594 - random snapshot after a lengthy debug

I'd caused a bug in Arc: https://github.com/arclanguage/anarki/commit/97b3464256

Almost done interrupting and restarting routines.

4 files changed, 860 insertions, 13 deletions

diff --git a/chessboard-cursor.arc.t.1 b/chessboard-cursor.arc.t.1
new file mode 100644
index 00000000..85ac8a78
--- /dev/null
+++ b/chessboard-cursor.arc.t.1
@@ -0,0 +1,384 @@
+(selective-load "mu.arc" section-level)
+
+;? (reset)
+;? (new-trace "read-move-legal")
+;? (add-code:readfile "chessboard-cursor.mu")
+;? (add-code
+;?   '((function! main [
+;?       (default-space:space-address <- new space:literal 30:literal/capacity)
+;?       (stdin:channel-address <- init-channel 1:literal)
+;?       (screen:terminal-address <- init-fake-terminal 20:literal 10:literal)
+;?       (2:string-address/raw <- get screen:terminal-address/deref data:offset)
+;?       (r:integer/routine <- fork read-move:fn nil:literal/globals 2000:literal/limit stdin:channel-address screen:terminal-address)
+;?       (c:character <- copy ((#\a literal)))
+;?       (x:tagged-value <- save-type c:character)
+;?       (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+;?       (c:character <- copy ((#\2 literal)))
+;?       (x:tagged-value <- save-type c:character)
+;?       (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+;?       (c:character <- copy ((#\- literal)))
+;?       (x:tagged-value <- save-type c:character)
+;?       (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+;?       (c:character <- copy ((#\a literal)))
+;?       (x:tagged-value <- save-type c:character)
+;?       (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+;?       (c:character <- copy ((#\4 literal)))
+;?       (x:tagged-value <- save-type c:character)
+;?       (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+;?       (sleep until-routine-done:literal r:integer/routine)
+;?      ])))
+;? ;? (set dump-trace*)
+;? ;? (= dump-trace* (obj whitelist '("schedule")))
+;? ;? (= dump-trace* (obj whitelist '("schedule" "run")))
+;? (run 'main)
+;? (each routine completed-routines*
+;? ;?   (prn "  " routine)
+;?   (awhen rep.routine!error
+;?     (prn "error - " it)))
+;? (when (~ran-to-completion 'read-move)
+;?   (prn "F - chessboard accepts legal moves (<rank><file>-<rank><file>)"))
+;? (when (~memory-contains-array memory*.2 "a2-a4")
+;?   (prn "F - chessboard prints moves read from keyboard"))
+;? ;? (quit)
+
+; todo: test that restarting a routine works
+;   when it died
+;   when it timed out
+;   when it completed
+; test that run checks status of sleep
+; run multiple routines in tandem
+
+(def restart (routine)
+  (while (in top.routine!fn-name 'read 'write)
+    (pop-stack routine))
+  (prn routine)
+;?   (let r read-move-routine
+;?     (each frame rep.r!call-stack
+;?       (prn " @frame!fn-name")
+;?       (each (key val) frame
+;?         (prn "  " key " " val))))
+  (wipe rep.routine!sleep)
+  (enq routine running-routines*))
+
+(reset)
+(new-trace "read-move-incomplete")
+(add-code:readfile "chessboard-cursor.mu")
+(prn "init")
+; initialize location 1 to stdin; location 2 to screen fake; 3 to the contents
+; of the fake
+(add-code 
+  '((function test-init [
+      (1:channel-address/raw <- init-channel 1:literal)
+      (2:terminal-address/raw <- init-fake-terminal 20:literal 10:literal)
+      (3:string-address/raw <- get 2:terminal-address/raw/deref data:offset)
+     ])))
+(prn "run init")
+(run 'test-init)
+(prn "make routine under test")
+; the component under test; we'll be running this repeatedly
+(let read-move-routine (make-routine 'read-move memory*.1 memory*.2)
+  (set rep.read-move-routine!helper)
+  (prn "send first key")
+  ; send in first letter
+  (add-code
+    '((function test-send-first-key [
+        (default-space:space-address <- new space:literal 30:literal/capacity)
+        (c:character <- copy ((#\a literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+       ])))
+  (run 'test-send-first-key)
+  (prn "consume first key")
+;?   (prn read-move-routine)
+  ; check that read-move consumes it and then goes to sleep
+  (enq read-move-routine running-routines*)
+;?   (set dump-trace*)
+;?   (prn int-canon.memory*)
+  (wipe completed-routines*)
+;?   (set dump-trace*)
+  (keep-running)
+  (prn rep.read-move-routine!sleep)
+;?   (prn int-canon.memory*)
+;?   (each routine completed-routines*
+;?     (prn routine))
+;?   (quit)
+  (prn "check routine state")
+  (when (ran-to-completion 'read-move)
+    (prn "F - chessboard waits after first letter of move"))
+  ; send in a few more letters
+  (prn "send and consume more keys")
+  (add-code
+    '((function test-send-next-keys [
+        (default-space:space-address <- new space:literal 30:literal/capacity)
+        (c:character <- copy ((#\2 literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+        (c:character <- copy ((#\- literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+        (c:character <- copy ((#\a literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+       ])))
+;?   (set dump-trace*)
+  (restart read-move-routine)
+  (run 'test-send-next-keys)
+;?   (each routine completed-routines*
+;?     (prn routine))
+;?   (quit)
+;?   (prn "-- before: " rep.read-move-routine!sleep)
+;?   (while (~empty running-routines*)
+;?     (prn "iter: " rep.read-move-routine!sleep)
+;?     (= routine* deq.running-routines*)
+;?     (when rep.routine*!limit
+;?       ; start the clock if it wasn't already running
+;?       (or= rep.routine*!running-since curr-cycle*))
+;?     (routine-mark
+;?       (run-for-time-slice scheduling-interval*))
+;?     (prn "after iter: " rep.read-move-routine!sleep)
+;?     (when routine*
+;?       (if
