utl: add ServiceRegistry and port parasitics/pin-access callbacks

docs/agents/coding.md

@@ -25,6 +25,21 @@
 ### Null Safety
 - Avoid adding too defensive null checks if the object cannot be null
 
+## Service Interfaces
+
+Abstract interfaces published through `utl::ServiceRegistry` use the
+`Service` suffix (e.g. `est::ParasiticsService`, `drt::PinAccessService`).
+Each interface lives in its owning module's public `include/<module>/`
+directory and is exposed as a small header-only Bazel target that
+consumers can depend on without pulling in the full implementation
+library. This keeps module dependency graphs acyclic and the decoupling
+visible at the build layer.
+
+Note that this is distinct from the `Abstract*` prefix used for
+graphics/visualization mock-swappable classes (e.g.
+`AbstractSteinerRenderer`); those are inherited for test/headless modes
+rather than looked up through a registry.
+
 ## Common Coding Mistakes
 
 ### OpenROAD Message ID Duplicate Checker

include/ord/OpenRoad.hh

@@ -108,7 +108,7 @@ class ICeWall;
 
 namespace utl {
 class Logger;
-class CallBackHandler;
+class ServiceRegistry;
 }  // namespace utl
 
 namespace dst {
@@ -151,7 +151,7 @@ class OpenRoad
 
   Tcl_Interp* tclInterp() { return tcl_interp_; }
   utl::Logger* getLogger() { return logger_; }
-  utl::CallBackHandler* getCallBackHandler() { return callback_handler_; }
+  utl::ServiceRegistry* getServiceRegistry() { return service_registry_; }
   odb::dbDatabase* getDb() { return db_; }
   sta::dbSta* getSta() { return sta_; }
   sta::dbNetwork* getDbNetwork();
@@ -288,7 +288,7 @@ class OpenRoad
   dft::Dft* dft_ = nullptr;
   est::EstimateParasitics* estimate_parasitics_ = nullptr;
   web::WebServer* web_server_ = nullptr;
-  utl::CallBackHandler* callback_handler_ = nullptr;
+  utl::ServiceRegistry* service_registry_ = nullptr;
 
   int threads_ = 1;
 

src/OpenRoad.cc

@@ -83,11 +83,11 @@
 #include "tap/MakeTapcell.h"
 #include "tap/tapcell.h"
 #include "upf/MakeUpf.h"
-#include "utl/CallBackHandler.h"
 #include "utl/Logger.h"
 #include "utl/MakeLogger.h"
 #include "utl/Progress.h"
 #include "utl/ScopedTemporaryFile.h"
+#include "utl/ServiceRegistry.h"
 #include "utl/decode.h"
 #include "web/MakeWeb.h"
 #include "web/web.h"
@@ -150,7 +150,7 @@ OpenRoad::~OpenRoad()
   delete web_server_;
   delete logger_;
   delete verilog_reader_;
-  delete callback_handler_;
+  delete service_registry_;
 }
 
 sta::dbNetwork* OpenRoad::getDbNetwork()
@@ -195,7 +195,7 @@ void OpenRoad::init(Tcl_Interp* tcl_interp,
   // Make components.
   utl::Progress::setBatchMode(batch_mode);
   logger_ = new utl::Logger(log_filename, metrics_filename);
-  callback_handler_ = new utl::CallBackHandler(logger_);
+  service_registry_ = new utl::ServiceRegistry(logger_);
   db_->setLogger(logger_);
   sta_ = new sta::dbSta(tcl_interp, db_, logger_);
   verilog_network_ = new dbVerilogNetwork(sta_);
@@ -204,7 +204,7 @@ void OpenRoad::init(Tcl_Interp* tcl_interp,
   antenna_checker_ = new ant::AntennaChecker(db_, logger_);
   opendp_ = new dpl::Opendp(db_, logger_);
   global_router_ = new grt::GlobalRouter(logger_,
-                                         callback_handler_,
+                                         service_registry_,
                                          stt_builder_,
                                          db_,
                                          sta_,
@@ -213,7 +213,7 @@ void OpenRoad::init(Tcl_Interp* tcl_interp,
   grt::initGui(global_router_, db_, logger_);
 
   estimate_parasitics_ = new est::EstimateParasitics(
-      logger_, callback_handler_, db_, sta_, stt_builder_, global_router_);
+      logger_, service_registry_, db_, sta_, stt_builder_, global_router_);
   est::initGui(estimate_parasitics_);
 
