atomic_store, atomic_store_explicit
| Defined in header <stdatomic.h>
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| void atomic_store( volatile A* obj , C desired ); |
(1) | (since C11) |
| void atomic_store_explicit( volatile A* obj, C desired, memory_order order ); |
(2) | (since C11) |
Atomically replaces the value of the atomic variable pointed to by obj with desired. The operation is atomic write operation.
The first version orders memory accesses according to memory_order_seq_cst, the second version orders memory accesses according to order. order must be one of memory_order_relaxed, memory_order_release or memory_order_seq_cst. Otherwise the behavior is undefined.
This is a generic function defined for all atomic object types A. The argument is pointer to a volatile atomic type to accept addresses of both non-volatile and volatile (e.g. memory-mapped I/O) atomic objects, and volatile semantic is preserved when applying this operation to volatile atomic objects. C is the non-atomic type corresponding to A.
It is unspecified whether the name of a generic function is a macro or an identifier declared with external linkage. If a macro definition is suppressed in order to access an actual function (e.g. parenthesized like (atomic_store)(...)), or a program defines an external identifier with the name of a generic function, the behavior is undefined.
Parameters
| obj | - | pointer to the atomic object to modify |
| order | - | the memory synchronization ordering for this operation |
Return value
(none)
References
- C17 standard (ISO/IEC 9899:2018):
- 7.17.7.1 The atomic_store generic functions (p: 206)
- C11 standard (ISO/IEC 9899:2011):
- 7.17.7.1 The atomic_store generic functions (p: 282)
See also
| reads a value from an atomic object (function) | |
| C++ documentation for atomic_store, atomic_store_explicit
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