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libshaderc_util: eliminate static mutex heap leak in GlslangInitializer (fixes #1473) - #1609
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…er (fixes google#1473) GlslangInitializer allocated a heap std::mutex via new to synchronize glslang initialization and finalization while deferring construction until first use. Because the allocated pointer was deliberately never deleted to avoid racing destructor calls, it leaked 80 bytes of heap memory on every run, surfacing in leak sanitizers and custom debug allocators. Replacing the raw heap pointer with a function-local static mutex reference achieves thread-safe deferred initialization under C++11 semantics without dynamic memory allocation, eliminating the memory leak while preserving concurrency guarantees across compiler instances. Signed-off-by: jdymitarai <o10040115@gmail.com>
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This is a net win: going from
- a function-scope static std::mutex
- a new'd std::mutex that is leaked
to:
- a function-scope static std::mutex
That's a net win, adding no dependencies.
thanks!
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In GlslangInitializer, a process-wide mutex was dynamically allocated on the heap via new to synchronize glslang initialization without triggering static construction before main. Because the pointer was never deleted to prevent racing destructor calls, it produced an 80-byte heap memory leak reported by leak checkers whenever compilers were initialized and released.
Replacing the raw heap pointer with a function-local static mutex reference achieves deferred thread-safe initialization under C++11 semantics without heap allocation. This resolves the memory leak while preserving concurrency guarantees across multiple compiler instances. Verified with all 61 tests passing cleanly under ctest.