pageResourceExample.cpp

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/**
 * @file
 * @copyright
 *   SPDX-FileCopyrightText: 2025-2025 European Southern Observatory (ESO)
 *
 *   SPDX-License-Identifier: LGPL-3.0-only
 */
#include <string>
#include <vector>
 
#include <numapp/memory.hpp>
 
void Example() {
    // Create a pool resource that allocates memory from NUMA node 1 with using
    // PageResource.
    auto resource = numapp::PageResource(numapp::MemPolicy::MakeBindNode(1),
                                         numapp::MemPolicyFlag::Strict);
 
    // Important Note
    // --------------
    //
    // Pool resource likely requires memory for its implementation, which will
    // use the same upstream memory resource `resource`. This is not necessarily
    // optimal as the pool implementation may perform multiple allocations, each
    // smaller than the page size, which will each take at minimum 1 page. This
    // overhead may be discounted by example sharing the pool resource for the
    // full application, or per NUMA node.
    auto pool = std::pmr::unsynchronized_pool_resource(&resource);
 
    // Now we can use the `pool` with e.g. STL containers that use
    // `std::pmr::polymorphic_allocator`
    [[maybe_unused]] auto vector = std::pmr::vector<std::uint8_t>(1024, &pool);
    [[maybe_unused]] auto string = std::pmr::string(1024, 'a', &pool);
}