From c0f0c8fafeaec847d9e777d669438705dbeba88e Mon Sep 17 00:00:00 2001
From: Olivier Nicole <olivier@chnik.fr>
Date: Thu, 12 Sep 2024 18:23:27 +0200
Subject: [PATCH 1/5] Handle primitives that depend on the OCaml version

---
 runtime/wasm/domain.wat         | 22 ++------
 runtime/wasm/dune               | 96 ++++++++++++++++++++++++++++++++-
 runtime/wasm/post-5.2.wat       | 57 ++++++++++++++++++++
 runtime/wasm/pre-5.2.wat        | 42 +++++++++++++++
 runtime/wasm/runtime_events.wat |  4 --
 5 files changed, 196 insertions(+), 25 deletions(-)
 create mode 100644 runtime/wasm/post-5.2.wat
 create mode 100644 runtime/wasm/pre-5.2.wat

diff --git a/runtime/wasm/domain.wat b/runtime/wasm/domain.wat
index 2ba72bcf9..d07d70053 100644
--- a/runtime/wasm/domain.wat
+++ b/runtime/wasm/domain.wat
@@ -19,11 +19,6 @@
    (type $block (array (mut (ref eq))))
    (type $function_1 (func (param (ref eq) (ref eq)) (result (ref eq))))
    (type $closure (sub (struct (;(field i32);) (field (ref $function_1)))))
-   (import "sync" "caml_ml_mutex_unlock"
-      (func $caml_ml_mutex_unlock (param (ref eq)) (result (ref eq))))
-   (import "obj" "caml_callback_1"
-      (func $caml_callback_1
-         (param (ref eq)) (param (ref eq)) (result (ref eq))))
 
    (func (export "caml_atomic_cas")
       (param $ref (ref eq)) (param $o (ref eq)) (param $n (ref eq))
@@ -96,20 +91,9 @@
       (param (ref eq)) (result (ref eq))
       (ref.i31 (i32.const 1)))
 
-   (global $caml_domain_id (mut i32) (i32.const 0))
-   (global $caml_domain_latest_id (mut i32) (i32.const 1))
-
-   (func (export "caml_domain_spawn")
-      (param $f (ref eq)) (param $mutex (ref eq)) (result (ref eq))
-      (local $id i32) (local $old i32)
-      (local.set $id (global.get $caml_domain_latest_id))
-      (global.set $caml_domain_latest_id
-         (i32.add (local.get $id) (i32.const 1)))
-      (local.set $old (global.get $caml_domain_id))
-      (drop (call $caml_callback_1 (local.get $f) (ref.i31 (i32.const 0))))
-      (global.set $caml_domain_id (local.get $old))
-      (drop (call $caml_ml_mutex_unlock (local.get $mutex)))
-      (ref.i31 (local.get $id)))
+   (global $caml_domain_id (export "caml_domain_id") (mut i32) (i32.const 0))
+   (global $caml_domain_latest_id (export "caml_domain_latest_id") (mut i32)
+      (i32.const 1))
 
    (func (export "caml_ml_domain_id") (param (ref eq)) (result (ref eq))
       (ref.i31 (global.get $caml_domain_id)))
diff --git a/runtime/wasm/dune b/runtime/wasm/dune
index 2923b1ac9..cf759a62b 100644
--- a/runtime/wasm/dune
+++ b/runtime/wasm/dune
@@ -3,11 +3,64 @@
  (package wasm_of_ocaml-compiler)
  (files runtime.wasm runtime.js))
 
