sample::PerTreeMemoryExample Struct Reference

an example for a per-tree memory allocator More...

Public Member Functions
ryml::Callbacks	callbacks () const
void *	allocate (size_t len)
void	free (void *mem, size_t len)
	~PerTreeMemoryExample ()
void	check_and_reset ()

Public Attributes
std::vector< char >	memory_pool = std::vector<char>(10u * 1024u)
size_t	num_allocs = 0
size_t	alloc_size = 0
size_t	num_deallocs = 0
size_t	dealloc_size = 0

Detailed Description

an example for a per-tree memory allocator

Definition at line 4863 of file quickstart.cpp.

Constructor & Destructor Documentation

~PerTreeMemoryExample()

sample::PerTreeMemoryExample::~PerTreeMemoryExample ( )

inline

Definition at line 4905 of file quickstart.cpp.

    {
        check_and_reset();
    }

References check_and_reset().

Member Function Documentation

callbacks()

ryml::Callbacks sample::PerTreeMemoryExample::callbacks ( ) const

inline

Definition at line 4869 of file quickstart.cpp.

    {
        // Above we used static functions to bridge to our methods.
        // To show a different approach, we employ lambdas here.
        // Note that there can be no captures in the lambdas
        // because these are C-style function pointers.
        ryml::Callbacks cb;
        cb.m_user_data = (void*) this;
        cb.m_allocate = [](size_t len, void *, void *data){ return ((PerTreeMemoryExample*) data)->allocate(len); };
        cb.m_free = [](void *mem, size_t len, void *data){ return ((PerTreeMemoryExample*) data)->free(mem, len); };
        return cb;
    }

References allocate(), free(), c4::yml::Callbacks::m_allocate, c4::yml::Callbacks::m_free, and c4::yml::Callbacks::m_user_data.

Referenced by sample::sample_per_tree_allocator().

allocate()

void* sample::PerTreeMemoryExample::allocate ( size_t  len )

inline

Definition at line 4882 of file quickstart.cpp.

    {
        void *ptr = &memory_pool[alloc_size];
        alloc_size += len;
        ++num_allocs;
        if(C4_UNLIKELY(alloc_size > memory_pool.size()))
        {
            std::cerr << "out of memory! requested=" << alloc_size << " vs " << memory_pool.size() << " available" << std::endl;
            std::abort();
        }
        return ptr;
    }

References alloc_size, memory_pool, and num_allocs.

Referenced by callbacks().

free()

void sample::PerTreeMemoryExample::free ( void *  mem, size_t  len  )

inline

Definition at line 4895 of file quickstart.cpp.

    {
        CHECK((char*)mem     >= &memory_pool.front() && (char*)mem     <  &memory_pool.back());
        CHECK((char*)mem+len >= &memory_pool.front() && (char*)mem+len <= &memory_pool.back());
        dealloc_size += len;
        ++num_deallocs;
        // no need to free here
    }

References CHECK, dealloc_size, memory_pool, and num_deallocs.

Referenced by callbacks().

check_and_reset()

void sample::PerTreeMemoryExample::check_and_reset ( )

inline

Definition at line 4909 of file quickstart.cpp.

    {
        std::cout << "size: alloc=" << alloc_size << " dealloc=" << dealloc_size << std::endl;
        std::cout << "count: #allocs=" << num_allocs << " #deallocs=" << num_deallocs << std::endl;
        CHECK(num_allocs == num_deallocs);
        CHECK(alloc_size >= dealloc_size); // failure here means a double free
        CHECK(alloc_size == dealloc_size); // failure here means a leak
        num_allocs = 0;
        num_deallocs = 0;
        alloc_size = 0;
        dealloc_size = 0;
    }

References alloc_size, CHECK, dealloc_size, num_allocs, and num_deallocs.

Referenced by ~PerTreeMemoryExample().

Member Data Documentation

memory_pool

std::vector<char> sample::PerTreeMemoryExample::memory_pool = std::vector<char>(10u * 1024u)

Definition at line 4865 of file quickstart.cpp.

Referenced by allocate(), and free().

num_allocs

size_t sample::PerTreeMemoryExample::num_allocs = 0

Definition at line 4866 of file quickstart.cpp.

Referenced by allocate(), check_and_reset(), and sample::sample_per_tree_allocator().

alloc_size

size_t sample::PerTreeMemoryExample::alloc_size = 0

Definition at line 4866 of file quickstart.cpp.

Referenced by allocate(), check_and_reset(), and sample::sample_per_tree_allocator().

num_deallocs

size_t sample::PerTreeMemoryExample::num_deallocs = 0

Definition at line 4867 of file quickstart.cpp.

Referenced by check_and_reset(), and free().

dealloc_size

size_t sample::PerTreeMemoryExample::dealloc_size = 0

Definition at line 4867 of file quickstart.cpp.

Referenced by check_and_reset(), and free().

---

The documentation for this struct was generated from the following file:

• /home/docs/checkouts/readthedocs.org/user_builds/rapidyaml/checkouts/v0.7.0/samples/quickstart.cpp