The
vmem
is a general purpose resource allocator.
Despite its name, it can be used for arbitrary resources
other than virtual memory.
vmem_create()
creates a new vmem arena.
|
| name
|
| |
The string to describe the vmem.
|
| base
|
| |
The start address of the initial span.
Pass
0
if no initial span is required.
|
| size
|
| |
The size of the initial span.
Pass
0
if no initial span is required.
|
| quantum
|
| |
The smallest unit of allocation.
|
| qcache_max
|
| |
The largest size of allocations which can be served by quantum cache.
It is merely a hint and can be ignored.
|
| flags
|
| |
malloc(9)
wait flag.
|
|
vmem_add()
adds a span of size
size
starting at
addr
to the arena.
Returns
0
on success,
ENOMEM
on failure.
flags
is
malloc(9)
wait flag.
vmem_xalloc()
allocates a resource from the arena.
| vm
|
| |
The arena which we allocate from.
|
| size
|
| |
Specify the size of the allocation.
|
| align
|
| |
If zero, don't care about the alignment of the allocation.
Otherwise, request a resource segment starting at
offset
phase
from an
align
aligned boundary.
|
| phase
|
| |
See the above description of
align.
If
align
is zero,
phase
should be zero.
Otherwise,
phase
should be smaller than
align.
|
| nocross
|
| |
Request a resource which doesn't cross
nocross
aligned boundary.
|
| minaddr
|
| |
Specify the minimum address which can be allocated, or
VMEM_ADDR_MIN
if the caller does not care.
|
| maxaddr
|
| |
Specify the maximum address which can be allocated, or
VMEM_ADDR_MAX
if the caller does not care.
|
| flags
|
| |
A bitwise OR of an allocation strategy and a
malloc(9)
wait flag.
The allocation strategy is one of:
|
|
| M_FIRSTFIT
|
Prefer allocation performance.
|
| M_BESTFIT
|
Prefer space efficiency.
|
| M_NEXTFIT
|
Perform an address-ordered search for free addresses, beginning where
the previous search ended.
|
|
| addrp
|
On success, if
addrp
is not
NULL,
vmem_xalloc()
overwrites it with the start address of the allocated span.
|
|
vmem_xfree()
frees resource allocated by
vmem_xalloc()
to the arena.
| vm
|
| |
The arena which we free to.
|
| addr
|
| |
The resource being freed.
It must be the one returned by
vmem_xalloc().
Notably, it must not be the one from
vmem_alloc().
Otherwise, the behaviour is undefined.
|
| size
|
| |
The size of the resource being freed.
It must be the same as the
size
argument used for
vmem_xalloc().
|
|
vmem_alloc()
allocates a resource from the arena.
| vm
|
| |
The arena which we allocate from.
|
| size
|
| |
Specify the size of the allocation.
|
| flags
|
| |
A bitwise OR of an
vmem
allocation strategy flag (see above) and a
malloc(9)
sleep flag.
|
| addrp
|
| |
On success, if
addrp
is not
NULL,
vmem_alloc()
overwrites it with the start address of the allocated span.
|
|
vmem_free()
frees resource allocated by
vmem_alloc()
to the arena.
| vm
|
| |
The arena which we free to.
|
| addr
|
| |
The resource being freed.
It must be the one returned by
vmem_alloc().
Notably, it must not be the one from
vmem_xalloc().
Otherwise, the behaviour is undefined.
|
| size
|
| |
The size of the resource being freed.
It must be the same as the
size
argument used for
vmem_alloc().
|
|
vmem_destroy()
destroys a vmem arena.
| vm
|
| |
The vmem arena being destroyed.
The caller should ensure that no one will use it anymore.
|
|
