Use m_cached_chaintip_recent in IsIBD removing the cs_main lock.

Author: pstratem

src/validation.cpp

@@ -2015,26 +2015,13 @@ void Chainstate::InitCoinsCache(size_t cache_size_bytes)
 //
 bool ChainstateManager::IsInitialBlockDownload() const
 {
-    // Optimization: pre-test latch before taking the lock.
-    if (m_cached_finished_ibd.load(std::memory_order_relaxed))
-        return false;
-
-    LOCK(cs_main);
     if (m_cached_finished_ibd.load(std::memory_order_relaxed))
         return false;
     if (m_blockman.LoadingBlocks()) {
         return true;
     }
-    CChain& chain{ActiveChain()};
-    if (chain.Tip() == nullptr) {
-        return true;
-    }
-    if (chain.Tip()->nChainWork < MinimumChainWork()) {
+    if (!m_cached_chaintip_recent)
         return true;
-    }
-    if (chain.Tip()->Time() < Now<NodeSeconds>() - m_options.max_tip_age) {
-        return true;
-    }
     LogInfo("Leaving InitialBlockDownload (latching to false)");
     m_cached_finished_ibd.store(true, std::memory_order_relaxed);
     return false;