diff options
Diffstat (limited to 'src/jansson.h')
| -rw-r--r-- | src/jansson.h | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/src/jansson.h b/src/jansson.h index ecf0e09..042390c 100644 --- a/src/jansson.h +++ b/src/jansson.h @@ -33,6 +33,11 @@ extern "C" { (JANSSON_MINOR_VERSION << 8) | \ (JANSSON_MICRO_VERSION << 0)) +/* If __atomic or __sync builtins are available the library is thread + * safe for all read-only functions plus reference counting. */ +#if JSON_HAVE_ATOMIC_BUILTINS || JSON_HAVE_SYNC_BUILTINS +#define JANSSON_THREAD_SAFE +#endif /* types */ @@ -49,7 +54,7 @@ typedef enum { typedef struct json_t { json_type type; - size_t refcount; + volatile size_t refcount; } json_t; #ifndef JANSSON_USING_CMAKE /* disabled if using cmake */ @@ -94,11 +99,23 @@ json_t *json_false(void); #define json_boolean(val) ((val) ? json_true() : json_false()) json_t *json_null(void); +/* do not call JSON_INTERNAL_INCREF or JSON_INTERNAL_DECREF directly */ +#if JSON_HAVE_ATOMIC_BUILTINS +#define JSON_INTERNAL_INCREF(json) __atomic_add_fetch(&json->refcount, 1, __ATOMIC_ACQUIRE) +#define JSON_INTERNAL_DECREF(json) __atomic_sub_fetch(&json->refcount, 1, __ATOMIC_RELEASE) +#elif JSON_HAVE_SYNC_BUILTINS +#define JSON_INTERNAL_INCREF(json) __sync_add_and_fetch(&json->refcount, 1) +#define JSON_INTERNAL_DECREF(json) __sync_sub_and_fetch(&json->refcount, 1) +#else +#define JSON_INTERNAL_INCREF(json) (++json->refcount) +#define JSON_INTERNAL_DECREF(json) (--json->refcount) +#endif + static JSON_INLINE json_t *json_incref(json_t *json) { if(json && json->refcount != (size_t)-1) - ++json->refcount; + JSON_INTERNAL_INCREF(json); return json; } @@ -108,7 +125,7 @@ void json_delete(json_t *json); static JSON_INLINE void json_decref(json_t *json) { - if(json && json->refcount != (size_t)-1 && --json->refcount == 0) + if(json && json->refcount != (size_t)-1 && JSON_INTERNAL_DECREF(json) == 0) json_delete(json); } |