Fix DbgCtl use-after-free shutdown crash via leaky singleton #12777
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The DbgCtl registry was experiencing use-after-free crashes during program shutdown, particularly visible in CI regression tests. The root cause was the undefined destruction order of static objects in C++. Problem: - DbgCtl objects can be static or thread-local with lifetimes spanning program execution - When one compilation unit's DbgCtl destructs and triggers registry cleanup, other compilation units may still have DbgCtl objects with pointers into that registry - Thread exit order is also unpredictable, causing similar issues when thread-local DbgCtl objects destruct This implements the "leaky singleton" pattern where the registry is: - Created on first use - Never destroyed (destructor is now = default) - Memory (~20KB) reclaimed by OS at process exit Fixes: apache#12776
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serrislew
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Jan 6, 2026
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The DbgCtl registry was experiencing use-after-free crashes during program shutdown, particularly visible in CI regression tests. The root cause was the undefined destruction order of static objects in C++.
Problem:
This implements the "leaky singleton" pattern where the registry is:
Fixes: #12776