Serialize managed Decky changes across desktop and headset

Co-authored-by: SAPHID <saphid@users.noreply.github.com>

app/package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "frame-control",
-  "version": "0.4.31",
+  "version": "0.4.32",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "frame-control",
-      "version": "0.4.31",
+      "version": "0.4.32",
       "license": "MIT",
       "devDependencies": {
         "electron": "^44.4.5",

app/package.json

@@ -1,7 +1,7 @@
 {
   "name": "frame-control",
   "productName": "Frame Control",
-  "version": "0.4.31",
+  "version": "0.4.32",
   "description": "Desktop app for managing a Valve Steam Frame over SSH",
   "private": true,
   "main": "main.js",

docs/current-support-matrix.md

@@ -1,6 +1,6 @@
 # What we have tested
 
-Current for Frame Control **v0.4.31**, 25 October 2026. “Real Frame + physical PC” means an actual headset and a non-virtual computer. “VM only” means a Windows virtual machine, sometimes connected to the real Frame. A CI test or a simulated device is **not** a physical hardware test. The date/version column is the last relevant check, not a promise that every new release was retested on that platform. See each link for the exact procedure and limits.
+Current for Frame Control **v0.4.32**, 25 October 2026. “Real Frame + physical PC” means an actual headset and a non-virtual computer. “VM only” means a Windows virtual machine, sometimes connected to the real Frame. A CI test or a simulated device is **not** a physical hardware test. The date/version column is the last relevant check, not a promise that every new release was retested on that platform. See each link for the exact procedure and limits.
 
 | Feature | Real Frame + physical PC tested | VM only | Untested or limited | Last check and proof |
 |---|---|---|---|---|
@@ -24,6 +24,6 @@ Current for Frame Control **v0.4.31**, 25 October 2026. “Real Frame + physical
 | Local Frame Control extensions | Example panel displayed live Frame status in a browser preview; the real Frame served a read-only example in the experimental headset panel | No | No wearer-visible extension view; third-party extensions and physical Windows/macOS extension folders untested | 25 Oct, v0.4.29: [PR #194](https://github.com/saphid/frame-control/pull/194), [PR #201](https://github.com/saphid/frame-control/pull/201), [extension guide](extensions.md) |
 | Experimental Frame Control SteamVR panel | Real Frame OS 0.5.6 installed its user service, registered an overlay, served authenticated live status and a read-only extension, saved a screenshot and short MP4, and removed owned resources | No | Headset was unworn in standby: overlay reported `not_visible`, stereo capture was dark; wearer-visible pixels and controller input are unverified. The new large read-only status screen has browser layout and packaging checks only | 25 Oct, v0.4.29 device check and v0.4.31 status screen: [PR #198](https://github.com/saphid/frame-control/pull/198), [PR #201](https://github.com/saphid/frame-control/pull/201), [PR #220](https://github.com/saphid/frame-control/pull/220), [panel guide](headset-app.md) |
 | Experimental Decky Loader manager | Real Frame OS 0.5.6 ARM64 user-service install, status, update and remove completed; seven official-store plugin backends loaded, and ProtonDB Badges completed managed store install/update/remove | No | Plugin pages, settings, routes, toasts and controller input in VR remain unverified; some plugins need root, x86_64 binaries or Deck-specific hardware | 25 Oct, v0.4.31: [PR #208](https://github.com/saphid/frame-control/pull/208), [compatibility table](decky-frame.md) |
-| Experimental Framey VR plugin panels | No live real-Frame panel test | No | ProtonDB Badges settings rendered and sent a setting call in local Chromium; the fake Frame exercised the store and method bridge. Wearer-visible pixels, controller input and live settings persistence remain unverified | 25 Oct, [PR #223](https://github.com/saphid/frame-control/pull/223), [browser/fake Frame evidence](evidence/framey-browser-2026-10-25.md), [guide](framey-loader.md) |
+| Experimental Framey VR plugin panels and store | No live real-Frame panel test | No | ProtonDB Badges settings rendered and sent a setting call in local Chromium. The fake Frame and CI exercised the store search, install progress, quick actions, settings, local routes and toasts. Wearer-visible pixels, controller input and live settings persistence remain unverified | 25 Oct, v0.4.32: [#223](https://github.com/saphid/frame-control/pull/223), [#224](https://github.com/saphid/frame-control/pull/224), [#225](https://github.com/saphid/frame-control/pull/225), [#226](https://github.com/saphid/frame-control/pull/226), [#227](https://github.com/saphid/frame-control/pull/227), [browser/fake Frame evidence](evidence/framey-browser-2026-10-25.md), [guide](framey-loader.md) |
 
