Skip to content

Commit

Permalink
[fix] db: memory leek on read transactions
Browse files Browse the repository at this point in the history
  • Loading branch information
Raja committed Jul 1, 2011
1 parent 114c5ec commit 017973e
Show file tree
Hide file tree
Showing 3 changed files with 43 additions and 59 deletions.
6 changes: 3 additions & 3 deletions database/badop_local.ml
View file
Expand Up @@ -145,17 +145,17 @@ type 'which write_op = ('which,transaction,revision) Badop.generic_write_op

let write trans path op k = match op with
| Badop.Set (D.Query data as q) ->
Badop.Set (D.Dialog_aux.respond q { trans with tr = Session.set trans.tr path data }) |> k
Badop.Set (D.Dialog_aux.respond q { trans with tr = Session.set trans.db.session trans.tr path data }) |> k
| Badop.Clear (D.Query () as q) ->
Badop.Clear
(D.Dialog_aux.respond q
(try
{ trans with tr = Session.remove trans.tr path }
{ trans with tr = Session.remove trans.db.session trans.tr path }
with Hldb.UnqualifiedPath -> trans)) |> k
| Badop.Link (D.Query linkpath as q) ->
Badop.Link
(D.Dialog_aux.respond q
{ trans with tr = Session.set_link trans.tr path linkpath }) |> k
{ trans with tr = Session.set_link trans.db.session trans.tr path linkpath }) |> k
| Badop.Copy (D.Query (copypath,copyrev) as q) ->
Badop.Copy
(D.Dialog_aux.respond q
Expand Down
90 changes: 37 additions & 53 deletions database/db3/session.ml
View file
Expand Up @@ -31,6 +31,12 @@ module DT = DbTypes
module List = BaseList
module Tr = Transaction

module WIM = Weak.Make(struct
type t = Tr.t
let equal a b = compare (Tr.get_num a) (Tr.get_num b) = 0
let hash = Tr.get_num
end)

(* The queue of transaction numbers, stored in order of appearance,
helps in choosing the next prepare to do (the longest waiting).
TODO: it's imperative; perhaps do this functionally? *)
Expand All @@ -53,7 +59,7 @@ module DT = DbTypes

type t = { mutable trans_num : int
(* counter for fresh transaciton serial numbers *)
; mutable init_map : (int list) intmap
; init_map : WIM.t
(* map of the not commited and not rolled back transactions
initialised under given revisions; no empty lists allowed;
used only for optimization, to shorten db_to_merge *)
Expand Down Expand Up @@ -251,7 +257,7 @@ module DT = DbTypes
| e -> raise (Open (None, Printexc.to_string e)) in
let db = Hldb.make () in
{ trans_num = 0
; init_map = IntMap.empty
; init_map = WIM.create 11
; db_ref = db
; db_to_merge = IntMap.empty
; with_dot = false
Expand Down Expand Up @@ -580,50 +586,30 @@ module DT = DbTypes
#<End>;
let tr =
match tr_read_only with
| Some read_only -> Tr.init t.db_ref ~read_only trans_num
| None -> Tr.init t.db_ref trans_num
| Some read_only -> Tr.init t.db_ref ~read_only trans_num
| None -> Tr.init t.db_ref trans_num
in

match read_only with
| Some (true, _) ->
tr
| _ ->
let rev = Hldb.get_rev t.db_ref in
let vrev = Revision.value rev in
let new_map =
let new_list =
match IntMap.find_opt vrev t.init_map with
| Some l -> trans_num :: l
| None -> [trans_num]
in
IntMap.add vrev new_list t.init_map
in
t.init_map <- new_map;
tr

let remove_from_init_map trans init_map =
let trans_rev = Hldb.get_rev (Tr.get_db trans) in
let t_num = Tr.get_num trans in
let vrev = Revision.value trans_rev in
let l = IntMap.find vrev init_map in
let l = List.remove_all t_num l in
if List.is_empty l then
(* no empty lists allowed *)
IntMap.remove vrev init_map
else
IntMap.add vrev l init_map
| Some (true, _) -> tr
| _ -> WIM.add t.init_map tr; tr

