atomic_signal

Fence between a thread and a signal handler executed in the same thread (C11)

Synopsis:

#include <stdatomic.h>

void atomic_signal_fence( memory_order order );

Arguments:

order: The memory_order to use for the fence.

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_signal_fence() function establishes a memory-synchronization ordering of non-atomic and relaxed atomic accesses, as instructed by order, between a thread and a signal handler executed on the same thread. Only reordering of the instructions by the compiler is suppressed as order instructs. For example, writes can't be moved past a fence with release semantics, and reads can't be moved ahead of a fence with acquire semantics.

Classification:

C11

Safety:
Cancellation point	No
Interrupt handler	Read the Caveats
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 an ISR or signal handler.