diff --git a/src/ctrl/ctrl_core.c b/src/ctrl/ctrl_core.c
index 65d42656..49f6be97 100644
--- a/src/ctrl/ctrl_core.c
+++ b/src/ctrl/ctrl_core.c
@@ -800,6 +800,7 @@ ctrl_init(void)
   Arena *arena = arena_alloc();
   ctrl_state = push_array(arena, CTRL_State, 1);
   ctrl_state->arena = arena;
+  ctrl_state->ctrl_run_mutex = os_mutex_alloc();
   for(Architecture arch = (Architecture)0; arch < Architecture_COUNT; arch = (Architecture)(arch+1))
   {
     String8 *reg_names = regs_reg_code_string_table_from_architecture(arch);
@@ -1344,12 +1345,17 @@ ctrl_query_cached_reg_block_from_thread(Arena *arena, CTRL_MachineID machine_id,
     if(node)
     {
       U64 current_reg_gen = dmn_reg_gen();
-      if(node->reg_gen != current_reg_gen && dmn_thread_read_reg_block(thread, result))
+      B32 need_stale = 1;
+      if(node->reg_gen != current_reg_gen)
       {
-        node->reg_gen = current_reg_gen;
-        MemoryCopy(node->block, result, reg_block_size);
+        OS_MutexScope(ctrl_state->ctrl_run_mutex) if(ctrl_state->ctrl_run_state == 0 && dmn_thread_read_reg_block(thread, result))
+        {
+          need_stale = 0;
+          node->reg_gen = current_reg_gen;
+          MemoryCopy(node->block, result, reg_block_size);
+        }
       }
-      else
+      if(need_stale)
       {
         MemoryCopy(result, node->block, reg_block_size);
       }
@@ -1719,6 +1725,12 @@ ctrl_thread__entry_point(void *p)
     //- rjf: get next messages
     CTRL_MsgList msgs = ctrl_u2c_pop_msgs(scratch.arena);
     
+    //- rjf: begin run state
+    OS_MutexScope(ctrl_state->ctrl_run_mutex)
+    {
+      ctrl_state->ctrl_run_state = 1;
+    }
+    
     //- rjf: process messages
     {
       B32 done = 0;
@@ -1753,6 +1765,12 @@ ctrl_thread__entry_point(void *p)
         }
       }
     }
+    
+    //- rjf: end run state
+    OS_MutexScope(ctrl_state->ctrl_run_mutex)
+    {
+      ctrl_state->ctrl_run_state = 0;
+    }
   }
   
   scratch_end(scratch);
@@ -2879,7 +2897,7 @@ ctrl_thread__run(CTRL_Msg *msg)
         if(process->kind != CTRL_EntityKind_Process) { continue; }
         for(CTRL_Entity *thread = process->first; thread != &ctrl_entity_nil; thread = thread->next)
         {
-          U64 rip = ctrl_query_cached_rip_from_thread(thread->machine_id, thread->handle);
+          U64 rip = dmn_rip_from_thread(thread->handle);
           
           // rjf: determine if thread is frozen
           B32 thread_is_frozen = !msg->freeze_state_is_frozen;
@@ -2998,7 +3016,7 @@ ctrl_thread__run(CTRL_Msg *msg)
   //
   if(stop_event == 0)
   {
-    U64 sp_check_value = ctrl_query_cached_rsp_from_thread(CTRL_MachineID_Local, target_thread);
+    U64 sp_check_value = dmn_rsp_from_thread(target_thread);
     B32 spoof_mode = 0;
     CTRL_Spoof spoof = {0};
     for(;;)
@@ -3085,9 +3103,7 @@ ctrl_thread__run(CTRL_Msg *msg)
       //
       CTRL_Entity *thread = ctrl_entity_from_machine_id_handle(ctrl_state->ctrl_thread_entity_store, CTRL_MachineID_Local, event->thread);
       Architecture arch = thread->arch;
-      U64 reg_size = regs_block_size_from_architecture(arch);
-      void *thread_regs_block = ctrl_query_cached_reg_block_from_thread(scratch.arena, CTRL_MachineID_Local, event->thread);
-      U64 thread_rip_vaddr = regs_rip_from_arch_block(arch, thread_regs_block);
+      U64 thread_rip_vaddr = dmn_rsp_from_thread(event->thread);
       DMN_Handle module = {0};
       String8 module_name = {0};
       U64 module_base_vaddr = 0;
@@ -3226,15 +3242,16 @@ ctrl_thread__run(CTRL_Msg *msg)
               if(bytecode.size != 0)
               {
                 U64 module_base = module_base_vaddr;
-                U64 tls_base = ctrl_query_cached_tls_root_vaddr_from_thread(CTRL_MachineID_Local, event->thread);
+                U64 tls_base = dmn_tls_root_vaddr_from_thread(event->thread);
                 EVAL_Machine machine = {0};
                 machine.u = &event->process;
                 machine.arch = arch;
                 machine.memory_read = ctrl_eval_memory_read;
-                machine.reg_data = thread_regs_block;
-                machine.reg_size = reg_size;
+                machine.reg_size = regs_block_size_from_architecture(arch);
+                machine.reg_data = push_array(scratch.arena, U8, machine.reg_size);
                 machine.module_base = &module_base;
                 machine.tls_base = &tls_base;
+                dmn_thread_read_reg_block(event->thread, machine.reg_data);
                 eval = eval_interpret(&machine, bytecode);
               }
               if(eval.code == EVAL_ResultCode_Good && eval.value.u64 == 0)
@@ -3335,7 +3352,7 @@ ctrl_thread__run(CTRL_Msg *msg)
       B32 stack_pointer_matches = 0;
       if(use_trap_net_logic)
       {
-        U64 sp = ctrl_query_cached_rsp_from_thread(CTRL_MachineID_Local, target_thread);
+        U64 sp = dmn_rsp_from_thread(target_thread);
         stack_pointer_matches = (sp == sp_check_value);
       }
       
