iffl::debug_memory_resource Class Reference

implements std::pmr::memory_resource interface. More...

#include <iffl_allocator.h>

Inheritance diagram for iffl::debug_memory_resource:

Public Member Functions
	~debug_memory_resource () noexcept
	Destructor triggers fail fast if there are outstanding allocations.
size_t	get_busy_blocks_count () const noexcept
	Can be used to query number of outstanding allocations. More...
void	validate_no_busy_blocks () const noexcept
	Triggers fail fast if there are outstanding allocations.

Detailed Description

implements std::pmr::memory_resource interface.

This class can be used with Polymorphic Memory Allocator. Forward Linked List has typedef for PMR called pmr_flat_forward_list.

Sample usage:

iffl::debug_memory_resource dbg_memory_resource;
iffl::pmr_flat_forward_list<FLAT_FORWARD_LIST_TEST> ffl{ &dbg_memory_resource };

Code should guarantee that memory resource is destroyed after all memory allocated from this allocator is deallocated.

This class provides:

• Basic buffer overrun and under-run detection by putting a well known patters at the end and at the beginning of the buffer. At deallocation time patterns we check that patterns did not change
• Detection that deallocation is done using same memory resource as allocation. Allocation header contains pointer to the memory resource. At deallocation time we check that pointer matches to the object that is deallocating memory.
• Helps detecting when objects use memory without previously initializing it. Allocate memory is filled with value that would trigger access violation if used as a pointer without initialization
• Basic memory leak and lifetime management issues by counting number of outstanding allocations. At memory resource destruction time we check that there are no outstanding allocations. Table below describes layout of each allocated block.

--------------------------------------------------------------------------------------------------------------------
|sizeof(size_t) bytes | pointer to | sizeof(size_t) prefix          | user data   | sizeof(size_t) suffix          |
|offset to the end of | memory     | 0xBEEFABCD - allocated block   | filled with | 0xDEADABCD - allocated block   |
|allocation           | resource   | 0xBEEFABCE - deallocated block | 0xFE        | 0xDEADABCE - deallocated block |
--------------------------------------------------------------------------------------------------------------------

Member Function Documentation

get_busy_blocks_count()

size_t iffl::debug_memory_resource::get_busy_blocks_count ( ) const

inlinenoexcept

Can be used to query number of outstanding allocations.

Returns

number of outstanding allocations

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

• include/iffl_allocator.h