Struct ChangeNotification 

pub struct ChangeNotification { /* private fields */ }

An owned change-notification handle.

Closed with FindCloseChangeNotification on drop. The type exists so that the close routine travels with the handle rather than being something each call site has to remember, which is the same shape windows-threadpool-sys already needed for wait targets.

Implementations

impl ChangeNotification

pub fn as_raw(&self) -> HANDLE

The raw handle, for passing to a wait.

Borrowed, not transferred: it stays owned by this value. Do not pass it to CloseHandle.

pub fn rearm(&self) -> Outcome<()>

Rearms the watch after it has signalled.

A notification handle signals once and then stays signalled until it is rearmed, so a consumer that waits in a loop must call this between waits.

Errors

Returns the raw Win32 code, unaltered.

Example

Without the rearm, the second wait returns immediately on the first change forever, and a consumer’s loop spins:

use std::fs;

use windows_namespace_request_sys::prepare;
use windows_namespace_request_sys::watch::{NotifyFilter, WatchDirectory};
use windows_sys::Win32::Foundation::WAIT_OBJECT_0;
use windows_sys::Win32::System::Threading::WaitForSingleObject;
use wtf_string::Wtf16String;

let directory = std::env::temp_dir().join(format!("wnrs-rearm-{}", std::process::id()));
let _ = fs::remove_dir_all(&directory);
fs::create_dir_all(&directory)?;

let text = directory.to_str().expect("a temporary path is valid UTF-8");
let notification = WatchDirectory::new(prepare(&Wtf16String::from(text))?)
    .with_filter(NotifyFilter::FILE_NAME)
    .perform()?;

fs::write(directory.join("first.t"), b"x")?;
// SAFETY: the handle is live for the notification's lifetime.
assert_eq!(unsafe { WaitForSingleObject(notification.as_raw(), 5_000) }, WAIT_OBJECT_0);

// The handle stays signalled until this runs.
notification.rearm()?;

fs::write(directory.join("second.t"), b"x")?;
// SAFETY: as above.
assert_eq!(unsafe { WaitForSingleObject(notification.as_raw(), 5_000) }, WAIT_OBJECT_0);

Trait Implementations

impl Debug for ChangeNotification

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Drop for ChangeNotification

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.

impl Send for ChangeNotification

impl Sync for ChangeNotification