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Reference Guide
TSpinMutex.hxx
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1// @(#)root/thread
2// Author: Danilo Piparo, 2016
3
4/*************************************************************************
5 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers. *
6 * All rights reserved. *
7 * *
8 * For the licensing terms see $ROOTSYS/LICENSE. *
9 * For the list of contributors see $ROOTSYS/README/CREDITS. *
10 *************************************************************************/
11
12#ifndef ROOT_TSpinMutex
13#define ROOT_TSpinMutex
14
15#include <atomic>
16
17namespace ROOT {
18
19 /**
20 * \class ROOT::TSpinMutex
21 * \brief A spin mutex class which respects the STL interface for mutexes.
22 * \ingroup Multicore
23 * This class allows to acquire spin locks also in combination with templates in the STL such as
24 * <a href="http://en.cppreference.com/w/cpp/thread/unique_lock">std::unique_lock</a> or
25 * <a href="http://en.cppreference.com/w/cpp/thread/condition_variable_any">std::condition_variable_any</a>.
26 * For example:
27 * ~~~ {.cpp}
28 * ROOT::TSpinMutex m;
29 * std::condition_variable cv;
30 * bool ready = false;
31 *
32 * void worker_thread()
33 * {
34 * // Wait until main() sends data
35 * std::unique_lock<ROOT::TSpinMutex> lk(m);
36 * cv.wait(lk, []{return ready;});
37 * [...]
38 * ~~~ {.cpp}
39 */
40 class TSpinMutex {
41
42 private:
43 std::atomic_flag fAFlag = ATOMIC_FLAG_INIT;
44
45 public:
46 TSpinMutex() = default;
47 TSpinMutex(const TSpinMutex&) = delete;
48 ~TSpinMutex() = default;
49 TSpinMutex& operator=(const TSpinMutex&) = delete;
50
51 void lock() { while (fAFlag.test_and_set(std::memory_order_acquire)); }
52 void unlock() { fAFlag.clear(std::memory_order_release); }
53 bool try_lock() { return !fAFlag.test_and_set(std::memory_order_acquire); }
54
55 };
56}
57
58#endif
A spin mutex class which respects the STL interface for mutexes.
Definition: TSpinMutex.hxx:40
TSpinMutex()=default
TSpinMutex(const TSpinMutex &)=delete
std::atomic_flag fAFlag
Definition: TSpinMutex.hxx:43
~TSpinMutex()=default
TSpinMutex & operator=(const TSpinMutex &)=delete
Namespace for new ROOT classes and functions.
Definition: StringConv.hxx:21