Allocators¶
The fundamental concept for accessing memory through Umpire is the
umpire::Allocator
. An umpire::Allocator
is a C++ object that
can be used to allocate and deallocate memory, as well as query a pointer to
get some extra information about it.
All umpire::Allocator
s are created and managed by Umpire’s
umpire::ResourceManager
. To get an Allocator, you need to ask for one:
auto& rm = umpire::ResourceManager::getInstance();
umpire::Allocator allocator = rm.getAllocator("HOST");
Once you have an umpire::Allocator
you can use it to allocate and deallocate memory:
double* data = static_cast<double*>(
allocator.allocate(SIZE*sizeof(double)));
std::cout << "Allocated " << (SIZE*sizeof(double)) << " bytes using the "
<< allocator.getName() << " allocator...";
allocator.deallocate(data);
In the next section, we will see how to allocate memory using different resources.
//////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2018-2019, Lawrence Livermore National Security, LLC.
// Produced at the Lawrence Livermore National Laboratory
//
// Created by David Beckingsale, david@llnl.gov
// LLNL-CODE-747640
//
// All rights reserved.
//
// This file is part of Umpire.
//
// For details, see https://github.com/LLNL/Umpire
// Please also see the LICENSE file for MIT license.
//////////////////////////////////////////////////////////////////////////////
#include "umpire/Allocator.hpp"
#include "umpire/ResourceManager.hpp"
int main(int, char**) {
constexpr size_t SIZE = 1024;
auto& rm = umpire::ResourceManager::getInstance();
umpire::Allocator allocator = rm.getAllocator("HOST");
double* data = static_cast<double*>(
allocator.allocate(SIZE*sizeof(double)));
std::cout << "Allocated " << (SIZE*sizeof(double)) << " bytes using the "
<< allocator.getName() << " allocator...";
allocator.deallocate(data);
std::cout << " deallocated." << std::endl;
return 0;
}