hakmem/core/box/wrapper_env_box.h

// wrapper_env_box.h - Environment variable cache for malloc/free wrappers
// Eliminates getenv() calls from malloc/free hot paths
#pragma once

#include <stdatomic.h>

typedef struct {
    int inited;
    int step_trace;          // HAKMEM_STEP_TRACE (default: 0)
    int ld_safe_mode;        // HAKMEM_LD_SAFE (default: 1)
    int free_wrap_trace;     // HAKMEM_FREE_WRAP_TRACE (default: 0)
    int wrap_diag;           // HAKMEM_WRAP_DIAG (default: 0) - log first few libc fallbacks
    int wrap_shape;          // HAKMEM_WRAP_SHAPE (default: 0) - Phase 2 B4: malloc/free hot/cold split
} wrapper_env_cfg_t;

extern wrapper_env_cfg_t g_wrapper_env;

void wrapper_env_init_once(void);

static inline const wrapper_env_cfg_t* wrapper_env_cfg(void) {
    // Constructor ensures init at library load time
    // This check prevents repeated initialization in multi-threaded context
    if (__builtin_expect(!g_wrapper_env.inited, 0)) {
        wrapper_env_init_once();
    }
    return &g_wrapper_env;
}