let shrink_db_to_merge t =
if (IntMap.is_empty t.db_to_merge
|| IntMap.is_empty t.init_map)
|| WIM.count t.init_map = 0)
then
IntMap.empty
else
let (min, _) = IntMap.min t.db_to_merge in
let (min_used, _) = IntMap.min t.init_map in
let rm k _v acc =
if IntMap.mem k acc then IntMap.remove k acc
else acc
in
let min_used =
(WIM.fold
(fun tr acc ->
if acc = -1 then
(Revision.value (Hldb.get_rev (Tr.get_db tr)))
else
(Pervasives.min acc (Revision.value (Hldb.get_rev (Tr.get_db tr)))))
t.init_map (-1)) in
let rm k _v acc = IntMap.remove k acc in
IntMap.fold_range rm t.db_to_merge min min_used t.db_to_merge

let abort_of_unprepared t _trans =
Expand Down Expand Up @@ -670,8 +656,7 @@ module DT = DbTypes
let trans_rev = Hldb.get_rev (Tr.get_db trans) in
let t_num = Tr.get_num trans in
let vrev = Revision.value trans_rev in
let l = IntMap.find_opt vrev t.init_map in
if not (Option.default_map false (List.mem t_num) l) then begin
if not (WIM.mem t.init_map trans) then begin
#<If>
Logger.log ~color:`magenta
"DB : transaction %d at revision %d has already been comitted or aborted. Cannot prepare it again." t_num vrev
Expand Down Expand Up @@ -774,8 +759,7 @@ module DT = DbTypes
(* Not removed from init_map, because at the higher level
it may be wiped up and rebuilt differently, so it still exists. *)
end else begin
let new_map = remove_from_init_map trans t.init_map in
t.init_map <- new_map;
WIM.remove t.init_map trans;
t.db_to_merge <- shrink_db_to_merge t;
(* Release the lock. *)
t.session_lock <- None;
Expand All @@ -793,11 +777,10 @@ module DT = DbTypes
let success =
try
assert (Tr.get_num transl = Tr.get_num trans);
let new_map = remove_from_init_map trans t.init_map in
t.init_map <- new_map;
WIM.remove t.init_map trans;
t.db_ref <- db;
let cur_rev = Hldb.get_rev db in
if IntMap.is_empty new_map then
if WIM.count t.init_map = 0 then
(* The most common case. No messing around with query maps. *)
t.db_to_merge <- IntMap.empty
else begin
Expand All @@ -813,10 +796,7 @@ module DT = DbTypes
t.db_to_merge <- db_to_merge;
t.db_to_merge <- shrink_db_to_merge t;
end;
(* TODO: without '~trans' it breaks tests; no idea why.
Perhaps when it reads db back, it replay trans,
which reinitializes some stuff left blank
in a freshly loaded db. *)

disk_writing t ~trans cur_rev;
t.db_ref <- Hldb.clean_tmp_maps db;
(* Release the lock. *)
Expand Down Expand Up @@ -868,12 +848,16 @@ module DT = DbTypes


(* writing to DB *)
let update_init_map t tr =
WIM.remove t.init_map tr;
WIM.add t.init_map tr;
tr

let set trans path data = Tr.set trans path data
let set t trans path data = update_init_map t (Tr.set trans path data)

let remove trans path = Tr.remove trans path
let remove t trans path = update_init_map t (Tr.remove trans path)

let set_link trans path link = Tr.set_link trans path link
let set_link t trans path link = update_init_map t (Tr.set_link trans path link)

let set_copy _t trans path (target_path, target_rev) =
Tr.set_copy trans path (target_path, target_rev)
let set_copy t trans path (target_path, target_rev) =
update_init_map t (Tr.set_copy trans path (target_path, target_rev))
6 changes: 3 additions & 3 deletions database/db3/session.mli
View file
Expand Up @@ -39,9 +39,9 @@
val really_commit : t -> Transaction.t -> bool

(* db writes *)
val set : Transaction.t -> Path.t -> DataImpl.t -> Transaction.t
val remove : Transaction.t -> Path.t -> Transaction.t
val set_link : Transaction.t -> Path.t -> Path.t -> Transaction.t
val set : t -> Transaction.t -> Path.t -> DataImpl.t -> Transaction.t
val remove : t -> Transaction.t -> Path.t -> Transaction.t
val set_link : t -> Transaction.t -> Path.t -> Path.t -> Transaction.t
val set_copy : t -> Transaction.t -> Path.t -> (Path.t * Revision.t option) -> Transaction.t

(* db reads *)
Expand Down

0 comments on commit 017973e

Please sign in to comment.