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diff --git a/src/core/lib/promise/promise_mutex.h b/src/core/lib/promise/promise_mutex.h
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+++ b/src/core/lib/promise/promise_mutex.h
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+// Copyright 2023 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef GRPC_SRC_CORE_LIB_PROMISE_PROMISE_MUTEX_H
+#define GRPC_SRC_CORE_LIB_PROMISE_PROMISE_MUTEX_H
+
+#include <grpc/support/port_platform.h>
+
+#include <utility>
+
+#include <grpc/support/log.h>
+
+#include "src/core/lib/promise/activity.h"
+#include "src/core/lib/promise/poll.h"
+
+namespace grpc_core {
+
+// A mutex that can be used to synchronize access to a value within one
+// activity.
+template <typename T>
+class PromiseMutex {
+ public:
+  class Lock {
+   public:
+    Lock() {}
+    ~Lock() {
+      if (mutex_ != nullptr) {
+        GPR_ASSERT(mutex_->locked_);
+        mutex_->locked_ = false;
+        mutex_->waiter_.Wake();
+      }
+    }
+
+    Lock(Lock&& other) noexcept
+        : mutex_(std::exchange(other.mutex_, nullptr)) {}
+    Lock& operator=(Lock&& other) noexcept {
+      std::swap(mutex_, other.mutex_);
+      return *this;
+    }
+
+    Lock(const Lock&) = delete;
+    Lock& operator=(const Lock&) noexcept = delete;
+
+    T* operator->() {
+      GPR_DEBUG_ASSERT(mutex_ != nullptr);
+      return &mutex_->value_;
+    }
+    T& operator*() {
+      GPR_DEBUG_ASSERT(mutex_ != nullptr);
+      return mutex_->value_;
+    }
+
+   private:
+    friend class PromiseMutex;
+    explicit Lock(PromiseMutex* mutex) : mutex_(mutex) {
+      GPR_DEBUG_ASSERT(!mutex_->locked_);
+      mutex_->locked_ = true;
+    }
+    PromiseMutex* mutex_ = nullptr;
+  };
+
+  PromiseMutex() = default;
+  explicit PromiseMutex(T value) : value_(std::move(value)) {}
+  ~PromiseMutex() { GPR_DEBUG_ASSERT(!locked_); }
+
+  auto Acquire() {
+    return [this]() -> Poll<Lock> {
+      if (locked_) return waiter_.pending();
+      return Lock(this);
+    };
+  }
+
+ private:
+  bool locked_ = false;
+  IntraActivityWaiter waiter_;
+  GPR_NO_UNIQUE_ADDRESS T value_;
+};
+
+}  // namespace grpc_core
+
+#endif  // GRPC_SRC_CORE_LIB_PROMISE_PROMISE_MUTEX_H