Add RLock._is_owned

Cargo.lock

@@ -1101,8 +1101,7 @@ checksum = "8dd5a6d5999d9907cda8ed67bbd137d3af8085216c2ac62de5be860bd41f304a"
 [[package]]
 name = "lock_api"
 version = "0.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dd96ffd135b2fd7b973ac026d28085defbe8983df057ced3eb4f2130b0831312"
+source = "git+https://github.com/coolreader18/parking_lot?branch=remutex-is_owned#391cf555e94c05450cea2e88b42c95c6631ab163"
 dependencies = [
  "scopeguard",
 ]

Cargo.toml

@@ -69,4 +69,4 @@ opt-level = 3
 [patch.crates-io]
 # REDOX START, Uncommment when you want to compile/check with redoxer
 # REDOX END
-
+lock_api = { git = "https://github.com/coolreader18/parking_lot", branch = "remutex-is_owned" }

vm/src/stdlib/thread.rs

@@ -191,6 +191,11 @@ impl PyRLock {
         Ok(())
     }
 
+    #[pymethod]
+    fn _is_owned(&self) -> bool {
+        self.mu.is_owned_by_current_thread()
+    }
+
     #[pymethod(magic)]
     fn exit(&self, _args: FuncArgs, vm: &VirtualMachine) -> PyResult<()> {
         self.release(vm)