Method create_jvm

rust/src/api/mod.rs:132–224

Creates a new Jvm. If a JavaVM is already created by the current process, it attempts to attach the current thread to it.

(jvm_options: &[String], lib_name_to_load: Option<String>)

    /// Creates a new Jvm.
    /// If a JavaVM is already created by the current process, it attempts to attach the current thread to it.
    fn create_jvm(jvm_options: &[String], lib_name_to_load: Option<String>) -> errors::Result<Jvm> {
        debug("Creating a Jvm");
        let mut jvm: *mut JavaVM = ptr::null_mut();
        let mut jni_environment: *mut JNIEnv = ptr::null_mut();

        // Create the Jvm atomically
        let _g = cache::MUTEX.lock()?;

        let result = if let Some(env) = cache::get_thread_local_env_opt() {
            debug("A JVM is already created for this thread. Retrieving it...");
            jni_environment = env;

            JNI_OK
        } else {
            let created_vm = Self::get_created_vm();

            let res_int = if created_vm.is_some() {
                debug("A JVM is already created by another thread. Retrieving it...");
                jni_environment = created_vm.unwrap();

                JNI_OK
            } else {
                info("No JVMs exist. Creating a new one...");
                let mut cstrings_to_drop: Vec<*mut c_char> = Vec::with_capacity(jvm_options.len());
                let mut jvm_options_vec: Vec<JavaVMOption> = jvm_options
                    .iter()
                    .map(|opt| {
                        let cstr = utils::to_c_string(opt);
                        let jo = JavaVMOption {
                            optionString: cstr,
                            extraInfo: ptr::null_mut() as *mut c_void,
                        };
                        cstrings_to_drop.push(cstr);
                        jo
                    })
                    .collect();

                let mut jvm_arguments = JavaVMInitArgs {
                    version: JNI_VERSION_1_6,
                    nOptions: jvm_options.len() as i32,
                    options: jvm_options_vec.as_mut_ptr(),
                    ignoreUnrecognized: JNI_TRUE,
                };

                let int_result = tweaks::create_java_vm(
                    &mut jvm,
                    (&mut jni_environment as *mut *mut JNIEnv) as *mut *mut c_void,
                    (&mut jvm_arguments as *mut JavaVMInitArgs) as *mut c_void,
                );

                cstrings_to_drop
                    .into_iter()
                    .for_each(|s| unsafe { utils::drop_c_string(s) });

                int_result
            };

            res_int