/*
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * 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 <folly/Executor.h>
#include <folly/SingletonThreadLocal.h>

#include <stdexcept>

#include <glog/logging.h>

namespace folly {

void Executor::addWithPriority(Func, int8_t /* priority */) {
  throw std::runtime_error(
      "addWithPriority() is not implemented for this Executor");
}

bool Executor::keepAliveAcquire() {
  return false;
}

void Executor::keepAliveRelease() {
  LOG(FATAL) << __func__ << "() should not be called for folly::Executor types "
             << "which do not override keepAliveAcquire()";
}

namespace {
using BlockingContextSingletonT =
    SingletonThreadLocal<folly::Optional<BlockingContext>>;
} // namespace

folly::Optional<BlockingContext> getBlockingContext() {
  return BlockingContextSingletonT::get();
}

BlockingGuard::BlockingGuard(folly::StringPiece executorName)
    : previousContext_{BlockingContextSingletonT::get()} {
  BlockingContextSingletonT::get() = BlockingContext{executorName};
}

BlockingGuard::BlockingGuard()
    : previousContext_{BlockingContextSingletonT::get()} {
  BlockingContextSingletonT::get() = folly::none;
}

BlockingGuard::~BlockingGuard() {
  BlockingContextSingletonT::get() = std::move(previousContext_);
}

BlockingGuard makeBlockingDisallowedGuard(folly::StringPiece executorName) {
  return BlockingGuard{executorName};
}

BlockingGuard makeBlockingAllowedGuard() {
  return BlockingGuard{};
}

} // namespace folly