Fix failed pulling stats from IC shared thread (ydb-platform#9384)

Author: kruall

ydb/library/actors/core/executor_pool_shared.cpp

@@ -143,16 +143,16 @@ void TSharedExecutorPool::GiveHalfThread(i16 from, i16 to) {
 }
 
 void TSharedExecutorPool::GetSharedStats(i16 poolId, std::vector<TExecutorThreadStats>& statsCopy) {
-    statsCopy.resize(SharedThreadCount + 1);
+    statsCopy.resize(SharedThreadCount);
     for (i16 i = 0; i < SharedThreadCount; ++i) {
-        Threads[i].Thread->GetSharedStats(poolId, statsCopy[i + 1]);
+        Threads[i].Thread->GetSharedStats(poolId, statsCopy[i]);
     }
 }
 
 void TSharedExecutorPool::GetSharedStatsForHarmonizer(i16 poolId, std::vector<TExecutorThreadStats>& statsCopy) {
-    statsCopy.resize(SharedThreadCount + 1);
+    statsCopy.resize(SharedThreadCount);
     for (i16 i = 0; i < SharedThreadCount; ++i) {
-        Threads[i].Thread->GetSharedStatsForHarmonizer(poolId, statsCopy[i + 1]);
+        Threads[i].Thread->GetSharedStatsForHarmonizer(poolId, statsCopy[i]);
     }
 }
 

ydb/library/actors/core/harmonizer.cpp

@@ -625,6 +625,7 @@ void THarmonizer::HarmonizeImpl(ui64 ts) {
                 i64 threadCount = pool.GetFullThreadCount();
                 if (hasSharedThread[poolIdx] && !hasSharedThreadWhichWasNotBorrowed[poolIdx]) {
                     Shared->ReturnOwnHalfThread(poolIdx);
+                    overbooked -= 0.5;
                 }
                 while (threadCount > pool.DefaultFullThreadCount) {
                     pool.SetFullThreadCount(--threadCount);
@@ -809,6 +810,8 @@ void THarmonizer::AddPool(IExecutorPool* pool, TSelfPingInfo *pingInfo) {
     if (poolInfo.BasicPool) {
         poolInfo.WaitingStats.reset(new TWaitingStats<ui64>());
         poolInfo.MovingWaitingStats.reset(new TWaitingStats<double>());
+    } else {
+        poolInfo.DefaultThreadCount = 0;
     }
     PriorityOrder.clear();
 }