From 3fa35115030fa8fbb11c82a864872d702de9bd13 Mon Sep 17 00:00:00 2001
From: Arkadiusz Szczepkowicz <arek.szczepkowicz@ng-analytics.com>
Date: Tue, 16 May 2023 18:30:23 +0200
Subject: [PATCH] #2074: Create LBDataRestartReader when there is OfflineLB in
 the config file

---
 src/vt/runtime/runtime.cc                | 13 +++++++++++--
 src/vt/vrt/collection/balance/read_lb.cc |  9 +++++++++
 src/vt/vrt/collection/balance/read_lb.h  |  1 +
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/vt/runtime/runtime.cc b/src/vt/runtime/runtime.cc
index 7d73260004..74a42e2f6d 100644
--- a/src/vt/runtime/runtime.cc
+++ b/src/vt/runtime/runtime.cc
@@ -423,9 +423,18 @@ bool Runtime::tryFinalize(bool const disable_sig) {
 }
 
 bool Runtime::needLBDataRestartReader() {
+  using vrt::collection::balance::ReadLBConfig;
+
   #if vt_check_enabled(lblite)
-  if (true) {
-    return arg_config_->config_.vt_lb_data_in;
+  if (arg_config_->config_.vt_lb_data_in) {
+    auto& config_file = arg_config_->config_.vt_lb_file_name;
+    if (config_file != "") {
+      bool const has_spec = ReadLBConfig::openConfig(config_file);
+      if (has_spec) {
+        return ReadLBConfig::hasOfflineLB();
+      }
+    }
+    return false;
   } else
   #endif
     return false;
diff --git a/src/vt/vrt/collection/balance/read_lb.cc b/src/vt/vrt/collection/balance/read_lb.cc
index f2aa22d20d..a32e99e45b 100644
--- a/src/vt/vrt/collection/balance/read_lb.cc
+++ b/src/vt/vrt/collection/balance/read_lb.cc
@@ -102,6 +102,15 @@ namespace vt { namespace vrt { namespace collection { namespace balance {
   }
 }
 
+/*static*/ bool ReadLBConfig::hasOfflineLB() {
+  for(auto&& ele : config_exact_) {
+    if(getLB(ele.first) == LBType::OfflineLB) {
+      return true;
+    }
+  }
+  return false;
+}
+
 /*static*/ ConfigEntry* ReadLBConfig::entry(ConfigIndex const& idx) {
   // First, search the exact iter config for this iteration: it has the highest
   // precedence
diff --git a/src/vt/vrt/collection/balance/read_lb.h b/src/vt/vrt/collection/balance/read_lb.h
index a1fbb6998a..60f4c88dd0 100644
--- a/src/vt/vrt/collection/balance/read_lb.h
+++ b/src/vt/vrt/collection/balance/read_lb.h
@@ -197,6 +197,7 @@ struct ReadLBConfig {
   static ConfigIndex numEntries() { return config_mod_.size() + config_exact_.size(); }
   static ConfigEntry* entry(ConfigIndex const& idx);
   static LBType getLB(ConfigIndex const& idx);
+  static bool hasOfflineLB();
   static ConfigMapType getModEntries() { return config_mod_; };
   static ConfigMapType getExactEntries() {return config_exact_; };
   static ParamMapType parseParams(std::vector<std::string> params);