+;?           rep.routine*!sleep
+;?             (do
+;?                 (set sleeping-routines*.routine*))
+;?           rep.routine*!error
+;?             (do
+;?                 (push routine* completed-routines*))
+;?           empty.routine*
+;?             (do
+;?                 (push routine* completed-routines*))
+;?           (no rep.routine*!limit)
+;?             (do
+;?                 (enq routine* running-routines*))
+;?           :else
+;?             (err "illegal scheduler state"))
+;?       (= routine* nil))
+;?     (each (routine _) canon.sleeping-routines*
+;?       (when (ready-to-wake-up routine)
+;?         (wipe sleeping-routines*.routine)  ; do this before modifying routine
+;?         (wipe rep.routine!sleep)
+;?         (++ pc.routine)
+;?         (enq routine running-routines*)))
+;?     (when (and (or (~empty running-routines*)
+;?                    (~empty sleeping-routines*))
+;?                (all [rep._ 'helper] (as cons running-routines*))
+;?                (all [rep._ 'helper] keys.sleeping-routines*))
+;?       (until (empty running-routines*)
+;?         (push (deq running-routines*) completed-routines*))
+;?       (each (routine _) sleeping-routines*
+;?         (wipe sleeping-routines*.routine)
+;?         (push routine completed-routines*)))
+;?     )
+;?   (prn "-- after: " rep.read-move-routine!sleep)
+;?   (quit)
+  ; check that read-move consumes it and then goes to sleep
+  (prn "check routine state")
+  (when (ran-to-completion 'read-move)
+    (prn "F - chessboard waits after each subsequent letter of move until the last"))
+  ; send final key
+  (prn "send final key")
+  (add-code
+    '((function test-send-final-key [
+        (default-space:space-address <- new space:literal 30:literal/capacity)
+        (c:character <- copy ((#\4 literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+       ])))
+  (run 'test-send-final-key)
+  ; check that read-move consumes it and -- this time -- returns
+  (prn "consume final key")
+  (restart read-move-routine)
+  (keep-running)
+  (prn rep.read-move-routine!sleep)
+  (prn "check routine done")
+;?   (each routine completed-routines*
+;?     (prn routine))
+  (when (~ran-to-completion 'read-move)
+    (prn "F - 'read-move' completes after final letter of move"))
+)
+
+;? (add-code
+;?   '((function! main [
+;?       (default-space:space-address <- new space:literal 30:literal/capacity)
+;?       (stdin:channel-address <- init-channel 1:literal)
+;?       (screen:terminal-address <- init-fake-terminal 20:literal 10:literal)
+;?       (2:string-address/raw <- get screen:terminal-address/deref data:offset)
+;?       (r:integer/routine <- fork-helper read-move:fn nil:literal/globals 2000:literal/limit stdin:channel-address screen:terminal-address)
+;?       (c:character <- copy ((#\a literal)))
+;?       (x:tagged-value <- save-type c:character)
+;?       (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+;?       (c:character <- copy ((#\2 literal)))
+;?       (x:tagged-value <- save-type c:character)
+;?       (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+;?       (c:character <- copy ((#\- literal)))
+;?       (x:tagged-value <- save-type c:character)
+;?       (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+;?       (c:character <- copy ((#\a literal)))
+;?       (x:tagged-value <- save-type c:character)
+;?       (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+;?       (sleep until-routine-done:literal r:integer/routine)
+;?      ])))
+;? (run 'main)
+;? (when (ran-to-completion 'read-move)
+;?   (prn "F - chessboard hangs until 5 characters are entered"))
+;? (when (~memory-contains-array memory*.2 "a2-a")
+;?   (prn "F - chessboard prints keys from keyboard before entire move is read"))
+
+;? (reset)
+;? (new-trace "read-move-quit")
+;? (add-code:readfile "chessboard-cursor.mu")
+;? (add-code
+;?   '((function! main [
+;?       (default-space:space-address <- new space:literal 30:literal/capacity)
+;?       (stdin:channel-address <- init-channel 1:literal)
+;?       (dummy:terminal-address <- init-fake-terminal 20:literal 10:literal)
+;?       (r:integer/routine <- fork-helper read-move:fn nil:literal/globals 2000:literal/limit stdin:channel-address dummy:terminal-address)
+;?       (c:character <- copy ((#\q literal)))
+;?       (x:tagged-value <- save-type c:character)
+;?       (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+;?       (sleep until-routine-done:literal r:integer/routine)
+;?      ])))
+;? (run 'main)
+;? (when (~ran-to-completion 'read-move)
+;?   (prn "F - chessboard quits on move starting with 'q'"))
+;? 
+;? (reset)
+;? (new-trace "read-illegal-file")
+;? (add-code:readfile "chessboard-cursor.mu")
+;? (add-code
+;?   '((function! main [
+;?       (default-space:space-address <- new space:literal 30:literal/capacity)
+;?       (stdin:channel-address <- init-channel 1:literal)
+;?       (dummy:terminal-address <- init-fake-terminal 20:literal 10:literal)
+;?       (r:integer/routine <- fork-helper read-file:fn nil:literal/globals 2000:literal/limit stdin:channel-address dummy:terminal-address)
+;?       (c:character <- copy ((#\i literal)))
+;?       (x:tagged-value <- save-type c:character)
+;?       (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+;?       (sleep until-routine-done:literal r:integer/routine)
+;?      ])))
+;? ;? (= dump-trace* (obj whitelist '("schedule")))
+;? (run 'main)
+;? ;? (each routine completed-routines*
+;? ;?   (prn "  " routine))
+;? (when (or (ran-to-completion 'read-file)
+;?           (let routine routine-running!read-file
+;?             (~posmatch "file too high" rep.routine!error)))
+;?   (prn "F - 'read-file' checks that file lies between 'a' and 'h'"))
+;? 
