Struct SharedMemoryObject

pub struct SharedMemoryObject<T> { /* private fields */ }

An object that can be shared between processes.

After spawning child process (using fork(), clone(), etc.) updates to this object will be seen by both processes. This is achieved by allocating memory using mmap with MAP_SHARED flag.

For more details see man page.

Example

let mut shared = SharedMemoryObject::new(123)?;

let pid = unsafe { fork() };
assert!(pid >= 0);

if pid == 0 {
    assert_eq!(*shared.get(), 123);
    *shared.get_mut() = 456;
    sleep(Duration::from_millis(40));
    assert_eq!(*shared.get(), 789);
} else {
    sleep(Duration::from_millis(20));
    assert_eq!(*shared.get(), 456);
    *shared.get_mut() = 789;
}

Implementations

impl<T: Sync + Send> SharedMemoryObject<T>

pub fn new(obj: T) -> Result<Self>

Allocates shared memory and moves obj there.

Errors

If allocation fails returns error from last_os_error.

pub fn get(&self) -> &T

Returns reference to underlying object.

Safety

See get_mut.

pub fn get_mut(&mut self) -> &mut T

Returns mutable reference to underlying object.

Safety

This function (and get) is always safe to call, but access to data under returned reference must be somehow synchronized with another processes to avoid data race.

Trait Implementations

impl<T> Drop for SharedMemoryObject<T>

fn drop(&mut self)

Executes the destructor for this type.