# HG changeset patch
# User wenzelm
# Date 1219504971 -7200
# Node ID 6eb0327c0b9bdafc863155d92f288fd6b3c9e592
# Parent  2638b611d3ce871b2cb3657c35fa33d153b2558e
Isabelle process management -- always reactive due to multi-threaded I/O.

diff -r 2638b611d3ce -r 6eb0327c0b9b src/Pure/Tools/isabelle_process.scala
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Pure/Tools/isabelle_process.scala	Sat Aug 23 17:22:51 2008 +0200
@@ -0,0 +1,337 @@
+/*  Title:      Pure/Tools/isabelle_process.ML   :folding=explicit:collapseFolds=1:
+    ID:         $Id$
+    Author:     Makarius
+
+Isabelle process management -- always reactive due to multi-threaded I/O.
+*/
+
+package isabelle
+
+import java.util.Properties
+import java.io.{BufferedReader, BufferedWriter, InputStreamReader, OutputStreamWriter, IOException}
+
+import scala.collection.mutable.{SynchronizedQueue, ArrayBuffer}
+import isabelle.{Symbol, XML, YXML}
+
+
+class IsabelleProcess(args: String*) {
+
+  class IsabelleProcessException(msg: String) extends Exception
+
+
+  /* process information */
+
+  private var proc: Process = null
+  private var pid: String = null
+  private var closing = false
+  private var session: String = null
+
+
+  /* encoding */
+
+  private val charset = "UTF-8"
+  private val symbols = new Symbol.Interpretation
+
+
+  /* results */
+
+  object Kind extends Enumeration {
+    //{{{ values
+    // Posix channels/events
+    val STDIN = Value("STDIN")
+    val STDOUT = Value("STDOUT")
+    val STDERR = Value("STDERR")
+    val SIGNAL = Value("SIGNAL")
+    val EXIT = Value("EXIT")
+    // Isabelle messages
+    val WRITELN = Value("WRITELN")
+    val PRIORITY = Value("PRIORITY")
+    val TRACING = Value("TRACING")
+    val WARNING = Value("WARNING")
+    val ERROR = Value("ERROR")
+    val DEBUG = Value("DEBUG")
+    val PROMPT = Value("PROMPT")
+    val INIT = Value("INIT")
+    val STATUS = Value("STATUS")
+    // internal system notification
+    val SYSTEM = Value("SYSTEM")
+    //}}}
+    def is_raw(kind: Value) =
+      kind == STDOUT ||
+      kind == STDERR
+    def is_system(kind: Value) =
+      kind == STDIN ||
+      kind == SIGNAL ||
+      kind == EXIT ||
+      kind == PROMPT ||
+      kind == STATUS ||
+      kind == SYSTEM
+  }
+
+  class Result(kind: Kind.Value, props: Properties, result: String) {
+    //{{{
+    override def toString = {
+      if (props == null) kind.toString + " [[" + result + "]]"
+      else kind.toString + " " + props.toString + " [[" + result + "]]"
+    }
+
+    private var the_tree: XML.Tree = null
+    def tree() = synchronized {
+      if (the_tree == null) the_tree = YXML.parse(symbols.decode(result));
+      the_tree
+    }
+    //}}}
+  }
+
+  val results = new SynchronizedQueue[Result]
+
+  private def put_result(kind: Kind.Value, props: Properties, result: String) {
+    results += new Result(kind, props, result)
+  }
+
+
+  /* output being piped into the process */
+
+  val output = new SynchronizedQueue[String]
+
+  def output_raw(text: String) = synchronized {
+    if (proc == null) throw new IsabelleProcessException("Cannot output: no process")
+    if (closing) throw new IsabelleProcessException("Cannot output: already closing")
+    output.enqueue(text)
+  }
+
+  def output_sync(text: String) = output_raw(" \\<^sync>\n; " + text + " \\<^sync>;\n")
+
+  def output_command(text: String) =
+    output_sync("Isabelle.command " + IsabelleSyntax.encode_string(text))
+
+  def output_command(props: Properties, text: String) =
+    output_sync("Isabelle.command " + IsabelleSyntax.encode_properties(props) + " " +
+      IsabelleSyntax.encode_string(text))
+
+  def output_ML(text: String) =
+    output_sync("ML_val " + IsabelleSyntax.encode_string(text))
+
+  def close() = synchronized {    // FIXME watchdog/timeout
+    output_raw("\u0000")
+    closing = true
+  }
+
+  def try_close() = synchronized {
+    if (proc != null && !closing) {
+      try { close() }
+      catch { case _: IsabelleProcessException => () }
+    }
+  }
+
+
+  /* stdin */
+
+  private class StdinThread(writer: BufferedWriter) extends Thread {
+    override def run() = {
+      var finished = false
+      while (!finished) {
+        try {
+          //{{{
+          val s = output.dequeue
+          if (s == "\u0000") {
+            writer.close
+            finished = true
+          }
+          else {
+            put_result(Kind.STDIN, null, s)
+            writer.write(s)
+            writer.flush
+          }
+          //}}}
+        }
+        catch {
+          case e: IOException => put_result(Kind.SYSTEM, null, "Stdin thread: " + e.getMessage)
+        }
+      }
+      put_result(Kind.SYSTEM, null, "Stdin thread terminated")
+    }
+  }
+
+
+  /* stdout */
+
+  private class StdoutThread(reader: BufferedReader) extends Thread {
+    override def run() = {
+      var kind = Kind.STDOUT
+      var props: Properties = null
+      var result = new StringBuilder
+
+      var finished = false
+      while (!finished) {
+        try {
+          if (kind == Kind.STDOUT) {
+            //{{{ Char mode
+            var c = -1
