[libcxx-commits] [libcxx] [libc++] add shared_recursive_mutex api (PR #82466)

[A. Jiang via libcxx-commits]

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@@ -0,0 +1,122 @@
+#include <cassert>
+#include <shared_recursive_mutex>
+
+constexpr uint32_t SHARED_USER_MAX_CNT = UINT32_MAX;
+constexpr pthread_t THREAD_ID_NOEXIST  = 0;
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frederick-vs-ja wrote:

If it's intended to support non-pthread platforms, `__thread_id` should be used. But it's a bit unfortunate that it's default constructor is not constexpr, and I _think_ we can drop this constant and use `__thread_id{}` instead.

https://github.com/llvm/llvm-project/pull/82466