FPPS4/sys/vm/vm_object.pas

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unit vm_object;
{$mode ObjFPC}{$H+}
{$CALLING SysV_ABI_CDecl}
interface
uses
mqueue,
vm,
kern_mtx;
type
obj_type=(
OBJT_DEFAULT,
OBJT_VNODE,
OBJT_DMEM,
OBJT_DEAD);
objtype_t=obj_type;
p_vm_object_t=^vm_object_t;
vm_object_t=^_vm_object;
_vm_object=packed record
mtx:mtx;
memq:TAILQ_HEAD; // list of resident pages
root:Pointer; // root of the resident page splay tree
size:vm_pindex_t; // Object size
generation:Integer; // generation ID
ref_count:Integer; // How many refs??
otype:objtype_t; // type of pager
flags:Word; // see below
handle:Pointer;
paging_in_progress:Integer;
un_pager:packed record
vnp:packed record
vnp_size:QWORD;
writemappings:vm_ooffset_t;
end;
end;
end;
const
//Flags
OBJ_ACTIVE =$0004; // active objects
OBJ_DEAD =$0008; // dead objects (during rundown)
OBJ_NOSPLIT =$0010; // dont split this object
OBJ_PIPWNT =$0040; // paging in progress wanted
OBJ_MIGHTBEDIRTY =$0100; // object might be dirty, only for vnode
OBJ_COLORED =$1000; // pg_color is defined
OBJ_ONEMAPPING =$2000; // One USE (a single, non-forked) mapping flag
OBJ_DISCONNECTWNT=$4000; // disconnect from vnode wanted
OBJPC_SYNC =$1; // sync I/O
OBJPC_INVAL =$2; // invalidate
OBJPC_NOSYNC=$4; // skip if PG_NOSYNC
//The following options are supported by vm_object_page_remove().
OBJPR_CLEANONLY=$1; // Don't remove dirty pages.
OBJPR_NOTMAPPED=$2; // Don't unmap pages.
OBJPR_NOTWIRED =$4; // Don't remove wired pages.
procedure vm_object_reference (_object:vm_object_t);
function vm_object_allocate (t:objtype_t;size:vm_pindex_t):vm_object_t;
procedure vm_object_deallocate(_object:vm_object_t);
procedure vm_object_clear_flag(_object:vm_object_t;bits:Word);
procedure vm_object_pip_add(_object:vm_object_t;i:word);
procedure vm_object_pip_subtract(_object:vm_object_t;i:word);
procedure vm_object_pip_wakeup(_object:vm_object_t);
procedure VM_OBJECT_LOCK (_object:vm_object_t);
function VM_OBJECT_TRYLOCK(_object:vm_object_t):Boolean;
procedure VM_OBJECT_UNLOCK (_object:vm_object_t);
function VM_OBJECT_LOCKED (_object:vm_object_t):Boolean;
procedure VM_OBJECT_LOCK_ASSERT(_object:vm_object_t);
function IDX_TO_OFF(x:DWORD):QWORD; inline;
function OFF_TO_IDX(x:QWORD):DWORD; inline;
function vm_object_coalesce(prev_object:vm_object_t;
prev_offset:vm_ooffset_t;
prev_size :vm_ooffset_t;
next_size :vm_ooffset_t;
reserved :Boolean):Boolean;
implementation
uses
vmparam;
function IDX_TO_OFF(x:DWORD):QWORD; inline;
begin
Result:=QWORD(x) shl PAGE_SHIFT;
end;
function OFF_TO_IDX(x:QWORD):DWORD; inline;
begin
Result:=QWORD(x) shr PAGE_SHIFT;
end;
procedure VM_OBJECT_LOCK(_object:vm_object_t);
begin
mtx_lock(_object^.mtx);
end;
function VM_OBJECT_TRYLOCK(_object:vm_object_t):Boolean;
begin
Result:=mtx_trylock(_object^.mtx);
end;
procedure VM_OBJECT_UNLOCK(_object:vm_object_t);
begin
mtx_unlock(_object^.mtx);
end;
function VM_OBJECT_LOCKED(_object:vm_object_t):Boolean;
begin
Result:=(mtx_owned(_object^.mtx));
end;
procedure VM_OBJECT_LOCK_ASSERT(_object:vm_object_t);