+            var done = false
+            while (!done && (result.length == 0 || reader.ready)) {
+              c = reader.read
+              if (c > 0 && c != 2) result.append(c.asInstanceOf[Char])
+              else done = true
+            }
+            if (result.length > 0) {
+              put_result(kind, null, result.toString)
+              result.length = 0
+            }
+            if (c == -1) {
+              reader.close
+              finished = true
+              try_close()
+            }
+            else if (c == 2) {
+              reader.read match {
+                case 'A' => kind = Kind.WRITELN
+                case 'B' => kind = Kind.PRIORITY
+                case 'C' => kind = Kind.TRACING
+                case 'D' => kind = Kind.WARNING
+                case 'E' => kind = Kind.ERROR
+                case 'F' => kind = Kind.DEBUG
+                case 'G' => kind = Kind.PROMPT
+                case 'H' => kind = Kind.INIT
+                case 'I' => kind = Kind.STATUS
+                case _ => kind = Kind.STDOUT
+              }
+              props = null
+            }
+            //}}}
+          }
+          else {
+            //{{{ Line mode
+            val line = reader.readLine
+            if (line == null) {
+              reader.close
+              finished = true
+              try_close()
+            }
+            else {
+              val len = line.length
+              // property
+              if (line.endsWith("\u0002,")) {
+                val i = line.indexOf('=')
+                if (i > 0) {
+                  val name = line.substring(0, i)
+                  val value = line.substring(i + 1, len - 2)
+                  if (props == null) props = new Properties
+                  if (!props.containsKey(name)) {
+                    props.setProperty(name, value)
+                  }
+                }
+              }
+              // last text line
+              else if (line.endsWith("\u0002.")) {
+                if (kind == Kind.INIT && props != null) {
+                  pid = props.getProperty("pid")
+                  session = props.getProperty("session")
+                }
+                result.append(line.substring(0, len - 2))
+                put_result(kind, props, result.toString)
+                result.length = 0
+                kind = Kind.STDOUT
+              }
+              // text line
+              else {
+                result.append(line)
+                result.append('\n')
+              }
+            }
+            //}}}
+          }
+        } catch {
+          case e: IOException => put_result(Kind.SYSTEM, null, "Stdout thread: " + e.getMessage)
+        }
+      }
+      put_result(Kind.SYSTEM, null, "Stdout thread terminated")
+    }
+  }
+
+
+  /* stderr */
+
+  private class StderrThread(reader: BufferedReader) extends Thread {
+    override def run() = {
+      var result = new StringBuilder(100)
+
+      var finished = false
+      while (!finished) {
+        try {
+          //{{{
+          var c = -1
+          var done = false
+          while (!done && (result.length == 0 || reader.ready)) {
+            c = reader.read
+            if (c > 0) result.append(c.asInstanceOf[Char])
+            else done = true
+          }
+          if (result.length > 0) {
+            put_result(Kind.STDERR, null, result.toString)
+            result.length = 0
+          }
+          else {
+            reader.close
+            finished = true
+            try_close()
+          }
+          //}}}
+        } catch {
+          case e: IOException => put_result(Kind.SYSTEM, null, "Stderr thread: " + e.getMessage)
+        }
+      }
+      put_result(Kind.SYSTEM, null, "Stderr thread terminated")
+    }
+  }
+
+
+  /* exit */
+
+  private class ExitThread extends Thread {
+    override def run() = {
+      val rc = proc.waitFor
+      Thread.sleep(300)
+      put_result(Kind.SYSTEM, null, "Exit thread terminated")
+      put_result(Kind.EXIT, null, Integer.toString(rc))
+      proc = null   // FIXME race!?
+    }
+  }
+
+
+
+  /** main **/
+
+  {
+    /* command line */
+
+    val cmdline = {
+      val cmdline = new ArrayBuffer[String]
+  
+      IsabelleSystem.shell_prefix match {
+        case None => ()
+        case Some(prefix) => cmdline + prefix
+      }
+      cmdline + IsabelleSystem.getenv_strict("ISABELLE_HOME") + "/bin/isabelle-process"
+      cmdline + "-W"
+      cmdline + "-m"; cmdline + "full_markup"  // FIXME
+      for (arg <- args) cmdline + arg
+      cmdline.toArray
+    }
+
+    try { proc = Runtime.getRuntime.exec(cmdline) }
+    catch {
+      case e: IOException => throw new IsabelleProcessException(e.getMessage)
+    }
+
+
+    /* process control via threads */
+
+    new StdinThread(new BufferedWriter(new OutputStreamWriter(proc.getOutputStream, charset))).start
+    new StdoutThread(new BufferedReader(new InputStreamReader(proc.getInputStream, charset))).start
+    new StderrThread(new BufferedReader(new InputStreamReader(proc.getErrorStream, charset))).start
+    new ExitThread().start
+  }
+
+}
+