| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| |
| // Date: Wed Aug 11 10:38:17 2010 |
| |
| // Measuring time |
| |
| #ifndef BUTIL_BAIDU_TIME_H |
| #define BUTIL_BAIDU_TIME_H |
| |
| #include <time.h> // timespec, clock_gettime |
| #include <sys/time.h> // timeval, gettimeofday |
| #include <stdint.h> // int64_t, uint64_t |
| |
| #if defined(NO_CLOCK_GETTIME_IN_MAC) |
| #include <mach/mach.h> |
| # define CLOCK_REALTIME CALENDAR_CLOCK |
| # define CLOCK_MONOTONIC SYSTEM_CLOCK |
| |
| typedef int clockid_t; |
| |
| // clock_gettime is not available in MacOS < 10.12 |
| int clock_gettime(clockid_t id, timespec* time); |
| |
| #endif |
| |
| namespace butil { |
| |
| // Get SVN revision of this copy. |
| const char* last_changed_revision(); |
| |
| // ---------------------- |
| // timespec manipulations |
| // ---------------------- |
| |
| // Let tm->tv_nsec be in [0, 1,000,000,000) if it's not. |
| inline void timespec_normalize(timespec* tm) { |
| if (tm->tv_nsec >= 1000000000L) { |
| const int64_t added_sec = tm->tv_nsec / 1000000000L; |
| tm->tv_sec += added_sec; |
| tm->tv_nsec -= added_sec * 1000000000L; |
| } else if (tm->tv_nsec < 0) { |
| const int64_t sub_sec = (tm->tv_nsec - 999999999L) / 1000000000L; |
| tm->tv_sec += sub_sec; |
| tm->tv_nsec -= sub_sec * 1000000000L; |
| } |
| } |
| |
| // Add timespec |span| into timespec |*tm|. |
| inline void timespec_add(timespec *tm, const timespec& span) { |
| tm->tv_sec += span.tv_sec; |
| tm->tv_nsec += span.tv_nsec; |
| timespec_normalize(tm); |
| } |
| |
| // Minus timespec |span| from timespec |*tm|. |
| // tm->tv_nsec will be inside [0, 1,000,000,000) |
| inline void timespec_minus(timespec *tm, const timespec& span) { |
| tm->tv_sec -= span.tv_sec; |
| tm->tv_nsec -= span.tv_nsec; |
| timespec_normalize(tm); |
| } |
| |
| // ------------------------------------------------------------------ |
| // Get the timespec after specified duration from |start_time| |
| // ------------------------------------------------------------------ |
| inline timespec nanoseconds_from(timespec start_time, int64_t nanoseconds) { |
| start_time.tv_nsec += nanoseconds; |
| timespec_normalize(&start_time); |
| return start_time; |
| } |
| |
| inline timespec microseconds_from(timespec start_time, int64_t microseconds) { |
| return nanoseconds_from(start_time, microseconds * 1000L); |
| } |
| |
| inline timespec milliseconds_from(timespec start_time, int64_t milliseconds) { |
| return nanoseconds_from(start_time, milliseconds * 1000000L); |
| } |
| |
| inline timespec seconds_from(timespec start_time, int64_t seconds) { |
| return nanoseconds_from(start_time, seconds * 1000000000L); |
| } |
| |
| // -------------------------------------------------------------------- |
| // Get the timespec after specified duration from now (CLOCK_REALTIME) |
| // -------------------------------------------------------------------- |
| inline timespec nanoseconds_from_now(int64_t nanoseconds) { |
| timespec time; |
| clock_gettime(CLOCK_REALTIME, &time); |
| return nanoseconds_from(time, nanoseconds); |
| } |
| |
| inline timespec microseconds_from_now(int64_t microseconds) { |
| return nanoseconds_from_now(microseconds * 1000L); |
| } |
| |
