[libc-commits] [libc] [libc] rework mutex (PR #92168)

[Michael Jones via libc-commits]

================
@@ -9,114 +9,74 @@
 #ifndef LLVM_LIBC_SRC___SUPPORT_THREADS_LINUX_MUTEX_H
 #define LLVM_LIBC_SRC___SUPPORT_THREADS_LINUX_MUTEX_H
 
+#include "hdr/types/pid_t.h"
+#include "src/__support/CPP/optional.h"
 #include "src/__support/threads/linux/futex_utils.h"
+#include "src/__support/threads/linux/raw_mutex.h"
 #include "src/__support/threads/mutex_common.h"
 
 namespace LIBC_NAMESPACE {
-struct Mutex {
+
+// TODO: support shared/recursive/robust mutexes.
+class Mutex final : private internal::RawMutex {
+  // reserved timed, may be useful when combined with other flags.
   unsigned char timed;
   unsigned char recursive;
   unsigned char robust;
+  unsigned char pshared;
 
-  void *owner;
+  // TLS address may not work across forked processes. Use thread id instead.
----------------
michaelrj-google wrote:

nit: `pid` is process ID instead of thread id.

https://github.com/llvm/llvm-project/pull/92168