+;? (reset)
+;? (new-trace "read-illegal-rank")
+;? (add-code:readfile "chessboard-cursor.mu")
+;? (add-code
+;?   '((function! main [
+;?       (default-space:space-address <- new space:literal 30:literal/capacity)
+;?       (stdin:channel-address <- init-channel 1:literal)
+;?       (dummy:terminal-address <- init-fake-terminal 20:literal 10:literal)
+;?       (r:integer/routine <- fork-helper read-rank:fn nil:literal/globals 2000:literal/limit stdin:channel-address dummy:terminal-address)
+;?       (c:character <- copy ((#\9 literal)))
+;?       (x:tagged-value <- save-type c:character)
+;?       (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+;?       (sleep until-routine-done:literal r:integer/routine)
+;?      ])))
+;? (run 'main)
+;? (when (or (ran-to-completion 'read-rank)
+;?           (let routine routine-running!read-rank
+;?             (~posmatch "rank too high" rep.routine!error)))
+;?   (prn "F - 'read-rank' checks that rank lies between '1' and '8'"))
+;? 
+;? (reset)
+;? (new-trace "print-board")
+;? (add-code:readfile "chessboard-cursor.mu")
+;? (add-code
+;?   '((function! main [
+;?       (default-space:space-address <- new space:literal 30:literal/capacity)
+;?       (initial-position:list-address <- init-list ((#\R literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\r literal))
+;?                                                   ((#\N literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\n literal))
+;?                                                   ((#\B literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\b literal))
+;?                                                   ((#\Q literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\q literal))
+;?                                                   ((#\K literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\k literal))
+;?                                                   ((#\B literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\b literal))
+;?                                                   ((#\N literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\n literal))
+;?                                                   ((#\R literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\r literal)))
+;?       (b:board-address <- init-board initial-position:list-address)
+;?       (screen:terminal-address <- init-fake-terminal 20:literal 10:literal)
+;?       (print-board screen:terminal-address b:board-address)
+;?       (5:string-address/raw <- get screen:terminal-address/deref data:offset)
+;?      ])))
+;? ;? (set dump-trace*)
+;? ;? (= dump-trace* (obj whitelist '("run")))
+;? (run 'main)
+;? (each routine completed-routines*
+;?   (awhen rep.routine!error
+;?     (prn "error - " it)))
+;? ;? (prn memory*.5)
+;? (when (~memory-contains-array memory*.5
+;?           (+ "8 | r n b q k b n r "
+;?              "7 | p p p p p p p p "
+;?              "6 | _ _ _ _ _ _ _ _ "
+;?              "5 | _ _ _ _ _ _ _ _ "
+;?              "4 | _ _ _ _ _ _ _ _ "
+;?              "3 | _ _ _ _ _ _ _ _ "
+;?              "2 | P P P P P P P P "
+;?              "1 | R N B Q K B N R "
+;?              "  +---------------- "
+;?              "    a b c d e f g h "))
+;?   (prn "F - print-board works; chessboard begins at @memory*.5"))
+;? 
+;? ; todo: how to fold this more elegantly with the previous test?
+;? (reset)
+;? (new-trace "make-move")
+;? (add-code:readfile "chessboard-cursor.mu")
+;? (add-code
+;?   '((function! main [
+;?       (default-space:space-address <- new space:literal 30:literal/capacity)
+;?       ; hook up stdin
+;?       (stdin:channel-address <- init-channel 1:literal)
+;?       ; fake screen
+;?       (screen:terminal-address <- init-fake-terminal 20:literal 10:literal)
+;?       ; initial position
+;?       (initial-position:list-address <- init-list ((#\R literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\r literal))
+;?                                                   ((#\N literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\n literal))
+;?                                                   ((#\B literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\b literal))
+;?                                                   ((#\Q literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\q literal))
+;?                                                   ((#\K literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\k literal))
+;?                                                   ((#\B literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\b literal))
+;?                                                   ((#\N literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\n literal))
+;?                                                   ((#\R literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\r literal)))
+;?       (b:board-address <- init-board initial-position:list-address)
+;?       ; move: a2-a4
+;?       (m:move-address <- new move:literal)
+;?       (f:integer-integer-pair-address <- get-address m:move-address/deref from:offset)
+;?       (dest:integer-address <- get-address f:integer-integer-pair-address/deref 0:offset)
+;?       (dest:integer-address/deref <- copy 0:literal)  ; from-file: a
+;?       (dest:integer-address <- get-address f:integer-integer-pair-address/deref 1:offset)
+;?       (dest:integer-address/deref <- copy 1:literal)  ; from-rank: 2
+;?       (t0:integer-integer-pair-address <- get-address m:move-address/deref to:offset)
+;?       (dest:integer-address <- get-address t0:integer-integer-pair-address/deref 0:offset)