@@ -3383,7 +3400,7 @@ ctrl_thread__run(CTRL_Msg *msg)
         {
           // rjf: setup spoof mode
           begin_spoof_mode = 1;
-          U64 spoof_sp = ctrl_query_cached_rsp_from_thread(CTRL_MachineID_Local, target_thread);
+          U64 spoof_sp = dmn_rsp_from_thread(target_thread);
           spoof_mode = 1;
           spoof.process = target_process;
           spoof.thread  = target_thread;
@@ -3401,7 +3418,7 @@ ctrl_thread__run(CTRL_Msg *msg)
           if(stack_pointer_matches)
           {
             save_stack_pointer = 1;
-            sp_check_value = ctrl_query_cached_rsp_from_thread(CTRL_MachineID_Local, target_thread);
+            sp_check_value = dmn_rsp_from_thread(target_thread);
           }
         }
       }
diff --git a/src/ctrl/ctrl_core.h b/src/ctrl/ctrl_core.h
index 916f3db4..f74f2a83 100644
--- a/src/ctrl/ctrl_core.h
+++ b/src/ctrl/ctrl_core.h
@@ -491,6 +491,10 @@ struct CTRL_State
   EVAL_String2NumMap arch_string2reg_tables[Architecture_COUNT];
   EVAL_String2NumMap arch_string2alias_tables[Architecture_COUNT];
   
+  // rjf: access locking mechanism
+  OS_Handle ctrl_run_mutex;
+  B32 ctrl_run_state;
+  
   // rjf: caches
   CTRL_ProcessMemoryCache process_memory_cache;
   CTRL_ThreadRegCache thread_reg_cache;
diff --git a/src/demon2/demon2_core.c b/src/demon2/demon2_core.c
index ee3b7ed6..86c1c3c6 100644
--- a/src/demon2/demon2_core.c
+++ b/src/demon2/demon2_core.c
@@ -116,3 +116,38 @@ dmn_event_list_push(Arena *arena, DMN_EventList *list)
   DMN_Event *result = &n->v;
   return result;
 }
+
+////////////////////////////////
+//~ rjf: Thread Reading Helper Functions (Helpers, Implemented Once)
+
+internal U64
+dmn_rip_from_thread(DMN_Handle thread)
+{
+  U64 result = 0;
+  Temp scratch = scratch_begin(0, 0);
+  {
+    Architecture arch = dmn_arch_from_thread(thread);
+    U64 reg_block_size = regs_block_size_from_architecture(arch);
+    void *reg_block = push_array(scratch.arena, U8, reg_block_size);
+    dmn_thread_read_reg_block(thread, reg_block);
+    result = regs_rip_from_arch_block(arch, reg_block);
+  }
+  scratch_end(scratch);
+  return result;
+}
+
+internal U64
+dmn_rsp_from_thread(DMN_Handle thread)
+{
+  U64 result = 0;
+  Temp scratch = scratch_begin(0, 0);
+  {
+    Architecture arch = dmn_arch_from_thread(thread);
+    U64 reg_block_size = regs_block_size_from_architecture(arch);
+    void *reg_block = push_array(scratch.arena, U8, reg_block_size);
+    dmn_thread_read_reg_block(thread, reg_block);
+    result = regs_rsp_from_arch_block(arch, reg_block);
+  }
+  scratch_end(scratch);
+  return result;
+}
diff --git a/src/demon2/demon2_core.h b/src/demon2/demon2_core.h
index dc79b254..2ae5efc8 100644
--- a/src/demon2/demon2_core.h
+++ b/src/demon2/demon2_core.h
@@ -160,6 +160,12 @@ internal DMN_HandleArray dmn_handle_array_copy(Arena *arena, DMN_HandleArray *sr
 //- rjf: event list building
 internal DMN_Event *dmn_event_list_push(Arena *arena, DMN_EventList *list);
 
