/* Title: Pure/System/session.scala
Author: Makarius
Options: :folding=explicit:collapseFolds=1:
Main Isabelle/Scala session, potentially with running prover process.
*/
package isabelle
import java.lang.System
import java.util.{Timer, TimerTask}
import scala.collection.mutable
import scala.collection.immutable.Queue
import scala.actors.TIMEOUT
import scala.actors.Actor._
object Session
{
/* events */
//{{{
case class Statistics(props: Properties.T)
case class Global_Options(options: Options)
case object Caret_Focus
case class Raw_Edits(edits: List[Document.Edit_Text])
case class Dialog_Result(id: Document_ID.Generic, serial: Long, result: String)
case class Commands_Changed(
assignment: Boolean, nodes: Set[Document.Node.Name], commands: Set[Command])
sealed abstract class Phase
case object Inactive extends Phase
case object Startup extends Phase // transient
case object Failed extends Phase
case object Ready extends Phase
case object Shutdown extends Phase // transient
//}}}
/* protocol handlers */
type Prover = Isabelle_Process with Protocol
abstract class Protocol_Handler
{
def stop(prover: Prover): Unit = {}
val functions: Map[String, (Prover, Isabelle_Process.Output) => Boolean]
}
class Protocol_Handlers(
handlers: Map[String, Session.Protocol_Handler] = Map.empty,
functions: Map[String, Isabelle_Process.Output => Boolean] = Map.empty)
{
def add(prover: Prover, name: String): Protocol_Handlers =
{
val (handlers1, functions1) =
handlers.get(name) match {
case Some(old_handler) =>
System.err.println("Redefining protocol handler: " + name)
old_handler.stop(prover)
(handlers - name, functions -- old_handler.functions.keys)
case None => (handlers, functions)
}
val (handlers2, functions2) =
try {
val new_handler = Class.forName(name).newInstance.asInstanceOf[Protocol_Handler]
val new_functions =
for ((a, f) <- new_handler.functions.toList) yield
(a, (output: Isabelle_Process.Output) => f(prover, output))
val dups = for ((a, _) <- new_functions if functions1.isDefinedAt(a)) yield a
if (!dups.isEmpty) error("Duplicate protocol functions: " + commas_quote(dups))
(handlers1 + (name -> new_handler), functions1 ++ new_functions)
}
catch {
case exn: Throwable =>
System.err.println("Failed to initialize protocol handler: " +
name + "\n" + Exn.message(exn))
(handlers1, functions1)
}
new Protocol_Handlers(handlers2, functions2)
}
def invoke(output: Isabelle_Process.Output): Boolean =
output.properties match {
case Markup.Function(a) if functions.isDefinedAt(a) =>
try { functions(a)(output) }
catch {
case exn: Throwable =>
System.err.println("Failed invocation of protocol function: " +
quote(a) + "\n" + Exn.message(exn))
false
}
case _ => false
}
def stop(prover: Prover): Protocol_Handlers =
{
for ((_, handler) <- handlers) handler.stop(prover)
new Protocol_Handlers()
}
}
}
class Session(val thy_load: Thy_Load)
{
/* global flags */
@volatile var timing: Boolean = false
@volatile var verbose: Boolean = false
/* tuning parameters */
def output_delay: Time = Time.seconds(0.1) // prover output (markup, common messages)
def message_delay: Time = Time.seconds(0.01) // incoming prover messages
def prune_delay: Time = Time.seconds(60.0) // prune history -- delete old versions
def prune_size: Int = 0 // size of retained history
def syslog_limit: Int = 100
def reparse_limit: Int = 0
/* pervasive event buses */
val statistics = new Event_Bus[Session.Statistics]
val global_options = new Event_Bus[Session.Global_Options]
val caret_focus = new Event_Bus[Session.Caret_Focus.type]
val raw_edits = new Event_Bus[Session.Raw_Edits]
val commands_changed = new Event_Bus[Session.Commands_Changed]
val phase_changed = new Event_Bus[Session.Phase]
val syslog_messages = new Event_Bus[Isabelle_Process.Output]
val raw_output_messages = new Event_Bus[Isabelle_Process.Output]
val all_messages = new Event_Bus[Isabelle_Process.Message] // potential bottle-neck
/** buffered command changes (delay_first discipline) **/
//{{{
private case object Stop
private val (_, commands_changed_buffer) =
Simple_Thread.actor("commands_changed_buffer", daemon = true)
{
var finished = false
while (!finished) {
receive {
case Stop => finished = true; reply(())
case changed: Session.Commands_Changed => commands_changed.event(changed)
case bad => System.err.println("commands_changed_buffer: ignoring bad message " + bad)
}
}
}
//}}}
/** pipelined change parsing **/
//{{{
private case class Text_Edits(
previous: Future[Document.Version],
text_edits: List[Document.Edit_Text],
version_result: Promise[Document.Version])
private val (_, change_parser) = Simple_Thread.actor("change_parser", daemon = true)
{
var finished = false
while (!finished) {
receive {
case Stop => finished = true; reply(())
case Text_Edits(previous, text_edits, version_result) =>
val prev = previous.get_finished
val (doc_edits, version) =
Timing.timeit("Thy_Load.text_edits", timing) {
thy_load.text_edits(reparse_limit, prev, text_edits)
}
version_result.fulfill(version)
sender ! Change(doc_edits, prev, version)
case bad => System.err.println("change_parser: ignoring bad message " + bad)
}
}
}
//}}}
/** main protocol actor **/
/* global state */
private val syslog = Volatile(Queue.empty[XML.Elem])
def current_syslog(): String = cat_lines(syslog().iterator.map(XML.content))