+;?       (dest:integer-address/deref <- copy 0:literal)  ; to-file: a
+;?       (dest:integer-address <- get-address t0:integer-integer-pair-address/deref 1:offset)
+;?       (dest:integer-address/deref <- copy 3:literal)  ; to-rank: 4
+;?       (b:board-address <- make-move b:board-address m:move-address)
+;?       (print-board screen:terminal-address b:board-address)
+;?       (5:string-address/raw <- get screen:terminal-address/deref data:offset)
+;?      ])))
+;? ;? (set dump-trace*)
+;? ;? (= dump-trace* (obj whitelist '("run")))
+;? (run 'main)
+;? (each routine completed-routines*
+;?   (awhen rep.routine!error
+;?     (prn "error - " it)))
+;? ;? (prn memory*.5)
+;? (when (~memory-contains-array memory*.5
+;?           (+ "8 | r n b q k b n r "
+;?              "7 | p p p p p p p p "
+;?              "6 | _ _ _ _ _ _ _ _ "
+;?              "5 | _ _ _ _ _ _ _ _ "
+;?              "4 | P _ _ _ _ _ _ _ "
+;?              "3 | _ _ _ _ _ _ _ _ "
+;?              "2 | _ P P P P P P P "
+;?              "1 | R N B Q K B N R "
+;?              "  +---------------- "
+;?              "    a b c d e f g h "))
+;?   (prn "F - make-move works; chessboard begins at @memory*.5"))
+
+(reset)
diff --git a/chessboard-cursor.arc.t.2 b/chessboard-cursor.arc.t.2
new file mode 100644
index 00000000..4bfcec80
--- /dev/null
+++ b/chessboard-cursor.arc.t.2
@@ -0,0 +1,280 @@
+(selective-load "mu.arc" section-level)
+
+(reset)
+(new-trace "read-move-legal")
+(add-code:readfile "chessboard-cursor.mu")
+(add-code
+  '((function! main [
+      (default-space:space-address <- new space:literal 30:literal/capacity)
+      (stdin:channel-address <- init-channel 1:literal)
+      (screen:terminal-address <- init-fake-terminal 20:literal 10:literal)
+      (2:string-address/raw <- get screen:terminal-address/deref data:offset)
+      (r:integer/routine <- fork read-move:fn nil:literal/globals 2000:literal/limit stdin:channel-address screen:terminal-address)
+      (c:character <- copy ((#\a literal)))
+      (x:tagged-value <- save-type c:character)
+      (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+      (c:character <- copy ((#\2 literal)))
+      (x:tagged-value <- save-type c:character)
+      (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+      (c:character <- copy ((#\- literal)))
+      (x:tagged-value <- save-type c:character)
+      (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+      (c:character <- copy ((#\a literal)))
+      (x:tagged-value <- save-type c:character)
+      (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+      (c:character <- copy ((#\4 literal)))
+      (x:tagged-value <- save-type c:character)
+      (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+      (sleep until-routine-done:literal r:integer/routine)
+     ])))
+;? (set dump-trace*)
+;? (= dump-trace* (obj whitelist '("schedule")))
+;? (= dump-trace* (obj whitelist '("schedule" "run")))
+(run 'main)
+(each routine completed-routines*
+;?   (prn "  " routine)
+  (awhen rep.routine!error
+    (prn "error - " it)))
+(when (~ran-to-completion 'read-move)
+  (prn "F - chessboard accepts legal moves (<rank><file>-<rank><file>)"))
+(when (~memory-contains-array memory*.2 "a2-a4")
+  (prn "F - chessboard prints moves read from keyboard"))
+;? (quit)
+
+; todo: test that restarting a routine works
+;   when it died
+;   when it timed out
+;   when it completed
+; test that run checks status of sleep
+; run multiple routines in tandem
+
+(def restart (routine)
+  (while (in top.routine!fn-name 'read 'write)
+    (pop-stack routine))
+  (wipe rep.routine!sleep)
+  (enq routine running-routines*))
+
+(reset)
+(new-trace "read-move-incomplete")
+(add-code:readfile "chessboard-cursor.mu")
+; initialize location 1 to stdin; location 2 to screen fake; 3 to the contents
+; of the fake
+(add-code 
+  '((function test-init [
+      (1:channel-address/raw <- init-channel 1:literal)
+      (2:terminal-address/raw <- init-fake-terminal 20:literal 10:literal)
+      (3:string-address/raw <- get 2:terminal-address/raw/deref data:offset)
+     ])))
+(run 'test-init)
+; the component under test; we'll be running this repeatedly
+(let read-move-routine (make-routine 'read-move memory*.1 memory*.2)
+  (set rep.read-move-routine!helper)
+  ; send in first letter
+  (add-code
+    '((function test-send-first-key [
+        (default-space:space-address <- new space:literal 30:literal/capacity)
+        (c:character <- copy ((#\a literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+       ])))
+  (run 'test-send-first-key)
+  ; check that read-move consumes it and then goes to sleep
+  (enq read-move-routine running-routines*)
+  (wipe completed-routines*)
+  (keep-running)
+  (when (ran-to-completion 'read-move)
+    (prn "F - chessboard waits after first letter of move"))
+  ; send in a few more letters
+  (add-code
+    '((function test-send-next-keys [
+        (default-space:space-address <- new space:literal 30:literal/capacity)
+        (c:character <- copy ((#\2 literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+        (c:character <- copy ((#\- literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+        (c:character <- copy ((#\a literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+       ])))
+  (restart read-move-routine)
+  (run 'test-send-next-keys)
+  ; check that read-move consumes it and then goes to sleep
+  (when (ran-to-completion 'read-move)
+    (prn "F - chessboard waits after each subsequent letter of move until the last"))
+  ; send final key
+  (add-code
