std::atomic_is_lock_free, ATOMIC_xxx_LOCK_FREE
Defined in header
<atomic>
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(1) | (since C++11) | |
template< class T >
bool atomic_is_lock_free( const volatile std::atomic<T>* obj ); |
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template< class T >
bool atomic_is_lock_free( const std::atomic<T>* obj ); |
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#define ATOMIC_BOOL_LOCK_FREE /* unspecified */
#define ATOMIC_CHAR_LOCK_FREE /* unspecified */ |
(2) | (since C++11) |
obj
is implemented lock-free, as if by calling obj->is_lock_free(). In any given program execution, the result of the lock-free query is the same for all pointers of the same type.- 0 for the built-in atomic types that are never lock-free
- 1 for the built-in atomic types that are sometimes lock-free
- 2 for the built-in atomic types that are always lock-free.
Contents |
[edit] Parameters
obj | - | pointer to the atomic object to examine |
[edit] Return value
true if *obj is a lock-free atomic, false otherwise.
[edit] Exceptions
[edit] Notes
All atomic types except for std::atomic_flag may be implemented using mutexes or other locking operations, rather than using the lock-free atomic CPU instructions. Atomic types are also allowed to be sometimes lock-free, e.g. if only aligned memory accesses are naturally atomic on a given architecture, misaligned objects of the same type have to use locks.
[edit] Example
This section is incomplete Reason: no example |
[edit] See also
checks if the atomic object is lock-free (public member function of std::atomic )
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specializes atomic operations for std::shared_ptr (function template) |
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(C++11)
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the lock-free boolean atomic type (class) |
C documentation for atomic_is_lock_free
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C documentation for ATOMIC_*_LOCK_FREE
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