memory.h

#ifndef SINGA_CORE_MEMORY_H_
#define SINGA_CORE_MEMORY_H_

#include <mutex>
#include <atomic>
#include "singa/proto/core.pb.h"
#include "singa/singa_config.h"

#ifdef USE_CUDA
#include "cnmem.h"
#endif


namespace singa {

class VirtualMemory {};

class DeviceMemPool {
 public:
  virtual void Malloc(void** ptr, const size_t size)  = 0;
  virtual void Free(void* ptr)  = 0;

  virtual std::pair<size_t, size_t> GetMemUsage() {
    return std::make_pair(0u, 0u);
  }
  virtual ~DeviceMemPool(){};

 protected:
  size_t usage_;
//  size_t init_size_ = 0, max_size_ = 0;
};

#ifdef USE_CUDA
class CnMemPool : public DeviceMemPool {
 public:
  // Create the mem pool by setting the devices [0, numDevices), and
  // initial pool size (MB), and max pool size (no effect currently).
  CnMemPool(int numDevices = 1, size_t init_size = 256, size_t max_size = 0);
  CnMemPool(const MemPoolConf& conf);

  void Malloc(void** ptr, const size_t size);
  void Free(void* ptr);

  std::pair<size_t, size_t> GetMemUsage() override;

  // release all memory and set cnmem manager to unintialized
  ~CnMemPool();

 protected:
  void Init();


 private:

  MemPoolConf conf_;
  // whether the (global) memory pool has been initialized
  bool initialized_ = false;
  // lock on the initialized variable
  std::mutex mtx_;

  static std::atomic<int> pool_count;
};

class CudaMemPool : public DeviceMemPool {
 public:
  void Malloc(void** ptr, const size_t size) override;
  void Free(void* ptr) override;
};
#endif
}  // namespace singa
#endif  // SINGA_CORE_MEMORY_H_