+////////////////////////////////
+//~ rjf: Thread Reading Helper Functions (Helpers, Implemented Once)
+
+internal U64 dmn_rip_from_thread(DMN_Handle thread);
+internal U64 dmn_rsp_from_thread(DMN_Handle thread);
+
 ////////////////////////////////
 //~ rjf: @dmn_os_hooks Main Layer Initialization (Implemented Per-OS)
 
diff --git a/src/df/core/df_core.c b/src/df/core/df_core.c
index 75c2525d..1d7c255c 100644
--- a/src/df/core/df_core.c
+++ b/src/df/core/df_core.c
@@ -6217,13 +6217,18 @@ internal U64
 df_query_cached_tls_base_vaddr_from_process_root_rip(DF_Entity *process, U64 root_vaddr, U64 rip_vaddr)
 {
   U64 result = 0;
+  for(U64 cache_idx = 0; cache_idx < ArrayCount(df_state->tls_base_caches); cache_idx += 1)
   {
-    DF_RunTLSBaseCache *cache = &df_state->tls_base_cache;
-    if(cache->slots_count == 0)
+    DF_RunTLSBaseCache *cache = &df_state->tls_base_caches[(df_state->tls_base_cache_gen+cache_idx)%ArrayCount(df_state->tls_base_caches)];
+    if(cache_idx == 0 && cache->slots_count == 0)
     {
       cache->slots_count = 256;
       cache->slots = push_array(cache->arena, DF_RunTLSBaseCacheSlot, cache->slots_count);
     }
+    else if(cache->slots_count == 0)
+    {
+      break;
+    }
     DF_Handle handle = df_handle_from_entity(process);
     U64 hash = df_hash_from_seed_string(df_hash_from_string(str8_struct(&handle)), str8_struct(&rip_vaddr));
     U64 slot_idx = hash%cache->slots_count;
@@ -6239,14 +6244,22 @@ df_query_cached_tls_base_vaddr_from_process_root_rip(DF_Entity *process, U64 roo
     }
     if(node == 0)
     {
-      node = push_array(cache->arena, DF_RunTLSBaseCacheNode, 1);
-      SLLQueuePush_N(slot->first, slot->last, node, hash_next);
-      node->process = handle;
-      node->root_vaddr = root_vaddr;
-      node->rip_vaddr = rip_vaddr;
-      node->tls_base_vaddr = df_tls_base_vaddr_from_process_root_rip(process, root_vaddr, rip_vaddr);
+      U64 tls_base_vaddr = df_tls_base_vaddr_from_process_root_rip(process, root_vaddr, rip_vaddr);
+      if(tls_base_vaddr != 0)
+      {
+        node = push_array(cache->arena, DF_RunTLSBaseCacheNode, 1);
+        SLLQueuePush_N(slot->first, slot->last, node, hash_next);
+        node->process = handle;
+        node->root_vaddr = root_vaddr;
+        node->rip_vaddr = rip_vaddr;
+        node->tls_base_vaddr = tls_base_vaddr;
+      }
+    }
+    if(node != 0 && node->tls_base_vaddr != 0)
+    {
+      result = node->tls_base_vaddr;
+      break;
     }
-    result = node->tls_base_vaddr;
   }
   return result;
 }
@@ -6256,13 +6269,18 @@ df_query_cached_locals_map_from_binary_voff(DF_Entity *binary, U64 voff)
 {
   ProfBeginFunction();
   EVAL_String2NumMap *map = &eval_string2num_map_nil;
+  for(U64 cache_idx = 0; cache_idx < ArrayCount(df_state->locals_caches); cache_idx += 1)
   {
-    DF_RunLocalsCache *cache = &df_state->locals_cache;
-    if(cache->table_size == 0)
+    DF_RunLocalsCache *cache = &df_state->locals_caches[(df_state->locals_cache_gen+cache_idx)%ArrayCount(df_state->locals_caches)];
+    if(cache_idx == 0 && cache->table_size == 0)
     {
       cache->table_size = 256;
       cache->table = push_array(cache->arena, DF_RunLocalsCacheSlot, cache->table_size);
     }
+    else if(cache->table_size == 0)
+    {
+      break;
+    }
     DF_Handle handle = df_handle_from_entity(binary);
     U64 hash = df_hash_from_string(str8_struct(&handle));
     U64 slot_idx = hash % cache->table_size;
@@ -6290,9 +6308,10 @@ df_query_cached_locals_map_from_binary_voff(DF_Entity *binary, U64 voff)
       }
       dbgi_scope_close(scope);
     }
-    if(node != 0)
+    if(node != 0 && node->locals_map->slots_count != 0)
     {
       map = node->locals_map;
+      break;
     }
   }
   ProfEnd();
@@ -6413,8 +6432,14 @@ df_core_init(CmdLine *cmdln, DF_StateDeltaHistory *hist)
   {
     df_state->unwind_caches[idx].arena = arena_alloc();
   }
-  df_state->tls_base_cache.arena = arena_alloc();
-  df_state->locals_cache.arena = arena_alloc();
+  for(U64 idx = 0; idx < ArrayCount(df_state->tls_base_caches); idx += 1)
+  {
+    df_state->tls_base_caches[idx].arena = arena_alloc();
+  }
+  for(U64 idx = 0; idx < ArrayCount(df_state->locals_caches); idx += 1)
+  {
+    df_state->locals_caches[idx].arena = arena_alloc();
+  }
   df_state->member_cache.arena = arena_alloc();
   
