1 //===-- ThreadSafeValue.h ---------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef LLDB_CORE_THREADSAFEVALUE_H
10 #define LLDB_CORE_THREADSAFEVALUE_H
11 
12 #include <mutex>
13 
14 #include "lldb/lldb-defines.h"
15 
16 namespace lldb_private {
17 
18 template <class T> class ThreadSafeValue {
19 public:
20   ThreadSafeValue() = default;
21   ThreadSafeValue(const T &value) : m_value(value) {}
22 
23   ~ThreadSafeValue() = default;
24 
25   T GetValue() const {
26     T value;
27     {
28       std::lock_guard<std::recursive_mutex> guard(m_mutex);
29       value = m_value;
30     }
31     return value;
32   }
33 
34   // Call this if you have already manually locked the mutex using the
35   // GetMutex() accessor
36   const T &GetValueNoLock() const { return m_value; }
37 
38   void SetValue(const T &value) {
39     std::lock_guard<std::recursive_mutex> guard(m_mutex);
40     m_value = value;
41   }
42 
43   // Call this if you have already manually locked the mutex using the
44   // GetMutex() accessor
45   // coverity[missing_lock]
46   void SetValueNoLock(const T &value) { m_value = value; }
47 
48   std::recursive_mutex &GetMutex() { return m_mutex; }
49 
50 private:
51   T m_value;
52   mutable std::recursive_mutex m_mutex;
53 
54   // For ThreadSafeValue only
55   ThreadSafeValue(const ThreadSafeValue &) = delete;
56   const ThreadSafeValue &operator=(const ThreadSafeValue &) = delete;
57 };
58 
59 } // namespace lldb_private
60 #endif // LLDB_CORE_THREADSAFEVALUE_H
61