| inline timespec milliseconds_from_now(int64_t milliseconds) { |
| return nanoseconds_from_now(milliseconds * 1000000L); |
| } |
| |
| inline timespec seconds_from_now(int64_t seconds) { |
| return nanoseconds_from_now(seconds * 1000000000L); |
| } |
| |
| inline timespec timespec_from_now(const timespec& span) { |
| timespec time; |
| clock_gettime(CLOCK_REALTIME, &time); |
| timespec_add(&time, span); |
| return time; |
| } |
| |
| // --------------------------------------------------------------------- |
| // Convert timespec to and from a single integer. |
| // For conversions between timespec and timeval, use TIMEVAL_TO_TIMESPEC |
| // and TIMESPEC_TO_TIMEVAL defined in <sys/time.h> |
| // ---------------------------------------------------------------------1 |
| inline int64_t timespec_to_nanoseconds(const timespec& ts) { |
| return ts.tv_sec * 1000000000L + ts.tv_nsec; |
| } |
| |
| inline int64_t timespec_to_microseconds(const timespec& ts) { |
| return timespec_to_nanoseconds(ts) / 1000L; |
| } |
| |
| inline int64_t timespec_to_milliseconds(const timespec& ts) { |
| return timespec_to_nanoseconds(ts) / 1000000L; |
| } |
| |
| inline int64_t timespec_to_seconds(const timespec& ts) { |
| return timespec_to_nanoseconds(ts) / 1000000000L; |
| } |
| |
| inline timespec nanoseconds_to_timespec(int64_t ns) { |
| timespec ts; |
| ts.tv_sec = ns / 1000000000L; |
| ts.tv_nsec = ns - ts.tv_sec * 1000000000L; |
| return ts; |
| } |
| |
| inline timespec microseconds_to_timespec(int64_t us) { |
| return nanoseconds_to_timespec(us * 1000L); |
| } |
| |
| inline timespec milliseconds_to_timespec(int64_t ms) { |
| return nanoseconds_to_timespec(ms * 1000000L); |
| } |
| |
| inline timespec seconds_to_timespec(int64_t s) { |
| return nanoseconds_to_timespec(s * 1000000000L); |
| } |
| |
| // --------------------------------------------------------------------- |
| // Convert timeval to and from a single integer. |
| // For conversions between timespec and timeval, use TIMEVAL_TO_TIMESPEC |
| // and TIMESPEC_TO_TIMEVAL defined in <sys/time.h> |
| // --------------------------------------------------------------------- |
| inline int64_t timeval_to_microseconds(const timeval& tv) { |
| return tv.tv_sec * 1000000L + tv.tv_usec; |
| } |
| |
| inline int64_t timeval_to_milliseconds(const timeval& tv) { |
| return timeval_to_microseconds(tv) / 1000L; |
| } |
| |
| inline int64_t timeval_to_seconds(const timeval& tv) { |
| return timeval_to_microseconds(tv) / 1000000L; |
| } |
| |
| inline timeval microseconds_to_timeval(int64_t us) { |
| timeval tv; |
| tv.tv_sec = us / 1000000L; |
| tv.tv_usec = us - tv.tv_sec * 1000000L; |
| return tv; |
| } |
| |
| inline timeval milliseconds_to_timeval(int64_t ms) { |
| return microseconds_to_timeval(ms * 1000L); |
| } |
| |
| inline timeval seconds_to_timeval(int64_t s) { |
| return microseconds_to_timeval(s * 1000000L); |
| } |
| |
| // --------------------------------------------------------------- |
| // Get system-wide monotonic time. |
| // --------------------------------------------------------------- |
| extern int64_t monotonic_time_ns(); |
| |
| inline int64_t monotonic_time_us() { |
| return monotonic_time_ns() / 1000L; |
| } |
| |
| inline int64_t monotonic_time_ms() { |
