memory_info.hpp

/* Copyright © 2017 Apple Inc. All rights reserved.
 *
 * Use of this source code is governed by a BSD-3-clause license that can
 * be found in the LICENSE.txt file or at https://opensource.org/licenses/BSD-3-Clause
 */
#ifndef TURI_MEMORY_INFO_HPP
#define TURI_MEMORY_INFO_HPP

#include <string>
#include <cstdint>
#include <iostream>
#ifdef HAS_TCMALLOC
#include <google/malloc_extension.h>
#endif
#include <core/logging/assertions.hpp>
namespace turi {
  /**
   * \internal \brief Memory info namespace contains functions used to
   * compute memory usage.
   *
   * The memory info functions require TCMalloc to actually compute
   * memory usage values. If TCMalloc is not present then calls to
   * memory info will generate warnings and return the default value.
   */
  namespace memory_info {

    /**
     * \internal
     *
     * \brief Returns whether memory info reporting is
     * available on this system (if memory_info was built with TCMalloc)
     *
     * @return if memory info is available on this system.
     */
    inline bool available() {
#ifdef HAS_TCMALLOC
      return true;
#else
      return false;
#endif
    }

    /**
     * \internal
     *
     * \brief Estimates the total current size of the memory heap in
     * bytes. If memory info is not available then 0 is returned.
     *
     * @return size of heap in bytes
     */
    inline size_t heap_bytes() {
      size_t heap_size(0);
#ifdef HAS_TCMALLOC
      MallocExtension::instance()->
        GetNumericProperty("generic.heap_size", &heap_size);
#else
      logstream(LOG_WARNING) <<
        "memory_info::heap_bytes() requires tcmalloc" << std::endl;
#endif
      return heap_size;
    }

    /**
     * \internal
     *
     * \brief Determines the total number of allocated bytes.  If
     * memory info is not available then 0 is returned.
     *
     * @return the total bytes allocated
     */
    inline size_t allocated_bytes() {
      size_t allocated_size(0);
#ifdef HAS_TCMALLOC
      MallocExtension::instance()->
        GetNumericProperty("generic.current_allocated_bytes",
                           &allocated_size);
#else
      logstream_once(LOG_WARNING) <<
        "memory_info::allocated_bytes() requires tcmalloc" << std::endl;
#endif
      return allocated_size;
    }

    /**
     * \internal
     *
     * \brief Print a memory usage summary prefixed by the string
     * argument.
     *
     * @param [in] label the string to print before the memory usage summary.
     */
    inline void print_usage(const std::string& label = "") {
#ifdef HAS_TCMALLOC
        const double BYTES_TO_MB = double(1) / double(1024 * 1024);
        std::cerr
          << "Memory Info: " << label << std::endl
          << "\t Heap: " << (heap_bytes() * BYTES_TO_MB) << " MB"
          << std::endl
          << "\t Allocated: " << (allocated_bytes() * BYTES_TO_MB) << " MB"
          << std::endl;
#else
        logstream_once(LOG_WARNING)
          << "Unable to print memory info for: " << label << ". "
          << "No memory extensions api available." << std::endl;
#endif
    }

    /**
     * \internal
     *
     * \brief Log a memory usage summary prefixed by the string
     * argument.
     *
     * @param [in] label the string to print before the memory usage summary.
     */
    inline void log_usage(const std::string& label = "") {
#ifdef HAS_TCMALLOC
        const double BYTES_TO_MB = double(1) / double(1024 * 1024);
        logstream(LOG_INFO)
          << "Memory Info: " << label
          << "\n\t Heap: " << (heap_bytes() * BYTES_TO_MB) << " MB"
          << "\n\t Allocated: " << (allocated_bytes() * BYTES_TO_MB) << " MB"
          << std::endl;
#else
        logstream_once(LOG_WARNING)
          << "Unable to print memory info for: " << label << ". "
          << "No memory extensions api available." << std::endl;
#endif
    }
  } // end of namespace memory info
};

#endif