erlang: Phase 9e — OP_SPAWN / OP_SEND + VM-process registry (+16 vm tests)

lib/erlang/scoreboard.json

@@ -1,7 +1,7 @@
 {
   "language": "erlang",
-  "total_pass": 675,
-  "total": 675,
+  "total_pass": 691,
+  "total": 691,
   "suites": [
     {"name":"tokenize","pass":62,"total":62,"status":"ok"},
     {"name":"parse","pass":52,"total":52,"status":"ok"},
@@ -13,6 +13,6 @@
     {"name":"echo","pass":7,"total":7,"status":"ok"},
     {"name":"fib","pass":8,"total":8,"status":"ok"},
     {"name":"ffi","pass":14,"total":14,"status":"ok"},
-    {"name":"vm","pass":38,"total":38,"status":"ok"}
+    {"name":"vm","pass":54,"total":54,"status":"ok"}
   ]
 }

lib/erlang/scoreboard.md

@@ -1,6 +1,6 @@
 # Erlang-on-SX Scoreboard
 
-**Total: 675 / 675 tests passing**
+**Total: 691 / 691 tests passing**
 
 |  | Suite | Pass | Total |
 |---|---|---|---|
@@ -14,7 +14,7 @@
 | ✅ | echo | 7 | 7 |
 | ✅ | fib | 8 | 8 |
 | ✅ | ffi | 14 | 14 |
-| ✅ | vm | 38 | 38 |
+| ✅ | vm | 54 | 54 |
 
 
 Generated by `lib/erlang/conformance.sh`.

lib/erlang/tests/vm.sx

@@ -251,4 +251,57 @@
 (er-vm-test "scan binds first match's var"
   (get er-vm-r4-env "X") 1)
 
+
+;; ── Phase 9e — OP_SPAWN / OP_SEND ───────────────────────────────
+(er-vm-procs-reset!)
+
+(er-vm-test "spawn opcode by id"
+  (get (er-vm-lookup-opcode-by-id 134) :name) "OP_SPAWN")
+(er-vm-test "send opcode by id"
+  (get (er-vm-lookup-opcode-by-id 135) :name) "OP_SEND")
+
+(define er-vm-fn (fn () "body"))
+(define er-vm-p1 (er-vm-dispatch 134 (list er-vm-fn (list))))
+(define er-vm-p2 (er-vm-dispatch 134 (list er-vm-fn (list "arg"))))
+(er-vm-test "spawn returns pid 0 first"
+  er-vm-p1 0)
+(er-vm-test "spawn returns pid 1 second"
+  er-vm-p2 1)
+(er-vm-test "proc count is 2"
+  (er-vm-proc-count) 2)
+(er-vm-test "spawned proc state runnable"
+  (er-vm-proc-state er-vm-p1) "runnable")
+(er-vm-test "spawned proc mailbox empty"
+  (len (er-vm-proc-mailbox er-vm-p1)) 0)
+(er-vm-test "spawned proc has 8 registers"
+  (len (get (er-vm-proc-get er-vm-p1) :registers)) 8)
+
+;; OP_SEND appends to target's mailbox, preserves arrival order.
+(er-vm-test "send returns true on valid pid"
+  (er-vm-dispatch 135 (list er-vm-p1 "msg1")) true)
+(er-vm-dispatch 135 (list er-vm-p1 "msg2")
+)
+(er-vm-dispatch 135 (list er-vm-p1 "msg3"))
+(er-vm-test "mailbox length after 3 sends"
+  (len (er-vm-proc-mailbox er-vm-p1)) 3)
+(er-vm-test "mailbox preserves order — first"
+  (nth (er-vm-proc-mailbox er-vm-p1) 0) "msg1")
+(er-vm-test "mailbox preserves order — last"
+  (nth (er-vm-proc-mailbox er-vm-p1) 2) "msg3")
+
+;; send to nonexistent pid returns false (doesn't crash)
+(er-vm-test "send to unknown pid is false"
+  (er-vm-dispatch 135 (list 99999 "x")) false)
+
+;; Isolation: msgs to p1 don't appear in p2's mailbox
+(er-vm-test "isolation — p2 mailbox empty"
+  (len (er-vm-proc-mailbox er-vm-p2)) 0)
+
+;; reset clears
+(er-vm-procs-reset!)
+(er-vm-test "reset clears procs"
+  (er-vm-proc-count) 0)
+(er-vm-test "reset resets pid counter"
+  (er-vm-dispatch 134 (list er-vm-fn (list))) 0)
+
 (define er-vm-test-summary (str "vm " er-vm-test-pass "/" er-vm-test-count))