| return monotonic_time_ns() / 1000000L; |
| } |
| |
| inline int64_t monotonic_time_s() { |
| return monotonic_time_ns() / 1000000000L; |
| } |
| |
| namespace detail { |
| inline uint64_t clock_cycles() { |
| #if defined(__x86_64__) || defined(__amd64__) |
| unsigned int lo = 0; |
| unsigned int hi = 0; |
| // We cannot use "=A", since this would use %rax on x86_64 |
| __asm__ __volatile__ ( |
| "rdtsc" |
| : "=a" (lo), "=d" (hi) |
| ); |
| return ((uint64_t)hi << 32) | lo; |
| #elif defined(__aarch64__) |
| uint64_t virtual_timer_value; |
| asm volatile("mrs %0, cntvct_el0" : "=r"(virtual_timer_value)); |
| return virtual_timer_value; |
| #elif defined(__ARM_ARCH) |
| #if (__ARM_ARCH >= 6) |
| unsigned int pmccntr; |
| unsigned int pmuseren; |
| unsigned int pmcntenset; |
| // Read the user mode perf monitor counter access permissions. |
| asm volatile ("mrc p15, 0, %0, c9, c14, 0" : "=r" (pmuseren)); |
| if (pmuseren & 1) { // Allows reading perfmon counters for user mode code. |
| asm volatile ("mrc p15, 0, %0, c9, c12, 1" : "=r" (pmcntenset)); |
| if (pmcntenset & 0x80000000ul) { // Is it counting? |
| asm volatile ("mrc p15, 0, %0, c9, c13, 0" : "=r" (pmccntr)); |
| // The counter is set up to count every 64th cycle |
| return static_cast<uint64_t>(pmccntr) * 64; // Should optimize to << 6 |
| } |
| } |
| #else |
| #error "unsupported arm_arch" |
| #endif |
| #elif defined(__loongarch64) |
| uint64_t stable_counter; |
| uint64_t counter_id; |
| __asm__ __volatile__ ( |
| "rdtime.d %1, %0" |
| : "=r" (stable_counter), "=r" (counter_id) |
| ); |
| return stable_counter; |
| #else |
| #error "unsupported arch" |
| #endif |
| } |
| extern int64_t read_invariant_cpu_frequency(); |
| // Be positive iff: |
| // 1 Intel x86_64 CPU (multiple cores) supporting constant_tsc and |
| // nonstop_tsc(check flags in /proc/cpuinfo) |
| extern int64_t invariant_cpu_freq; |
| } // namespace detail |
| |
| // --------------------------------------------------------------- |
| // Get cpu-wide (wall-) time. |
| // Cost ~9ns on Intel(R) Xeon(R) CPU E5620 @ 2.40GHz |
| // --------------------------------------------------------------- |
| // note: Inlining shortens time cost per-call for 15ns in a loop of many |
| // calls to this function. |
| inline int64_t cpuwide_time_ns() { |
| #if !defined(BAIDU_INTERNAL) |
| // nearly impossible to get the correct invariant cpu frequency on |
| // different CPU and machines. CPU-ID rarely works and frequencies |
| // in "model name" and "cpu Mhz" are both unreliable. |
| // Since clock_gettime() in newer glibc/kernel is much faster(~30ns) |
| // which is closer to the previous impl. of cpuwide_time(~10ns), we |
| // simply use the monotonic time to get rid of all related issues. |
| timespec now; |
| clock_gettime(CLOCK_MONOTONIC, &now); |
| return now.tv_sec * 1000000000L + now.tv_nsec; |
| #else |
| int64_t cpu_freq = detail::invariant_cpu_freq; |
| if (cpu_freq > 0) { |
| const uint64_t tsc = detail::clock_cycles(); |
| //Try to avoid overflow |
| const uint64_t sec = tsc / cpu_freq; |
| const uint64_t remain = tsc % cpu_freq; |
| // TODO: should be OK until CPU's frequency exceeds 16GHz. |
| return remain * 1000000000L / cpu_freq + sec * 1000000000L; |
| } else if (!cpu_freq) { |