 Release notes must preserve these limits until a newer recorded check changes them. When a feature is retested, add its date, exact app/Frame version, host type and proof here. The older [v0.3.1 matrix](support-matrix.html) is a historical snapshot and does not describe current coverage.

docs/decky-frame.md

@@ -165,6 +165,8 @@ It preserves plugin files and settings so unrelated user data is not deleted.
 Open **Official plugin store** to review a plugin, then confirm each install,
 update, or remove. Root and x86-only plugins are blocked. The manager only
 removes plugin folders that it installed; it leaves other Decky folders alone.
+The desktop app and headset panel share one lock for managed Decky changes.
+If another change is in progress, wait for it to finish and try again.
 Restart Steam or the headset to clear the frontend already injected into its
 current web helper process. No action wipes the headset.
 

tests/test_frame_decky_store.py

@@ -15,6 +15,7 @@ import zipfile
 
 sys.path.insert(0, str(Path(__file__).resolve().parent.parent / 'ui'))
 import frame_decky_store
+import frame_decky
 
 
 def archive(flags=(), extra=None):
@@ -111,6 +112,28 @@ class StoreTransaction(unittest.TestCase):
         self.assertNotEqual(result.returncode, 0)
         self.assertTrue(external.exists())
 
+    def test_shared_lock_rejects_plugin_and_loader_changes(self):
+        import fcntl
+
+        lock_path = Path(self.tmp.name) / '.local/share/frame-control/decky-transaction.lock'
+        lock_path.parent.mkdir(parents=True, exist_ok=True)
+        data, _ = archive()
+        with lock_path.open('w+b') as held:
+            fcntl.flock(held, fcntl.LOCK_EX | fcntl.LOCK_NB)
+            plugin = self.apply('install', data)
+            loader = subprocess.run([sys.executable, '-', 'remove', 'none', 'none', 'none'],
+                                    input=frame_decky.APPLY, text=True, capture_output=True,
+                                    env=self.env, timeout=15)
+            self.assertNotEqual(plugin.returncode, 0)
+            self.assertNotEqual(loader.returncode, 0)
+            self.assertIn('Another Decky change is in progress', plugin.stderr)
+            self.assertIn('Another Decky change is in progress', loader.stderr)
+            self.assertFalse(self.folder.exists())
+
+        installed = self.apply('install', data)
+        self.assertEqual(installed.returncode, 0, installed.stderr)
+        self.assertEqual(self.apply('remove').returncode, 0)
+
 
 class StoreHost(unittest.TestCase):
     def test_owned_plugin_can_be_removed_without_store_network(self):

ui/frame_decky.py

@@ -63,7 +63,7 @@ print(json.dumps({'arch':platform.machine(), 'frameOS':os_release.get('VERSION_I
 
 
 APPLY = r'''
-import hashlib, json, os, pathlib, subprocess, sys
+import fcntl, hashlib, json, os, pathlib, subprocess, sys
 action, token, digest, version = sys.argv[1:]
 home = pathlib.Path.home()
 base = home / '.local/share/frame-control/decky'
@@ -72,6 +72,7 @@ binary = base / 'PluginLoader'
 receipt = base / '.frame-control/receipt.json'
 legacy = base / 'settings/release.json'
 stage = pathlib.Path('/tmp/frame-control-decky-' + token)
+transaction_lock = None
 def systemd(*args):
     p = subprocess.run(['systemctl','--user',*args], capture_output=True, text=True, timeout=20)
     if p.returncode: raise RuntimeError((p.stderr or p.stdout).strip() or 'systemd failed')
@@ -79,6 +80,13 @@ def owned():
     try: return json.loads((receipt if receipt.exists() else legacy).read_text()).get('managedBy') == 'Frame Control' and service.is_file()
     except (OSError, ValueError): return False
 try:
+    # The desktop and headset servers are separate processes. Lock the shared
+    # user-service transaction on the Frame before inspecting or changing it.
+    base.parent.mkdir(parents=True, exist_ok=True)
+    lock_path = base.parent / 'decky-transaction.lock'
+    transaction_lock = os.fdopen(os.open(lock_path, os.O_CREAT | os.O_RDWR | os.O_NOFOLLOW, 0o600), 'r+b')
+    try: fcntl.flock(transaction_lock, fcntl.LOCK_EX | fcntl.LOCK_NB)
+    except BlockingIOError: raise RuntimeError('Another Decky change is in progress; try again after it finishes')
     if action == 'remove':
         if not owned(): raise RuntimeError('No Frame Control managed Decky install to remove')
         systemd('disable','--now','frame-control-decky.service')
@@ -141,6 +149,7 @@ try:
         print(json.dumps({'message':'Decky Loader '+version+' is running as a user service. The VR menu is experimental.'}))
 finally:
     stage.unlink(missing_ok=True)
+    if transaction_lock is not None: transaction_lock.close()
 '''
 