   resizer_ = new rsz::Resizer(logger_,
@@ -240,7 +240,7 @@ void OpenRoad::init(Tcl_Interp* tcl_interp,
   extractor_ = new rcx::Ext(db_, logger_, getVersion());
   distributer_ = new dst::Distributed(logger_);
   detailed_router_ = new drt::TritonRoute(
-      db_, logger_, callback_handler_, distributer_, stt_builder_);
+      db_, logger_, service_registry_, distributer_, stt_builder_);
   drt::initGui(detailed_router_);
 
   replace_ = new gpl::Replace(db_, sta_, resizer_, global_router_, logger_);

src/drt/BUILD

@@ -12,6 +12,15 @@ package(
     features = ["layering_check"],
 )
 
+# Abstract service interface published through utl::ServiceRegistry.
+# Consumers depend only on this target, not on //src/drt, which keeps
+# them free of the full drt implementation surface.
+cc_library(
+    name = "pin_access_service",
+    hdrs = ["include/drt/PinAccessService.h"],
+    includes = ["include"],
+)
+
 cc_library(
     name = "db_hdrs",
     hdrs = [
@@ -79,7 +88,6 @@ cc_library(
         "src/AbstractGraphicsFactory.h",
         "src/DesignCallBack.cpp",
         "src/DesignCallBack.h",
-        "src/PACallBack.h",
         "src/TritonRoute.cpp",
         "src/db/drObj/drAccessPattern.cpp",
         "src/db/drObj/drNet.cpp",
@@ -181,6 +189,7 @@ cc_library(
     ],
     deps = [
         ":db_hdrs",
+        ":pin_access_service",
         "//src/dst",
         "//src/odb",
         "//src/stt",
@@ -245,6 +254,7 @@ cc_library(
     deps = [
         ":db_hdrs",
         ":drt",
+        ":pin_access_service",
         "//:ord",
         "//src/dst",
         "//src/gui",

src/drt/include/drt/PinAccessService.h

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright (c) 2026-2026, The OpenROAD Authors
+
+#pragma once
+
+namespace drt {
+
+// Service interface published by the detailed router. Consumers look
+// it up through utl::ServiceRegistry and do not depend on the concrete
+// drt::TritonRoute type.
+class PinAccessService
+{
+ public:
+  virtual ~PinAccessService() = default;
+
+  // Recompute pin access for any instances that have become dirty.
+  virtual void updateDirtyPinAccess() = 0;
+};
+
+}  // namespace drt

src/drt/include/drt/TritonRoute.h

@@ -15,6 +15,7 @@
 
 #include "absl/synchronization/mutex.h"
 #include "boost/asio/thread_pool.hpp"
+#include "drt/PinAccessService.h"
 #include "odb/geom.h"
 
 namespace odb {
@@ -27,7 +28,7 @@ class dbWire;
 
 namespace utl {
 class Logger;
-class CallBackHandler;
+class ServiceRegistry;
 }  // namespace utl
 
 namespace stt {
@@ -43,7 +44,6 @@ namespace drt {
 class frDesign;
 class frInst;
 class DesignCallBack;
-class PACallBack;
 class FlexDR;
 class FlexPA;
 class FlexTA;
@@ -80,15 +80,17 @@ struct ParamStruct
   int num_threads = 1;
 };
 
-class TritonRoute
+class TritonRoute : public PinAccessService
 {
  public:
   TritonRoute(odb::dbDatabase* db,
               utl::Logger* logger,
-              utl::CallBackHandler* callback_handler,
+              utl::ServiceRegistry* service_registry,
               dst::Distributed* dist,
               stt::SteinerTreeBuilder* stt_builder);
-  ~TritonRoute();
+  ~TritonRoute() override;
+
+  void updateDirtyPinAccess() override;
 
   void initGraphics(std::unique_ptr<AbstractGraphicsFactory> graphics_factory);
 
