Struct SharedCondvar

pub struct SharedCondvar { /* private fields */ }

Simple conditional variable that can be shared between processes and used with SharedMutex

Dropping conditional variable in creating process while it being used by another process will cause undefined behaviour. It is recommended to drop this conditional variable in creating process only after no other process has access to it.

For more information see pthread_cond_init, pthread_cond_wait, SharedMutex and SharedMemoryObject.

Example

let mut mutex = SharedMutex::new()?;
let mut condvar = SharedCondvar::new()?;

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

if pid == 0 {
    println!("child lock()");
    mutex.lock()?;
    println!("child wait()");
    condvar.wait(&mut mutex)?;
    println!("child notified");
    mutex.unlock()?;
    println!("child unlocked");
} else {
    sleep(Duration::from_millis(40));
    println!("parent notify()");
    condvar.notify_one()?;
}

Output:

child lock()
child wait()
parent notify()
child notified
child unlocked

Implementations

impl SharedCondvar

pub fn new() -> Result<Self>

Creates new SharedCondvar

Errors

If allocation or initialization fails returns error from last_os_error.

pub fn wait(&mut self, mutex: &mut SharedMutex) -> Result<()>

Waits on given mutex

This function will block until notified by another process

Errors

If any pthread call fails, returns error from last_os_error. For possible errors see pthread_cond_wait.

pub fn notify_one(&mut self) -> Result<()>

Notifies one of processes that are waiting on this condvar

Errors

If any pthread call fails, returns error from last_os_error. For possible errors see pthread_cond_signal.

pub fn notify_all(&mut self) -> Result<()>

Notifies all processes that are waiting on this condvar

Errors

If any pthread call fails, returns error from last_os_error. For possible errors see pthread_cond_broadcast.

Trait Implementations

impl Drop for SharedCondvar

fn drop(&mut self)

Executes the destructor for this type.