implements PLN-0090

crates/console/prometeu-system/src/services/vm_runtime/frame_scheduler.rs

@@ -0,0 +1,97 @@
+use prometeu_hal::FrameId;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum FrameAuthorizationError {
+    GameFrameAlreadyActive { active_frame_id: FrameId },
+}
+
+#[derive(Debug, Clone, Default)]
+pub struct FrameScheduler {
+    next_game_frame_id: FrameId,
+    active_game_frame_id: Option<FrameId>,
+    completed_game_frames: u64,
+    logical_frame_overruns: u64,
+}
+
+impl FrameScheduler {
+    pub fn authorize_game_frame(&mut self) -> Result<FrameId, FrameAuthorizationError> {
+        if let Some(active_frame_id) = self.active_game_frame_id {
+            return Err(FrameAuthorizationError::GameFrameAlreadyActive { active_frame_id });
+        }
+
+        let frame_id = self.next_game_frame_id;
+        self.next_game_frame_id = self.next_game_frame_id.next();
+        self.active_game_frame_id = Some(frame_id);
+        Ok(frame_id)
+    }
+
+    pub fn complete_game_frame(&mut self) -> Option<FrameId> {
+        let completed = self.active_game_frame_id.take();
+        if completed.is_some() {
+            self.completed_game_frames = self.completed_game_frames.wrapping_add(1);
+        }
+        completed
+    }
+
+    pub fn record_logical_frame_overrun(&mut self) {
+        self.logical_frame_overruns = self.logical_frame_overruns.wrapping_add(1);
+    }
+
+    pub fn active_game_frame_id(&self) -> Option<FrameId> {
+        self.active_game_frame_id
+    }
+
+    pub fn completed_game_frames(&self) -> u64 {
+        self.completed_game_frames
+    }
+
+    pub fn logical_frame_overruns(&self) -> u64 {
+        self.logical_frame_overruns
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn authorizes_one_game_frame_until_completion() {
+        let mut scheduler = FrameScheduler::default();
+
+        assert_eq!(scheduler.authorize_game_frame(), Ok(FrameId::ZERO));
+        assert_eq!(
+            scheduler.authorize_game_frame(),
+            Err(FrameAuthorizationError::GameFrameAlreadyActive { active_frame_id: FrameId::ZERO })
+        );
+
+        assert_eq!(scheduler.complete_game_frame(), Some(FrameId::ZERO));
+        assert_eq!(scheduler.authorize_game_frame(), Ok(FrameId::new(1)));
+    }
+
+    #[test]
+    fn completion_is_sequential_without_catch_up_frames() {
+        let mut scheduler = FrameScheduler::default();
+
+        for expected in 0..3 {
+            let frame_id = scheduler.authorize_game_frame().expect("frame authorization");
+            assert_eq!(frame_id, FrameId::new(expected));
+            assert_eq!(scheduler.complete_game_frame(), Some(FrameId::new(expected)));
+        }
+
+        assert_eq!(scheduler.completed_game_frames(), 3);
+    }
+
+    #[test]
+    fn records_logical_frame_overrun_without_advancing_frame_id() {
+        let mut scheduler = FrameScheduler::default();
+
+        assert_eq!(scheduler.authorize_game_frame(), Ok(FrameId::ZERO));
+        scheduler.record_logical_frame_overrun();
+        scheduler.record_logical_frame_overrun();
+
+        assert_eq!(scheduler.logical_frame_overruns(), 2);
+        assert_eq!(scheduler.active_game_frame_id(), Some(FrameId::ZERO));
+        assert_eq!(scheduler.complete_game_frame(), Some(FrameId::ZERO));
+        assert_eq!(scheduler.authorize_game_frame(), Ok(FrameId::new(1)));
+    }
+}

crates/console/prometeu-system/src/services/vm_runtime/lifecycle.rs

@@ -22,6 +22,7 @@ impl VirtualMachineRuntime {
             current_cartridge_title: String::new(),
             current_cartridge_app_version: String::new(),
             current_cartridge_app_mode: AppMode::Game,
+            frame_scheduler: FrameScheduler::default(),
             render_manager: RenderManager::new(AppMode::Game),
             gfx2d_commands: Vec::new(),
             gfxui_commands: Vec::new(),
@@ -119,6 +120,7 @@ impl VirtualMachineRuntime {
         self.current_cartridge_title.clear();
         self.current_cartridge_app_version.clear();
         self.current_cartridge_app_mode = AppMode::Game;
+        self.frame_scheduler = FrameScheduler::default();
         self.render_manager = RenderManager::new(AppMode::Game);
         self.gfx2d_commands.clear();
         self.gfxui_commands.clear();

