runtime/native/java_lang_Runtime.cc

/*
 * Copyright (C) 2008 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 "java_lang_Runtime.h"

#include <dlfcn.h>
#include <limits.h>
#include <unistd.h>

#include "gc/heap.h"
#include "handle_scope-inl.h"
#include "jni_internal.h"
#include "mirror/class_loader.h"
#include "runtime.h"
#include "scoped_thread_state_change.h"
#include "ScopedUtfChars.h"
#include "verify_object-inl.h"

namespace art {

static void Runtime_gc(JNIEnv*, jclass) {
  if (Runtime::Current()->IsExplicitGcDisabled()) {
      LOG(INFO) << "Explicit GC skipped.";
      return;
  }
  Runtime::Current()->GetHeap()->CollectGarbage(false);
}

[[noreturn]] static void Runtime_nativeExit(JNIEnv*, jclass, jint status) {
  LOG(INFO) << "System.exit called, status: " << status;
  Runtime::Current()->CallExitHook(status);
  exit(status);
}

static jstring Runtime_nativeLoad(JNIEnv* env, jclass, jstring javaFilename, jobject javaLoader,
                                  jstring javaLdLibraryPath) {
  // TODO: returns NULL on success or an error message describing the failure on failure. This
  // should be refactored in terms of suppressed exceptions.
  ScopedUtfChars filename(env, javaFilename);
  if (filename.c_str() == NULL) {
    return NULL;
  }

  if (javaLdLibraryPath != NULL) {
    ScopedUtfChars ldLibraryPath(env, javaLdLibraryPath);
    if (ldLibraryPath.c_str() == NULL) {
      return NULL;
    }
    void* sym = dlsym(RTLD_DEFAULT, "android_update_LD_LIBRARY_PATH");
    if (sym != NULL) {
      typedef void (*Fn)(const char*);
      Fn android_update_LD_LIBRARY_PATH = reinterpret_cast<Fn>(sym);
      (*android_update_LD_LIBRARY_PATH)(ldLibraryPath.c_str());
    } else {
      LOG(ERROR) << "android_update_LD_LIBRARY_PATH not found; .so dependencies will not work!";
    }
  }

  std::string error_msg;
  {
    JavaVMExt* vm = Runtime::Current()->GetJavaVM();
    bool success = vm->LoadNativeLibrary(env, filename.c_str(), javaLoader, &error_msg);
    if (success) {
      return nullptr;
    }
  }

  // Don't let a pending exception from JNI_OnLoad cause a CheckJNI issue with NewStringUTF.
  env->ExceptionClear();
  return env->NewStringUTF(error_msg.c_str());
}

static jlong Runtime_maxMemory(JNIEnv*, jclass) {
  return Runtime::Current()->GetHeap()->GetMaxMemory();
}

static jlong Runtime_totalMemory(JNIEnv*, jclass) {
  return Runtime::Current()->GetHeap()->GetTotalMemory();
}

static jlong Runtime_freeMemory(JNIEnv*, jclass) {
  return Runtime::Current()->GetHeap()->GetFreeMemory();
}

static JNINativeMethod gMethods[] = {
  NATIVE_METHOD(Runtime, freeMemory, "!()J"),
  NATIVE_METHOD(Runtime, gc, "()V"),
  NATIVE_METHOD(Runtime, maxMemory, "!()J"),
  NATIVE_METHOD(Runtime, nativeExit, "(I)V"),
  NATIVE_METHOD(Runtime, nativeLoad, "(Ljava/lang/String;Ljava/lang/ClassLoader;Ljava/lang/String;)Ljava/lang/String;"),
  NATIVE_METHOD(Runtime, totalMemory, "!()J"),
};

void register_java_lang_Runtime(JNIEnv* env) {
  REGISTER_NATIVE_METHODS("java/lang/Runtime");
}

}  // namespace art