Struct rp6::avr::interrupt::CriticalSection

pub struct CriticalSection(PhantomData<()>);

Helper struct that automatically restores interrupts on drop. The wrapped PhantomData creates a private field to ensure that this struct cannot be initialized from outside of this module without using its unsafe initializer function new. The recommended use to enter a CriticalSection is to pass a closure to without_interrupts.

When the feature unsafe-no-critical-section-count is disabled, this implementation is also safe w.r.t. nested calls of without_interrupts. This is achieved by counting how many CriticalSections were entered, and only enabling device interrupts once the last CriticalSection is exited. However, as these checks incur a small runtime overhead, they can be disabled with the feature unsafe-no-critical-section-count. Note that, for execution consistency, a user must then ensure that without_interrupts will never be nested!

Tuple Fields

0: PhantomData<()>

Implementations

impl CriticalSection

pub unsafe fn new() -> Self

Upon entering any CriticalSection, disable global device interrupts.

Safety

When the feature unsafe-no-critical-section-count is disabled, this implementation is also safe w.r.t. nested CriticalSections, e.g., by nesting calls to without_interrupts. This is achieved by counting how many CriticalSections were entered, and only enabling device interrupts once the last CriticalSection is exited. However, as these checks incur a small runtime overhead, they can be disabled with the feature unsafe-no-critical-section-count. Note that, for execution consistency, a user must then ensure that CriticalSections will never be nested!

Trait Implementations

impl Drop for CriticalSection

fn drop(&mut self)

Upon dropping the last CriticalSection, enable global device interrupts.