let close_if_open fd = (try (ignore(close fd);) with _ -> ())
-let direct_fifo_table: (string,(string*string*string*Unix.file_descr) option) Hashtbl.t = Hashtbl.create 1024
-let pidmap: (int,string*Unix.file_descr) Hashtbl.t = Hashtbl.create 1024
-
-let rec list_check lst elt =
- match lst with
- | [] -> false
- | car::cdr -> if (car==elt) then true else list_check cdr elt
+type in_pathname = string
+type directory = string
+type base_pathname = string
+type slice_name = string
+
+let direct_fifo_table: (in_pathname,(directory*base_pathname*slice_name*Unix.file_descr) option) Hashtbl.t =
+ Hashtbl.create 1024
+
+let pidmap: (int,in_pathname * Unix.file_descr) Hashtbl.t = Hashtbl.create 1024
+
+let move_gate fname =
+ let tmpfname=String.concat "." [fname;"tmp"] in
+ Unix.rename fname tmpfname;
+ tmpfname
+
+let move_ungate fname restore =
+ Unix.rename restore fname
+
+let list_check lst elt _ =
+ let rec list_check_rec lst =
+ match lst with
+ | [] -> false
+ | car::cdr ->
+ if (car==elt) then
+ true
+ else
+ list_check_rec cdr
+ in
+ list_check_rec lst
let openentry_int fifoin =
let fdin =
try openfile fifoin [O_RDONLY;O_NONBLOCK] 0o777 with
- e->fprintf logfd "Error opening and connecting FIFO: %s,%o\n" fifoin 0o777;flush logfd;raise e
+ e->logprint "Error opening and connecting FIFO: %s,%o\n" fifoin 0o777;raise e
in
fdin
-
-(** Open fifos for a session. SHOULD NOt shutdown vsys if the fifos don't exist *)
-let openentry_in root_dir fqp_in backend_spec =
- Dirwatcher.mask_watch root_dir;
- let fd_in = openentry_int fqp_in in
- Dirwatcher.unmask_watch root_dir [S_Open];
- let (fqp,slice_name) = backend_spec in
- Hashtbl.replace direct_fifo_table fqp_in (Some(root_dir,fqp,slice_name,fd_in))
+(** Open entry safely, by first masking out the file to be opened *)
+let openentry_safe root_dir fqp_in backend_spec =
+ let restore = move_gate fqp_in in
+ let fd_in = openentry_int restore in
+ move_ungate fqp_in restore;
+ let (fqp,slice_name) = backend_spec in
+ Hashtbl.replace direct_fifo_table fqp_in (Some(root_dir,fqp,slice_name,fd_in))
let openentry root_dir fqp backend_spec =
let fqp_in = String.concat "." [fqp;"in"] in
- openentry_in root_dir fqp_in backend_spec
+ openentry_safe root_dir fqp_in backend_spec
let reopenentry fifoin =
let entry = try Hashtbl.find direct_fifo_table fifoin with _ -> None in
match entry with
- | Some(dir, fqp,slice_name,fd) -> close_if_open fd;openentry_in dir fifoin (fqp,slice_name)
+ | Some(dir, fqp,slice_name,fd) -> close_if_open fd;openentry_safe dir fifoin (fqp,slice_name)
| None -> ()
(* vsys is activated when a client opens an in file *)
Hashtbl.find direct_fifo_table fqp_in with _ -> None in
match entry_info with
| Some(_,execpath,slice_name,fifo_fdin) ->
- fprintf logfd "Executing %s for slice %s\n" execpath slice_name;flush logfd;
begin
let len = String.length fqp_in in
let fqp = String.sub fqp_in 0 (len-3) in
let fqp_out = String.concat "." [fqp;"out"] in
let fifo_fdout =
try openfile fqp_out [O_WRONLY;O_NONBLOCK] 0o777 with
- _->fprintf logfd "%s Output pipe not open, using stdout in place of %s\n" slice_name fqp_out;flush logfd;stdout
+ _-> (* The client is opening the descriptor too fast *)
+ sleep 1;try openfile fqp_out [O_WRONLY;O_NONBLOCK] 0o777 with
+ _->
+ logprint "%s Output pipe not open, using stdout in place of %s\n" slice_name fqp_out;stdout
in
- ignore(sigprocmask SIG_BLOCK [Sys.sigchld]);
- (
- clear_nonblock fifo_fdin;
- let pid=try Some(create_process execpath [|execpath;slice_name|] fifo_fdin fifo_fdout fifo_fdout) with e -> None in
- match pid with
- | Some(pid) ->
- if (fifo_fdout <> stdout) then close_if_open fifo_fdout;
- Hashtbl.add pidmap pid (fqp_in,fifo_fdout)
- | None ->fprintf logfd "Error executing service: %s\n" execpath;flush logfd;reopenentry fqp_in
- );
- ignore(sigprocmask SIG_UNBLOCK [Sys.sigchld]);
+ ignore(sigprocmask SIG_BLOCK [Sys.sigchld]);
+ (
+ clear_nonblock fifo_fdin;
+ let pid=try Some(create_process execpath [|execpath;slice_name|] fifo_fdin fifo_fdout fifo_fdout) with e -> None in
+ match pid with
+ | Some(pid) ->
+ if (fifo_fdout <> stdout) then close_if_open fifo_fdout;
+ Hashtbl.add pidmap pid (fqp_in,fifo_fdout)
+ | None ->logprint "Error executing service: %s\n" execpath;reopenentry fqp_in
+ );
+ ignore(sigprocmask SIG_UNBLOCK [Sys.sigchld]);
end
| None -> ()
(** Make a pair of fifo entries *)
let mkentry fqp abspath perm uname =
- fprintf logfd "Making entry %s->%s\n" fqp abspath;flush logfd;
+ logprint "Making entry %s->%s\n" fqp abspath;
let fifoin=sprintf "%s.in" fqp in
let fifoout=sprintf "%s.out" fqp in
(try Unix.unlink fifoin with _ -> ());
);
Success
with
- e->fprintf logfd "Error creating FIFO: %s->%s. May be something wrong at the frontend.\n" fqp fifoout;flush logfd;Failed)
+ e->logprint "Error creating FIFO: %s->%s. May be something wrong at the frontend.\n" fqp fifoout;Failed)
(** Close fifos that just got removed *)
try
let fqp_in,fd_out = Hashtbl.find pidmap pid in
begin
- reopenentry fqp_in
+ reopenentry fqp_in
end
-
with _ -> ()
let rec add_dir_watch fqp =
Dirwatcher.add_watch fqp [S_Open] direct_fifo_handler
and
-direct_fifo_handler wd dirname evlist fname =
+ direct_fifo_handler wd dirname evlist fname =
let is_event = list_check evlist in
- if (is_event Open) then
+ if (is_event Open Attrib) then
let fqp_in = String.concat "/" [dirname;fname] in
- begin
- connect_file fqp_in;
- add_dir_watch dirname
- end
+ connect_file fqp_in
let del_dir_watch fqp =
- (* XXX Dirwatcher.del_watch fqp *)
()
let initialize () =
- Sys.set_signal Sys.sigchld (Sys.Signal_handle sigchld_handle)
+ Sys.set_signal Sys.sigchld (Sys.Signal_handle sigchld_handle)