+    '((function test-send-final-key [
+        (default-space:space-address <- new space:literal 30:literal/capacity)
+        (c:character <- copy ((#\4 literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+       ])))
+  (run 'test-send-final-key)
+  ; check that read-move consumes it and -- this time -- returns
+  (restart read-move-routine)
+  (keep-running)
+  (prn rep.read-move-routine!sleep)
+  (when (~ran-to-completion 'read-move)
+    (prn "F - 'read-move' completes after final letter of move"))
+)
+
+(reset)
+(new-trace "read-move-quit")
+(add-code:readfile "chessboard-cursor.mu")
+(add-code
+  '((function! main [
+      (default-space:space-address <- new space:literal 30:literal/capacity)
+      (stdin:channel-address <- init-channel 1:literal)
+      (dummy:terminal-address <- init-fake-terminal 20:literal 10:literal)
+      (r:integer/routine <- fork-helper read-move:fn nil:literal/globals 2000:literal/limit stdin:channel-address dummy:terminal-address)
+      (c:character <- copy ((#\q literal)))
+      (x:tagged-value <- save-type c:character)
+      (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+      (sleep until-routine-done:literal r:integer/routine)
+     ])))
+(run 'main)
+(when (~ran-to-completion 'read-move)
+  (prn "F - chessboard quits on move starting with 'q'"))
+
+(reset)
+(new-trace "read-illegal-file")
+(add-code:readfile "chessboard-cursor.mu")
+(add-code
+  '((function! main [
+      (default-space:space-address <- new space:literal 30:literal/capacity)
+      (stdin:channel-address <- init-channel 1:literal)
+      (dummy:terminal-address <- init-fake-terminal 20:literal 10:literal)
+      (r:integer/routine <- fork-helper read-file:fn nil:literal/globals 2000:literal/limit stdin:channel-address dummy:terminal-address)
+      (c:character <- copy ((#\i literal)))
+      (x:tagged-value <- save-type c:character)
+      (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+      (sleep until-routine-done:literal r:integer/routine)
+     ])))
+;? (= dump-trace* (obj whitelist '("schedule")))
+(run 'main)
+;? (each routine completed-routines*
+;?   (prn "  " routine))
+(when (or (ran-to-completion 'read-file)
+          (let routine routine-running!read-file
+            (~posmatch "file too high" rep.routine!error)))
+  (prn "F - 'read-file' checks that file lies between 'a' and 'h'"))
+
+(reset)
+(new-trace "read-illegal-rank")
+(add-code:readfile "chessboard-cursor.mu")
+(add-code
+  '((function! main [
+      (default-space:space-address <- new space:literal 30:literal/capacity)
+      (stdin:channel-address <- init-channel 1:literal)
+      (dummy:terminal-address <- init-fake-terminal 20:literal 10:literal)
+      (r:integer/routine <- fork-helper read-rank:fn nil:literal/globals 2000:literal/limit stdin:channel-address dummy:terminal-address)
+      (c:character <- copy ((#\9 literal)))
+      (x:tagged-value <- save-type c:character)
+      (stdin:channel-address/deref <- write stdin:channel-address x:tagged-value)
+      (sleep until-routine-done:literal r:integer/routine)
+     ])))
+(run 'main)
+(when (or (ran-to-completion 'read-rank)
+          (let routine routine-running!read-rank
+            (~posmatch "rank too high" rep.routine!error)))
+  (prn "F - 'read-rank' checks that rank lies between '1' and '8'"))
+
+(reset)
+(new-trace "print-board")
+(add-code:readfile "chessboard-cursor.mu")
+(add-code
+  '((function! main [
+      (default-space:space-address <- new space:literal 30:literal/capacity)
+      (initial-position:list-address <- init-list ((#\R literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\r literal))
+                                                  ((#\N literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\n literal))
+                                                  ((#\B literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\b literal))
+                                                  ((#\Q literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\q literal))
+                                                  ((#\K literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\k literal))
+                                                  ((#\B literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\b literal))
+                                                  ((#\N literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\n literal))
+                                                  ((#\R literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\r literal)))
+      (b:board-address <- init-board initial-position:list-address)
+      (screen:terminal-address <- init-fake-terminal 20:literal 10:literal)
+      (print-board screen:terminal-address b:board-address)
+      (5:string-address/raw <- get screen:terminal-address/deref data:offset)
+     ])))
+;? (set dump-trace*)
+;? (= dump-trace* (obj whitelist '("run")))
+(run 'main)
+(each routine completed-routines*
+  (awhen rep.routine!error
+    (prn "error - " it)))
+;? (prn memory*.5)
+(when (~memory-contains-array memory*.5
+          (+ "8 | r n b q k b n r "
+             "7 | p p p p p p p p "
+             "6 | _ _ _ _ _ _ _ _ "
+             "5 | _ _ _ _ _ _ _ _ "
+             "4 | _ _ _ _ _ _ _ _ "
+             "3 | _ _ _ _ _ _ _ _ "
+             "2 | P P P P P P P P "
+             "1 | R N B Q K B N R "
+             "  +---------------- "
+             "    a b c d e f g h "))
+  (prn "F - print-board works; chessboard begins at @memory*.5"))
+
+; todo: how to fold this more elegantly with the previous test?
