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diff --git a/contrib/llvm-project/compiler-rt/lib/scudo/standalone/mutex.h b/contrib/llvm-project/compiler-rt/lib/scudo/standalone/mutex.h
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+++ b/contrib/llvm-project/compiler-rt/lib/scudo/standalone/mutex.h
@@ -0,0 +1,97 @@
+//===-- mutex.h -------------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SCUDO_MUTEX_H_
+#define SCUDO_MUTEX_H_
+
+#include "atomic_helpers.h"
+#include "common.h"
+#include "thread_annotations.h"
+
+#include <string.h>
+
+#if SCUDO_FUCHSIA
+#include <lib/sync/mutex.h> // for sync_mutex_t
+#endif
+
+namespace scudo {
+
+class CAPABILITY("mutex") HybridMutex {
+public:
+  bool tryLock() TRY_ACQUIRE(true);
+  NOINLINE void lock() ACQUIRE() {
+    if (LIKELY(tryLock()))
+      return;
+      // The compiler may try to fully unroll the loop, ending up in a
+      // NumberOfTries*NumberOfYields block of pauses mixed with tryLocks. This
+      // is large, ugly and unneeded, a compact loop is better for our purpose
+      // here. Use a pragma to tell the compiler not to unroll the loop.
+#ifdef __clang__
+#pragma nounroll
+#endif
+    for (u8 I = 0U; I < NumberOfTries; I++) {
+      delayLoop();
+      if (tryLock())
+        return;
+    }
+    lockSlow();
+  }
+  void unlock() RELEASE();
+
+  // TODO(chiahungduan): In general, we may want to assert the owner of lock as
+  // well. Given the current uses of HybridMutex, it's acceptable without
+  // asserting the owner. Re-evaluate this when we have certain scenarios which
+  // requires a more fine-grained lock granularity.
+  ALWAYS_INLINE void assertHeld() ASSERT_CAPABILITY(this) {
+    if (SCUDO_DEBUG)
+      assertHeldImpl();
+  }
+
+private:
+  void delayLoop() {
+    // The value comes from the average time spent in accessing caches (which
+    // are the fastest operations) so that we are unlikely to wait too long for
+    // fast operations.
+    constexpr u32 SpinTimes = 16;
+    volatile u32 V = 0;
+    for (u32 I = 0; I < SpinTimes; ++I) {
+      u32 Tmp = V + 1;
+      V = Tmp;
+    }
+  }
+
+  void assertHeldImpl();
+
+  // TODO(chiahungduan): Adapt this value based on scenarios. E.g., primary and
+  // secondary allocator have different allocation times.
+  static constexpr u8 NumberOfTries = 32U;
+
+#if SCUDO_LINUX
+  atomic_u32 M = {};
+#elif SCUDO_FUCHSIA
+  sync_mutex_t M = {};
+#endif
+
+  void lockSlow() ACQUIRE();
+};
+
+class SCOPED_CAPABILITY ScopedLock {
+public:
+  explicit ScopedLock(HybridMutex &M) ACQUIRE(M) : Mutex(M) { Mutex.lock(); }
+  ~ScopedLock() RELEASE() { Mutex.unlock(); }
+
+private:
+  HybridMutex &Mutex;
+
+  ScopedLock(const ScopedLock &) = delete;
+  void operator=(const ScopedLock &) = delete;
+};
+
+} // namespace scudo
+
+#endif // SCUDO_MUTEX_H_