+(rule
+  (target version-dependent.wat)
+  (deps post-5.2.wat)
+  (enabled_if (>= %{ocaml_version} 5.2.0))
+  (action
+    (copy %{deps} %{target})))
+
+(rule
+  (target version-dependent.wat)
+  (deps pre-5.2.wat)
+  (enabled_if (< %{ocaml_version} 5.2.0))
+  (action
+    (copy %{deps} %{target})))
+
 (rule
  (target runtime.wasm)
  (deps
   args
-  (glob_files *.wat))
+  array.wat
+  backtrace.wat
+  bigarray.wat
+  bigstring.wat
+  compare.wat
+  custom.wat
+  domain.wat
+  dynlink.wat
+  effect.wat
+  fail.wat
+  float.wat
+  fs.wat
+  gc.wat
+  hash.wat
+  int32.wat
+  int64.wat
+  ints.wat
+  io.wat
+  jslib.wat
+  jslib_js_of_ocaml.wat
+  jsstring.wat
+  lexing.wat
+  marshal.wat
+  md5.wat
+  nat.wat
+  obj.wat
+  parsing.wat
+  printexc.wat
+  prng.wat
+  runtime_events.wat
+  stdlib.wat
+  str.wat
+  string.wat
+  sync.wat
+  sys.wat
+  toplevel.wat
+  unix.wat
+  version-dependent.wat
+  weak.wat
+  zstd.wat)
  (action
   (progn
    (system
@@ -47,7 +100,46 @@
  (target args)
  (deps
   args.ml
-  (glob_files *.wat))
+  array.wat
+  backtrace.wat
+  bigarray.wat
+  bigstring.wat
+  compare.wat
+  custom.wat
+  domain.wat
+  dynlink.wat
+  effect.wat
+  fail.wat
+  float.wat
+  fs.wat
+  gc.wat
+  hash.wat
+  int32.wat
+  int64.wat
+  ints.wat
+  io.wat
+  jslib.wat
+  jslib_js_of_ocaml.wat
+  jsstring.wat
+  lexing.wat
+  marshal.wat
+  md5.wat
+  nat.wat
+  obj.wat
+  parsing.wat
+  printexc.wat
+  prng.wat
+  runtime_events.wat
+  stdlib.wat
+  str.wat
+  string.wat
+  sync.wat
+  sys.wat
+  toplevel.wat
+  unix.wat
+  version-dependent.wat
+  weak.wat
+  zstd.wat)
  (action
   (with-stdout-to
    %{target}
diff --git a/runtime/wasm/post-5.2.wat b/runtime/wasm/post-5.2.wat
new file mode 100644
index 000000000..cd99832f1
--- /dev/null
+++ b/runtime/wasm/post-5.2.wat
@@ -0,0 +1,57 @@
+;; Wasm_of_ocaml runtime support
+;; http://www.ocsigen.org/js_of_ocaml/
+;;
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU Lesser General Public License as published by
+;; the Free Software Foundation, with linking exception;
+;; either version 2.1 of the License, or (at your option) any later version.
+;;
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU Lesser General Public License for more details.
+;;
+;; You should have received a copy of the GNU Lesser General Public License
+;; along with this program; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+(module
+   (type $block (array (mut (ref eq))))
+   (import "obj" "caml_callback_1"
+      (func $caml_callback_1
+         (param (ref eq)) (param (ref eq)) (result (ref eq))))
+   (import "sync" "caml_ml_mutex_unlock"
+      (func $caml_ml_mutex_unlock (param (ref eq)) (result (ref eq))))
+   (import "domain" "caml_domain_latest_id"
+     (global $caml_domain_latest_id (mut i32)))
+   (import "domain" "caml_domain_id"
+     (global $caml_domain_id (mut i32)))
+
+   (func (export "caml_runtime_events_user_write")
+      (param (ref eq)) (param (ref eq)) (param (ref eq)) (result (ref eq))
+      (ref.i31 (i32.const 0)))
+
+   (func (export "caml_domain_spawn")
+      (param $f (ref eq)) (param $term_sync_v (ref eq)) (result (ref eq))
+      (local $id i32) (local $old i32) (local $ts (ref $block)) (local $res (ref eq))
+      (local.set $id (global.get $caml_domain_latest_id))
+      (global.set $caml_domain_latest_id
+         (i32.add (local.get $id) (i32.const 1)))
+      (local.set $old (global.get $caml_domain_id))
+      (local.set $res
+         (call $caml_callback_1 (local.get $f) (ref.i31 (i32.const 0))))
+      (global.set $caml_domain_id (local.get $old))
+      (local.set $ts (ref.cast (ref $block) (local.get $term_sync_v)))
+      (drop (call $caml_ml_mutex_unlock (array.get $block (local.get $ts) (i32.const 2))))
+      ;; TODO: fix exn case
+      (array.set
+         $block
+         (local.get $ts)
+         (i32.const 1)
+         (array.new_fixed
+            $block
+            2
+            (ref.i31 (i32.const 0))
+            (array.new_fixed $block 2 (ref.i31 (i32.const 0)) (local.get $res))))
+      (ref.i31 (local.get $id)))
+)
diff --git a/runtime/wasm/pre-5.2.wat b/runtime/wasm/pre-5.2.wat
new file mode 100644
index 000000000..fafc0413c
--- /dev/null
+++ b/runtime/wasm/pre-5.2.wat
@@ -0,0 +1,42 @@
+;; Wasm_of_ocaml runtime support
+;; http://www.ocsigen.org/js_of_ocaml/
+;;
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU Lesser General Public License as published by
+;; the Free Software Foundation, with linking exception;
+;; either version 2.1 of the License, or (at your option) any later version.
+;;
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU Lesser General Public License for more details.
+;;
+;; You should have received a copy of the GNU Lesser General Public License
+;; along with this program; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+(module
+   (import "obj" "caml_callback_1"
+      (func $caml_callback_1
+         (param (ref eq)) (param (ref eq)) (result (ref eq))))
+   (import "sync" "caml_ml_mutex_unlock"
+      (func $caml_ml_mutex_unlock (param (ref eq)) (result (ref eq))))
+   (import "domain" "caml_domain_latest_id"
+     (global $caml_domain_latest_id (mut i32)))
+
+   (func (export "caml_runtime_events_user_write")
+      (param (ref eq)) (param (ref eq)) (result (ref eq))
+      (ref.i31 (i32.const 0)))
+
+   (func (export "caml_domain_spawn")
+      (param $f (ref eq)) (param $mutex (ref eq)) (result (ref eq))
+      (local $id i32) (local $old i32)
+      (local.set $id (global.get $caml_domain_latest_id))
+      (global.set $caml_domain_latest_id
+         (i32.add (local.get $id) (i32.const 1)))
+      (local.set $old (global.get $caml_domain_id))
+      (drop (call $caml_callback_1 (local.get $f) (ref.i31 (i32.const 0))))
+      (global.set $caml_domain_id (local.get $old))
+      (drop (call $caml_ml_mutex_unlock (local.get $mutex)))
+      (ref.i31 (local.get $id)))
+)
diff --git a/runtime/wasm/runtime_events.wat b/runtime/wasm/runtime_events.wat
index ff77e5570..8a50583cd 100644
--- a/runtime/wasm/runtime_events.wat
+++ b/runtime/wasm/runtime_events.wat
@@ -33,10 +33,6 @@
          (local.get $evtag)
          (local.get $evtype)))
 
