src/Pure/System/bash.ML

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Pure/System/bash.ML	Thu Mar 10 09:50:53 2016 +0100
@@ -0,0 +1,102 @@
+(*  Title:      Pure/System/bash.ML
+    Author:     Makarius
+
+GNU bash processes, with propagation of interrupts -- POSIX version.
+*)
+
+signature BASH =
+sig
+  val process: string -> {out: string, err: string, rc: int, terminate: unit -> unit}
+end;
+
+structure Bash: BASH =
+struct
+
+val process = uninterruptible (fn restore_attributes => fn script =>
+  let
+    datatype result = Wait | Signal | Result of int;
+    val result = Synchronized.var "bash_result" Wait;
+
+    val id = serial_string ();
+    val script_path = File.tmp_path (Path.basic ("bash_script" ^ id));
+    val out_path = File.tmp_path (Path.basic ("bash_out" ^ id));
+    val err_path = File.tmp_path (Path.basic ("bash_err" ^ id));
+    val pid_path = File.tmp_path (Path.basic ("bash_pid" ^ id));
+
+    fun cleanup_files () =
+     (try File.rm script_path;
+      try File.rm out_path;
+      try File.rm err_path;
+      try File.rm pid_path);
+    val _ = cleanup_files ();
+
+    val system_thread =
+      Standard_Thread.fork {name = "bash", stack_limit = NONE, interrupts = false} (fn () =>
+        Multithreading.with_attributes Multithreading.private_interrupts (fn _ =>
+          let
+            val _ = File.write script_path script;
+            val _ = getenv_strict "ISABELLE_BASH_PROCESS";
+            val status =
+              OS.Process.system
+                ("exec \"$ISABELLE_BASH_PROCESS\" " ^ File.bash_path pid_path ^ " \"\"" ^
+                  " bash " ^ File.bash_path script_path ^
+                  " > " ^ File.bash_path out_path ^
+                  " 2> " ^ File.bash_path err_path);
+            val res =
+              (case Posix.Process.fromStatus status of
+                Posix.Process.W_EXITED => Result 0
+              | Posix.Process.W_EXITSTATUS 0wx82 => Signal
+              | Posix.Process.W_EXITSTATUS w => Result (Word8.toInt w)
+              | Posix.Process.W_SIGNALED s =>
+                  if s = Posix.Signal.int then Signal
+                  else Result (256 + LargeWord.toInt (Posix.Signal.toWord s))
+              | Posix.Process.W_STOPPED s =>
+                  Result (512 + LargeWord.toInt (Posix.Signal.toWord s)));
+          in Synchronized.change result (K res) end
+          handle exn =>
+            (Synchronized.change result (fn Wait => Signal | res => res); Exn.reraise exn)));
+
+    fun read_pid 0 = NONE
+      | read_pid count =
+          (case (Int.fromString (File.read pid_path) handle IO.Io _ => NONE) of
+            NONE => (OS.Process.sleep (seconds 0.1); read_pid (count - 1))
+          | some => some);
+
+    fun terminate NONE = ()
+      | terminate (SOME pid) =
+          let
+            fun kill s =
+              (Posix.Process.kill
+                (Posix.Process.K_GROUP (Posix.Process.wordToPid (LargeWord.fromInt pid)), s); true)
+              handle OS.SysErr _ => false;
+
+            fun multi_kill count s =
+              count = 0 orelse
+                (kill s; kill (Posix.Signal.fromWord 0w0)) andalso
+                (OS.Process.sleep (seconds 0.1); multi_kill (count - 1) s);
+            val _ =
+              multi_kill 10 Posix.Signal.int andalso
+              multi_kill 10 Posix.Signal.term andalso
+              multi_kill 10 Posix.Signal.kill;
+          in () end;
+
+    fun cleanup () =
+     (Standard_Thread.interrupt_unsynchronized system_thread;
+      cleanup_files ());
+  in
+    let
+      val _ =
+        restore_attributes (fn () =>
+          Synchronized.guarded_access result (fn Wait => NONE | x => SOME ((), x))) ();
+
+      val out = the_default "" (try File.read out_path);
+      val err = the_default "" (try File.read err_path);
+      val rc = (case Synchronized.value result of Signal => Exn.interrupt () | Result rc => rc);
+      val pid = read_pid 1;
+      val _ = cleanup ();
+    in {out = out, err = err, rc = rc, terminate = fn () => terminate pid} end
+    handle exn => (terminate (read_pid 10); cleanup (); Exn.reraise exn)
+  end);
+
+end;
+