+(reset)
+(new-trace "make-move")
+(add-code:readfile "chessboard-cursor.mu")
+(add-code
+  '((function! main [
+      (default-space:space-address <- new space:literal 30:literal/capacity)
+      ; hook up stdin
+      (stdin:channel-address <- init-channel 1:literal)
+      ; fake screen
+      (screen:terminal-address <- init-fake-terminal 20:literal 10:literal)
+      ; initial position
+      (initial-position:list-address <- init-list ((#\R literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\r literal))
+                                                  ((#\N literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\n literal))
+                                                  ((#\B literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\b literal))
+                                                  ((#\Q literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\q literal))
+                                                  ((#\K literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\k literal))
+                                                  ((#\B literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\b literal))
+                                                  ((#\N literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\n literal))
+                                                  ((#\R literal)) ((#\P literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\_ literal)) ((#\p literal)) ((#\r literal)))
+      (b:board-address <- init-board initial-position:list-address)
+      ; move: a2-a4
+      (m:move-address <- new move:literal)
+      (f:integer-integer-pair-address <- get-address m:move-address/deref from:offset)
+      (dest:integer-address <- get-address f:integer-integer-pair-address/deref 0:offset)
+      (dest:integer-address/deref <- copy 0:literal)  ; from-file: a
+      (dest:integer-address <- get-address f:integer-integer-pair-address/deref 1:offset)
+      (dest:integer-address/deref <- copy 1:literal)  ; from-rank: 2
+      (t0:integer-integer-pair-address <- get-address m:move-address/deref to:offset)
+      (dest:integer-address <- get-address t0:integer-integer-pair-address/deref 0:offset)
+      (dest:integer-address/deref <- copy 0:literal)  ; to-file: a
+      (dest:integer-address <- get-address t0:integer-integer-pair-address/deref 1:offset)
+      (dest:integer-address/deref <- copy 3:literal)  ; to-rank: 4
+      (b:board-address <- make-move b:board-address m:move-address)
+      (print-board screen:terminal-address b:board-address)
+      (5:string-address/raw <- get screen:terminal-address/deref data:offset)
+     ])))
+;? (set dump-trace*)
+;? (= dump-trace* (obj whitelist '("run")))
+(run 'main)
+(each routine completed-routines*
+  (awhen rep.routine!error
+    (prn "error - " it)))
+;? (prn memory*.5)
+(when (~memory-contains-array memory*.5
+          (+ "8 | r n b q k b n r "
+             "7 | p p p p p p p p "
+             "6 | _ _ _ _ _ _ _ _ "
+             "5 | _ _ _ _ _ _ _ _ "
+             "4 | P _ _ _ _ _ _ _ "
+             "3 | _ _ _ _ _ _ _ _ "
+             "2 | _ P P P P P P P "
+             "1 | R N B Q K B N R "
+             "  +---------------- "
+             "    a b c d e f g h "))
+  (prn "F - make-move works; chessboard begins at @memory*.5"))
+
+(reset)
diff --git a/chessboard-cursor.arc.t.3 b/chessboard-cursor.arc.t.3
new file mode 100644
index 00000000..dd9fe694
--- /dev/null
+++ b/chessboard-cursor.arc.t.3
@@ -0,0 +1,116 @@
+(selective-load "mu.arc" section-level)
+
+(def restart (routine)
+  (dump "before restart" routine)
+  (while (in top.routine!fn-name 'read 'write)
+    (pop-stack routine))
+  (wipe rep.routine!sleep)
+  (dump "after restart" routine)
+  (when foo-routine*
+    (prn "AAA " (is routine foo-routine*)))
+  (enq routine running-routines*))
+
+(def dump (msg r)
+  (prn "= @msg " rep.r!sleep)
+  (prn:rem [in car._ 'sleep 'call-stack] (as cons rep.r))
+  (each frame rep.r!call-stack
+    (prn " @frame!fn-name")
+    (each (key val) frame
+      (unless (is key 'fn-name)
+        (prn "  " key " " val)))))
+
+(reset)
+(add-code:readfile "chessboard-cursor.mu")
+; initialize location 1 to stdin; location 2 to screen fake; 3 to the contents
+; of the fake
+(add-code 
+  '((function test-init [
+      (1:channel-address/raw <- init-channel 1:literal)
+      (2:terminal-address/raw <- init-fake-terminal 20:literal 10:literal)
+      (3:string-address/raw <- get 2:terminal-address/raw/deref data:offset)
+     ])))
+;? (= dump-trace* (obj whitelist '("schedule")))
+(run 'test-init)
+; the component under test; we'll be running this repeatedly
+(let read-move-routine (make-routine 'read-move memory*.1 memory*.2)
+  (= foo-routine* read-move-routine)
+;?   (set rep.read-move-routine!helper)
+  ; send in first letter
+  (add-code
+    '((function test-send-first-key [
+        (default-space:space-address <- new space:literal 30:literal/capacity)
+        (c:character <- copy ((#\a literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+       ])))
+  (run 'test-send-first-key)
+  ; check that read-move consumes it and then goes to sleep
+  (prn "AAA routine: " (routine-running 'read-move))
+  (prn "AAA routine changed? " (is read-move-routine (routine-running 'read-move)))
+  (enq read-move-routine running-routines*)
+  (wipe completed-routines*)
+  (keep-running)
+  (prn "AAA routine: " (routine-running 'read-move))
+  (prn "AAA routine changed? " (is read-move-routine (routine-running 'read-move)))
+  (prn "=======================")
+  (when (ran-to-completion 'read-move)
+    (prn "F - chessboard waits after first letter of move"))
+  ; send in a few more letters
+  (add-code
+    '((function test-send-next-keys [
+        (default-space:space-address <- new space:literal 30:literal/capacity)
+        (c:character <- copy ((#\2 literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+        (c:character <- copy ((#\- literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+        (c:character <- copy ((#\a literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+       ])))
+  (prn "== restart: read-move")
+  (prn "AAA routine3: " (routine-running 'read-move))
+  (prn "AAA routine changed? " (is read-move-routine (routine-running 'read-move)))
+  (wipe completed-routines*)
+  (restart read-move-routine)
+;?   (= dump-trace* (obj blacklist '("c{0" "c{1" "cn0" "cn1" "maybe-add")))
+  (= dump-trace* (obj whitelist '("schedule")))
+  (prn "AAA routine4: " (routine-running 'read-move))
+  (prn "AAA routine changed? " (is read-move-routine (routine-running 'read-move)))
+  (run 'test-send-next-keys)
+  (prn "AAA routine5: " (routine-running 'read-move))
+  (prn "AAA routine changed? " (is read-move-routine (routine-running 'read-move)))
+  (dump "Final" read-move-routine)
+  (quit)
+  ; check that read-move consumes it and then goes to sleep
+  (when (ran-to-completion 'read-move)
+    (prn "F - chessboard waits after each subsequent letter of move until the last"))
+  ; send final key
+  (add-code
+    '((function test-send-final-key [
+        (default-space:space-address <- new space:literal 30:literal/capacity)
+        (c:character <- copy ((#\4 literal)))
+        (x:tagged-value <- save-type c:character)
+        (1:channel-address/raw/deref <- write 1:channel-address/raw x:tagged-value)
+       ])))
+  (run 'test-send-final-key)
+  ; check that read-move consumes it and -- this time -- returns
+  (prn "== restart: read-move")
+  (restart read-move-routine)
+  (keep-running)
+  (dump "5" read-move-routine)
+  (when (~ran-to-completion 'read-move)
+    (prn "F - 'read-move' completes after final letter of move"))
+)
+
+; log
+;   drop helper bit in component under test
+;   canon messing up 'is' over table contents
+;   mergesort not preserving pointers of list members!!!