-   (func (export "caml_runtime_events_user_write")
-      (param (ref eq)) (param (ref eq)) (param (ref eq)) (result (ref eq))
-      (ref.i31 (i32.const 0)))
-
    (func (export "caml_runtime_events_user_resolve")
       (param (ref eq)) (param (ref eq)) (param (ref eq)) (result (ref eq))
       (ref.i31 (i32.const 0)))

From d30fe1f1f98eb001cc6c77c1551a0572438c0b86 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Vouillon?= <jerome.vouillon@gmail.com>
Date: Fri, 13 Sep 2024 11:45:06 +0200
Subject: [PATCH 2/5] Move version-dependant files to subdirectory

---
 runtime/wasm/dune                             | 86 +------------------
 .../wasm/{ => version-dependent}/post-5.2.wat |  0
 .../wasm/{ => version-dependent}/pre-5.2.wat  |  0
 3 files changed, 4 insertions(+), 82 deletions(-)
 rename runtime/wasm/{ => version-dependent}/post-5.2.wat (100%)
 rename runtime/wasm/{ => version-dependent}/pre-5.2.wat (100%)

diff --git a/runtime/wasm/dune b/runtime/wasm/dune
index cf759a62b..8f501d40f 100644
--- a/runtime/wasm/dune
+++ b/runtime/wasm/dune
@@ -5,14 +5,14 @@
 
