1 //===-- Timer.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_UTILITY_TIMER_H
10 #define LLDB_UTILITY_TIMER_H
11 
12 #include "lldb/lldb-defines.h"
13 #include "llvm/Support/Chrono.h"
14 #include <atomic>
15 #include <cstdint>
16 
17 namespace lldb_private {
18 class Stream;
19 
20 /// \class Timer Timer.h "lldb/Utility/Timer.h"
21 /// A timer class that simplifies common timing metrics.
22 
23 class Timer {
24 public:
25   class Category {
26   public:
27     explicit Category(const char *category_name);
28     llvm::StringRef GetName() { return m_name; }
29 
30   private:
31     friend class Timer;
32     const char *m_name;
33     std::atomic<uint64_t> m_nanos;
34     std::atomic<uint64_t> m_nanos_total;
35     std::atomic<uint64_t> m_count;
36     std::atomic<Category *> m_next;
37 
38     Category(const Category &) = delete;
39     const Category &operator=(const Category &) = delete;
40   };
41 
42   /// Default constructor.
43   Timer(Category &category, const char *format, ...)
44 #if !defined(_MSC_VER)
45   // MSVC appears to have trouble recognizing the this argument in the constructor.
46       __attribute__((format(printf, 3, 4)))
47 #endif
48     ;
49 
50   /// Destructor
51   ~Timer();
52 
53   void Dump();
54 
55   static void SetDisplayDepth(uint32_t depth);
56 
57   static void SetQuiet(bool value);
58 
59   static void DumpCategoryTimes(Stream &s);
60 
61   static void ResetCategoryTimes();
62 
63 protected:
64   using TimePoint = std::chrono::steady_clock::time_point;
65   void ChildDuration(TimePoint::duration dur) { m_child_duration += dur; }
66 
67   Category &m_category;
68   TimePoint m_total_start;
69   TimePoint::duration m_child_duration{0};
70 
71   static std::atomic<bool> g_quiet;
72   static std::atomic<unsigned> g_display_depth;
73 
74 private:
75   Timer(const Timer &) = delete;
76   const Timer &operator=(const Timer &) = delete;
77 };
78 
79 } // namespace lldb_private
80 
81 // Use a format string because LLVM_PRETTY_FUNCTION might not be a string
82 // literal.
83 #define LLDB_SCOPED_TIMER()                                                    \
84   static ::lldb_private::Timer::Category _cat(LLVM_PRETTY_FUNCTION);           \
85   ::lldb_private::Timer _scoped_timer(_cat, "%s", LLVM_PRETTY_FUNCTION)
86 #define LLDB_SCOPED_TIMERF(...)                                                \
87   static ::lldb_private::Timer::Category _cat(LLVM_PRETTY_FUNCTION);           \
88   ::lldb_private::Timer _scoped_timer(_cat, __VA_ARGS__)
89 
90 #endif // LLDB_UTILITY_TIMER_H
91