41 lines
1.3 KiB
Rust
41 lines
1.3 KiB
Rust
use std::{io, ptr};
|
|
|
|
use winapi::um::synchapi::{CreateSemaphoreW, ReleaseSemaphore};
|
|
|
|
use crate::{nonnull_handle_result, result, Handle};
|
|
|
|
/// A [Windows semaphore](https://docs.microsoft.com/en-us/windows/win32/sync/semaphore-objects).
|
|
#[derive(Clone, Debug)]
|
|
pub struct Semaphore(Handle);
|
|
|
|
impl Semaphore {
|
|
/// Construct a new semaphore.
|
|
///
|
|
/// This wraps
|
|
/// [`CreateSemaphoreW`](https://docs.microsoft.com/en-us/windows/win32/api/synchapi/nf-synchapi-createsemaphorew).
|
|
pub fn new() -> io::Result<Self> {
|
|
let handle = nonnull_handle_result(unsafe {
|
|
CreateSemaphoreW(ptr::null_mut(), 0, 1, ptr::null_mut())
|
|
})?;
|
|
|
|
let handle = unsafe { Handle::from_raw(handle) };
|
|
Ok(Self(handle))
|
|
}
|
|
|
|
/// Release a permit on the semaphore.
|
|
///
|
|
/// This wraps
|
|
/// [`ReleaseSemaphore`](https://docs.microsoft.com/en-us/windows/win32/api/synchapi/nf-synchapi-releasesemaphore).
|
|
pub fn release(&self) -> io::Result<()> {
|
|
result(unsafe { ReleaseSemaphore(*self.0, 1, ptr::null_mut()) })
|
|
}
|
|
|
|
/// Access the underlying handle to the semaphore.
|
|
pub fn handle(&self) -> &Handle {
|
|
&self.0
|
|
}
|
|
}
|
|
|
|
unsafe impl Send for Semaphore {}
|
|
|
|
unsafe impl Sync for Semaphore {}
|