Home

Allocators

An allocator is a software component responsible for reserving and releasing resources, most often memory, within a program or system. In memory management, an allocator obtains blocks of memory from a larger pool and hands them to clients, while reclaiming memory when it is no longer needed. Effective allocators minimize overhead and fragmentation, provide predictable performance, and preserve alignment requirements for data types.

Common allocator classes include stack allocators, which allocate memory in a last-in, first-out fashion and release

In programming languages, allocators are often exposed as abstractions: in C++, the allocator concept describes how

Design goals include fast allocation/deallocation, minimal fragmentation, thread safety, alignment guarantees, and predictable latency. Trade-offs exist

Allocators are central to systems programming, game engines, real-time applications, and memory-constrained environments. They are less

it
when
the
current
scope
ends;
heap
or
free‑list
allocators,
which
manage
a
general
pool
of
variable-sized
blocks;
pool
allocators,
which
allocate
objects
of
fixed
size
from
preallocated
chunks;
arena
allocators,
which
bulk‑allocate
and
then
free
an
entire
region;
and
slab
allocators,
which
cache
objects
per
type
to
reduce
fragmentation
and
improve
locality.
Modern
general‑purpose
allocators
such
as
jemalloc,
tcmalloc,
and
nedmalloc
implement
sophisticated
strategies
to
balance
speed,
fragmentation,
and
multi‑threading.
Some
systems
use
region
or
arena
allocation
to
batch
releases.
containers
request
memory;
in
Rust,
allocator
APIs
are
defined
by
the
GlobalAlloc
trait
and
related
interfaces,
with
evolving
support
for
custom
allocators.
between
speed
and
fragmentation
control,
and
between
per‑allocation
metadata
overhead
and
usable
memory.
Debugging
tools
and
memory
profilers
help
detect
leaks
and
corruption.
relevant
in
managed
languages
with
built‑in
garbage
collection,
though
those
runtimes
still
implement
their
own
allocation
hierarchies.
Proper
selection
and
tuning
of
an
allocator
can
yield
noticeable
performance
improvements.