1 //===-- Timer.cpp ---------------------------------------------------------===// 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 #include "lldb/Utility/Timer.h" 9 #include "lldb/Utility/Stream.h" 10 #include "llvm/Support/ManagedStatic.h" 11 #include "llvm/Support/Signposts.h" 12 13 #include <algorithm> 14 #include <map> 15 #include <mutex> 16 #include <utility> 17 #include <vector> 18 19 #include <cassert> 20 #include <cinttypes> 21 #include <cstdarg> 22 #include <cstdio> 23 24 using namespace lldb_private; 25 26 #define TIMER_INDENT_AMOUNT 2 27 28 namespace { 29 typedef std::vector<Timer *> TimerStack; 30 static std::atomic<Timer::Category *> g_categories; 31 } // end of anonymous namespace 32 33 /// Allows llvm::Timer to emit signposts when supported. 34 static llvm::ManagedStatic<llvm::SignpostEmitter> Signposts; 35 36 llvm::SignpostEmitter &lldb_private::GetSignposts() { return *Signposts; } 37 38 std::atomic<bool> Timer::g_quiet(true); 39 std::atomic<unsigned> Timer::g_display_depth(0); 40 static std::mutex &GetFileMutex() { 41 static std::mutex *g_file_mutex_ptr = new std::mutex(); 42 return *g_file_mutex_ptr; 43 } 44 45 static TimerStack &GetTimerStackForCurrentThread() { 46 static thread_local TimerStack g_stack; 47 return g_stack; 48 } 49 50 Timer::Category::Category(const char *cat) : m_name(cat) { 51 m_nanos.store(0, std::memory_order_release); 52 m_nanos_total.store(0, std::memory_order_release); 53 m_count.store(0, std::memory_order_release); 54 Category *expected = g_categories; 55 do { 56 m_next = expected; 57 } while (!g_categories.compare_exchange_weak(expected, this)); 58 } 59 60 void Timer::SetQuiet(bool value) { g_quiet = value; } 61 62 Timer::Timer(Timer::Category &category, const char *format, ...) 63 : m_category(category), m_total_start(std::chrono::steady_clock::now()) { 64 TimerStack &stack = GetTimerStackForCurrentThread(); 65 66 stack.push_back(this); 67 if (g_quiet && stack.size() <= g_display_depth) { 68 std::lock_guard<std::mutex> lock(GetFileMutex()); 69 70 // Indent 71 ::fprintf(stdout, "%*s", int(stack.size() - 1) * TIMER_INDENT_AMOUNT, ""); 72 // Print formatted string 73 va_list args; 74 va_start(args, format); 75 ::vfprintf(stdout, format, args); 76 va_end(args); 77 78 // Newline 79 ::fprintf(stdout, "\n"); 80 } 81 } 82 83 Timer::~Timer() { 84 using namespace std::chrono; 85 86 auto stop_time = steady_clock::now(); 87 auto total_dur = stop_time - m_total_start; 88 auto timer_dur = total_dur - m_child_duration; 89 90 TimerStack &stack = GetTimerStackForCurrentThread(); 91 if (g_quiet && stack.size() <= g_display_depth) { 92 std::lock_guard<std::mutex> lock(GetFileMutex()); 93 ::fprintf(stdout, "%*s%.9f sec (%.9f sec)\n", 94 int(stack.size() - 1) * TIMER_INDENT_AMOUNT, "", 95 duration<double>(total_dur).count(), 96 duration<double>(timer_dur).count()); 97 } 98 99 assert(stack.back() == this); 100 stack.pop_back(); 101 if (!stack.empty()) 102 stack.back()->ChildDuration(total_dur); 103 104 // Keep total results for each category so we can dump results. 105 m_category.m_nanos += std::chrono::nanoseconds(timer_dur).count(); 106 m_category.m_nanos_total += std::chrono::nanoseconds(total_dur).count(); 107 m_category.m_count++; 108 } 109 110 void Timer::SetDisplayDepth(uint32_t depth) { g_display_depth = depth; } 111 112 /* binary function predicate: 113 * - returns whether a person is less than another person 114 */ 115 namespace { 116 struct Stats { 117 const char *name; 118 uint64_t nanos; 119 uint64_t nanos_total; 120 uint64_t count; 121 }; 122 } // namespace 123 124 static bool CategoryMapIteratorSortCriterion(const Stats &lhs, 125 const Stats &rhs) { 126 return lhs.nanos > rhs.nanos; 127 } 128 129 void Timer::ResetCategoryTimes() { 130 for (Category *i = g_categories; i; i = i->m_next) { 131 i->m_nanos.store(0, std::memory_order_release); 132 i->m_nanos_total.store(0, std::memory_order_release); 133 i->m_count.store(0, std::memory_order_release); 134 } 135 } 136 137 void Timer::DumpCategoryTimes(Stream *s) { 138 std::vector<Stats> sorted; 139 for (Category *i = g_categories; i; i = i->m_next) { 140 uint64_t nanos = i->m_nanos.load(std::memory_order_acquire); 141 if (nanos) { 142 uint64_t nanos_total = i->m_nanos_total.load(std::memory_order_acquire); 143 uint64_t count = i->m_count.load(std::memory_order_acquire); 144 Stats stats{i->m_name, nanos, nanos_total, count}; 145 sorted.push_back(stats); 146 } 147 } 148 if (sorted.empty()) 149 return; // Later code will break without any elements. 150 151 // Sort by time 152 llvm::sort(sorted.begin(), sorted.end(), CategoryMapIteratorSortCriterion); 153 154 for (const auto &stats : sorted) 155 s->Printf("%.9f sec (total: %.3fs; child: %.3fs; count: %" PRIu64 156 ") for %s\n", 157 stats.nanos / 1000000000., stats.nanos_total / 1000000000., 158 (stats.nanos_total - stats.nanos) / 1000000000., stats.count, 159 stats.name); 160 } 161