+/* This refcounted he structure is used for storing the hints used for lexical
+ pragmas. Without threads, it's basically struct he + refcount.
+ With threads, life gets more complex as the structure needs to be shared
+ between threads (because it hangs from OPs, which are shared), hence the
+ alternate definition and mutex. */
+
+#ifdef PERL_CORE
+
+/* Gosh. This really isn't a good name any longer. */
+struct refcounted_he {
+ struct refcounted_he *refcounted_he_next; /* next entry in chain */
+#ifdef USE_ITHREADS
+ U32 refcounted_he_hash;
+ U32 refcounted_he_keylen;
+#else
+ HEK *refcounted_he_hek; /* hint key */
+#endif
+ U32 refcounted_he_refcnt; /* reference count */
+ union {
+ IV refcounted_he_u_iv;
+ UV refcounted_he_u_uv;
+ STRLEN refcounted_he_u_len;
+ } refcounted_he_val;
+ /* First byte is flags. Then NUL-terminated value. Then for ithreads,
+ non-NUL terminated key. */
+ char refcounted_he_data[1];
+};
+
+/* Flag bits are HVhek_UTF8, HVhek_WASUTF8, then */
+#define HVrhek_undef 0x00 /* Value is undef. */
+#define HVrhek_PV 0x10 /* Value is a string. */
+#define HVrhek_IV 0x20 /* Value is IV/UV. */
+#define HVrhek_delete 0x30 /* Value is placeholder - signifies delete. */
+#define HVrhek_typemask 0x30
+#define HVrhek_UTF8 0x40 /* string value is utf8. */
+#define HVrhek_UV 0x40 /* integer value is UV. */
+
+# ifdef USE_ITHREADS
+# define HINTS_REFCNT_LOCK MUTEX_LOCK(&PL_hints_mutex)
+# define HINTS_REFCNT_UNLOCK MUTEX_UNLOCK(&PL_hints_mutex)
+# else
+# define HINTS_REFCNT_LOCK NOOP
+# define HINTS_REFCNT_UNLOCK NOOP
+# endif
+#endif
+
+#ifdef USE_ITHREADS
+# define HINTS_REFCNT_INIT MUTEX_INIT(&PL_hints_mutex)
+# define HINTS_REFCNT_TERM MUTEX_DESTROY(&PL_hints_mutex)
+#else
+# define HINTS_REFCNT_INIT NOOP
+# define HINTS_REFCNT_TERM NOOP
+#endif
+