skyline/app/src/main/cpp/skyline/jvm.cpp

// SPDX-License-Identifier: MPL-2.0
// Copyright © 2020 Skyline Team and Contributors (https://github.com/skyline-emu/)

#include "jvm.h"

namespace skyline {
    /*
     * @brief A thread-local wrapper over JNIEnv and JavaVM which automatically handles attaching and detaching threads
     */
    struct JniEnvironment {
        JNIEnv *env{};
        static inline JavaVM *vm{};
        bool attached{};

        void Initialize(JNIEnv *environment) {
            env = environment;
            if (env->GetJavaVM(&vm) < 0)
                throw exception("Cannot get JavaVM from environment");
            attached = true;
        }

        JniEnvironment() {
            if (vm && !attached) {
                vm->AttachCurrentThread(&env, nullptr);
                attached = true;
            }
        }

        ~JniEnvironment() {
            if (vm && attached)
                vm->DetachCurrentThread();
        }

        operator JNIEnv *() {
            if (!attached)
                throw exception("Not attached");
            return env;
        }

        JNIEnv *operator->() {
            if (!attached)
                throw exception("Not attached");
            return env;
        }
    };

    thread_local inline JniEnvironment env;

    JvmManager::JvmManager(JNIEnv *environ, jobject instance) : instance(environ->NewGlobalRef(instance)), instanceClass(reinterpret_cast<jclass>(environ->NewGlobalRef(environ->GetObjectClass(instance)))), initializeControllersId(environ->GetMethodID(instanceClass, "initializeControllers", "()V")), vibrateDeviceId(environ->GetMethodID(instanceClass, "vibrateDevice", "(I[J[I)V")), clearVibrationDeviceId(environ->GetMethodID(instanceClass, "clearVibrationDevice", "(I)V")) {
        env.Initialize(environ);
    }

    JvmManager::~JvmManager() {
        env->DeleteGlobalRef(instanceClass);
        env->DeleteGlobalRef(instance);
    }

    JNIEnv *JvmManager::GetEnv() {
        return env;
    }

    jobject JvmManager::GetField(const char *key, const char *signature) {
        return env->GetObjectField(instance, env->GetFieldID(instanceClass, key, signature));
    }

    bool JvmManager::CheckNull(const char *key, const char *signature) {
        return env->IsSameObject(env->GetObjectField(instance, env->GetFieldID(instanceClass, key, signature)), nullptr);
    }

    bool JvmManager::CheckNull(jobject &object) {
        return env->IsSameObject(object, nullptr);
    }

    void JvmManager::InitializeControllers() {
        env->CallVoidMethod(instance, initializeControllersId);
    }

    void JvmManager::VibrateDevice(jint index, const span<jlong> &timings, const span<jint> &amplitudes) {
        auto jTimings{env->NewLongArray(timings.size())};
        env->SetLongArrayRegion(jTimings, 0, timings.size(), timings.data());
        auto jAmplitudes{env->NewIntArray(amplitudes.size())};
        env->SetIntArrayRegion(jAmplitudes, 0, amplitudes.size(), amplitudes.data());

        env->CallVoidMethod(instance, vibrateDeviceId, index, jTimings, jAmplitudes);

        env->DeleteLocalRef(jTimings);
        env->DeleteLocalRef(jAmplitudes);
    }

    void JvmManager::ClearVibrationDevice(jint index) {
        env->CallVoidMethod(instance, clearVibrationDeviceId, index);
    }
}