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45
#define OVS_UNLIKELY(CONDITION) (!!(CONDITION))
48
#if __has_feature(c_thread_safety_attributes)
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/* "clang" annotations for thread safety check.
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* OVS_LOCKABLE indicates that the struct contains mutex element
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* which can be locked by functions like ovs_mutex_lock().
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* Below, the word MUTEX stands for the name of an object with an OVS_LOCKABLE
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* struct type. It can also be a comma-separated list of multiple structs,
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* e.g. to require a function to hold multiple locks while invoked.
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* - OVS_GUARDED indicates that the variable may only be accessed some mutex
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* - OVS_GUARDED_BY(MUTEX) indicates that the variable may only be accessed
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* while the specific MUTEX is held.
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* On a function, the following attributes apply to mutexes:
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* - OVS_ACQUIRES(MUTEX) indicate that the function must be called without
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* holding MUTEX and that it returns holding MUTEX.
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* - OVS_RELEASES(MUTEX) indicates that the function may only be called with
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* MUTEX held and that it returns with MUTEX released. It can be used for
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* - OVS_TRY_LOCK(RETVAL, MUTEX) indicate that the function will try to
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* acquire MUTEX. RETVAL is an integer or boolean value specifying the
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* return value of a successful lock acquisition.
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* - OVS_REQUIRES(MUTEX) indicate that the function may only be called with
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* MUTEX held and that the function does not release MUTEX.
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* - OVS_LOCKS_EXCLUDED(MUTEX) indicates that the function may only be
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* called when MUTEX is not held.
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* The following variants, with the same syntax, apply to reader-writer locks:
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* mutex rwlock, for reading rwlock, for writing
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* ------------------- ------------------- -------------------
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* OVS_ACQUIRES OVS_ACQ_RDLOCK OVS_ACQ_WRLOCK
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* OVS_RELEASES OVS_RELEASES OVS_RELEASES
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* OVS_TRY_LOCK OVS_TRY_RDLOCK OVS_TRY_WRLOCK
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* OVS_REQUIRES OVS_REQ_RDLOCK OVS_REQ_WRLOCK
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* OVS_LOCKS_EXCLUDED OVS_LOCKS_EXCLUDED OVS_LOCKS_EXCLUDED
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#define OVS_LOCKABLE __attribute__((lockable))
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#define OVS_REQ_RDLOCK(...) __attribute__((shared_locks_required(__VA_ARGS__)))
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#define OVS_ACQ_RDLOCK(...) __attribute__((shared_lock_function(__VA_ARGS__)))
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#define OVS_REQ_WRLOCK(...) \
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__attribute__((exclusive_locks_required(__VA_ARGS__)))
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#define OVS_ACQ_WRLOCK(...) \
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__attribute__((exclusive_lock_function(__VA_ARGS__)))
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#define OVS_REQUIRES(...) \
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__attribute__((exclusive_locks_required(__VA_ARGS__)))
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#define OVS_ACQUIRES(...) \
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__attribute__((exclusive_lock_function(__VA_ARGS__)))
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#define OVS_TRY_WRLOCK(RETVAL, ...) \
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__attribute__((exclusive_trylock_function(RETVAL, __VA_ARGS__)))
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#define OVS_TRY_RDLOCK(RETVAL, ...) \
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__attribute__((shared_trylock_function(RETVAL, __VA_ARGS__)))
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#define OVS_TRY_LOCK(RETVAL, ...) \
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__attribute__((exclusive_trylock_function(RETVAL, __VA_ARGS__)))
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#define OVS_GUARDED __attribute__((guarded_var))
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#define OVS_GUARDED_BY(...) __attribute__((guarded_by(__VA_ARGS__)))
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#define OVS_RELEASES(...) __attribute__((unlock_function(__VA_ARGS__)))
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#define OVS_EXCLUDED(...) __attribute__((locks_excluded(__VA_ARGS__)))
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/* "sparse" annotations for mutexes and mutex-like constructs.
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* Change the thread-safety check annotations to use "context" attribute.
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* OVS_MACRO_LOCK and OVS_MACRO_RELEASE are suitable for use within macros,
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* where there is no function prototype to annotate. */
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#define OVS_REQ_RDLOCK(...) __attribute__((context(MUTEX, 1, 1)))
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#define OVS_ACQ_RDLOCK(...) __attribute__((context(MUTEX, 0, 1)))
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#define OVS_REQ_WRLOCK(...) __attribute__((context(MUTEX, 1, 1)))
129
#define OVS_ACQ_WRLOCK(...) __attribute__((context(MUTEX, 0, 1)))
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#define OVS_REQUIRES(...) __attribute__((context(MUTEX, 1, 1)))
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#define OVS_ACQUIRES(...) __attribute__((context(MUTEX, 0, 1)))
132
#define OVS_TRY_WRLOCK(RETVAL, ...)
133
#define OVS_TRY_RDLOCK(RETVAL, ...)
134
#define OVS_TRY_LOCK(REVAL, ...)
136
#define OVS_GUARDED_BY(...)
137
#define OVS_EXCLUDED(...)
138
#define OVS_RELEASES(...) __attribute__((context(MUTEX, 1, 0)))
139
#define OVS_MACRO_LOCK(...) __context__(MUTEX, 0, 1)
140
#define OVS_MACRO_RELEASE(...) __context__(MUTEX, 1, 0)
143
#define OVS_REQ_RDLOCK(...)
144
#define OVS_ACQ_RDLOCK(...)
145
#define OVS_REQ_WRLOCK(...)
146
#define OVS_ACQ_WRLOCK(...)
147
#define OVS_REQUIRES(...)
148
#define OVS_ACQUIRES(...)
149
#define OVS_TRY_WRLOCK(...)
150
#define OVS_TRY_RDLOCK(...)
151
#define OVS_TRY_LOCK(...)
153
#define OVS_GUARDED_BY(...)
154
#define OVS_EXCLUDED(...)
155
#define OVS_RELEASES(...)
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#define OVS_MACRO_LOCK(...)
157
#define OVS_MACRO_RELEASE(...)
44
160
/* ISO C says that a C implementation may choose any integer type for an enum
45
161
* that is sufficient to hold all of its values. Common ABIs (such as the
46
162
* System V ABI used on i386 GNU/Linux) always use a full-sized "int", even
added
removed
lib/compiler.h
