09a263e607
git-subtree-dir: deps/memkind/src git-subtree-split: bb9f19dd1b3ed6cc5e1b35919564ccf6f4b32f69
81 lines
3.0 KiB
Plaintext
81 lines
3.0 KiB
Plaintext
# Memkind examples
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The example directory contains example codes that use the memkind
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interface.
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## PMEM
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The pmem_*.c(pp) demonstrates how to create and use a file-backed memory kind.
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The default pmem path is "/tmp/".
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Custom directory is pass as first argument to all of PMEM example programs,
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e.g. to execute pmem_malloc example in /mnt/pmem location, call:
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./pmem_malloc /mnt/pmem/
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### pmem_kinds.c
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This example shows how to create and destroy pmem kind with defined or unlimited size.
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### pmem_malloc.c
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This example shows how to allocate memory and possibility to exceed pmem kind size.
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### pmem_malloc_unlimited.c
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This example shows how to allocate memory with unlimited kind size.
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### pmem_usable_size.c
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This example shows difference between the expected and the actual allocation size.
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### pmem_alignment.c
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This example shows how to use memkind alignment and how it affects allocations.
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### pmem_multithreads.c
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This example shows how to use multithreading with independent pmem kinds.
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### pmem_multithreads_onekind.c
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This example shows how to use multithreading with one main pmem kind.
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### pmem_and_default_kind.c
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This example shows how to allocate in standard memory and file-backed memory (pmem kind).
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### pmem_free_with_unknown_kind.c
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This example shows how to allocate in standard memory and file-backed memory (pmem kind)
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and free memory without a need to remember which kind it belongs to.
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### pmem_cpp_allocator.cpp
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This example shows usage of C++ allocator mechanism designed for file-backed memory
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kind with different data structures like: vector, list and map.
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## Other memkind examples
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The simplest example is the hello_example.c which is a hello world
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variant. The filter_example.c shows how you would use high bandwidth
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memory to store a reduction of a larger data set stored in DDR. There is
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also an example of how to create user defined kinds. This example
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creates kinds which isolate allocations to a single NUMA node each
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backed by a single arena.
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The memkind_allocated example is simple usage of memkind in C++11 which
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shows how memkind can be used to allocate objects, and consists of two files:
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memkind_allocated.hpp - which is definition of template class that should be
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inherited and parametrized by derived type (curiously recurring template
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pattern), to let deriving class allocate their objects using specified kind.
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memkind_allocated_example.cpp - which is usage example of this approach.
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Logic of memkind_allocated is based on overriding operator new() in template,
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and allocating memory on kind specified in new() parameter, or by overridable
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static method getClassKind(). This implementation also supports alignment
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specifier's (alignas() - new feature in C++11).
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The downside of this approach is that it will work properly only if
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memkind_allocated template is inherited once in inheritance chain (which
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probably makes that not very useful for most scenarios). Other thing is that it
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overriding class new() operator which can cause various problems if used
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unwisely.
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