Add backend selectors

src/proactor.rs

@@ -7,6 +7,7 @@ use once_cell::sync::Lazy;
 use super::syscore::*;
 use super::waker::*;
 use crate::spawn_blocking;
+use crate::sys::IoBackend;
 
 pub use super::handle::*;
 
@@ -39,6 +40,11 @@ impl Proactor {
     pub(crate) fn inner(&self) -> &SysProactor {
         &self.0
     }
+
+    /// Get the IO backend that is used with Nuclei's proactor.
+    pub(crate) fn backend() -> IoBackend {
+        BACKEND
+    }
 }
 
 ///

src/sys.rs

@@ -1,3 +1,14 @@
+///
+/// Backends that are possible to use with Nuclei
+pub enum IoBackend {
+    /// BSD-like backend
+    Kqueue,
+    /// Linux backend
+    Epoll,
+    /// Linux backend
+    IoUring
+}
+
 #[cfg(unix)]
 fn check_err(res: libc::c_int) -> Result<libc::c_int, std::io::Error> {
     if res == -1 {

src/syscore/bsd/mod.rs

@@ -7,3 +7,5 @@ pub(crate) use fs::*;
 pub(crate) use kqueue::*;
 
 pub(crate) use processor::*;
+
+pub const BACKEND: crate::sys::IoBackend = crate::sys::IoBackend::Kqueue;

src/syscore/linux/epoll/mod.rs

@@ -7,3 +7,5 @@ pub(crate) use epoll::*;
 pub(crate) use fs::*;
 
 pub(crate) use processor::*;
+
+pub const BACKEND: crate::sys::IoBackend = crate::sys::IoBackend::Epoll;

src/syscore/linux/iouring/mod.rs

@@ -9,3 +9,5 @@ pub(crate) use fs::*;
 pub(crate) use iouring::*;
 pub(crate) use nethandle::*;
 pub(crate) use processor::*;
+
+pub const BACKEND: crate::sys::IoBackend = crate::sys::IoBackend::IoUring;