/* Title: Pure/System/session.scala
Author: Makarius
Isabelle session, potentially with running prover.
*/
package isabelle
import scala.actors.TIMEOUT
import scala.actors.Actor._
object Session
{
/* events */
case object Global_Settings
/* managed entities */
type Entity_ID = String
trait Entity
{
val id: Entity_ID
def consume(session: Session, message: XML.Tree): Unit
}
}
class Session(system: Isabelle_System)
{
/* pervasive event buses */
val global_settings = new Event_Bus[Session.Global_Settings.type]
val raw_results = new Event_Bus[Isabelle_Process.Result]
val raw_output = new Event_Bus[Isabelle_Process.Result]
val results = new Event_Bus[Command]
val command_change = new Event_Bus[Command]
/* unique ids */
private var id_count: BigInt = 0
def create_id(): Session.Entity_ID = synchronized { id_count += 1; "j" + id_count }
/** main actor **/
@volatile private var syntax = new Outer_Syntax(system.symbols)
def current_syntax: Outer_Syntax = syntax
@volatile private var entities = Map[Session.Entity_ID, Session.Entity]()
def lookup_entity(id: Session.Entity_ID): Option[Session.Entity] = entities.get(id)
def lookup_command(id: Session.Entity_ID): Option[Command] =
lookup_entity(id) match {
case Some(cmd: Command) => Some(cmd)
case _ => None
}
private case class Start(timeout: Int, args: List[String])
private case object Stop
private case class Begin_Document(path: String)
private val session_actor = actor {
var prover: Isabelle_Process with Isar_Document = null
def register(entity: Session.Entity) { entities += (entity.id -> entity) }
var documents = Map[Isar_Document.Document_ID, Document]()
def register_document(doc: Document) { documents += (doc.id -> doc) }
/* document changes */
def handle_change(change: Change)
{
require(change.parent.isDefined)
val (changes, doc) = change.result.join
val id_changes = changes map {
case (c1, c2) =>
(c1.map(_.id).getOrElse(""),
c2 match {
case None => None
case Some(command) =>
if (!lookup_command(command.id).isDefined) {
register(command)
prover.define_command(command.id, system.symbols.encode(command.source))
}
Some(command.id)
})
}
register_document(doc)
prover.edit_document(change.parent.get.id, doc.id, id_changes)
}
/* 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_results.event(result)
val target_id: Option[Session.Entity_ID] = Position.get_id(result.props)
val target: Option[Session.Entity] =
target_id match {
case None => None
case Some(id) => lookup_entity(id)
}
if (target.isDefined) target.get.consume(this, result.message)
else if (result.kind == Isabelle_Process.Kind.STATUS) {
// global status message
result.body match {
// document state assignment
case List(Isar_Document.Assign(edits)) if target_id.isDefined =>
documents.get(target_id.get) match {
case Some(doc) =>
val states =
for {
Isar_Document.Edit(cmd_id, state_id) <- edits
cmd <- lookup_command(cmd_id)
} yield {
val st = cmd.assign_state(state_id)
register(st)
(cmd, st)
}
doc.assign_states(states)
case None => bad_result(result)
}
// keyword declarations
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 == Isabelle_Process.Kind.EXIT)
prover = null
else if (result.is_raw)
raw_output.event(result)
else if (!result.is_system) // FIXME syslog (!?)
bad_result(result)
}
/* 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 == Isabelle_Process.Kind.INIT =>
while (receive {
case result: Isabelle_Process.Result =>
handle_result(result); !result.is_ready
}) {}
None
case result: Isabelle_Process.Result
if result.kind == Isabelle_Process.Kind.EXIT =>
Some(startup_error())
case TIMEOUT => // FIXME clarify
prover.kill; Some(startup_error())
}
}
/* main loop */
val xml_cache = new XML.Cache(131071)
loop {
react {
case Start(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 clarify; synchronous
if (prover != null) {
prover.kill
prover = null
}
case Begin_Document(path: String) if prover != null =>
val id = create_id()
val doc = Document.empty(id)
register_document(doc)
prover.begin_document(id, path)
reply(doc)
case change: Change if prover != null =>
handle_change(change)
case result: Isabelle_Process.Result =>
handle_result(result.cache(xml_cache))
case TIMEOUT => // FIXME clarify!
case bad if prover != null =>
System.err.println("session_actor: ignoring bad message " + bad)
}
}
}
/* main methods */
def start(timeout: Int, args: List[String]): Option[String] =
(session_actor !? Start(timeout, args)).asInstanceOf[Option[String]]
def stop() { session_actor ! Stop }
def input(change: Change) { session_actor ! change }
def begin_document(path: String): Document =
(session_actor !? Begin_Document(path)).asInstanceOf[Document]
}