lib/erlang/vm/dispatcher.sx

@@ -161,6 +161,63 @@
   (fn (operands)
     (er-vm-receive-scan-loop (nth operands 0) (nth operands 1) (nth operands 2) 0)))
 
+;; ── Phase 9e — spawn / send + lightweight scheduler ─────────────
+;; Stub register-machine process layout for the eventual fast scheduler.
+;; A VM-process is `{:id :registers :mailbox :state :initial-fn :initial-args}`.
+;; Registers is a vector (SX list, mutated via set-nth!) — fixed slot count
+;; per process so cells don't grow during execution. Mailbox is an SX list.
+;; State is one of "runnable" / "waiting" / "dead". This sits PARALLEL to
+;; the existing `er-scheduler` (which is the language-level scheduler) —
+;; the VM scheduler will eventually take over once 9a integrates and
+;; bytecode-compiled Erlang runs against it.
+
+(define er-vm-procs (list {}))
+(define er-vm-procs-get (fn () (nth er-vm-procs 0)))
+(define er-vm-procs-reset!
+  (fn () (do (set-nth! er-vm-procs 0 {}) (set-nth! er-vm-next-pid 0 0))))
+
+(define er-vm-next-pid (list 0))
+
+(define er-vm-proc-new!
+  (fn (initial-fn initial-args)
+    (let ((pid (nth er-vm-next-pid 0)))
+      (set-nth! er-vm-next-pid 0 (+ pid 1))
+      (let ((proc
+              {:id pid
+               :registers (list nil nil nil nil nil nil nil nil)
+               :mailbox (list)
+               :state "runnable"
+               :initial-fn initial-fn
+               :initial-args initial-args}))
+        (dict-set! (er-vm-procs-get) (str pid) proc)
+        pid))))
+
+(define er-vm-proc-get (fn (pid) (get (er-vm-procs-get) (str pid))))
+
+(define er-vm-proc-send!
+  (fn (pid msg)
+    (let ((proc (er-vm-proc-get pid)))
+      (cond
+        (= proc nil) false
+        :else
+          (do
+            (dict-set! proc :mailbox (append (get proc :mailbox) (list msg)))
+            (when (= (get proc :state) "waiting")
+              (dict-set! proc :state "runnable"))
+            true)))))
+
+(define er-vm-proc-mailbox (fn (pid) (get (er-vm-proc-get pid) :mailbox)))
+(define er-vm-proc-state (fn (pid) (get (er-vm-proc-get pid) :state)))
+(define er-vm-proc-count (fn () (len (keys (er-vm-procs-get)))))
+
+(define er-vm-op-spawn
+  (fn (operands)
+    (er-vm-proc-new! (nth operands 0) (nth operands 1))))
+
+(define er-vm-op-send
+  (fn (operands)
+    (er-vm-proc-send! (nth operands 0) (nth operands 1))))
+
 ;; ── Phase 9b — pattern-match opcodes ────────────────────────────
 ;; Each handler takes a list (pattern-ast value env) and returns
 ;; true/false, mutating env on success (same contract as the
@@ -202,6 +259,8 @@
     (er-vm-register-opcode! 131 "OP_PERFORM" er-vm-op-perform)
     (er-vm-register-opcode! 132 "OP_HANDLE" er-vm-op-handle)
     (er-vm-register-opcode! 133 "OP_RECEIVE_SCAN" er-vm-op-receive-scan)
+    (er-vm-register-opcode! 134 "OP_SPAWN" er-vm-op-spawn)
+    (er-vm-register-opcode! 135 "OP_SEND" er-vm-op-send)
     (er-mk-atom "ok")))
 
 (er-vm-register-erlang-opcodes!)