 (rule
   (target version-dependent.wat)
-  (deps post-5.2.wat)
+  (deps version-dependent/post-5.2.wat)
   (enabled_if (>= %{ocaml_version} 5.2.0))
   (action
     (copy %{deps} %{target})))
 
 (rule
   (target version-dependent.wat)
-  (deps pre-5.2.wat)
+  (deps version-dependent/pre-5.2.wat)
   (enabled_if (< %{ocaml_version} 5.2.0))
   (action
     (copy %{deps} %{target})))
@@ -21,46 +21,7 @@
  (target runtime.wasm)
  (deps
   args
-  array.wat
-  backtrace.wat
-  bigarray.wat
-  bigstring.wat
-  compare.wat
-  custom.wat
-  domain.wat
-  dynlink.wat
-  effect.wat
-  fail.wat
-  float.wat
-  fs.wat
-  gc.wat
-  hash.wat
-  int32.wat
-  int64.wat
-  ints.wat
-  io.wat
-  jslib.wat
-  jslib_js_of_ocaml.wat
-  jsstring.wat
-  lexing.wat
-  marshal.wat
-  md5.wat
-  nat.wat
-  obj.wat
-  parsing.wat
-  printexc.wat
-  prng.wat
-  runtime_events.wat
-  stdlib.wat
-  str.wat
-  string.wat
-  sync.wat
-  sys.wat
-  toplevel.wat
-  unix.wat
-  version-dependent.wat
-  weak.wat
-  zstd.wat)
+  (glob_files *.wat))
  (action
   (progn
    (system
@@ -100,46 +61,7 @@
  (target args)
  (deps
   args.ml
-  array.wat
-  backtrace.wat
-  bigarray.wat
-  bigstring.wat
-  compare.wat
-  custom.wat
-  domain.wat
-  dynlink.wat
-  effect.wat
-  fail.wat
-  float.wat
-  fs.wat
-  gc.wat
-  hash.wat
-  int32.wat
-  int64.wat
-  ints.wat
-  io.wat
-  jslib.wat
-  jslib_js_of_ocaml.wat
-  jsstring.wat
-  lexing.wat
-  marshal.wat
-  md5.wat
-  nat.wat
-  obj.wat
-  parsing.wat
-  printexc.wat
-  prng.wat
-  runtime_events.wat
-  stdlib.wat
-  str.wat
-  string.wat
-  sync.wat
-  sys.wat
-  toplevel.wat
-  unix.wat
-  version-dependent.wat
-  weak.wat
-  zstd.wat)
+  (glob_files *.wat))
  (action
   (with-stdout-to
    %{target}
diff --git a/runtime/wasm/post-5.2.wat b/runtime/wasm/version-dependent/post-5.2.wat
similarity index 100%
rename from runtime/wasm/post-5.2.wat
rename to runtime/wasm/version-dependent/post-5.2.wat
diff --git a/runtime/wasm/pre-5.2.wat b/runtime/wasm/version-dependent/pre-5.2.wat
similarity index 100%
rename from runtime/wasm/pre-5.2.wat
rename to runtime/wasm/version-dependent/pre-5.2.wat

From 5e9c0ea5c52a1c975924a79fb4208dd93075c5d3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Vouillon?= <jerome.vouillon@gmail.com>
Date: Fri, 13 Sep 2024 11:45:14 +0200
Subject: [PATCH 3/5] Small fix

---
 runtime/wasm/version-dependent/pre-5.2.wat | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/runtime/wasm/version-dependent/pre-5.2.wat b/runtime/wasm/version-dependent/pre-5.2.wat
index fafc0413c..27c671a24 100644
--- a/runtime/wasm/version-dependent/pre-5.2.wat
+++ b/runtime/wasm/version-dependent/pre-5.2.wat
@@ -23,6 +23,8 @@
       (func $caml_ml_mutex_unlock (param (ref eq)) (result (ref eq))))
    (import "domain" "caml_domain_latest_id"
      (global $caml_domain_latest_id (mut i32)))
+   (import "domain" "caml_domain_id"
+     (global $caml_domain_id (mut i32)))
 
