THUAI6/CAPI/cpp/grpc/include/grpcpp/resource_quota.h

/*
 *
 * Copyright 2016 gRPC authors.
 *
 * 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.
 *
 */

#ifndef GRPCPP_RESOURCE_QUOTA_H
#define GRPCPP_RESOURCE_QUOTA_H

struct grpc_resource_quota;

#include <grpcpp/impl/codegen/config.h>
#include <grpcpp/impl/codegen/grpc_library.h>

namespace grpc
{

    /// ResourceQuota represents a bound on memory and thread usage by the gRPC
    /// library. A ResourceQuota can be attached to a server (via \a ServerBuilder),
    /// or a client channel (via \a ChannelArguments).
    /// gRPC will attempt to keep memory and threads used by all attached entities
    /// below the ResourceQuota bound.
    class ResourceQuota final : private grpc::GrpcLibraryCodegen
    {
    public:
        /// \param name - a unique name for this ResourceQuota.
        explicit ResourceQuota(const std::string& name);
        ResourceQuota();
        ~ResourceQuota() override;

        /// Resize this \a ResourceQuota to a new size. If \a new_size is smaller
        /// than the current size of the pool, memory usage will be monotonically
        /// decreased until it falls under \a new_size.
        /// No time bound is given for this to occur however.
        ResourceQuota& Resize(size_t new_size);

        /// Set the max number of threads that can be allocated from this
        /// ResourceQuota object.
        ///
        /// If the new_max_threads value is smaller than the current value, no new
        /// threads are allocated until the number of active threads fall below
        /// new_max_threads. There is no time bound on when this may happen i.e none
        /// of the current threads are forcefully destroyed and all threads run their
        /// normal course.
        ResourceQuota& SetMaxThreads(int new_max_threads);

        grpc_resource_quota* c_resource_quota() const
        {
            return impl_;
        }

    private:
        ResourceQuota(const ResourceQuota& rhs);
        ResourceQuota& operator=(const ResourceQuota& rhs);

        grpc_resource_quota* const impl_;
    };

}  // namespace grpc

#endif  // GRPCPP_RESOURCE_QUOTA_H