feat: add arena allocation tracking + JSON dump by gimploo · Pull Request #30 · gimploo/poglib

gimploo · 2026-07-09T09:19:53Z

Add alloc_log linked list to arena_t for recording every arena_reserve/arena_store call
Macro-wrap arena_init/arena_reserve to auto-capture FILE, LINE, func
Arenas self-register into global registry on first allocation
arena_dump_json() writes all arena allocation data as JSON
arena_clear and arena_destroy free alloc log records

- Add alloc_log linked list to arena_t for recording every arena_reserve/arena_store call - Macro-wrap arena_init/arena_reserve to auto-capture __FILE__, __LINE__, __func__ - Arenas self-register into global registry on first allocation - arena_dump_json() writes all arena allocation data as JSON - arena_clear and arena_destroy free alloc log records

gimploo · 2026-07-09T09:20:31Z

-arena_t     arena_init(arena_t *const, const u64 capacity);
-void *      arena_reserve(arena_t *const self, const u64 memory_size);
-bool        arena_is_init(const arena_t *const self);
+arena_t     arena__internal_init(arena_t *const, const u64 capacity, const char *file, int line);


these declarations must be under impelmentation if def

Generates flamegraph-compatible JSON for speedscope.app: - Drag arena_map.json into speedscope.app for interactive flamegraph - Wide bars = heavy memory consumers, click to drill down - Arena → file → function → (line + bytes) hierarchy - Unused arena space shown as '(unused)' frame

gimploo · 2026-07-09T10:02:25Z

+#define arena_init(arena, capacity) \
+    arena__internal_init((arena), (capacity), __FILE__, __LINE__)
+
+#define arena_reserve(self, memory_size) \
+    arena__internal_reserve_tracked((self), (memory_size), __FILE__, __LINE__, __func__)


move these two above arena_store

gimploo · 2026-07-09T10:02:57Z

+void *      arena__internal_reserve_tracked(arena_t *const self, const u64 memory_size, const char *file, int line, const char *func);

-arena_t arena_init(arena_t *const arena, const u64 capacity)
+static arena_t *arena_registry = NULL;


put this into dbg.h

gimploo · 2026-07-09T10:04:27Z

+        free_chunks_t *new_chunk;
+        if (self->meta.lifetime_owner) {
+            new_chunk = (free_chunks_t *)arena__internal_reserve_memory_16byte_aligned(
+                self->meta.lifetime_owner, sizeof(free_chunks_t));
+            if (new_chunk) {
+                new_chunk->memory = ptr;
+                new_chunk->size = size;
+                new_chunk->next = NULL;
+            }
+        } else {
+            new_chunk = calloc(1, sizeof(free_chunks_t));
+        }


reason for this change ?

gimploo · 2026-07-09T10:07:26Z

+    }
+}
+
+static void arena__internal_ensure_registered(arena_t *self)


replace static with INTERNAL and have an extra _ after internal_ -> it should look like internal

gimploo · 2026-07-09T10:08:04Z

+static u32 arena__frame_idx(const char *name, char fnames[][256], u32 *count)
 {
-    ASSERT(mem_size > 0);
-    ASSERT(mem);
-    void *raw_mem = arena_reserve(self, mem_size);
-    memcpy(raw_mem, mem, mem_size);
-    return raw_mem;
+    for (u32 i = 0; i < *count; i++) {
+        if (strcmp(fnames[i], name) == 0) return i;
+    }
+    strncpy(fnames[*count], name, 255);
+    fnames[*count][255] = '\0';
+    return (*count)++;


make the function name descriptive enough - also this is internal so use the internal code design

…l fns with __, replace static with INTERNAL

…tests pass

gimploo · 2026-07-09T10:49:58Z

+    struct {
+        arena_alloc_record_t *head;
+        u32 count;
+    } alloc_log;
+    const char *init_file;
+    int         init_line;
+    arena_t    *next_in_registry;


dont put this in here, have another struct called arena_logger or something and have it called in dbg.h during init. also create a init and destroy function for it.

…dbg.h - Remove alloc_log, init_file, init_line, next_in_registry from arena_t - Add arena_logger_t struct, registry, init/destroy/log_alloc/clear_log to dbg.h - arena_logger_init is lazy — fires on first arena_reserve call - arena_dump_json now iterates arena_logger_registry instead of arena_registry - All 16 arena tests pass

gimploo · 2026-07-09T15:00:45Z

 void        arena_giveback(arena_t *const self, void *const ptr, const u64 size);
 void        arena_clear(arena_t *const self);
 void        arena_destroy(arena_t *const self);
+void        arena_dump_json(const char *filepath);


gimploo · 2026-07-09T15:01:06Z

+arena_t     arena__internal__init(arena_t *const, const u64 capacity);
+void *      arena__internal__reserve_memory_16byte_aligned(arena_t * const self, const u64 memory_size);
+void *      arena__internal__reserve_tracked(arena_t *const self, const u64 memory_size, const char *file, int line, const char *func);

-arena_t arena_init(arena_t *const arena, const u64 capacity)
-{
-    arena_t o = {
-        .capacity = capacity,
-        .size = 0,
-        .memory = arena ? arena__internal_reserve_memory_16byte_aligned(arena, capacity) : calloc(capacity, sizeof(u8)),
-        .freelist = {0},
-        .meta = {
-            .lifetime_owner = arena,
-        }
-    };
-    atomic_flag_clear(&o.meta.lock);
-    return o;
-}
+static u32  arena__internal__frame_lookup(const char *name, char fnames[][256], u32 *count);


use INTERNAL macro here

gimploo · 2026-07-09T15:03:10Z

+struct _arena_alloc_record {
+    const char  *file;
+    int          line;
+    const char  *func;
+    uint64_t     size;
+    struct _arena_alloc_record *next;
+};
+typedef struct _arena_alloc_record arena_alloc_record_t;


dont use _ at the front have internal in the name instead

gimploo commented Jul 9, 2026

View reviewed changes

gimploo added 3 commits July 9, 2026 14:53

fix: move macros and internal declarations under implementation guard

bddb57b

fix: normalize speedscope at values to 0..1M to avoid Map overflow

8e25909

gimploo commented Jul 9, 2026

View reviewed changes

gimploo added 2 commits July 9, 2026 15:43

style: address review — move macros above arena_store, rename interna…

7d40bd0

…l fns with __, replace static with INTERNAL

fix: top-level arena giveback not restoring freelist entries, all 16 …

994eba9

…tests pass

gimploo commented Jul 9, 2026

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

feat: add arena allocation tracking + JSON dump#30

feat: add arena allocation tracking + JSON dump#30
gimploo wants to merge 7 commits into
devfrom
feat/arena-tracking

gimploo commented Jul 9, 2026

Uh oh!

gimploo Jul 9, 2026

Uh oh!

gimploo Jul 9, 2026 •

edited

Loading

Uh oh!

gimploo Jul 9, 2026

Uh oh!

gimploo Jul 9, 2026

Uh oh!

gimploo Jul 9, 2026

Uh oh!

gimploo Jul 9, 2026 •

edited

Loading

Uh oh!

gimploo Jul 9, 2026

Uh oh!

gimploo Jul 9, 2026

Uh oh!

gimploo Jul 9, 2026

Uh oh!

gimploo Jul 9, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

Conversation

gimploo commented Jul 9, 2026

Uh oh!

Choose a reason for hiding this comment

Uh oh!

gimploo Jul 9, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

gimploo Jul 9, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

gimploo Jul 9, 2026 •

edited

Loading

gimploo Jul 9, 2026 •

edited

Loading