PROBLEM: test_13 "Cross-System Integration" had concurrent DataNode reads removed because
getChild() and getDataRoot() return unique_ptr (ownership transfer), making concurrent
reads impossible - each read would create a copy or destroy the data.
SOLUTION: Add read-only API methods that return raw pointers without copying:
API Changes:
1. **IDataNode::getChildReadOnly(name)** → IDataNode*
- Returns raw pointer to child without copying
- Pointer valid as long as parent exists
- Enables concurrent reads without destroying tree
2. **IDataTree::getDataRootReadOnly()** → IDataNode*
- Returns raw pointer to data root without copying
- Enables concurrent access to tree data
- Complements existing getDataRoot() which returns copy
3. **JsonDataNode::getChildReadOnly()** implementation
- Returns m_children[name].get() directly
- Zero-overhead, no allocation
4. **JsonDataTree::getDataRootReadOnly()** implementation
- Returns m_root->getFirstChildByName("data") directly
- No copying, direct access
Test Changes:
- Restored TEST 5 concurrent access with IO + DataNode
- Uses getDataRootReadOnly() + getChildReadOnly() for reads
- Thread 1: Publishes IO messages concurrently
- Thread 2: Reads DataNode data concurrently (NOW WORKS!)
- Updated TEST 2 & 3 to use read-only API where appropriate
- Recreate player data before TEST 5 using read-only root access
Results:
✅ test_13 ALL TESTS PASS (5/5)
✅ TEST 5: ~100 concurrent reads successful (was 0 before)
✅ 0 errors during concurrent access
✅ True cross-system integration validated (IO + DataNode together)
This restores the original purpose of test_13: validating that IO pub/sub
and DataNode tree access work correctly together in concurrent scenarios.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>