BIN(2)BIN(2)
NAME
binalloc, bingrow, binfree – grouped memory allocation
SYNOPSIS
#include <u.h>
#include <libc.h>
#include <bin.h>
typedef struct Bin Bin;
void *binalloc(Bin **bp, ulong size, int clr);
void *bingrow(Bin **bp, void *op, ulong osize,
ulong size, int clr);
void binfree(Bin **bp);
DESCRIPTION
These routines provide simple grouped memory allocation and deallocation.
Items allocated with
binalloc
are added to the
Bin
pointed to by
bp.
All items in a bin may be freed with one call to
binfree;
there is no way to free a single item.
Binalloc
returns a pointer to a new block of at least
size
bytes.
The block is suitably aligned for storage of any type of object.
No two active pointers from
binalloc
will have the same value.
The call
binalloc(0)
returns a valid pointer rather than null.
If
clr
is non-zero, the allocated memory is set to 0;
otherwise, the contents are undefined.
Bingrow
is used to extend the size of a block of memory returned by
binalloc.
Bp
must point to the same bin group used to allocate the original block,
and
osize
must be the last size used to allocate or grow the block.
A pointer to a block of at least
size
bytes is returned, with the same contents in the first
osize
locations.
If
clr
is non-zero, the remaining bytes are set to 0,
and are undefined otherwise.
If
op
is
nil,
it and
osize
are ignored, and the result is the same as calling
binalloc.
Binalloc
and
bingrow
allocate large chunks of memory using
malloc(2)
and return pieces of these chunks.
The chunks are
free’d
upon a call to
binfree.
SOURCE
/sys/src/libbin
SEE
malloc(2)
DIAGNOSTICS
binalloc
and
bingrow
return 0 if there is no available memory.