// dvxMem.h  -- Per-app memory tracking for DVX
//
// REQUIRED: Every .c file compiled into a DXE (library, widget, shell,
// or app) MUST include this header AFTER all system includes. This
// ensures every malloc/free/calloc/realloc call goes through the
// tracking wrappers, maintaining pointer consistency.
//
// The implementation (dvxPlatformDos.c) does NOT include this header,
// so its dvxMalloc/dvxFree/dvxCalloc/dvxRealloc call the real libc
// functions with no recursion.
//
// How it works:
//   1. dvxMalloc prepends a 16-byte header (magic, appId, size) to
//      each allocation and returns a pointer past the header.
//   2. dvxFree checks the magic value at ptr-16. If it matches, the
//      header is valid and the allocation is tracked. If not, the
//      pointer came from code outside DVX (libc internals, loader)
//      and is passed through to the real free() unchanged.
//   3. The appId in the header comes from *dvxMemAppIdPtr, which the
//      shell points at ctx->currentAppId.
//
// The magic check makes cross-boundary frees safe: if DXE code frees
// a pointer allocated by libc (e.g. from strdup, stb_ds internals),
// dvxFree detects the missing header and falls through to real free.

#ifndef DVX_MEM_H
#define DVX_MEM_H

#include <stdint.h>
#include <stdlib.h>

extern int32_t *dvxMemAppIdPtr;

void    *dvxMalloc(size_t size);
void    *dvxCalloc(size_t nmemb, size_t size);
void    *dvxRealloc(void *ptr, size_t size);
void     dvxFree(void *ptr);
void     dvxMemSnapshotLoad(int32_t appId);
uint32_t dvxMemGetAppUsage(int32_t appId);
void     dvxMemResetApp(int32_t appId);

// The dvxMalloc/dvxFree functions are passthrough wrappers.
// Header-based per-allocation tracking was attempted but is unsafe
// in the DXE3 environment (loader-compiled code like stb_ds uses
// libc malloc while DXE code would use the wrapped version).
// Per-app memory is tracked via DPMI snapshots instead.

#endif // DVX_MEM_H