+;     (should have chased down why canon was breaking things a whole day ago)
+;   bad commit in anarki:
+;     commit 4a5bad8a4fa3c60a6e270285c5a98af9d0faf17f
+;     Date:   Sun Nov 11 17:40:58 2012 -0800
+;
+;         make copy work with nested lists and tables
diff --git a/mu.arc b/mu.arc
index b66ec3bb..648890eb 100644
--- a/mu.arc
+++ b/mu.arc
@@ -206,11 +206,13 @@
 ;; managing concurrent routines
 
 (on-init
+;?   (prn "-- resetting memory allocation")
   (= Memory-allocated-until 1000))
 
 ; routine = runtime state for a serial thread of execution
 (def make-routine (fn-name . args)
   (let curr-alloc Memory-allocated-until
+;?     (prn "-- allocating routine: @curr-alloc")
     (++ Memory-allocated-until 100000)
     (annotate 'routine (obj alloc curr-alloc  alloc-max Memory-allocated-until
         call-stack
@@ -301,17 +303,29 @@
   (= traces* (queue))
   (each it fn-names
     (enq make-routine.it running-routines*))
+  (keep-running))
+
+(def keep-running ()
+;?   (prn "---")
   (while (~empty running-routines*)
+    (when foo-routine*
+      (prn "AAA keep-running0 " (is foo-routine* (routine-running2 'read-move))))
     (= routine* deq.running-routines*)
     (when rep.routine*!limit
       ; start the clock if it wasn't already running
       (or= rep.routine*!running-since curr-cycle*))
     (trace "schedule" top.routine*!fn-name)
+    (when foo-routine*
+      (prn "AAA keep-running1 " (is foo-routine* (routine-running2 'read-move))))
     (routine-mark
       (run-for-time-slice scheduling-interval*))
+    (when foo-routine*
+      (prn "AAA keep-running2 " (is foo-routine* (routine-running2 'read-move))))
     (update-scheduler-state)
 ;?     (tr "after run iter " running-routines*)
 ;?     (tr "after run iter " empty.running-routines*)
+    (when foo-routine*
+      (prn "AAA keep-running3 " (is foo-routine* (routine-running2 'read-move))))
     ))
 
 ; prepare next iteration of round-robin scheduler
@@ -326,13 +340,17 @@
 ;   detect termination: all non-helper routines completed
 ;   detect deadlock: kill all sleeping routines when none can be woken
 (def update-scheduler-state ()
-;?   (tr curr-cycle*)
   (when routine*
     (if
         rep.routine*!sleep
           (do (trace "schedule" "pushing " top.routine*!fn-name " to sleep queue")
+              (when foo-routine*
+                (prn "AAA update1 " (is foo-routine* (routine-running2 'read-move))))
               ; keep the clock ticking at rep.routine*!running-since
-              (set sleeping-routines*.routine*))
+              (set sleeping-routines*.routine*)
+              (when foo-routine*
+                (prn "AAA update2 " (is foo-routine* (routine-running2 'read-move))))
+              )
         rep.routine*!error
           (do (trace "schedule" "done with dead routine " top.routine*!fn-name)
 ;?               (tr rep.routine*)
@@ -354,24 +372,38 @@
                 (enq routine* running-routines*)))
         :else
           (err "illegal scheduler state"))
+    (when foo-routine*
+      (prn "AAA update3 " (is foo-routine* (routine-running2 'read-move))))
     (= routine* nil))
-;?   (tr 111)
+  (when foo-routine*
+    (prn "AAA update4 " (is foo-routine* (routine-running2 'read-move))))
   (each (routine _) canon.sleeping-routines*
-;?     (tr routine)
     (when (aand rep.routine!limit (<= it (- curr-cycle* rep.routine!running-since)))
       (trace "schedule" "routine timed out")
       (wipe sleeping-routines*.routine)
       (push routine completed-routines*)
 ;?       (tr completed-routines*)
       ))
+  (when foo-routine*
+    (prn "AAA update5 " (is foo-routine* (routine-running2 'read-move))))
   (each (routine _) canon.sleeping-routines*
+    (when foo-routine*
+      (prn "AAA update5.1 " (is foo-routine* (routine-running2 'read-move))))
     (when (ready-to-wake-up routine)
       (trace "schedule" "waking up " top.routine!fn-name)
+      (when foo-routine*
+        (prn "AAA update5.3 " (is foo-routine* (prn:routine-running2 'read-move)))
+        (prn "AAA update5.3.2 " (is foo-routine* routine)))
       (wipe sleeping-routines*.routine)  ; do this before modifying routine
+      (when foo-routine*
+        (prn "AAA update5.4 " (is foo-routine* (routine-running2 'read-move))))
       (wipe rep.routine!sleep)
+      (when foo-routine*
+        (prn "AAA update5.5 " (is foo-routine* (routine-running2 'read-move))))
       (++ pc.routine)
       (enq routine running-routines*)))
-;?   (tr 112)
+  (when foo-routine*
+    (prn "AAA update6 " (is foo-routine* (routine-running2 'read-move))))
   ; optimization for simulated time
   (when (empty running-routines*)
     (whenlet exact-sleeping-routines (keep waiting-for-exact-cycle? keys.sleeping-routines*)
@@ -379,21 +411,29 @@
         (= curr-cycle* (+ 1 next-wakeup-cycle)))
       (trace "schedule" "skipping to cycle " curr-cycle*)
       (update-scheduler-state)))
