ 64
+    LAlloc a;
+    char *ptrs[SZ] = {};
+    alignas(16) char buff[1023];
+    lalloc_init(&a, buff, sizeof(buff));
+    debug_lalloc(&a);
+    ptrs[0] = lalloc(&a, 1023 - 16 * 2 - 144);
+    ptrs[1] = lalloc(&a, 80);
+    ptrs[2] = lalloc(&a, 32);
+    debug_lalloc(&a);
+    lfree(&a, ptrs[0]);
+    ptrs[3] = lalloc(&a, 12);
+    ptrs[4] = lalloc(&a, 12);
+    debug_lalloc(&a);
+
+    lfree(&a, ptrs[1]);
+    lfree(&a, ptrs[2]);
+    lfree(&a, ptrs[3]);
+    lfree(&a, ptrs[4]);
+
+    for (int i = 0; i < SZ; i++) {
+        ptrs[i] = lalloc(&a, rand() % 256 + 1);
+    }
+
+    for (int i = 0; i < SZ; i++) {
+        // if (rand() % 2 == 0) {
+        lfree(&a, ptrs[i]);
+        // }
+    }
+    debug_lalloc(&a);
+}
 int main(int argc, char *argv[])
 {
     arena_test_1();
@@ -693,6 +753,7 @@ int main(int argc, char *argv[])
     string_test_hex();
     string_test_slist();
     string_test_dlist();
+    lalloc_test_basic();
 
 }
 

src/pool.c

@@ -1,57 +0,0 @@
-#include "pool.h"
-
-APool *apool_create_ex(Allocator *allocator, U32 n_elements, U32 element_size, U32 element_align)
-{
-    Assert(IsPow2(element_align));
-    U32 align = element_align;
-    if (element_align < alignof(APoolElement)) {
-        element_align = alignof(APoolElement);
-    }
-    U32 size = AlignUp(element_size, element_align);
-
-    APool *pool = allocator_push_type(allocator, APool);
-    Assert(pool != NULL);
-    pool->align = align;
-    pool->element_size = size;
-    pool->allocator = allocator;
-    pool->n_elements = n_elements;
-    pool->free_list = NULL;
-    pool->start = NULL;
-
-    if (size != APOOL_AUTOGROW) {
-        Assert(n_elements <= U32_Max / size );
-        U32 total_size = n_elements * size;
-        U8 * start = allocator_push(allocator, total_size, align);
-        for (U32 i = 0; i < total_size; i += size) {
-            APoolElement *element = (APoolElement *)&start[i];
-            element->next = pool->free_list;
-            pool->free_list = element;
-        }
-        pool->start = start;
-    }
-
-    return pool;
-}
-
-void *apool_alloc(APool *pool)
-{
-    APoolElement *element = pool->free_list;
-    if (element != NULL) {
-        pool->free_list = element->next;
-    } else if(pool->n_elements == APOOL_AUTOGROW) {
-        element = allocator_push(pool->allocator, pool->element_size, pool->align);
-    }
-
-    return element;
-}
-
-void apool_free(APool *pool, void *ptr)
-{
-    if (ptr != NULL) {
-        Assert((U8 *)ptr >= pool->start);
-
-        APoolElement *element = (APoolElement *)ptr;
-        element->next = pool->free_list;
-        pool->free_list = element;
-    }
-}

src/pool.h

@@ -1,26 +0,0 @@
-#pragma once
-#include "base_core.h"
-
-typedef union APoolElement APoolElement;
-union APoolElement {
-    APoolElement *next;       // offset from start to next free block (when not allocated)
-};
-
-typedef struct APool APool;
-struct APool {
-    APoolElement *free_list;  // free list
-    U8 *start;                // start of user buffer
-    Allocator *allocator;
-    U32 element_size;         // aligned size of each block
-    U32 n_elements;           // total number of blocks
-    U32 align;                // alignment
-};
-enum {
-    APOOL_AUTOGROW = 0
-};
-
-#define apool_create(arena, n_elements, type) \
-        apool_create_ex(arena, n_elements, sizeof(type), alignof(type));
-APool *apool_create_ex(Allocator *allocator, U32 n_elements, U32 element_size, uint32_t element_align);
-void *apool_alloc(APool *pool);
-void apool_free(APool *pool, void *element);