   // rjf: set up eval view cache
@@ -6901,7 +6926,8 @@ df_core_begin_frame(Arena *arena, DF_CmdList *cmds, F32 dt)
         df_state->tls_base_cache_memgen_idx != new_mem_gen) &&
        !df_ctrl_targets_running())
     {
-      DF_RunTLSBaseCache *cache = &df_state->tls_base_cache;
+      df_state->tls_base_cache_gen += 1;
+      DF_RunTLSBaseCache *cache = &df_state->tls_base_caches[df_state->tls_base_cache_gen%ArrayCount(df_state->tls_base_caches)];
       arena_clear(cache->arena);
       cache->slots_count = 0;
       cache->slots = 0;
@@ -6910,9 +6936,11 @@ df_core_begin_frame(Arena *arena, DF_CmdList *cmds, F32 dt)
     }
     
     //- rjf: clear locals cache
-    if(df_state->locals_cache_reggen_idx != new_reg_gen && !df_ctrl_targets_running())
+    if(df_state->locals_cache_reggen_idx != new_reg_gen &&
+       !df_ctrl_targets_running())
     {
-      DF_RunLocalsCache *cache = &df_state->locals_cache;
+      df_state->locals_cache_gen += 1;
+      DF_RunLocalsCache *cache = &df_state->locals_caches[df_state->locals_cache_gen%ArrayCount(df_state->locals_caches)];
       arena_clear(cache->arena);
       cache->table_size = 0;
       cache->table = 0;
diff --git a/src/df/core/df_core.h b/src/df/core/df_core.h
index 76c97340..4df932cd 100644
--- a/src/df/core/df_core.h
+++ b/src/df/core/df_core.h
@@ -1139,9 +1139,11 @@ struct DF_State
   U64 unwind_cache_gen;
   U64 tls_base_cache_reggen_idx;
   U64 tls_base_cache_memgen_idx;
-  DF_RunTLSBaseCache tls_base_cache;
+  DF_RunTLSBaseCache tls_base_caches[2];
+  U64 tls_base_cache_gen;
   U64 locals_cache_reggen_idx;
-  DF_RunLocalsCache locals_cache;
+  DF_RunLocalsCache locals_caches[2];
+  U64 locals_cache_gen;
   U64 member_cache_reggen_idx;
   DF_RunLocalsCache member_cache;
   
diff --git a/src/df/gfx/df_views.c b/src/df/gfx/df_views.c
index d411c08c..a6f1eacb 100644
--- a/src/df/gfx/df_views.c
+++ b/src/df/gfx/df_views.c
@@ -6244,7 +6244,7 @@ DF_VIEW_UI_FUNCTION_DEF(Disassembly)
         DF_Entity *thread = thread_n->entity;
         U64 unwind_count = (thread == selected_thread) ? ctrl_ctx.unwind_count : 0;
         U64 rip_vaddr = df_query_cached_rip_from_thread_unwind(thread, unwind_count);
-        if(contains_1u64(disasm_vaddr_rng, rip_vaddr)) ProfScope("in-range rip scan")
+        if(contains_1u64(disasm_vaddr_rng, rip_vaddr))
         {
           U64 rip_off = rip_vaddr - disasm_vaddr_rng.min;
           S64 line_num = dasm_inst_array_idx_from_off__linear_scan(&insts, rip_off)+1;