GNU Info

(libc.info)Obstacks

---

Next: Variable Size Automatic Prev: Allocation Debugging Up: Memory Allocation

---

Enter node , (file) or (file)node

Obstacks
--------

   An "obstack" is a pool of memory containing a stack of objects.  You
can create any number of separate obstacks, and then allocate objects in
specified obstacks.  Within each obstack, the last object allocated must
always be the first one freed, but distinct obstacks are independent of
each other.

   Aside from this one constraint of order of freeing, obstacks are
totally general: an obstack can contain any number of objects of any
size.  They are implemented with macros, so allocation is usually very
fast as long as the objects are usually small.  And the only space
overhead per object is the padding needed to start each object on a
suitable boundary.

Creating Obstacks

How to declare an obstack in your program.

Preparing for Obstacks

Preparations needed before you can

use obstacks.

Allocation in an Obstack

Allocating objects in an obstack.

Freeing Obstack Objects

Freeing objects in an obstack.

Obstack Functions

The obstack functions are both

functions and macros.

Growing Objects

Making an object bigger by stages.

Extra Fast Growing

Extra-high-efficiency (though more

complicated) growing objects.

Status of an Obstack

Inquiries about the status of an obstack.

Obstacks Data Alignment

Controlling alignment of objects in obstacks.

Obstack Chunks

How obstacks obtain and release chunks;

efficiency considerations.

Summary of Obstacks