-;?   (prn running-routines*)
-;?   (prn sleeping-routines*)
+  (when foo-routine*
+    (prn "AAA update7 " (is foo-routine* (routine-running2 'read-move))))
   (when (and (or (~empty running-routines*)
                  (~empty sleeping-routines*))
              (all [rep._ 'helper] (as cons running-routines*))
              (all [rep._ 'helper] keys.sleeping-routines*))
     (trace "schedule" "just helpers left; stopping everything")
     (until (empty running-routines*)
-      (push (deq running-routines*) completed-routines*))
+      (= routine* (deq running-routines*))
+;?       (routine-mark
+;?         (run-for-time-slice scheduling-interval*))
+      (push routine* completed-routines*))
     (each (routine _) sleeping-routines*
       (wipe sleeping-routines*.routine)
+      (= routine* routine)
+;?       (routine-mark
+;?         (run-for-time-slice scheduling-interval*))
       (push routine completed-routines*)))
-;?   (tr 113)
+  (when foo-routine*
+    (prn "AAA update8 " (is foo-routine* (routine-running2 'read-move))))
   (detect-deadlock)
-;?   (tr 114)
+  (when foo-routine*
+    (prn "AAA update9 " (is foo-routine* (routine-running2 'read-move))))
   )
 
 (def detect-deadlock ()
@@ -459,6 +499,8 @@
 ($:require graphics/graphics)
 (= Viewport nil)
 
+(= foo-routine* nil)
+
 ; run instructions from 'routine*' for 'time-slice'
 (def run-for-time-slice (time-slice)
   (point return
@@ -643,6 +685,12 @@
                         (die "badly formed 'sleep' call @(tostring:prn (body.routine* pc.routine*))")
                       )
                     ((abort-routine*)))
+                foo
+                  (when foo-routine*
+                    (prn "AAAA " (is routine* foo-routine*))
+;?                     (dump (m arg.0) foo-routine*)
+;?                     (dump "routine*" routine*)
+                    )
                 assert
                   (unless (m arg.0)
                     (die (v arg.1)))  ; other routines will be able to look at the error status
@@ -664,7 +712,7 @@
                   (do1 nil ($.charterm-newline))
                 print-primitive-to-host
                   (do1 nil
-;?                        (prn (m arg.0) " => " (type (m arg.0)))
+;?                        (write (m arg.0))  (pr " => ")  (prn (type (m arg.0)))
                        ((if ($.current-charterm) $.charterm-display pr) (m arg.0))
                        )
                 read-key
@@ -717,8 +765,6 @@
                   (let pixel (($.get-color-pixel Viewport) ($.make-posn (m arg.0) (m arg.1)))
                     (prn ($.rgb-red pixel) " " ($.rgb-blue pixel) " " ($.rgb-green pixel))
                     ($:rgb-red pixel))
-                foo
-                  (= times* (table))
 
                 ; user-defined functions
                 next-input
@@ -1442,6 +1488,18 @@
   (find [some [is f _!fn-name] stack._]
         completed-routines*))
 
+(def routine-running2 (f)
+  (or
+    (find [some [is f _!fn-name] stack._]
+          completed-routines*)
+    (find [some [is f _!fn-name] stack._]
+          (as cons running-routines*))
+    (find [some [is f _!fn-name] stack._]
+          (keys sleeping-routines*))
+    (and routine*
+         (some [is f _!fn-name] stack.routine*)
+         routine*)))
+
 (def ran-to-completion (f)
   ; if a routine calling f ran to completion there'll be no sign of it in any
   ; completed call-stacks.
@@ -1596,8 +1654,12 @@
     (full:boolean <- full? chan:channel-address/deref)
     (break-unless full:boolean)
     (full-address:integer-address <- get-address chan:channel-address/deref first-full:offset)
+;?     (print-primitive-to-host (("write sleep: " literal)))
+;?     (print-primitive-to-host full-address:integer-address/deref)
+;?     (print-primitive-to-host (("\n" literal)))
     (sleep until-location-changes:literal full-address:integer-address/deref)
   }
+;?   (print-primitive-to-host (("continuing write" literal)))
   ; store val
   (q:tagged-value-array-address <- get chan:channel-address/deref circular-buffer:offset)
   (free:integer-address <- get-address chan:channel-address/deref first-free:offset)
@@ -1622,8 +1684,13 @@
     (empty:boolean <- empty? chan:channel-address/deref)
     (break-unless empty:boolean)
     (free-address:integer-address <- get-address chan:channel-address/deref first-free:offset)
+;?     (foo (("blocking read" literal)))
+;?     (print-primitive-to-host (("read sleep: " literal)))
+;?     (print-primitive-to-host free-address:integer-address/deref)
+;?     (print-primitive-to-host (("\n" literal)))
     (sleep until-location-changes:literal free-address:integer-address/deref)
   }
+;?   (foo (("continuing read" literal)))
   ; read result
   (full:integer-address <- get-address chan:channel-address/deref first-full:offset)
   (q:tagged-value-array-address <- get chan:channel-address/deref circular-buffer:offset)