sketch out msg processing loop, to replace cmd processing loop, in dbg engine

src/dbg_frontend/dbg_frontend.mdesk

@@ -112,7 +112,8 @@ DF_MsgKindTable:
 
 @enum DF_MsgKind:
 {
-  @expand(DF_MsgKindTable a) `$(a.name)`
+  @expand(DF_MsgKindTable a) `$(a.name)`,
+  COUNT
 }
 
 @data(String8) df_msg_kind_name_lower_table:

src/dbg_frontend/dbg_frontend_core.c

@@ -7809,6 +7809,19 @@ df_request_frame(void)
   df_state->num_frames_requested = 4;
 }
 
+////////////////////////////////
+//~ rjf: Message Functions
+
+internal void
+df_msg_(DF_MsgKind kind, D_Regs *regs)
+{
+  DF_MsgNode *n = push_array(df_state->msgs_arena, DF_MsgNode, 1);
+  SLLQueuePush(df_state->msgs.first, df_state->msgs.last, n);
+  df_state->msgs.count += 1;
+  n->v.kind = kind;
+  n->v.regs = d_regs_copy(df_state->msgs_arena, regs);
+}
+
 ////////////////////////////////
 //~ rjf: Main Layer Top-Level Calls
 
@@ -10601,9 +10614,12 @@ df_end_frame(void)
 }
 
 internal void
-df_frame(Arena *arena, D_CmdList *cmds)
+df_frame(D_CmdList *cmds, F32 dt)
 {
-  df_begin_frame(arena, cmds);
+  Temp scratch = scratch_begin(0, 0);
+  DI_Scope *di_scope = di_scope_open();
+  d_tick(scratch.arena, di_scope, cmds, dt);
+  df_begin_frame(scratch.arena, cmds);
   {
     B32 queue_drag_drop = 0;
     if(queue_drag_drop)
@@ -10620,7 +10636,7 @@ df_frame(Arena *arena, D_CmdList *cmds)
       }
       d_push_regs();
       d_regs()->window = df_handle_from_window(w);
-      df_window_update_and_render(arena, w, cmds);
+      df_window_update_and_render(scratch.arena, w, cmds);
       D_Regs *window_regs = d_pop_regs();
       if(df_window_from_handle(last_focused_window) == w)
       {
@@ -10644,4 +10660,7 @@ df_frame(Arena *arena, D_CmdList *cmds)
     }
     r_end_frame();
   }
+  
+  di_scope_close(di_scope);
+  scratch_end(scratch);
 }

src/dbg_frontend/dbg_frontend_core.h

@@ -365,6 +365,31 @@ struct DF_ViewRuleSpec
 
 #include "generated/dbg_frontend.meta.h"
 
+////////////////////////////////
+//~ rjf: Message Types
+
+typedef struct DF_Msg DF_Msg;
+struct DF_Msg
+{
+  DF_MsgKind kind;
+  D_Regs *regs;
+};
+
+typedef struct DF_MsgNode DF_MsgNode;
+struct DF_MsgNode
+{
+  DF_MsgNode *next;
+  DF_Msg v;
+};
+
+typedef struct DF_MsgList DF_MsgList;
+struct DF_MsgList
+{
+  DF_MsgNode *first;
+  DF_MsgNode *last;
+  U64 count;
+};
+
 ////////////////////////////////
 //~ rjf: Theme Types
 
@@ -583,6 +608,10 @@ struct DF_State
   // rjf: arenas
   Arena *arena;
   
+  // rjf: messages
+  Arena *msgs_arena;
+  DF_MsgList msgs;
+  
   // rjf: frame request state
   U64 num_frames_requested;
   
@@ -922,7 +951,13 @@ internal void df_request_frame(void);
 ////////////////////////////////
 //~ rjf: Message Functions
 
-
+internal void df_msg_(DF_MsgKind kind, D_Regs *regs);
+#define df_msg(kind, ...) df_msg_((kind),\
+&(D_Regs)\
+{\
+d_regs_lit_init_top\
+__VA_ARGS__\
+})
 
 ////////////////////////////////
 //~ rjf: Main Layer Top-Level Calls
@@ -930,6 +965,6 @@ internal void df_request_frame(void);
 internal void df_init(OS_WindowRepaintFunctionType *window_repaint_entry_point, D_StateDeltaHistory *hist);
 internal void df_begin_frame(Arena *arena, D_CmdList *cmds);
 internal void df_end_frame(void);
-internal void df_frame(Arena *arena, D_CmdList *cmds);
+internal void df_frame(D_CmdList *cmds, F32 dt);
 
 #endif // DBG_FRONTEND_CORE_H

src/dbg_frontend/generated/dbg_frontend.meta.h

@@ -69,6 +69,7 @@ DF_MsgKind_FindThread,
 DF_MsgKind_FindSelectedThread,
 DF_MsgKind_GoToName,
 DF_MsgKind_FindCodeLocation,
+DF_MsgKind_COUNT,
 } DF_MsgKind;
 
 typedef enum DF_IconKind