/*
 * Copyright (C) 2013 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.
 */

#include <pthread.h>

#include <cstdio>
#include <iostream>
#include <mutex>
#include <vector>

#include "android-base/logging.h"
#include "android-base/stringprintf.h"
#include "jni.h"
#include "jvmti.h"
#include "scoped_local_ref.h"
#include "scoped_utf_chars.h"

// Test infrastructure
#include "jvmti_helper.h"
#include "test_env.h"

namespace art {
namespace Test904ObjectAllocation {

static JavaVM* vm;

static std::string GetClassName(JNIEnv* jni_env, jclass cls) {
  ScopedLocalRef<jclass> class_class(jni_env, jni_env->GetObjectClass(cls));
  jmethodID mid = jni_env->GetMethodID(class_class.get(), "getName", "()Ljava/lang/String;");
  ScopedLocalRef<jstring> str(
      jni_env, reinterpret_cast<jstring>(jni_env->CallObjectMethod(cls, mid)));
  ScopedUtfChars utf_chars(jni_env, str.get());
  return utf_chars.c_str();
}

template <typename T>
class ScopedGlobalRef {
 public:
  ScopedGlobalRef(JNIEnv* env, T obj) : obj_(env->NewGlobalRef(obj)) {}
  ScopedGlobalRef(const ScopedGlobalRef<T>& src) noexcept
      : obj_(GetEnv()->NewGlobalRef(src.obj_)) {}
  ScopedGlobalRef(ScopedGlobalRef<T>&& src) noexcept : obj_(src.obj_) {
    src.obj_ = nullptr;
  }

  ~ScopedGlobalRef() {
    GetEnv()->DeleteGlobalRef(obj_);
  }

  T Get(JNIEnv* env) const {
    return env->NewLocalRef(obj_);
  }

 private:
  JNIEnv* GetEnv() const {
    JNIEnv* env = nullptr;
    CHECK_EQ(vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6), 0);
    return env;
  }

  jobject obj_;
};

struct EventLog {
  std::string msg_;
  ScopedGlobalRef<jthread> thr_;
};

static std::mutex gEventsMutex;
static std::vector<EventLog> gEvents;

static void JNICALL ObjectAllocated(jvmtiEnv* ti_env ATTRIBUTE_UNUSED,
                                    JNIEnv* jni_env,
                                    jthread thread,
                                    jobject object,
                                    jclass object_klass,
                                    jlong size) {
  std::string object_klass_descriptor = GetClassName(jni_env, object_klass);
  ScopedLocalRef<jclass> object_klass2(jni_env, jni_env->GetObjectClass(object));
  std::string object_klass_descriptor2 = GetClassName(jni_env, object_klass2.get());

  std::lock_guard<std::mutex> guard(gEventsMutex);
  gEvents.push_back({android::base::StringPrintf("ObjectAllocated type %s/%s size %zu",
                                                 object_klass_descriptor.c_str(),
                                                 object_klass_descriptor2.c_str(),
                                                 static_cast<size_t>(size)),
                     ScopedGlobalRef<jthread>(jni_env, thread)});
}

extern "C" JNIEXPORT void JNICALL Java_art_Test904_setupObjectAllocCallback(
    JNIEnv* env, jclass klass ATTRIBUTE_UNUSED, jboolean enable) {
  env->GetJavaVM(&vm);
  jvmtiEventCallbacks callbacks;
  memset(&callbacks, 0, sizeof(jvmtiEventCallbacks));
  callbacks.VMObjectAlloc = enable ? ObjectAllocated : nullptr;

  jvmtiError ret = jvmti_env->SetEventCallbacks(&callbacks, sizeof(callbacks));
  JvmtiErrorToException(env, jvmti_env, ret);
}

extern "C" JNIEXPORT void JNICALL Java_art_Test904_enableAllocationTracking(
    JNIEnv* env, jclass, jthread thread, jboolean enable) {
  jvmtiError ret = jvmti_env->SetEventNotificationMode(
      enable ? JVMTI_ENABLE : JVMTI_DISABLE,
      JVMTI_EVENT_VM_OBJECT_ALLOC,
      thread);
  JvmtiErrorToException(env, jvmti_env, ret);
}

extern "C" JNIEXPORT jobjectArray JNICALL Java_art_Test904_getTrackingEventMessages(
    JNIEnv* env, jclass Main_klass ATTRIBUTE_UNUSED, jobjectArray threads) {
  std::lock_guard<std::mutex> guard(gEventsMutex);
  std::vector<std::string> real_events;
  std::vector<jthread> thread_lst;
  jint nthreads = env->GetArrayLength(threads);
  {
    env->PushLocalFrame(nthreads + 1);
    for (jint i = 0; i < nthreads; i++) {
      thread_lst.push_back(reinterpret_cast<jthread>(env->GetObjectArrayElement(threads, i)));
    }
    for (const EventLog& ev : gEvents) {
      ScopedLocalRef<jthread> thr(env, ev.thr_.Get(env));
      for (jthread req_thread : thread_lst) {
        if (env->IsSameObject(req_thread, thr.get())) {
          real_events.push_back(ev.msg_);
          break;
        }
      }
    }
    env->PopLocalFrame(nullptr);
  }
  jobjectArray ret = CreateObjectArray(env,
                                       static_cast<jint>(real_events.size()),
                                       "java/lang/String",
                                       [&](jint i) {
    return env->NewStringUTF(real_events[i].c_str());
  });
  gEvents.clear();
  return ret;
}

}  // namespace Test904ObjectAllocation
}  // namespace art