src/emulator/shrooms_vb_core.rs

@@ -1,4 +1,4 @@
-use std::{ffi::c_void, ptr, slice};
+use std::{borrow::Cow, ffi::c_void, ptr, slice};
 
 use anyhow::{Result, anyhow};
 use bitflags::bitflags;
@@ -191,6 +191,9 @@ extern "C" fn on_frame(sim: *mut VB) -> c_int {
     // There is no way for the userdata to be null or otherwise invalid.
     let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
     data.frame_seen = true;
+    if data.monitor.enabled {
+        data.monitor.event = Some(SimEvent::Marker(Cow::Borrowed("Frame Drawn")));
+    }
     1
 }
 
@@ -328,6 +331,7 @@ pub enum SimEvent {
     Halt,
     Interrupt(u16, u32),
     Reti,
+    Marker(Cow<'static, str>),
 }
 
 struct EventMonitor {

src/profiler.rs

@@ -213,11 +213,23 @@ impl ProfilerSession {
     }
 
     fn track_event(&mut self, event: SimEvent) -> Result<()> {
-        if let Some(program) = &mut self.program {
-            program.track_event(event)?;
-        }
+        let Some(program) = &mut self.program else {
+            return Ok(());
+        };
+        match event {
+            SimEvent::Call(address) => program.track_call(address),
+            SimEvent::Return => program.track_return(),
+            SimEvent::Halt => program.track_halt(),
+            SimEvent::Interrupt(code, address) => program.track_interrupt(code, address),
+            SimEvent::Reti => program.track_reti(),
+            SimEvent::Marker(name) => {
+                if let Some(recording) = &mut self.recording {
+                    recording.track_marker(name);
+                };
                 Ok(())
             }
+        }
+    }
 
     fn start_recording(&mut self) {
         if let Some(program) = &self.program {

src/profiler/recording.rs

@@ -1,8 +1,9 @@
-use std::collections::HashMap;
+use std::{borrow::Cow, collections::HashMap};
 
 use fxprof_processed_profile::{
-    CategoryHandle, CpuDelta, Frame, FrameFlags, FrameInfo, ProcessHandle, Profile,
-    ReferenceTimestamp, SamplingInterval, StackHandle, ThreadHandle, Timestamp,
+    CategoryHandle, CpuDelta, Frame, FrameFlags, FrameInfo, MarkerTiming, ProcessHandle, Profile,
+    ReferenceTimestamp, SamplingInterval, StackHandle, StaticSchemaMarker, StringHandle,
+    ThreadHandle, Timestamp,
 };
 
 use crate::profiler::state::{ProgramState, RESET_CODE, StackFrame};
@@ -72,6 +73,15 @@ impl Recording {
         }
     }
 
+    pub fn track_marker(&mut self, name: Cow<'static, str>) {
+        let Some(thread) = self.threads.get(&RESET_CODE) else {
+            return;
+        };
+        let timing = MarkerTiming::Instant(Timestamp::from_nanos_since_reference(self.now * 50));
+        let marker = SimpleMarker(name);
+        self.profile.add_marker(*thread, timing, marker);
+    }
+
     pub fn finish(self) -> Vec<u8> {
         serde_json::to_vec(&self.profile).expect("could not serialize profile")
     }
@@ -92,6 +102,29 @@ impl Recording {
     }
 }
 
+struct SimpleMarker(Cow<'static, str>);
+
+impl StaticSchemaMarker for SimpleMarker {
+    const UNIQUE_MARKER_TYPE_NAME: &'static str = "Simple";
+    const FIELDS: &'static [fxprof_processed_profile::StaticSchemaMarkerField] = &[];
+
+    fn name(&self, profile: &mut Profile) -> StringHandle {
+        profile.intern_string(&self.0)
+    }
+
+    fn category(&self, _profile: &mut Profile) -> CategoryHandle {
+        CategoryHandle::OTHER
+    }
+
+    fn string_field_value(&self, _field_index: u32) -> StringHandle {
+        unreachable!()
+    }
+
+    fn number_field_value(&self, _field_index: u32) -> f64 {
+        unreachable!()
+    }
+}
+
 fn thread_name_for_code(code: u16) -> std::borrow::Cow<'static, str> {
     match code {
         RESET_CODE => "Main".into(),

src/profiler/state.rs

@@ -2,7 +2,7 @@ use std::{collections::HashMap, path::PathBuf};
 
 use anyhow::{Result, bail};
 
-use crate::{emulator::SimEvent, profiler::symbols::SymbolFile};
+use crate::profiler::symbols::SymbolFile;
 
 pub struct ProgramState {
     symbol_file: SymbolFile,
@@ -42,9 +42,7 @@ impl ProgramState {
         Some((*code, call_stack))
     }
 
-    pub fn track_event(&mut self, event: SimEvent) -> Result<()> {
-        match event {
-            SimEvent::Call(address) => {
+    pub fn track_call(&mut self, address: u32) -> Result<()> {
         let Some(code) = self.context_stack.last() else {
             bail!("How did we call anything when we're halted?");
         };
@@ -52,8 +50,10 @@ impl ProgramState {
             bail!("missing stack {code:04x}");
         };
         stack.push(StackFrame { address });
+        Ok(())
     }
-            SimEvent::Return => {
+
+    pub fn track_return(&mut self) -> Result<()> {
         let Some(code) = self.context_stack.last() else {
             bail!("how did we return when we're halted?");
         };
@@ -66,13 +66,17 @@ impl ProgramState {
         if stack.is_empty() {
             bail!("returned to oblivion");
         }
+        Ok(())
     }
-            SimEvent::Halt => {
+
+    pub fn track_halt(&mut self) -> Result<()> {
         let Some(RESET_CODE) = self.context_stack.pop() else {
             bail!("halted when not in an interrupt");
         };
+        Ok(())
     }
-            SimEvent::Interrupt(code, address) => {
+
+    pub fn track_interrupt(&mut self, code: u16, address: u32) -> Result<()> {
         // if the CPU was halted before, wake it up now
         if self.context_stack.is_empty() {
             self.context_stack.push(RESET_CODE);
@@ -86,8 +90,10 @@ impl ProgramState {
         {
             bail!("{code:04x} fired twice");
         }
+        Ok(())
     }
-            SimEvent::Reti => {
+
+    pub fn track_reti(&mut self) -> Result<()> {
         let Some(code) = self.context_stack.pop() else {
             bail!("RETI when halted");
         };
@@ -97,8 +103,6 @@ impl ProgramState {
         if self.call_stacks.remove(&code).is_none() {
             bail!("{code:04x} popped but never called");
         }
-            }
-        }
         Ok(())
     }
 }