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/*
 * shm_generic.h -- Macro-template for shared-memory hash maps.
 *
 * Before including, define:
 *   SHM_PREFIX         -- function prefix (e.g., shm_ii)
 *   SHM_NODE_TYPE      -- node struct name
 *   SHM_VARIANT_ID     -- unique integer for header validation
 *
 * Key type (choose one):
 *   SHM_KEY_IS_INT + SHM_KEY_INT_TYPE  -- integer key
 *   (leave undefined for string keys via arena)
 *
 * Value type (choose one):
 *   SHM_VAL_IS_STR                      -- string value via arena
 *   SHM_VAL_INT_TYPE                    -- integer value
 *
 * Optional:
 *   SHM_HAS_COUNTERS  -- generate incr/decr/incr_by, max/min, and integer cas (integer values only)
 */

/* ---- Part 1: shared definitions (included once) ---- */

#ifndef SHM_DEFS_H
#define SHM_DEFS_H

#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <time.h>
#include <sys/mman.h>
#include <sys/stat.h>

#if defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
#error "shm_generic.h: inline string packing requires little-endian architecture"
#endif
#include <sys/file.h>
#include <pthread.h>  /* pthread_atfork -- available in libc on modern glibc; no -lpthread needed */
#include <sys/syscall.h>
#include <limits.h>
#include <signal.h>
#include <errno.h>
#include <linux/futex.h>

#ifdef __SSE2__
#include <emmintrin.h>
#endif

#define XXH_INLINE_ALL
#include "xxhash.h"

/* ---- Constants ---- */

#define SHM_MAGIC       0x53484D31U  /* "SHM1" */
#define SHM_VERSION     10U  /* 10: added the occupancy bitmap region (layout change) */
/* Ceiling on new_sharded's shard count: the power-of-two round-up must not
 * overflow. */
#define SHM_MAX_SHARDS  4096U

#ifndef SHM_READER_SLOTS