| // Lack of necessary features, return system-wide monotonic time instead. |
| return monotonic_time_ns(); |
| } else { |
| // Use a thread-unsafe method(OK to us) to initialize the freq |
| // to save a "if" test comparing to using a local static variable |
| detail::invariant_cpu_freq = detail::read_invariant_cpu_frequency(); |
| return cpuwide_time_ns(); |
| } |
| #endif // defined(BAIDU_INTERNAL) |
| } |
| |
| inline int64_t cpuwide_time_us() { |
| return cpuwide_time_ns() / 1000L; |
| } |
| |
| inline int64_t cpuwide_time_ms() { |
| return cpuwide_time_ns() / 1000000L; |
| } |
| |
| inline int64_t cpuwide_time_s() { |
| return cpuwide_time_ns() / 1000000000L; |
| } |
| |
| // -------------------------------------------------------------------- |
| // Get elapse since the Epoch. |
| // No gettimeofday_ns() because resolution of timeval is microseconds. |
| // Cost ~40ns on 2.6.32_1-12-0-0, Intel(R) Xeon(R) CPU E5620 @ 2.40GHz |
| // -------------------------------------------------------------------- |
| inline int64_t gettimeofday_us() { |
| timeval now; |
| gettimeofday(&now, NULL); |
| return now.tv_sec * 1000000L + now.tv_usec; |
| } |
| |
| inline int64_t gettimeofday_ms() { |
| return gettimeofday_us() / 1000L; |
| } |
| |
| inline int64_t gettimeofday_s() { |
| return gettimeofday_us() / 1000000L; |
| } |
| |
| // ---------------------------------------- |
| // Control frequency of operations. |
| // ---------------------------------------- |
| // Example: |
| // EveryManyUS every_1s(1000000L); |
| // while (1) { |
| // ... |
| // if (every_1s) { |
| // // be here at most once per second |
| // } |
| // } |
| class EveryManyUS { |
| public: |
| explicit EveryManyUS(int64_t interval_us) |
| : _last_time_us(cpuwide_time_us()) |
| , _interval_us(interval_us) {} |
| |
| operator bool() { |
| const int64_t now_us = cpuwide_time_us(); |
| if (now_us < _last_time_us + _interval_us) { |
| return false; |
| } |
| _last_time_us = now_us; |
| return true; |
| } |
| |
| private: |
| int64_t _last_time_us; |
| const int64_t _interval_us; |
| }; |
| |
| // --------------- |
| // Count elapses |
| // --------------- |
| class Timer { |
| public: |
| |
| enum TimerType { |
| STARTED, |
| }; |
| |
| Timer() : _stop(0), _start(0) {} |
| explicit Timer(const TimerType) { |
| start(); |
| } |
| |
| // Start this timer |
| void start() { |
| _start = cpuwide_time_ns(); |
| _stop = _start; |
| } |
| |
| // Stop this timer |
| void stop() { |
| _stop = cpuwide_time_ns(); |
| } |
| |
| // Get the elapse from start() to stop(), in various units. |
| int64_t n_elapsed() const { return _stop - _start; } |
| int64_t u_elapsed() const { return n_elapsed() / 1000L; } |
| int64_t m_elapsed() const { return u_elapsed() / 1000L; } |
| int64_t s_elapsed() const { return m_elapsed() / 1000L; } |
| |
| double n_elapsed(double) const { return (double)(_stop - _start); } |
| double u_elapsed(double) const { return (double)n_elapsed() / 1000.0; } |
| double m_elapsed(double) const { return (double)u_elapsed() / 1000.0; } |
| double s_elapsed(double) const { return (double)m_elapsed() / 1000.0; } |
| |
| private: |
| int64_t _stop; |
| int64_t _start; |
| }; |
| |
| } // namespace butil |
| |
| #endif // BUTIL_BAIDU_TIME_H |