Add AccessorProvider to libbinder_rs

This allows Rust clients to inject AccessorProviders into libbinder to
enable the use of service management APIs to get services over sockets.

Test: atest vm_accessor_test
Bug: 358427181
Change-Id: I88bd4df2ece890d74c40a781eab0303182b680cf
diff --git a/libs/binder/rust/tests/integration.rs b/libs/binder/rust/tests/integration.rs
index 489fa0a..0e793e5 100644
--- a/libs/binder/rust/tests/integration.rs
+++ b/libs/binder/rust/tests/integration.rs
@@ -384,8 +384,8 @@
     use std::time::Duration;
 
     use binder::{
-        Accessor, BinderFeatures, DeathRecipient, FromIBinder, IBinder, Interface, SpIBinder,
-        StatusCode, Strong,
+        Accessor, AccessorProvider, BinderFeatures, DeathRecipient, FromIBinder, IBinder,
+        Interface, SpIBinder, StatusCode, Strong,
     };
     // Import from impl API for testing only, should not be necessary as long as
     // you are using AIDL.
@@ -982,6 +982,62 @@
         assert_eq!(delegator_binder, Err(StatusCode::NAME_NOT_FOUND));
     }
 
+    #[test]
+    fn test_accessor_provider_simple() {
+        let instances: Vec<String> = vec!["foo.service".to_owned(), "foo.other_service".to_owned()];
+        let accessor = AccessorProvider::new(&instances, move |_inst: &str| None);
+        assert!(accessor.is_some());
+    }
+
+    #[test]
+    fn test_accessor_provider_no_instance() {
+        let instances: Vec<String> = vec![];
+        let accessor = AccessorProvider::new(&instances, move |_inst: &str| None);
+        assert!(accessor.is_none());
+    }
+
+    #[test]
+    fn test_accessor_provider_double_register() {
+        let instances: Vec<String> = vec!["foo.service".to_owned(), "foo.other_service".to_owned()];
+        let accessor = AccessorProvider::new(&instances, move |_inst: &str| None);
+        assert!(accessor.is_some());
+        let accessor2 = AccessorProvider::new(&instances, move |_inst: &str| None);
+        assert!(accessor2.is_none());
+    }
+
+    #[test]
+    fn test_accessor_provider_register_drop_register() {
+        let instances: Vec<String> = vec!["foo.service".to_owned(), "foo.other_service".to_owned()];
+        {
+            let accessor = AccessorProvider::new(&instances, move |_inst: &str| None);
+            assert!(accessor.is_some());
+            // accessor drops and unregisters the provider
+        }
+        {
+            let accessor = AccessorProvider::new(&instances, move |_inst: &str| None);
+            assert!(accessor.is_some());
+        }
+    }
+
+    #[test]
+    fn test_accessor_provider_callback_destruction() {
+        let deleted: Arc<AtomicBool> = Arc::new(AtomicBool::new(false));
+        let instances: Vec<String> = vec!["foo.service".to_owned(), "foo.other_service".to_owned()];
+        {
+            let accessor: Option<AccessorProvider>;
+            {
+                let helper = ToBeDeleted { deleted: deleted.clone() };
+                accessor = AccessorProvider::new(&instances, move |_inst: &str| {
+                    let _ = &helper;
+                    None
+                });
+            }
+            assert!(accessor.is_some());
+            assert!(!deleted.load(Ordering::Relaxed));
+        }
+        assert!(deleted.load(Ordering::Relaxed));
+    }
+
     #[tokio::test]
     async fn reassociate_rust_binder_async() {
         let service_name = "testing_service";