162 lines · cpp
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-exception6//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 24using namespace lldb_private;25 26#define TIMER_INDENT_AMOUNT 227 28namespace {29typedef std::vector<Timer *> TimerStack;30static std::atomic<Timer::Category *> g_categories;31} // end of anonymous namespace32 33/// Allows llvm::Timer to emit signposts when supported.34static llvm::ManagedStatic<llvm::SignpostEmitter> Signposts;35 36std::atomic<bool> Timer::g_quiet(true);37std::atomic<unsigned> Timer::g_display_depth(0);38static std::mutex &GetFileMutex() {39 static std::mutex *g_file_mutex_ptr = new std::mutex();40 return *g_file_mutex_ptr;41}42 43static TimerStack &GetTimerStackForCurrentThread() {44 static thread_local TimerStack g_stack;45 return g_stack;46}47 48Timer::Category::Category(const char *cat) : m_name(cat) {49 m_nanos.store(0, std::memory_order_release);50 m_nanos_total.store(0, std::memory_order_release);51 m_count.store(0, std::memory_order_release);52 Category *expected = g_categories;53 do {54 m_next = expected;55 } while (!g_categories.compare_exchange_weak(expected, this));56}57 58void Timer::SetQuiet(bool value) { g_quiet = value; }59 60Timer::Timer(Timer::Category &category, const char *format, ...)61 : m_category(category), m_total_start(std::chrono::steady_clock::now()) {62 Signposts->startInterval(this, m_category.GetName());63 TimerStack &stack = GetTimerStackForCurrentThread();64 65 stack.push_back(this);66 if (!g_quiet && stack.size() <= g_display_depth) {67 std::lock_guard<std::mutex> lock(GetFileMutex());68 69 // Indent70 ::fprintf(stdout, "%*s", int(stack.size() - 1) * TIMER_INDENT_AMOUNT, "");71 // Print formatted string72 va_list args;73 va_start(args, format);74 ::vfprintf(stdout, format, args);75 va_end(args);76 77 // Newline78 ::fprintf(stdout, "\n");79 }80}81 82Timer::~Timer() {83 using namespace std::chrono;84 85 auto stop_time = steady_clock::now();86 auto total_dur = stop_time - m_total_start;87 auto timer_dur = total_dur - m_child_duration;88 89 Signposts->endInterval(this, m_category.GetName());90 91 TimerStack &stack = GetTimerStackForCurrentThread();92 if (!g_quiet && stack.size() <= g_display_depth) {93 std::lock_guard<std::mutex> lock(GetFileMutex());94 ::fprintf(stdout, "%*s%.9f sec (%.9f sec)\n",95 int(stack.size() - 1) * TIMER_INDENT_AMOUNT, "",96 duration<double>(total_dur).count(),97 duration<double>(timer_dur).count());98 }99 100 assert(stack.back() == this);101 stack.pop_back();102 if (!stack.empty())103 stack.back()->ChildDuration(total_dur);104 105 // Keep total results for each category so we can dump results.106 m_category.m_nanos += std::chrono::nanoseconds(timer_dur).count();107 m_category.m_nanos_total += std::chrono::nanoseconds(total_dur).count();108 m_category.m_count++;109}110 111void Timer::SetDisplayDepth(uint32_t depth) { g_display_depth = depth; }112 113/* binary function predicate:114 * - returns whether a person is less than another person115 */116namespace {117struct Stats {118 const char *name;119 uint64_t nanos;120 uint64_t nanos_total;121 uint64_t count;122};123} // namespace124 125static bool CategoryMapIteratorSortCriterion(const Stats &lhs,126 const Stats &rhs) {127 return lhs.nanos > rhs.nanos;128}129 130void Timer::ResetCategoryTimes() {131 for (Category *i = g_categories; i; i = i->m_next) {132 i->m_nanos.store(0, std::memory_order_release);133 i->m_nanos_total.store(0, std::memory_order_release);134 i->m_count.store(0, std::memory_order_release);135 }136}137 138void Timer::DumpCategoryTimes(Stream &s) {139 std::vector<Stats> sorted;140 for (Category *i = g_categories; i; i = i->m_next) {141 uint64_t nanos = i->m_nanos.load(std::memory_order_acquire);142 if (nanos) {143 uint64_t nanos_total = i->m_nanos_total.load(std::memory_order_acquire);144 uint64_t count = i->m_count.load(std::memory_order_acquire);145 Stats stats{i->m_name, nanos, nanos_total, count};146 sorted.push_back(stats);147 }148 }149 if (sorted.empty())150 return; // Later code will break without any elements.151 152 // Sort by time153 llvm::sort(sorted, CategoryMapIteratorSortCriterion);154 155 for (const auto &stats : sorted)156 s.Printf("%.9f sec (total: %.3fs; child: %.3fs; count: %" PRIu64157 ") for %s\n",158 stats.nanos / 1000000000., stats.nanos_total / 1000000000.,159 (stats.nanos_total - stats.nanos) / 1000000000., stats.count,160 stats.name);161}162