    (func (export "caml_runtime_events_user_write")
       (param (ref eq)) (param (ref eq)) (result (ref eq))

From 6d43b92a1c96cf11e6f2bc686ba505e11525dda0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Vouillon?= <jerome.vouillon@gmail.com>
Date: Fri, 13 Sep 2024 11:54:58 +0200
Subject: [PATCH 4/5] Format dune file

---
 runtime/wasm/dune | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/runtime/wasm/dune b/runtime/wasm/dune
index 8f501d40f..e9afd68df 100644
--- a/runtime/wasm/dune
+++ b/runtime/wasm/dune
@@ -4,18 +4,20 @@
  (files runtime.wasm runtime.js))
 
 (rule
-  (target version-dependent.wat)
-  (deps version-dependent/post-5.2.wat)
-  (enabled_if (>= %{ocaml_version} 5.2.0))
-  (action
-    (copy %{deps} %{target})))
+ (target version-dependent.wat)
+ (deps version-dependent/post-5.2.wat)
+ (enabled_if
+  (>= %{ocaml_version} 5.2.0))
+ (action
+  (copy %{deps} %{target})))
 
 (rule
-  (target version-dependent.wat)
-  (deps version-dependent/pre-5.2.wat)
-  (enabled_if (< %{ocaml_version} 5.2.0))
-  (action
-    (copy %{deps} %{target})))
+ (target version-dependent.wat)
+ (deps version-dependent/pre-5.2.wat)
+ (enabled_if
+  (< %{ocaml_version} 5.2.0))
+ (action
+  (copy %{deps} %{target})))
 
 (rule
  (target runtime.wasm)

From f41575cdf32d793f8ebfceb44003469032b2f7fe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Vouillon?= <jerome.vouillon@gmail.com>
Date: Fri, 13 Sep 2024 11:54:10 +0200
Subject: [PATCH 5/5] Marshal header size change in OCaml 5.1

---
 runtime/wasm/dune                             | 14 +++++-
 runtime/wasm/marshal.wat                      |  4 +-
 .../{pre-5.2.wat => post-5.1.wat}             |  2 +
 runtime/wasm/version-dependent/post-5.2.wat   |  2 +
 runtime/wasm/version-dependent/pre-5.1.wat    | 46 +++++++++++++++++++
 5 files changed, 64 insertions(+), 4 deletions(-)
 rename runtime/wasm/version-dependent/{pre-5.2.wat => post-5.1.wat} (96%)
 create mode 100644 runtime/wasm/version-dependent/pre-5.1.wat

diff --git a/runtime/wasm/dune b/runtime/wasm/dune
index e9afd68df..4ec8e8693 100644
--- a/runtime/wasm/dune
+++ b/runtime/wasm/dune
@@ -13,9 +13,19 @@
 
 (rule
  (target version-dependent.wat)
- (deps version-dependent/pre-5.2.wat)
+ (deps version-dependent/post-5.2.wat)
+ (enabled_if
+  (and
+   (>= %{ocaml_version} 5.1.0)
+   (< %{ocaml_version} 5.2.0)))
+ (action
+  (copy %{deps} %{target})))
+
+(rule
+ (target version-dependent.wat)
+ (deps version-dependent/pre-5.1.wat)
  (enabled_if
-  (< %{ocaml_version} 5.2.0))
+  (< %{ocaml_version} 5.1.0))
  (action
   (copy %{deps} %{target})))
 
diff --git a/runtime/wasm/marshal.wat b/runtime/wasm/marshal.wat
index 491d84385..46373b2bf 100644
--- a/runtime/wasm/marshal.wat
+++ b/runtime/wasm/marshal.wat
@@ -48,8 +48,8 @@
       (func $caml_find_custom_operations
          (param (ref $string)) (result (ref null $custom_operations))))
 