@volatile private var _phase: Session.Phase = Session.Inactive
private def phase_=(new_phase: Session.Phase)
{
_phase = new_phase
phase_changed.event(new_phase)
}
def phase = _phase
def is_ready: Boolean = phase == Session.Ready
private val global_state = Volatile(Document.State.init)
def current_state(): Document.State = global_state()
def recent_syntax(): Outer_Syntax =
{
val version = current_state().recent_finished.version.get_finished
if (version.is_init) thy_load.base_syntax
else version.syntax
}
def snapshot(name: Document.Node.Name = Document.Node.Name.empty,
pending_edits: List[Text.Edit] = Nil): Document.Snapshot =
global_state().snapshot(name, pending_edits)
/* theory files */
def header_edit(name: Document.Node.Name, header: Document.Node.Header): Document.Edit_Text =
{
val header1 =
if (thy_load.loaded_theories(name.theory))
header.error("Attempt to update loaded theory " + quote(name.theory))
else header
(name, Document.Node.Deps(header1))
}
/* actor messages */
private case class Start(args: List[String])
private case object Cancel_Execution
private case class Change(
doc_edits: List[Document.Edit_Command],
previous: Document.Version,
version: Document.Version)
private case class Messages(msgs: List[Isabelle_Process.Message])
private case class Update_Options(options: Options)
private val (_, session_actor) = Simple_Thread.actor("session_actor", daemon = true)
{
val this_actor = self
var protocol_handlers = new Session.Protocol_Handlers()
var prune_next = System.currentTimeMillis() + prune_delay.ms
/* buffered prover messages */
object receiver
{
private var buffer = new mutable.ListBuffer[Isabelle_Process.Message]
def flush(): Unit = synchronized {
if (!buffer.isEmpty) {
val msgs = buffer.toList
this_actor ! Messages(msgs)
buffer = new mutable.ListBuffer[Isabelle_Process.Message]
}
}
def invoke(msg: Isabelle_Process.Message): Unit = synchronized {
buffer += msg
msg match {
case output: Isabelle_Process.Output =>
if (output.is_syslog)
syslog >> (queue =>
{
val queue1 = queue.enqueue(output.message)
if (queue1.length > syslog_limit) queue1.dequeue._2 else queue1
})
if (output.is_protocol) flush()
case _ =>
}
}
private val timer = new Timer("session_actor.receiver", true)
timer.schedule(new TimerTask { def run = flush }, message_delay.ms, message_delay.ms)
def cancel() { timer.cancel() }
}
var prover: Option[Session.Prover] = None
/* delayed command changes */
object delay_commands_changed
{
private var changed_assignment: Boolean = false
private var changed_nodes: Set[Document.Node.Name] = Set.empty
private var changed_commands: Set[Command] = Set.empty
private var flush_time: Option[Long] = None
def flush_timeout: Long =
flush_time match {
case None => 5000L
case Some(time) => (time - System.currentTimeMillis()) max 0
}
def flush()
{
if (changed_assignment || !changed_nodes.isEmpty || !changed_commands.isEmpty)
commands_changed_buffer !
Session.Commands_Changed(changed_assignment, changed_nodes, changed_commands)
changed_assignment = false
changed_nodes = Set.empty
changed_commands = Set.empty
flush_time = None
}
def invoke(assign: Boolean, commands: List[Command])
{
changed_assignment |= assign
for (command <- commands) {
changed_nodes += command.node_name
changed_commands += command
}
val now = System.currentTimeMillis()
flush_time match {
case None => flush_time = Some(now + output_delay.ms)
case Some(time) => if (now >= time) flush()
}
}
}
/* resulting changes */
def handle_change(change: Change)
//{{{
{
val previous = change.previous
val version = change.version
val doc_edits = change.doc_edits
def id_command(command: Command)
{
if (!global_state().defined_command(command.id)) {
global_state >> (_.define_command(command))
prover.get.define_command(command)
}
}
doc_edits foreach {
case (_, edit) =>
edit foreach { case (c1, c2) => c1 foreach id_command; c2 foreach id_command }
}
val assignment = global_state().the_assignment(previous).check_finished
global_state >> (_.define_version(version, assignment))
prover.get.update(previous.id, version.id, doc_edits)
}
//}}}
/* prover output */
def handle_output(output: Isabelle_Process.Output)
//{{{
{
def bad_output()
{
if (verbose)
System.err.println("Ignoring prover output: " + output.message.toString)
}
def accumulate(state_id: Document_ID.Generic, message: XML.Elem)
{
try {
val st = global_state >>> (_.accumulate(state_id, message))
delay_commands_changed.invoke(false, List(st.command))
}
catch {
case _: Document.State.Fail => bad_output()
}
}
if (output.is_protocol) {
val handled = protocol_handlers.invoke(output)
if (!handled) {
output.properties match {
case Markup.Protocol_Handler(name) =>
protocol_handlers = protocol_handlers.add(prover.get, name)
case Protocol.Command_Timing(state_id, timing) =>
val message = XML.elem(Markup.STATUS, List(XML.Elem(Markup.Timing(timing), Nil)))
accumulate(state_id, prover.get.xml_cache.elem(message))
case Markup.Assign_Execs =>
XML.content(output.body) match {
case Protocol.Assign(id, assign) =>
try {
val cmds = global_state >>> (_.assign(id, assign))
delay_commands_changed.invoke(true, cmds)
}
catch { case _: Document.State.Fail => bad_output() }
case _ => bad_output()
}
// FIXME separate timeout event/message!?