 

ui/frame_decky_store.py

@@ -104,7 +104,7 @@ def archive_info(data, expected_hash, expected_name):
 
 
 APPLY = r'''
-import hashlib,json,pathlib,shutil,subprocess,sys,zipfile
+import fcntl,hashlib,json,os,pathlib,shutil,subprocess,sys,zipfile
 action,token,plugin_id,digest,folder,version = sys.argv[1:]
 base=pathlib.Path.home()/'.local/share/frame-control/decky/plugins'
 unit=pathlib.Path.home()/'.config/systemd/user/frame-control-decky.service'
@@ -113,6 +113,7 @@ archive=pathlib.Path('/tmp/frame-control-decky-plugin-'+token)
 stage=base/('.frame-control-stage-'+token)
 backup=base/('.frame-control-old-'+token)
 marker='.frame-control-store.json'
+transaction_lock=None
 def owned():
     if target.is_symlink() or not target.is_dir(): return False
     try: return json.loads((target/marker).read_text()).get('storeId') == int(plugin_id)
@@ -120,12 +121,19 @@ def owned():
 def service(*args):
     p=subprocess.run(['systemctl','--user',*args],capture_output=True,text=True,timeout=25)
     if p.returncode: raise RuntimeError((p.stderr or p.stdout).strip()[-400:] or 'Decky service failed')
-if not unit.is_file(): raise RuntimeError('Install Frame Control managed Decky first')
-if action not in ('install','update','remove'): raise RuntimeError('Invalid plugin action')
-if action=='install' and (target.exists() or target.is_symlink()): raise RuntimeError('Plugin folder already exists')
-if action in ('update','remove') and not owned(): raise RuntimeError('Only a Frame Control store plugin can be changed')
-running=subprocess.run(['systemctl','--user','is-active','--quiet','frame-control-decky.service']).returncode==0
 try:
+    # A desktop request and a headset-panel request must not change the same
+    # Decky user service at once. Keep this lock until rollback/cleanup ends.
+    base.parent.parent.mkdir(parents=True,exist_ok=True)
+    lock_path=base.parent.parent/'decky-transaction.lock'
+    transaction_lock=os.fdopen(os.open(lock_path,os.O_CREAT|os.O_RDWR|os.O_NOFOLLOW,0o600),'r+b')
+    try: fcntl.flock(transaction_lock,fcntl.LOCK_EX|fcntl.LOCK_NB)
+    except BlockingIOError: raise RuntimeError('Another Decky change is in progress; try again after it finishes')
+    if not unit.is_file(): raise RuntimeError('Install Frame Control managed Decky first')
+    if action not in ('install','update','remove'): raise RuntimeError('Invalid plugin action')
+    if action=='install' and (target.exists() or target.is_symlink()): raise RuntimeError('Plugin folder already exists')
+    if action in ('update','remove') and not owned(): raise RuntimeError('Only a Frame Control store plugin can be changed')
+    running=subprocess.run(['systemctl','--user','is-active','--quiet','frame-control-decky.service']).returncode==0
     if action!='remove':
         data=archive.read_bytes()
         if not 1024<len(data)<=50*1024*1024 or hashlib.sha256(data).hexdigest()!=digest:
@@ -159,6 +167,7 @@ try:
 finally:
     archive.unlink(missing_ok=True)
     if stage.exists(): shutil.rmtree(stage)
+    if transaction_lock is not None: transaction_lock.close()
 '''