-   (global $caml_marshal_header_size (export "caml_marshal_header_size")
-      (mut i32) (i32.const 20))
+   (import "version-dependent" "caml_marshal_header_size"
+      (global $caml_marshal_header_size i32))
 
    (global $input_val_from_string (ref $string)
       (array.new_fixed $string 21
diff --git a/runtime/wasm/version-dependent/pre-5.2.wat b/runtime/wasm/version-dependent/post-5.1.wat
similarity index 96%
rename from runtime/wasm/version-dependent/pre-5.2.wat
rename to runtime/wasm/version-dependent/post-5.1.wat
index 27c671a24..258505a5e 100644
--- a/runtime/wasm/version-dependent/pre-5.2.wat
+++ b/runtime/wasm/version-dependent/post-5.1.wat
@@ -41,4 +41,6 @@
       (global.set $caml_domain_id (local.get $old))
       (drop (call $caml_ml_mutex_unlock (local.get $mutex)))
       (ref.i31 (local.get $id)))
+
+   (global (export "caml_marshal_header_size") i32 (i32.const 16))
 )
diff --git a/runtime/wasm/version-dependent/post-5.2.wat b/runtime/wasm/version-dependent/post-5.2.wat
index cd99832f1..b4183d2dc 100644
--- a/runtime/wasm/version-dependent/post-5.2.wat
+++ b/runtime/wasm/version-dependent/post-5.2.wat
@@ -54,4 +54,6 @@
             (ref.i31 (i32.const 0))
             (array.new_fixed $block 2 (ref.i31 (i32.const 0)) (local.get $res))))
       (ref.i31 (local.get $id)))
+
+   (global (export "caml_marshal_header_size") i32 (i32.const 16))
 )
diff --git a/runtime/wasm/version-dependent/pre-5.1.wat b/runtime/wasm/version-dependent/pre-5.1.wat
new file mode 100644
index 000000000..cc23b90ad
--- /dev/null
+++ b/runtime/wasm/version-dependent/pre-5.1.wat
@@ -0,0 +1,46 @@
+;; Wasm_of_ocaml runtime support
+;; http://www.ocsigen.org/js_of_ocaml/
+;;
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU Lesser General Public License as published by
+;; the Free Software Foundation, with linking exception;
+;; either version 2.1 of the License, or (at your option) any later version.
+;;
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU Lesser General Public License for more details.
+;;
+;; You should have received a copy of the GNU Lesser General Public License
+;; along with this program; if not, write to the Free Software
+;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+(module
+   (import "obj" "caml_callback_1"
+      (func $caml_callback_1
+         (param (ref eq)) (param (ref eq)) (result (ref eq))))
+   (import "sync" "caml_ml_mutex_unlock"
+      (func $caml_ml_mutex_unlock (param (ref eq)) (result (ref eq))))
+   (import "domain" "caml_domain_latest_id"
+     (global $caml_domain_latest_id (mut i32)))
+   (import "domain" "caml_domain_id"
+     (global $caml_domain_id (mut i32)))
+
+   (func (export "caml_runtime_events_user_write")
+      (param (ref eq)) (param (ref eq)) (result (ref eq))
+      (ref.i31 (i32.const 0)))
+
+   (func (export "caml_domain_spawn")
+      (param $f (ref eq)) (param $mutex (ref eq)) (result (ref eq))
+      (local $id i32) (local $old i32)
+      (local.set $id (global.get $caml_domain_latest_id))
+      (global.set $caml_domain_latest_id
+         (i32.add (local.get $id) (i32.const 1)))
+      (local.set $old (global.get $caml_domain_id))
+      (drop (call $caml_callback_1 (local.get $f) (ref.i31 (i32.const 0))))
+      (global.set $caml_domain_id (local.get $old))
+      (drop (call $caml_ml_mutex_unlock (local.get $mutex)))
+      (ref.i31 (local.get $id)))
+
+   (global (export "caml_marshal_header_size") i32 (i32.const 20))
+)