Implement Discovery PLATFORM logic in Rust
This commit introduces new PAL that is used by ReamoteAuth protocol
communicate with remote device
Design doc: go/remote-auth-manager-fishfood-design
Test: built successfully.
Bug: : 291333048
Change-Id: I9c78137ccf2fd6c86735bef0dd0c9cedf589d704
diff --git a/remoteauth/service/jni/src/unique_jvm.rs b/remoteauth/service/jni/src/unique_jvm.rs
new file mode 100644
index 0000000..46cc361
--- /dev/null
+++ b/remoteauth/service/jni/src/unique_jvm.rs
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//! takes a JavaVM to a static reference.
+//!
+//! JavaVM is shared as multiple JavaVM within a single process is not allowed
+//! per [JNI spec](https://docs.oracle.com/javase/8/docs/technotes/guides/jni/spec/invocation.html)
+//! The unique JavaVM need to be shared over (potentially) different threads.
+
+use std::sync::{Arc, Once};
+
+use anyhow::Result;
+use jni::JavaVM;
+
+static mut JVM: Option<Arc<JavaVM>> = None;
+static INIT: Once = Once::new();
+/// set_once sets the unique JavaVM that can be then accessed using get_static_ref()
+///
+/// The function shall only be called once.
+pub(crate) fn set_once(jvm: JavaVM) -> Result<()> {
+ // Safety: follows [this pattern](https://doc.rust-lang.org/std/sync/struct.Once.html).
+ // Modification to static mut is nested inside call_once.
+ unsafe {
+ INIT.call_once(|| {
+ JVM = Some(Arc::new(jvm));
+ });
+ }
+ Ok(())
+}
+/// Gets a 'static reference to the unique JavaVM. Returns None if set_once() was never called.
+pub(crate) fn get_static_ref() -> Option<&'static Arc<JavaVM>> {
+ // Safety: follows [this pattern](https://doc.rust-lang.org/std/sync/struct.Once.html).
+ // Modification to static mut is nested inside call_once.
+ unsafe { JVM.as_ref() }
+}