crates/console/prometeu-system/src/services/vm_runtime/mod.rs

@@ -1,4 +1,5 @@
 mod dispatch;
+mod frame_scheduler;
 mod lifecycle;
 pub mod render_manager;
 #[cfg(test)]
@@ -6,6 +7,7 @@ mod tests;
 mod tick;
 
 use crate::CrashReport;
+pub use frame_scheduler::FrameScheduler;
 use prometeu_bytecode::string_materialization_count;
 use prometeu_hal::app_mode::AppMode;
 use prometeu_hal::log::LogService;
@@ -28,6 +30,7 @@ pub struct VirtualMachineRuntime {
     pub current_cartridge_title: String,
     pub current_cartridge_app_version: String,
     pub current_cartridge_app_mode: AppMode,
+    pub frame_scheduler: FrameScheduler,
     pub render_manager: RenderManager,
     pub gfx2d_commands: Vec<Gfx2dCommand>,
     pub gfxui_commands: Vec<GfxUiCommand>,

crates/console/prometeu-system/src/services/vm_runtime/tick.rs

@@ -141,6 +141,11 @@ impl VirtualMachineRuntime {
         self.update_fs(log_service, fs, fs_state);
 
         if !self.logical_frame_active {
+            if self.current_cartridge_app_mode == AppMode::Game {
+                self.frame_scheduler
+                    .authorize_game_frame()
+                    .expect("logical frame cannot start while another Game frame is active");
+            }
             self.logical_frame_active = true;
             self.logical_frame_remaining_cycles = Self::CYCLES_PER_LOGICAL_FRAME;
             self.begin_logical_frame(signals, hw);
@@ -317,6 +322,9 @@ impl VirtualMachineRuntime {
                         self.logical_frame_index += 1;
                         self.logical_frame_active = false;
                         self.logical_frame_remaining_cycles = 0;
+                        if self.current_cartridge_app_mode == AppMode::Game {
+                            self.frame_scheduler.complete_game_frame();
+                        }
 
                         if run.reason == LogicalFrameEndingReason::FrameSync {
                             self.needs_prepare_entry_call = true;
@@ -326,6 +334,10 @@ impl VirtualMachineRuntime {
                             self.paused = true;
                             self.debug_step_request = false;
                         }
+                    } else if run.reason == LogicalFrameEndingReason::BudgetExhausted
+                        && self.current_cartridge_app_mode == AppMode::Game
+                    {
+                        self.frame_scheduler.record_logical_frame_overrun();
                     }
                 }
                 Err(e) => {

