diff options
Diffstat (limited to 'include/linux/cleanup.h')
| -rw-r--r-- | include/linux/cleanup.h | 52 |
1 files changed, 49 insertions, 3 deletions
diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h index 9f1a9c455b68..c2d09bc4f976 100644 --- a/include/linux/cleanup.h +++ b/include/linux/cleanup.h @@ -125,25 +125,55 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ * trivial wrapper around DEFINE_CLASS() above specifically * for locks. * + * DEFINE_GUARD_COND(name, ext, condlock) + * wrapper around EXTEND_CLASS above to add conditional lock + * variants to a base class, eg. mutex_trylock() or + * mutex_lock_interruptible(). + * * guard(name): - * an anonymous instance of the (guard) class + * an anonymous instance of the (guard) class, not recommended for + * conditional locks. * * scoped_guard (name, args...) { }: * similar to CLASS(name, scope)(args), except the variable (with the * explicit name 'scope') is declard in a for-loop such that its scope is * bound to the next (compound) statement. * + * for conditional locks the loop body is skipped when the lock is not + * acquired. + * + * scoped_cond_guard (name, fail, args...) { }: + * similar to scoped_guard(), except it does fail when the lock + * acquire fails. + * */ #define DEFINE_GUARD(_name, _type, _lock, _unlock) \ - DEFINE_CLASS(_name, _type, _unlock, ({ _lock; _T; }), _type _T) + DEFINE_CLASS(_name, _type, if (_T) { _unlock; }, ({ _lock; _T; }), _type _T); \ + static inline void * class_##_name##_lock_ptr(class_##_name##_t *_T) \ + { return *_T; } + +#define DEFINE_GUARD_COND(_name, _ext, _condlock) \ + EXTEND_CLASS(_name, _ext, \ + ({ void *_t = _T; if (_T && !(_condlock)) _t = NULL; _t; }), \ + class_##_name##_t _T) \ + static inline void * class_##_name##_ext##_lock_ptr(class_##_name##_t *_T) \ + { return class_##_name##_lock_ptr(_T); } #define guard(_name) \ CLASS(_name, __UNIQUE_ID(guard)) +#define __guard_ptr(_name) class_##_name##_lock_ptr + #define scoped_guard(_name, args...) \ for (CLASS(_name, scope)(args), \ - *done = NULL; !done; done = (void *)1) + *done = NULL; __guard_ptr(_name)(&scope) && !done; done = (void *)1) + +#define scoped_cond_guard(_name, _fail, args...) \ + for (CLASS(_name, scope)(args), \ + *done = NULL; !done; done = (void *)1) \ + if (!__guard_ptr(_name)(&scope)) _fail; \ + else /* * Additional helper macros for generating lock guards with types, either for @@ -152,6 +182,7 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ * * DEFINE_LOCK_GUARD_0(name, lock, unlock, ...) * DEFINE_LOCK_GUARD_1(name, type, lock, unlock, ...) + * DEFINE_LOCK_GUARD_1_COND(name, ext, condlock) * * will result in the following type: * @@ -173,6 +204,11 @@ typedef struct { \ static inline void class_##_name##_destructor(class_##_name##_t *_T) \ { \ if (_T->lock) { _unlock; } \ +} \ + \ +static inline void *class_##_name##_lock_ptr(class_##_name##_t *_T) \ +{ \ + return _T->lock; \ } @@ -201,4 +237,14 @@ __DEFINE_LOCK_GUARD_1(_name, _type, _lock) __DEFINE_UNLOCK_GUARD(_name, void, _unlock, __VA_ARGS__) \ __DEFINE_LOCK_GUARD_0(_name, _lock) +#define DEFINE_LOCK_GUARD_1_COND(_name, _ext, _condlock) \ + EXTEND_CLASS(_name, _ext, \ + ({ class_##_name##_t _t = { .lock = l }, *_T = &_t;\ + if (_T->lock && !(_condlock)) _T->lock = NULL; \ + _t; }), \ + typeof_member(class_##_name##_t, lock) l) \ + static inline void * class_##_name##_ext##_lock_ptr(class_##_name##_t *_T) \ + { return class_##_name##_lock_ptr(_T); } + + #endif /* __LINUX_GUARDS_H */ |