begin
Assert(mtx_owned(_object^.mtx));
end;
procedure vm_object_clear_flag(_object:vm_object_t;bits:Word);
begin
VM_OBJECT_LOCK_ASSERT(_object);
_object^.flags:=_object^.flags and (not bits);
end;
function vm_object_allocate(t:objtype_t;size:vm_pindex_t):vm_object_t;
begin
Result:=AllocMem(SizeOf(_vm_object));
mtx_init(Result^.mtx);
TAILQ_INIT(@Result^.memq);
Result^.otype :=t;
Result^.size :=size;
Result^.generation:=1;
Result^.ref_count :=1;
end;
procedure _vm_object_deallocate(_object:vm_object_t);
begin
Case _object^.otype of
OBJT_DEFAULT:;
OBJT_VNODE :;
OBJT_DMEM :;
OBJT_DEAD :;
end;
mtx_destroy(_object^.mtx);
FreeMem(_object);
end;
procedure vm_object_reference(_object:vm_object_t);
begin
if (_object=nil) then Exit;
System.InterlockedIncrement(_object^.ref_count);
end;
procedure vm_object_deallocate(_object:vm_object_t);
begin
if (_object=nil) then Exit;
if (System.InterlockedDecrement(_object^.ref_count)=0) then
begin
_vm_object_deallocate(_object);
end;
end;
procedure vm_object_destroy(_object:vm_object_t);
begin
vm_object_deallocate(_object);
end;
procedure vm_object_pip_add(_object:vm_object_t;i:word);
begin
if (_object=nil) then Exit;
VM_OBJECT_LOCK_ASSERT(_object);
_object^.paging_in_progress:=_object^.paging_in_progress+i;
end;
procedure vm_object_pip_subtract(_object:vm_object_t;i:word);
begin
if (_object=nil) then Exit;
VM_OBJECT_LOCK_ASSERT(_object);
_object^.paging_in_progress:=_object^.paging_in_progress-i;
end;
procedure vm_object_pip_wakeup(_object:vm_object_t);
begin
if (_object=nil) then Exit;
VM_OBJECT_LOCK_ASSERT(_object);
Dec(_object^.paging_in_progress);
if ((_object^.flags and OBJ_PIPWNT)<>0) and (_object^.paging_in_progress=0) then
begin
vm_object_clear_flag(_object, OBJ_PIPWNT);
//wakeup(_object);
end;
end;
procedure vm_object_page_remove(_object:vm_object_t;
start:vm_pindex_t;
__end:vm_pindex_t;
options:Integer);
begin
end;
procedure vm_object_collapse(_object:vm_object_t);
begin
//
end;
function vm_object_coalesce(prev_object:vm_object_t;
prev_offset:vm_ooffset_t;
prev_size :vm_ooffset_t;
next_size :vm_ooffset_t;
reserved :Boolean):Boolean;
var
next_pindex:vm_pindex_t;
begin
if (prev_object=nil) then Exit(TRUE);
VM_OBJECT_LOCK(prev_object);
if (prev_object^.otype<>OBJT_DEFAULT) then
begin
VM_OBJECT_UNLOCK(prev_object);
Exit(FALSE);
end;
{
* Try to collapse the object first
}
vm_object_collapse(prev_object);
prev_size:=prev_size shr PAGE_SHIFT;
next_size:=next_size shr PAGE_SHIFT;
next_pindex:=OFF_TO_IDX(prev_offset) + prev_size;
if (prev_object^.ref_count > 1) and
(prev_object^.size<>next_pindex) then
begin
VM_OBJECT_UNLOCK(prev_object);
Exit(FALSE);
end;
{
* Remove any pages that may still be in the object from a previous
* deallocation.
}
if (next_pindex<prev_object^.size) then
begin
vm_object_page_remove(prev_object,next_pindex,next_pindex+next_size,0);
end;
{
* Extend the object if necessary.
}
if (next_pindex + next_size > prev_object^.size) then
prev_object^.size:=next_pindex + next_size;
VM_OBJECT_UNLOCK(prev_object);
Result:=(TRUE);
end;
end.