fix: allow wasi-nn to compile with threads changes

Co-authored-by: Alex Crichton <[email protected]>

Author: abrown

crates/wasi-nn/src/api.rs

@@ -7,7 +7,7 @@ use thiserror::Error;
 use wiggle::GuestError;
 
 /// A [Backend] contains the necessary state to load [BackendGraph]s.
-pub(crate) trait Backend: Send {
+pub(crate) trait Backend: Send + Sync {
     fn name(&self) -> &str;
     fn load(
         &mut self,
@@ -18,7 +18,7 @@ pub(crate) trait Backend: Send {
 
 /// A [BackendGraph] can create [BackendExecutionContext]s; this is the backing
 /// implementation for a [crate::witx::types::Graph].
-pub(crate) trait BackendGraph: Send {
+pub(crate) trait BackendGraph: Send + Sync {
     fn init_execution_context(&mut self) -> Result<Box<dyn BackendExecutionContext>, BackendError>;
 }
 

crates/wasi-nn/src/openvino.rs

@@ -1,4 +1,5 @@
 //! Implements the wasi-nn API.
+
 use crate::api::{Backend, BackendError, BackendExecutionContext, BackendGraph};
 use crate::witx::types::{ExecutionTarget, GraphBuilderArray, Tensor, TensorType};
 use openvino::{InferenceError, Layout, Precision, SetupError, TensorDesc};
@@ -7,6 +8,9 @@ use std::sync::Arc;
 #[derive(Default)]
 pub(crate) struct OpenvinoBackend(Option<openvino::Core>);
 
+unsafe impl Send for OpenvinoBackend {}
+unsafe impl Sync for OpenvinoBackend {}
+
 impl Backend for OpenvinoBackend {
     fn name(&self) -> &str {
         "openvino"
@@ -65,6 +69,9 @@ impl Backend for OpenvinoBackend {
 
 struct OpenvinoGraph(Arc<openvino::CNNNetwork>, openvino::ExecutableNetwork);
 
+unsafe impl Send for OpenvinoGraph {}
+unsafe impl Sync for OpenvinoGraph {}
+
 impl BackendGraph for OpenvinoGraph {
     fn init_execution_context(&mut self) -> Result<Box<dyn BackendExecutionContext>, BackendError> {
         let infer_request = self.1.create_infer_request()?;