atomic_store(), atomic_store_explicit()
QNX SDP8.0C Library ReferenceAPIDeveloper
Atomically set the value of an atomic object (C11)
Synopsis:
#include <stdatomic.h>
void atomic_store( volatile A *obj,
C desired );
void atomic_store_explicit( volatile A *obj,
C desired,
memory_order order );
Arguments:
- obj
- A pointer to the atomic object (see the atomic_* types) whose value you want to set.
- desired
- The value for the object.
The
C
represents the non-atomic data type that corresponds to the atomic object. - order
- (atomic_store_explicit() only) The memory_order to use for the operation. This must be memory_order_relaxed, memory_order_release, or memory_order_seq_cst.
Library:
- If the atomic function is lock-free (see atomic_is_lock_free()), no extra library is required.
- If the function isn't lock-free, you need to link against libatomic. Use the -l atomic option to qcc to link against this library.
Description:
The atomic_store() and atomic_store_explicit() functions are generic functions that atomically set the given atomic object to the given value. The atomic_store() function orders memory access according to memory_order_seq_cst; atomic_store_explicit() orders them as specified by order.
The implementation of atomic functions may depend on the architecture.
For more information, see
LL/SC vs LSE atomic operations
in the description in Building Embedded Systems of the cpuinfo area of the system page.
Classification:
| Safety: | |
|---|---|
| Cancellation point | No |
| Signal handler | Read the Caveats |
| Thread | Yes |
Caveats:
If this function is lock-free (see atomic_is_lock_free()), it's safe to call it from a signal handler.
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