use Future.get_finished where this is the intended meaning -- prefer immediate crash over deadlock due to promises that are never fulfilled;
clarified session signalling;
/* Title: Pure/System/session.scala
Author: Makarius
Options: :folding=explicit:collapseFolds=1:
Isabelle session, potentially with running prover.
*/
package isabelle
import scala.actors.TIMEOUT
import scala.actors.Actor
import scala.actors.Actor._
object Session
{
/* events */
case object Global_Settings
case object Perspective
case class Commands_Changed(set: Set[Command])
}
class Session(system: Isabelle_System)
{
/* real time parameters */ // FIXME properties or settings (!?)
// user input (e.g. text edits, cursor movement)
val input_delay = 300
// prover output (markup, common messages)
val output_delay = 100
// GUI layout updates
val update_delay = 500
/* pervasive event buses */
val global_settings = new Event_Bus[Session.Global_Settings.type]
val raw_protocol = new Event_Bus[Isabelle_Process.Result]
val raw_output = new Event_Bus[Isabelle_Process.Result]
val commands_changed = new Event_Bus[Session.Commands_Changed]
val perspective = new Event_Bus[Session.Perspective.type]
/* unique ids */
private var id_count: Document.ID = 0
def new_id(): Document.ID = synchronized {
require(id_count > java.lang.Long.MIN_VALUE)
id_count -= 1
id_count
}
/** buffered command changes (delay_first discipline) **/
private case object Stop
private val command_change_buffer = Simple_Thread.actor("command_change_buffer", daemon = true)
//{{{
{
import scala.compat.Platform.currentTime
var changed: Set[Command] = Set()
var flush_time: Option[Long] = None
def flush_timeout: Long =
flush_time match {
case None => 5000L
case Some(time) => (time - currentTime) max 0
}
def flush()
{
if (!changed.isEmpty) commands_changed.event(Session.Commands_Changed(changed))
changed = Set()
flush_time = None
}
def invoke()
{
val now = currentTime
flush_time match {
case None => flush_time = Some(now + output_delay)
case Some(time) => if (now >= time) flush()
}
}
var finished = false
while (!finished) {
receiveWithin(flush_timeout) {
case command: Command => changed += command; invoke()
case TIMEOUT => flush()
case Stop => finished = true
case bad => System.err.println("command_change_buffer: ignoring bad message " + bad)
}
}
}
//}}}
/** main protocol actor **/
@volatile private var syntax = new Outer_Syntax(system.symbols)
def current_syntax(): Outer_Syntax = syntax
private val global_state = new Volatile(Document.State.init)
def current_state(): Document.State = global_state.peek()
private case class Edit_Version(edits: List[Document.Node_Text_Edit])
private case class Started(timeout: Int, args: List[String])
private val session_actor = Simple_Thread.actor("session_actor", daemon = true)
{
var prover: Isabelle_Process with Isar_Document = null
/* document changes */
def handle_change(change: Document.Change)
//{{{
{
val previous = change.previous.get_finished
val (node_edits, current) = change.result.get_finished
var former_assignment = global_state.peek().the_assignment(previous).get_finished
for {
(name, Some(cmd_edits)) <- node_edits
(prev, None) <- cmd_edits
removed <- previous.nodes(name).commands.get_after(prev)
} former_assignment -= removed
val id_edits =
node_edits map {
case (name, None) => (name, None)
case (name, Some(cmd_edits)) =>
val ids =
cmd_edits map {
case (c1, c2) =>
val id1 = c1.map(_.id)
val id2 =
c2 match {
case None => None
case Some(command) =>
if (global_state.peek().lookup_command(command.id).isEmpty) {
global_state.change(_.define_command(command))
prover.define_command(command.id, system.symbols.encode(command.source))
}
Some(command.id)
}
(id1, id2)
}
(name -> Some(ids))
}
global_state.change(_.define_version(current, former_assignment))
prover.edit_version(previous.id, current.id, id_edits)
}
//}}}
/* prover results */
def bad_result(result: Isabelle_Process.Result)
{
System.err.println("Ignoring prover result: " + result.message.toString)
}
def handle_result(result: Isabelle_Process.Result)
//{{{
{
raw_protocol.event(result)
result.properties match {
case Position.Id(state_id) =>
try {
val st = global_state.change_yield(_.accumulate(state_id, result.message))
command_change_buffer ! st.command
}
catch { case _: Document.State.Fail => bad_result(result) }
case _ =>
if (result.is_status) {
result.body match {
case List(Isar_Document.Assign(id, edits)) =>
try { global_state.change(_.assign(id, edits)) }
catch { case _: Document.State.Fail => bad_result(result) }
case List(Keyword.Command_Decl(name, kind)) => syntax += (name, kind)
case List(Keyword.Keyword_Decl(name)) => syntax += name
case _ => if (!result.is_ready) bad_result(result)
}
}
else if (result.kind == Markup.EXIT) prover = null
else if (result.is_raw) raw_output.event(result)
else if (!result.is_system) bad_result(result) // FIXME syslog for system messages (!?)
}
}
//}}}
/* prover startup */
def startup_error(): String =
{
val buf = new StringBuilder
while (
receiveWithin(0) {
case result: Isabelle_Process.Result =>
if (result.is_raw) {
for (text <- XML.content(result.message))
buf.append(text)
}
true
case TIMEOUT => false
}) {}
buf.toString
}
def prover_startup(timeout: Int): Option[String] =
{
receiveWithin(timeout) {
case result: Isabelle_Process.Result
if result.kind == Markup.INIT =>
while (receive {
case result: Isabelle_Process.Result =>
handle_result(result); !result.is_ready
}) {}
None
case result: Isabelle_Process.Result
if result.kind == Markup.EXIT =>
Some(startup_error())
case TIMEOUT => // FIXME clarify
prover.kill; Some(startup_error())
}
}
/* main loop */
var finished = false
while (!finished) {
receive {
case Edit_Version(edits) =>
val previous = global_state.peek().history.tip.current
val result = Future.fork { Thy_Syntax.text_edits(Session.this, previous.join, edits) }
val change = global_state.change_yield(_.extend_history(previous, edits, result))
val this_actor = self; change.current.map(_ => this_actor ! change)
reply(())
case change: Document.Change if prover != null =>
handle_change(change)
case result: Isabelle_Process.Result =>
handle_result(result)
case Started(timeout, args) =>
if (prover == null) {
prover = new Isabelle_Process(system, self, args:_*) with Isar_Document
val origin = sender
val opt_err = prover_startup(timeout)
if (opt_err.isDefined) prover = null
origin ! opt_err
}
else reply(None)
case Stop => // FIXME synchronous!?
if (prover != null) {
prover.kill
prover = null
finished = true
}
case bad if prover != null =>
System.err.println("session_actor: ignoring bad message " + bad)
}
}
}
/** main methods **/
def started(timeout: Int, args: List[String]): Option[String] =
(session_actor !? Started(timeout, args)).asInstanceOf[Option[String]]
def stop() { command_change_buffer ! Stop; session_actor ! Stop }
def edit_version(edits: List[Document.Node_Text_Edit]) { session_actor !? Edit_Version(edits) }
def snapshot(name: String, pending_edits: List[Text.Edit]): Document.Snapshot =
global_state.peek().snapshot(name, pending_edits)
}