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## Type advice_types

boost::interprocess::mapped_region::advice_types

## Synopsis

    // In header: <boost/interprocess/mapped_region.hpp>

    enum advice_types { advice_normal, advice_sequential, advice_random,
                        advice_willneed, advice_dontneed };

## Description

This enum specifies region usage behaviors that an application can specify to the mapped region implementation.

`advice_normal`

  Specifies that the application has no advice to give on its behavior with respect to the region. It is the default characteristic if no advice is given for a range of memory.

`advice_sequential`

  Specifies that the application expects to access the region sequentially from lower addresses to higher addresses. The implementation can lower the priority of preceding pages within the region once a page have been accessed.

`advice_random`

  Specifies that the application expects to access the region in a random order, and prefetching is likely not advantageous.

`advice_willneed`

  Specifies that the application expects to access the region in the near future. The implementation can prefetch pages of the region.

`advice_dontneed`

  Specifies that the application expects that it will not access the region in the near future. The implementation can unload pages within the range to save system resources.