discussion/index.ndjson

@@ -1,6 +1,6 @@
 {"type":"meta","next_id":{"DSC":42,"AGD":42,"DEC":32,"PLN":98,"LSN":48,"CLSN":1}}
 {"type":"discussion","id":"DSC-0039","status":"abandoned","ticket":"render-pipeline-family-and-future-3d","title":"Render Pipeline Family and Future 3D","created_at":"2026-06-04","updated_at":"2026-06-04","tags":["gfx","renderer","runtime","architecture","pipeline"],"agendas":[{"id":"AGD-0039","file":"AGD-0039-render-pipeline-family-and-future-3d.md","status":"abandoned","created_at":"2026-06-04","updated_at":"2026-06-04","_override_reason":"User explicitly chose to close this agenda without a new decision because DSC-0038 already established enough architecture for future extension, and 3D is intentionally deferred."}],"decisions":[],"plans":[],"lessons":[],"_override_reason":"User explicitly chose to close this agenda without a new decision because DSC-0038 already established enough architecture for future extension, and 3D is intentionally deferred."}
-{"type":"discussion","id":"DSC-0040","status":"in_progress","ticket":"vm-render-parallel-execution-boundary","title":"VM and Render Parallel Execution Boundary","created_at":"2026-06-04","updated_at":"2026-06-05","tags":["runtime","renderer","vm","concurrency","architecture","perf"],"agendas":[{"id":"AGD-0040","file":"AGD-0040-vm-and-render-parallel-execution-boundary.md","status":"accepted","created_at":"2026-06-04","updated_at":"2026-06-05"}],"decisions":[{"id":"DEC-0031","file":"DEC-0031-vm-and-render-parallel-execution-boundary.md","status":"accepted","created_at":"2026-06-05","updated_at":"2026-06-05","ref_agenda":"AGD-0040"}],"plans":[{"id":"PLN-0087","file":"PLN-0087-fix-game2d-packet-overlay-composition.md","status":"done","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0088","file":"PLN-0088-define-read-only-render-resource-boundary.md","status":"done","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0089","file":"PLN-0089-introduce-render-handoff-abstraction.md","status":"done","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0090","file":"PLN-0090-add-render-frame-pacing-contract.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0091","file":"PLN-0091-implement-appmode-render-policy-matrix.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0092","file":"PLN-0092-add-render-epoch-ownership-transitions.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0093","file":"PLN-0093-add-render-telemetry-counters-and-events.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0094","file":"PLN-0094-specify-async-render-boundary.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0095","file":"PLN-0095-prototype-local-render-worker-capability.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0096","file":"PLN-0096-define-render-shutdown-and-failure-handling.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0097","file":"PLN-0097-add-async-render-integration-test-matrix.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]}],"lessons":[]}
+{"type":"discussion","id":"DSC-0040","status":"in_progress","ticket":"vm-render-parallel-execution-boundary","title":"VM and Render Parallel Execution Boundary","created_at":"2026-06-04","updated_at":"2026-06-05","tags":["runtime","renderer","vm","concurrency","architecture","perf"],"agendas":[{"id":"AGD-0040","file":"AGD-0040-vm-and-render-parallel-execution-boundary.md","status":"accepted","created_at":"2026-06-04","updated_at":"2026-06-05"}],"decisions":[{"id":"DEC-0031","file":"DEC-0031-vm-and-render-parallel-execution-boundary.md","status":"accepted","created_at":"2026-06-05","updated_at":"2026-06-05","ref_agenda":"AGD-0040"}],"plans":[{"id":"PLN-0087","file":"PLN-0087-fix-game2d-packet-overlay-composition.md","status":"done","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0088","file":"PLN-0088-define-read-only-render-resource-boundary.md","status":"done","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0089","file":"PLN-0089-introduce-render-handoff-abstraction.md","status":"done","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0090","file":"PLN-0090-add-render-frame-pacing-contract.md","status":"done","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0091","file":"PLN-0091-implement-appmode-render-policy-matrix.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0092","file":"PLN-0092-add-render-epoch-ownership-transitions.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0093","file":"PLN-0093-add-render-telemetry-counters-and-events.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0094","file":"PLN-0094-specify-async-render-boundary.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0095","file":"PLN-0095-prototype-local-render-worker-capability.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0096","file":"PLN-0096-define-render-shutdown-and-failure-handling.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]},{"id":"PLN-0097","file":"PLN-0097-add-async-render-integration-test-matrix.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05","ref_decisions":["DEC-0031"]}],"lessons":[]}
 {"type":"discussion","id":"DSC-0041","status":"open","ticket":"foreground-stack-game-pause-shell-vm-backed","title":"Foreground Stack, Game Pause, and VM-Backed Shell Coexistence","created_at":"2026-06-05","updated_at":"2026-06-05","tags":["runtime","os","lifecycle","shell","game","vm","foreground","architecture"],"agendas":[{"id":"AGD-0041","file":"AGD-0041-foreground-stack-game-pause-shell-vm-backed.md","status":"open","created_at":"2026-06-05","updated_at":"2026-06-05"}],"decisions":[],"plans":[],"lessons":[]}
 {"type":"discussion","id":"DSC-0038","status":"done","ticket":"render-frame-packet-boundary","title":"Logical Render Pipelines and Command Packets","created_at":"2026-05-25","updated_at":"2026-06-04","tags":["gfx","renderer","runtime","frame-composer","architecture","ui","pipeline"],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0047","file":"discussion/lessons/DSC-0038-render-frame-packet-boundary/LSN-0047-typed-render-submissions-preserve-domain-boundaries.md","status":"done","created_at":"2026-06-04","updated_at":"2026-06-04"}]}
 {"type":"discussion","id":"DSC-0035","status":"done","ticket":"task-owned-shell-windows","title":"Agenda - Task-Owned Shell Windows","created_at":"2026-05-15","updated_at":"2026-05-15","tags":["runtime","os","task","window-manager","shell","lifecycle"],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0044","file":"discussion/lessons/DSC-0035-task-owned-shell-windows/LSN-0044-task-window-liveness-belongs-to-the-task.md","status":"done","created_at":"2026-05-15","updated_at":"2026-05-15"}]}

discussion/workflow/plans/PLN-0090-add-render-frame-pacing-contract.md

@@ -2,7 +2,7 @@
 id: PLN-0090
 ticket: vm-render-parallel-execution-boundary
 title: Add Render Frame Pacing Contract
-status: open
+status: done
 created: 2026-06-05
 ref_decisions: [DEC-0031]
 tags: [runtime, frame-clock, scheduler, vm]