shm.h

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/*
 * Copyright 2025 Stanford University, NVIDIA Corporation
 * SPDX-License-Identifier: Apache-2.0
 *
 * 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 REALM_SHM_H
#define REALM_SHM_H
#include "realm/realm_config.h"
#include "realm/utils.h"
#include <string>
 
namespace Realm {
 
  class SharedMemoryInfo {
  public:
    SharedMemoryInfo(void);
    SharedMemoryInfo(SharedMemoryInfo &&other);
    SharedMemoryInfo &operator=(SharedMemoryInfo &&other);
 
    ~SharedMemoryInfo(void);
 
    // disable copying of SharedMemoryInfo
    SharedMemoryInfo(const SharedMemoryInfo &) = delete;
    SharedMemoryInfo &operator=(const SharedMemoryInfo &) = delete;
 
    template <typename T>
    T *get_ptr() const
    {
      return reinterpret_cast<T *>(base);
    }
    OsHandle get_handle() const { return handle; }
    size_t get_size() const { return size; }
    std::string get_name() const { return name; }
    explicit operator bool() const { return base != nullptr; }
 
    void unlink(void);
 
    static bool create(SharedMemoryInfo &info, size_t size, const char *name = nullptr,
                       int numa_node = -1);
 
    static bool open(SharedMemoryInfo &info, const std::string &name, size_t size);
 
    static bool open(SharedMemoryInfo &info, OsHandle handle, size_t size);
 
  private:
    std::string name; // name of the shared memory object, if applicable
    void *base;       // base address of the mapped memory object
    size_t size;      // Size of the mapped memory object
    OsHandle handle;  // OS-native handle to mapped memory object
    bool owner;       // True if this SharedMemoryInfo was created via
                      // \sa SharedMemoryInfo::create, false otherwise
  };
 
}; // namespace Realm
 
#endif // ifndef REALM_SHM_H