@@ -191,10 +193,10 @@ class TritonRoute
   std::unique_ptr<frDesign> design_;
   std::unique_ptr<frDebugSettings> debug_;
   std::unique_ptr<DesignCallBack> db_callback_;
-  std::unique_ptr<PACallBack> pa_callback_;
   std::unique_ptr<RouterConfiguration> router_cfg_;
   odb::dbDatabase* db_{nullptr};
   utl::Logger* logger_{nullptr};
+  utl::ServiceRegistry* service_registry_{nullptr};
   std::unique_ptr<FlexDR> dr_;  // kept for single stepping
   stt::SteinerTreeBuilder* stt_builder_{nullptr};
   int num_drvs_{-1};

src/drt/src/TritonRoute.cpp

@@ -17,7 +17,6 @@
 
 #include "AbstractGraphicsFactory.h"
 #include "DesignCallBack.h"
-#include "PACallBack.h"
 #include "absl/synchronization/mutex.h"
 #include "boost/asio/post.hpp"
 #include "boost/bind/bind.hpp"
@@ -35,6 +34,7 @@
 #include "distributed/frArchive.h"
 #include "dr/AbstractDRGraphics.h"
 #include "dr/FlexDR.h"
+#include "drt/PinAccessService.h"
 #include "dst/Distributed.h"
 #include "dst/JobMessage.h"
 #include "frBaseTypes.h"
@@ -57,36 +57,47 @@
 #include "stt/SteinerTreeBuilder.h"
 #include "ta/AbstractTAGraphics.h"
 #include "ta/FlexTA.h"
-#include "utl/CallBackHandler.h"
 #include "utl/Logger.h"
 #include "utl/ScopedTemporaryFile.h"
+#include "utl/ServiceRegistry.h"
 
 using odb::dbTechLayerType;
 
 namespace drt {
 TritonRoute::TritonRoute(odb::dbDatabase* db,
                          utl::Logger* logger,
-                         utl::CallBackHandler* callback_handler,
+                         utl::ServiceRegistry* service_registry,
                          dst::Distributed* dist,
                          stt::SteinerTreeBuilder* stt_builder)
     : debug_(std::make_unique<frDebugSettings>()),
       db_callback_(std::make_unique<DesignCallBack>(this)),
-      pa_callback_(std::make_unique<PACallBack>(this)),
       router_cfg_(std::make_unique<RouterConfiguration>())
 {
   if (distributed_) {
     dist_pool_.emplace(1);
   }
   db_ = db;
   logger_ = logger;
+  service_registry_ = service_registry;
   dist_ = dist;
   stt_builder_ = stt_builder;
   design_ = std::make_unique<frDesign>(logger_, router_cfg_.get());
   dist->addCallBack(new RoutingCallBack(this, dist, logger));
-  pa_callback_->setOwner(callback_handler);
+  service_registry_->provide<PinAccessService>(this);
 }
 
-TritonRoute::~TritonRoute() = default;
+TritonRoute::~TritonRoute()
+{
+  service_registry_->withdraw<PinAccessService>(this);
+}
+
+void TritonRoute::updateDirtyPinAccess()
+{
+  if (design_ == nullptr || design_->getTopBlock() == nullptr) {
+    return;
+  }
+  updateDirtyPAData();
+}
 
 void TritonRoute::initGraphics(
     std::unique_ptr<AbstractGraphicsFactory> graphics_factory)

src/est/BUILD

@@ -14,7 +14,6 @@ cc_library(
     name = "private_hdrs",
     hdrs = [
         "src/AbstractSteinerRenderer.h",
-        "src/EstimateParasiticsCallBack.h",
         "src/MakeWireParasitics.h",
         "src/OdbCallBack.h",
         "src/SteinerRenderer.h",
@@ -26,11 +25,19 @@ cc_library(
     ],
 )
 
+# Abstract service interface published through utl::ServiceRegistry.
+# Consumers depend only on this target, not on //src/est, which keeps
+# them free of the full est implementation surface.
+cc_library(
+    name = "parasitics_service",
+    hdrs = ["include/est/ParasiticsService.h"],
+    includes = ["include"],
+)
+
 cc_library(
     name = "est",
     srcs = [
         "src/EstimateParasitics.cpp",
-        "src/EstimateParasiticsCallBack.cpp",
         "src/MakeWireParasitics.cpp",
         "src/OdbCallBack.cpp",
         "src/SteinerTree.cpp",
@@ -43,6 +50,7 @@ cc_library(
         "include",
     ],
     deps = [
+        ":parasitics_service",
         ":private_hdrs",
         "//src/dbSta",
         "//src/dbSta:SpefWriter",