From 7587098fb8bcd6d0f2100ab5386541bc841ff4c7 Mon Sep 17 00:00:00 2001
From: Doug Torrance <dtorrance@piedmont.edu>
Date: Thu, 21 Nov 2024 08:18:47 -0500
Subject: [PATCH] Raise an error when calling taskResult on an unscheduled task

Otherwise, M2 hangs waiting for a task that will never start
---
 M2/Macaulay2/d/pthread.d | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/M2/Macaulay2/d/pthread.d b/M2/Macaulay2/d/pthread.d
index 5a87ce2868..f396bba20f 100644
--- a/M2/Macaulay2/d/pthread.d
+++ b/M2/Macaulay2/d/pthread.d
@@ -209,6 +209,8 @@ setupfun("schedule",schedule);
 taskResult(e:Expr):Expr := (
      when e is c:TaskCell do
      if c.body.resultRetrieved then buildErrorPacket("task result already retrieved")
+     else if !taskReady(c.body.task)
+     then buildErrorPacket("task not scheduled yet")
      else if !taskKeepRunning(c.body.task) then buildErrorPacket("task canceled")
      else if !taskDone(c.body.task) then (
 	  Ccode(voidPointer, "waitOnTask(",c.body.task,")");