Generic allocators

Sometimes, we want to define data structures, whose memory allocation can be parametrized. If we wish to squeeze out the last bit of performance, we tie the structure to a certain allocator in compile time (as we do for hash tables). If performance is not so critical, allocators can be swapped in run time.

This module defines a generic interface to memory allocators. You can use the following pre-defined allocators, or define some of your own.

Standard malloc-based allocator
Zeroing malloc-based allocator
Memory pools

These data structures accept an allocator (more will come later):

Growing arrays

ucw/alloc.h

struct ucw_allocator {
  void * (*alloc)(struct ucw_allocator *alloc, size_t size);
  void * (*realloc)(struct ucw_allocator *alloc, void *ptr, size_t old_size, size_t new_size);
  void (*free)(struct ucw_allocator *alloc, void *ptr);
};

This structure describes a generic allocator. It provides pointers to three functions, which handle the actual (re)allocations.

extern struct ucw_allocator ucw_allocator_std;

This allocator uses xmalloc(), xrealloc() and xfree(). The memory it allocates is left unitialized.

extern struct ucw_allocator ucw_allocator_zeroed;

This allocator uses xmalloc(), xrealloc() and xfree(). All memory is zeroed upon allocation.