X-Git-Url: http://git.annexia.org/?p=whenjobs.git;a=blobdiff_plain;f=daemon%2Fdaemon.ml;h=fd986fb6f191c7dbd32b5bf59740a3c03e27a1e6;hp=347aff7176ab5400a3165f3450f8fe55cfec505d;hb=c6ac020d503360f4944fefcd91364c1f5b037c54;hpb=afad75cdd3a3b9a4b17f4fc25645bca7cecf5a16

diff --git a/daemon/daemon.ml b/daemon/daemon.ml
index 347aff7..fd986fb 100644
--- a/daemon/daemon.ml
+++ b/daemon/daemon.ml
@@ -21,6 +21,9 @@ open Whenutils
 open Unix
 open Printf
 
+(* See [exit.c]. *)
+external _exit : int -> 'a = "whenjobs__exit"
+
 (* All jobs that are loaded.  Maps name -> [job] structure. *)
 let jobs = ref StringMap.empty
 
@@ -36,12 +39,15 @@ let dependencies = ref StringMap.empty
  *)
 let variables : variables ref = ref StringMap.empty
 
-(* Last time that an every job ran.  See schedule_next_everyjob below. *)
-let last_t = ref (time ())
-
 (* $HOME/.whenjobs *)
 let jobsdir = ref ""
 
+(* Jobs that are running; map of PID -> (job, other data).  Note that
+ * the job may no longer exist *OR* it may have been renamed,
+ * eg. if the jobs file was reloaded.
+ *)
+let running = ref IntMap.empty
+
 (* Was debugging requested on the command line? *)
 let debug = ref false
 
@@ -49,7 +55,6 @@ let debug = ref false
 let server = ref None
 
 let esys = Unixqueue.standard_event_system ()
-let timer_group = ref None
 
 let rec init j d =
   jobsdir := j;
@@ -72,7 +77,10 @@ let rec init j d =
       Rpc.Tcp (* not TCP, this is the same as SOCK_STREAM *)
       Rpc.Socket
       esys
-  )
+  );
+
+  (* Handle SIGCHLD to clean up jobs. *)
+  Sys.set_signal Sys.sigchld (Sys.Signal_handle handle_sigchld)
 
 and proc_reload_file () =
   if !debug then Syslog.notice "remote call: reload_file";
@@ -164,7 +172,6 @@ and reload_file () =
   reevaluate_whenjobs (StringMap.keys !jobs);
 
   (* Schedule the next every job to run. *)
-  last_t := time ();
   schedule_next_everyjob ()
 
 (* Re-evaluate each named when-statement job, in a loop until we reach
@@ -210,11 +217,12 @@ and reevaluate_whenjobs jobnames =
 (* Schedule the next every-statement job to run, if there is one.  We
  * look at the every jobs, work out the time that each must run at,
  * pick the job(s) which must run soonest, and schedule a timer to run
- * them.  When the timer fires, it runs those jobs, then call this
- * function again.  'last_t' is the base time used for scheduling (or
- * the time that the file was last reloaded).
+ * them.  When the timer fires, it runs those jobs, then calls this
+ * function again.
  *)
 and schedule_next_everyjob () =
+  let t = time () in
+
   (* Get only everyjobs. *)
   let jobs = StringMap.values !jobs in
   let jobs = filter_map (
@@ -226,8 +234,8 @@ and schedule_next_everyjob () =
   (* Map everyjob to next time it must run. *)
   let jobs = List.map (
     fun (job, period) ->
-      let t' = next_periodexpr !last_t period in
-      assert (t' > !last_t); (* serious bug in next_periodexpr if false *)
+      let t' = next_periodexpr t period in
+      assert (t' > t); (* serious bug in next_periodexpr if false *)
       job, t'
   ) jobs in
 
