term% cat index.txt BIN(2) System Calls Manual BIN(2)
NAME
binalloc, bingrow, binfree - grouped memory allocation
SYNOPSIS
#include <u.h>
#include <libc.h>
#include <bin.h>
typedef struct BinBin;
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 dealloca‐
tion. 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 bi‐
nalloc(0) returns a valid pointer rather than null. If clr is non-
zero, the allocated memory is set to 0; otherwise, the contents are un‐
defined.
Bingrow is used to extend the size of a block of memory returned by bi‐
nalloc. Bp must point to the same bin group used to allocate the orig‐
inal 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 ALSO
malloc(2)
DIAGNOSTICS
binalloc and bingrow return 0 if there is no available memory.
BIN(2)