Have createNewBlock() wait for a tip

Additionally it returns null if the node started to shutdown before TipBlock() was set.
Sjors · Feb 3, 2025 · be15f2e · be15f2e
1 parent ad3af40
commit be15f2e
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/src/interfaces/mining.h b/src/interfaces/mining.h
@@ -88,10 +88,14 @@ class Mining
     virtual std::optional<BlockRef> waitTipChanged(uint256 current_tip, MillisecondsDouble timeout = MillisecondsDouble::max()) = 0;
 
    /**
-     * Construct a new block template
+     * Construct a new block template.
+     *
+     * During node initialization, this will
+     * wait until the tip is connected.
      *
      * @param[in] options options for creating the block
-     * @returns a block template
+     * @retval BlockTemplate a block template.
+     * @retval empty if node is shutting down
      */
     virtual std::unique_ptr<BlockTemplate> createNewBlock(const node::BlockCreateOptions& options = {}) = 0;
 

diff --git a/src/node/interfaces.cpp b/src/node/interfaces.cpp
@@ -994,6 +994,9 @@ class MinerImpl : public Mining
 
     std::unique_ptr<BlockTemplate> createNewBlock(const BlockCreateOptions& options) override
     {
+        // Ensure m_tip_block is set so consumers of BlockTemplate can rely on that.
+        if (!waitTipChanged(uint256::ZERO, MillisecondsDouble::max())) return {};
+
         BlockAssembler::Options assemble_options{options};
         ApplyArgsManOptions(*Assert(m_node.args), assemble_options);
         return std::make_unique<BlockTemplateImpl>(BlockAssembler{chainman().ActiveChainstate(), context()->mempool.get(), assemble_options}.CreateNewBlock(), m_node);