@@ -252,26 +260,26 @@ and schedule_next_everyjob () =
   let t, jobs = pick jobs in
 
   if t > 0. then (
-    last_t := t;
-
     if jobs <> [] then (
+      (* Ensure the jobs always run in predictable (name) order. *)
+      let jobs =
+        List.sort (fun { job_name = a } { job_name = b } -> compare a b) jobs in
+
       if !debug then
         Syslog.notice "scheduling job(s) %s to run at %s"
           (String.concat ", " (List.map (fun { job_name = name } -> name) jobs))
           (string_of_time_t t);
 
       (* Schedule them to run at time t. *)
-      let g = new_timer_group () in
-      let w = Unixqueue.new_wait_id esys in
+      let g = Unixqueue.new_group esys in
       let t_diff = t -. Unix.time () in
       let t_diff = if t_diff < 0. then 0. else t_diff in
-      Unixqueue.add_weak_resource esys g (Unixqueue.Wait w, t_diff);
-      let run_jobs _ _ _ =
+      let run_jobs () =
+        Unixqueue.clear esys g;         (* Delete the timer. *)
         List.iter run_job jobs;
-        delete_timer ();
-        schedule_next_everyjob ();
+        schedule_next_everyjob ()
       in
-      Unixqueue.add_handler esys g run_jobs;
+      Unixqueue.weak_once esys g t_diff run_jobs;
     )
   )
 
@@ -281,22 +289,72 @@ and string_of_time_t t =
     (1900+tm.tm_year) (1+tm.tm_mon) tm.tm_mday
     tm.tm_hour tm.tm_min tm.tm_sec
 
-and new_timer_group () =
-  delete_timer ();
-  let g = Unixqueue.new_group esys in
-  timer_group := Some g;
-  g
-
-and delete_timer () =
-  match !timer_group with
-  | None -> ()
-  | Some g ->
-    Unixqueue.clear esys g;
-    timer_group := None
-
 and run_job job =
   Syslog.notice "running %s" job.job_name;
-  () (* XXX *)
+
+  (* Create a temporary directory.  The current directory of the job
+   * will be in this directory.  The directory is removed when the
+   * child process exits.
+   *)
+  let dir = tmpdir () in
+
+  let pid = fork () in
+  if pid = 0 then ( (* child process running the job *)
+    chdir dir;
+
+    (* Set environment variables corresponding to each variable. *)
+    StringMap.iter
+      (fun name value -> putenv name (string_of_variable value)) !variables;
+
+    (* Set the $JOBNAME environment variable. *)
+    putenv "JOBNAME" job.job_name;
+
+    (* Create a temporary file containing the shell script fragment. *)
+    let script = dir // "script" in
+    let chan = open_out script in
+    output_string chan job.job_script.sh_script;
+    close_out chan;
+    chmod script 0o700;
+
+    (* Execute the shell script. *)
+    (try execvp "bash" [| "bash"; "-c"; script |];
+     with Unix_error (err, fn, _) ->
+       Syslog.error "%s failed: %s: %s" fn script (error_message err)
+    );
+    _exit 1
+  );
+
+  (* Remember this PID, the job and the temporary directory, so we
+   * can clean up when the child exits.
+   *)
+  running := IntMap.add pid (job, dir) !running
+
+and tmpdir () =
+  let chan = open_in "/dev/urandom" in
+  let data = String.create 16 in
+  really_input chan data 0 (String.length data);
+  close_in chan;
+  let data = Digest.to_hex (Digest.string data) in
+  let dir = Filename.temp_dir_name // sprintf "whenjobs%s" data in
+  mkdir dir 0o700;
+  dir
+
+(* This is called when a job (child process) exits. *)
+and handle_sigchld _ =
+  try
+    let pid, status = waitpid [WNOHANG] 0 in
+    if pid > 0 then (
+      (* Look up the PID in the running jobs map. *)
+      let job, dir = IntMap.find pid !running in
+      running := IntMap.remove pid !running;
+      cleanup_job job dir
+    )
+  with Unix_error _ | Not_found -> ()
+
+and cleanup_job job dir =
+  (* This should be safe because the path cannot contain shell metachars. *)
+  let cmd = sprintf "rm -rf '%s'" dir in
+  ignore (Sys.command cmd)
 
 let main_loop () =
   Unixqueue.run esys