libcruft-util/test/pool.cpp

#include <cruft/util/pool.hpp>

#include <cruft/util/tap.hpp>
#include <cruft/util/random.hpp>

#include <set>
#include <vector>
#include <algorithm>


//-----------------------------------------------------------------------------
void
check_single (cruft::TAP::logger &tap)
{
    // Ensure a single element doesn't break the circular linked list
    cruft::pool<uint64_t> single(1);
    tap.expect_nothrow ([&] {
        single.deallocate (single.allocate ());
    }, "single element acquire-release");
}


//-----------------------------------------------------------------------------
void
check_unique_ptr (cruft::TAP::logger &tap)
{
    constexpr std::size_t element_count = 1025;
    cruft::pool<uint64_t> uintpool (element_count);
    std::set<uint64_t *> uintset;

    // Take all pointers out, checking they are unique, then replace for destruction.
    while (!uintpool.full ())
        uintset.insert (uintpool.allocate ());

    tap.expect_eq (uintset.size (), uintpool.capacity (), "extracted maximum elements");

    for (auto i: uintset)
        uintpool.deallocate (i);

    tap.expect_eq (uintpool.size (), 0u, "re-inserted maximum elements");
    uintset.clear ();

    // Do the above one more time to ensure that releasing works right
    while (!uintpool.full ())
        uintset.insert (uintpool.allocate ());
    tap.expect_eq (uintset.size (), uintpool.capacity (), "re-extracted maximum elements");
}


//-----------------------------------------------------------------------------
// Test that every element in a pool points to a unique location.
void
check_keep_value (cruft::TAP::logger &tap)
{
    // Allocate a source pool, and a storage vector.
    cruft::pool<std::size_t > uintpool (64);
    std::vector<std::size_t*> uintvector;
    uintvector.reserve(uintpool.capacity ());

    // Generate a list of pointers to ints, then fill them with sequential values.
    //
    // Do this as a two step process rather than all at once. This separates
    // the concerns of performing the allocation from whether the allocation
    // points to a safe area. There's a tendency for the pool and vector to be
    // adjacent in memory and overruns in the former impact the latter.
    std::generate_n (
        std::back_inserter (uintvector),
        uintpool.capacity (),
        [&] () { return uintpool.allocate (); }
    );

    for (std::size_t i = 0; i < uintpool.capacity (); ++i)
        *uintvector[i] = i;

    CHECK_EQ (uintvector.size (), uintpool.capacity ());

    // Ensure they're all still present
    std::vector<bool> present(uintpool.capacity (), false);
    for (auto i = uintvector.begin (); i != uintvector.end (); ++i) {
        CHECK (**i < uintpool.capacity ());
        CHECK (present[**i] != true);

        present[**i] = true;
    }

    // All must have been marked as present...
    tap.expect (std::find (present.begin (), present.end (), false) == present.end (), "values retained");

    // Release all back into the pool for destruction
    //for (auto i = uintvector.begin (); i != uintvector.end (); ++i)
    //    uintpool.release (*i);
    //uintvector.clear ();
}


//-----------------------------------------------------------------------------
void
check_keep_variadic_value (cruft::TAP::logger &tap)
{
    struct foo_t {
        foo_t (uint64_t _a, uint64_t _b, uint64_t _c, uint64_t _d):
            a (_a),
            b (_b),
            c (_c),
            d (_d)
        { ; }

        uint64_t a, b, c, d;
    };

    cruft::pool<foo_t> alloc (512);

    bool success = true;

    for (uint64_t a = 0; a < 8; ++a)
        for (uint64_t b = 0; b < 8; ++b)
            for (uint64_t c = 0; c < 8; ++c) {
                uint64_t d = (a << 24) | (b << 16) | (c << 8);
                auto ptr = alloc.construct (a, b, c, d);

                if (ptr->a != a || ptr->b != b || ptr->c != c || ptr->d != d) {
                    success = false;
                    goto done;
                }
            }

done:
    tap.expect (success, "variadiac construction retains values");
}


//-----------------------------------------------------------------------------
void
check_size_queries (cruft::TAP::logger &tap)
{
    cruft::pool<int> data (8);

    tap.expect_eq (data.size (), 0u, "initial size is zero");
    tap.expect (data.empty (),  "initial object is empty");

    auto first = data.allocate ();
    tap.expect_eq (data.size (), 1u, "1 allocation has size of 1");
    tap.expect (!data.empty (), "1 allocation is not empty");

    data.deallocate (first);
    tap.expect (data.empty (), "full deallocation is empty");
}


//-----------------------------------------------------------------------------
static void
check_destructors (cruft::TAP::logger &tap)
{
    struct counter {
        counter (int *_target): target (_target) { ; }

        counter (counter const &) = delete;
        counter& operator= (counter const &) = delete;

        counter (counter &&) = delete;
        counter& operator= (counter &&) = delete;

        ~counter () { if (target) ++*target; }

        int *target;
    };

    int count = 0;
    int expected = 0;

    {
        cruft::pool<counter> data (8);
        auto *first = data.construct (&count);
        auto const *second = data.construct (&count);
        (void)second;

        CHECK_EQ (count, 0);

        data.destroy (first);
        ++expected;
        tap.expect_eq (count, expected, "destructors run on destroy");
    }

    expected++;
    tap.expect_eq (count, expected, "single destructor run on pool destructor");

    // Make an pool without allocations and destroy it. This isn't reported
    // via TAP, but is used as a sanity check that the destructor doesn't run
    // into infinite loops or other such problems.
    {
        cruft::pool<counter> data (8);
    }

    // Destroy a full pool
    {
        cruft::pool<counter> data (8);
        for (int i = 0; i < 8; ++i) {
            data.construct (&count);
            ++expected;
        }
    }

    tap.expect_eq (count, expected, "prestine full pool destructor triggers all data destructors");

    {
        cruft::pool<counter> data (8);
        counter* items[8];
        for (int i = 0; i < 8; ++i) {
            items[i] = data.construct (&count);
            ++expected;
        }

        for (int round = 0; round < 128; ++round) {
            auto idx = cruft::random::uniform (std::size (items) - 1);
            data.destroy (items[idx]);
            items[idx] = data.construct (&count);
            ++expected;
        }
    }

    tap.expect_eq (count, expected, "randomised full pool destructor triggers all data destructors");

    cruft::pool<int> data (100*1024);
    (void)data;
}


//-----------------------------------------------------------------------------
int
main (int, char **)
{
    return cruft::TAP::logger::run ([] (auto &tap) {
        check_single (tap);
        check_unique_ptr (tap);
        check_keep_value (tap);
        check_keep_variadic_value (tap);
        check_size_queries (tap);
        check_destructors (tap);
    });
}