if (prover.isDefined && System.currentTimeMillis() > prune_next) {
val old_versions = global_state >>> (_.prune_history(prune_size))
if (!old_versions.isEmpty) prover.get.remove_versions(old_versions)
prune_next = System.currentTimeMillis() + prune_delay.ms
}
case Markup.Removed_Versions =>
XML.content(output.body) match {
case Protocol.Removed(removed) =>
try {
global_state >> (_.removed_versions(removed))
}
catch { case _: Document.State.Fail => bad_output() }
case _ => bad_output()
}
case Markup.ML_Statistics(props) =>
statistics.event(Session.Statistics(props))
case Markup.Task_Statistics(props) =>
// FIXME
case _ => bad_output()
}
}
}
else {
output.properties match {
case Position.Id(state_id) =>
accumulate(state_id, output.message)
case _ if output.is_init =>
phase = Session.Ready
case Markup.Return_Code(rc) if output.is_exit =>
if (rc == 0) phase = Session.Inactive
else phase = Session.Failed
case _ => bad_output()
}
}
}
//}}}
/* main loop */
//{{{
var finished = false
while (!finished) {
receiveWithin(delay_commands_changed.flush_timeout) {
case TIMEOUT => delay_commands_changed.flush()
case Start(args) if prover.isEmpty =>
if (phase == Session.Inactive || phase == Session.Failed) {
phase = Session.Startup
prover = Some(new Isabelle_Process(receiver.invoke _, args) with Protocol)
}
case Stop =>
if (phase == Session.Ready) {
protocol_handlers = protocol_handlers.stop(prover.get)
global_state >> (_ => Document.State.init) // FIXME event bus!?
phase = Session.Shutdown
prover.get.terminate
prover = None
phase = Session.Inactive
}
finished = true
receiver.cancel()
reply(())
case Update_Options(options) if prover.isDefined =>
if (is_ready) prover.get.options(options)
global_options.event(Session.Global_Options(options))
reply(())
case Cancel_Execution if prover.isDefined =>
prover.get.cancel_execution()
case raw @ Session.Raw_Edits(edits) if prover.isDefined =>
prover.get.discontinue_execution()
val previous = global_state().history.tip.version
val version = Future.promise[Document.Version]
val change = global_state >>> (_.continue_history(previous, edits, version))
raw_edits.event(raw)
change_parser ! Text_Edits(previous, edits, version)
reply(())
case Session.Dialog_Result(id, serial, result) if prover.isDefined =>
prover.get.dialog_result(serial, result)
handle_output(new Isabelle_Process.Output(Protocol.Dialog_Result(id, serial, result)))
case Messages(msgs) =>
msgs foreach {
case input: Isabelle_Process.Input =>
all_messages.event(input)
case output: Isabelle_Process.Output =>
if (output.is_stdout || output.is_stderr) raw_output_messages.event(output)
else handle_output(output)
if (output.is_syslog) syslog_messages.event(output)
all_messages.event(output)
}
case change: Change
if prover.isDefined && global_state().is_assigned(change.previous) =>
handle_change(change)
case bad if !bad.isInstanceOf[Change] =>
System.err.println("session_actor: ignoring bad message " + bad)
}
}
//}}}
}
/* actions */
def start(args: List[String])
{
session_actor ! Start(args)
}
def stop()
{
commands_changed_buffer !? Stop
change_parser !? Stop
session_actor !? Stop
}
def cancel_execution() { session_actor ! Cancel_Execution }
def update(edits: List[Document.Edit_Text])
{ if (!edits.isEmpty) session_actor !? Session.Raw_Edits(edits) }
def update_options(options: Options)
{ session_actor !? Update_Options(options) }
def dialog_result(id: Document_ID.Generic, serial: Long, result: String)
{ session_actor ! Session.Dialog_Result(id, serial, result) }
}