roc::core::HeapArena Class Reference

Heap arena implementation. More...

#include <heap_arena.h>

Inheritance diagram for roc::core::HeapArena:

Collaboration diagram for roc::core::HeapArena:

Public Member Functions
	HeapArena ()
	Initialize. More...
size_t	num_allocations () const
	Get number of allocated blocks. More...
size_t	num_guard_failures () const
	Get number of guard failures. More...
virtual void *	allocate (size_t size)
	Allocate memory. More...
virtual void	deallocate (void *ptr)
	Deallocate previously allocated memory. More...
virtual size_t	compute_allocated_size (size_t size) const
	Computes how many bytes will be actually allocated if allocate() is called with given size. Covers all internal overhead, if any. More...
virtual size_t	allocated_size (void *ptr) const
	Returns how many bytes was allocated for given pointer returned by allocate(). Covers all internal overhead, if any. Returns same value as computed by compute_allocated_size(size). More...
Public Member Functions inherited from roc::core::IArena
template<class T >
void	destroy_object (T &object)
	Destroy object and deallocate its memory. More...

Static Public Member Functions
static void	set_guards (size_t guards)
	Set enabled guards, for all instances. Parameters. More...

Detailed Description

Heap arena implementation.

Uses malloc() and free().

The memory is always maximum aligned.

Implements three safety measures:

• to catch double-free and other logical bugs, inserts link to owning arena before user data, and panics if it differs when memory is returned to arena
• to catch buffer overflow bugs, inserts "canary guards" before and after user data, and panics if they are overwritten when memory is returned to arena
• to catch uninitialized-access and use-after-free bugs, "poisons" memory when it returned to user, and when it returned back to the arena

Allocated chunks have the following format:

+-------------+-------------+-----------+-------------+
| ChunkHeader | ChunkCanary | user data | ChunkCanary |
+-------------+-------------+-----------+-------------+

ChunkHeader contains pointer to the owning arena, checked when returning memory to arena. ChunkCanary contains magic bytes filled when returning memory to user, and checked when returning memory to arena.

Thread-safe.

Definition at line 65 of file heap_arena.h.

Constructor & Destructor Documentation

HeapArena()

roc::core::HeapArena::HeapArena

(

)

Initialize.

Member Function Documentation

allocate()

virtual void* roc::core::HeapArena::allocate ( size_t  size )

virtual

Allocate memory.

Implements roc::core::IArena.

allocated_size()

virtual size_t roc::core::HeapArena::allocated_size ( void *  ptr ) const

virtual

Returns how many bytes was allocated for given pointer returned by allocate(). Covers all internal overhead, if any. Returns same value as computed by compute_allocated_size(size).

Implements roc::core::IArena.

compute_allocated_size()

virtual size_t roc::core::HeapArena::compute_allocated_size ( size_t  size ) const

virtual

Computes how many bytes will be actually allocated if allocate() is called with given size. Covers all internal overhead, if any.

Implements roc::core::IArena.

deallocate()

virtual void roc::core::HeapArena::deallocate ( void *  ptr )

virtual

Deallocate previously allocated memory.

Implements roc::core::IArena.

num_allocations()

size_t roc::core::HeapArena::num_allocations

(

)

const

Get number of allocated blocks.

num_guard_failures()

size_t roc::core::HeapArena::num_guard_failures

(

)

const

Get number of guard failures.

set_guards()

static void roc::core::HeapArena::set_guards ( size_t  guards )

static

Set enabled guards, for all instances. Parameters.

• guards defines options to modify behaviour as indicated in HeapArenaGuard

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

• roc_core/heap_arena.h