feat(driver): allow specifying driver type

Author: Berrysoft

compio-driver/src/fusion/mod.rs

@@ -38,20 +38,25 @@ pub(crate) struct Driver {
 impl Driver {
     /// Create a new fusion driver with given number of entries
     pub fn new(builder: &ProactorBuilder) -> io::Result<Self> {
-        match DriverType::suggest() {
+        let (ty, fallback) = match &builder.driver_type {
+            Some(t) => (*t, false),
+            None => (DriverType::suggest(), true),
+        };
+        match ty {
             DriverType::Poll => Ok(Self {
                 fuse: FuseDriver::Poll(poll::Driver::new(builder)?),
             }),
             DriverType::IoUring => match iour::Driver::new(builder) {
                 Ok(driver) => Ok(Self {
                     fuse: FuseDriver::IoUring(driver),
                 }),
-                Err(_e) => {
+                Err(_e) if fallback => {
                     warn!("Fail to create io-uring driver: {_e:?}, fallback to polling driver.");
                     Ok(Self {
                         fuse: FuseDriver::Poll(poll::Driver::new(builder)?),
                     })
                 }
+                Err(e) => Err(e),
             },
             _ => unreachable!("Fuse driver will only be enabled on linux"),
         }

compio-driver/src/lib.rs

@@ -458,6 +458,7 @@ pub struct ProactorBuilder {
     coop_taskrun: bool,
     taskrun_flag: bool,
     eventfd: Option<RawFd>,
+    driver_type: Option<DriverType>,
 }
 
 // Safety: `RawFd` is thread safe.
@@ -480,6 +481,7 @@ impl ProactorBuilder {
             coop_taskrun: false,
             taskrun_flag: false,
             eventfd: None,
+            driver_type: None,
         }
     }
 
@@ -585,6 +587,13 @@ impl ProactorBuilder {
         self
     }
 
+    /// Force a driver type to use. It is ignored if the fusion driver is
+    /// disabled.
+    pub fn driver_type(&mut self, t: DriverType) -> &mut Self {
+        self.driver_type = Some(t);
+        self
+    }
+
     /// Build the [`Proactor`].
     pub fn build(&self) -> io::Result<Proactor> {
         Proactor::with_builder(self)