atomic_load, atomic_load_explicit

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< clrm; | atomic
Defined in header <stdatomic.h>
C atomic_load( const volatile A* obj );
(1) (since C11)
C atomic_load_explicit( const volatile A* obj, memory_order order );
(2) (since C11)

Atomically loads and returns the current value of the atomic variable pointed to by obj. The operation is atomic read 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_consume, memory_order_acquire 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 variables.C is the non-atomic type corresponding to A.

Parameters

obj - pointer to the atomic object to access
order - the memory synchronization ordering for this operation

Return value

The current value of the atomic variable pointed to by obj.

References

  • C11 standard (ISO/IEC 9899:2011):
  • 7.17.7.2 The atomic_load generic functions (p: 282)

See also

stores a value in an atomic object
(function)