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