1
0
Fork 0
mirror of https://github.com/ossrs/srs.git synced 2025-02-15 04:42:04 +00:00
srs/trunk/3rdparty/srt-1-fit/srtcore/sync.cpp

359 lines
9.4 KiB
C++

/*
* SRT - Secure, Reliable, Transport
* Copyright (c) 2019 Haivision Systems Inc.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
*/
#include "platform_sys.h"
#include <iomanip>
#include <stdexcept>
#include <cmath>
#include "sync.h"
#include "srt.h"
#include "srt_compat.h"
#include "logging.h"
#include "common.h"
// HAVE_CXX11 is defined in utilities.h, included with common.h.
// The following conditional inclusion must go after common.h.
#if HAVE_CXX11
#include <random>
#endif
namespace srt_logging
{
extern Logger inlog;
}
using namespace srt_logging;
using namespace std;
namespace srt
{
namespace sync
{
std::string FormatTime(const steady_clock::time_point& timestamp)
{
if (is_zero(timestamp))
{
// Use special string for 0
return "00:00:00.000000 [STDY]";
}
const int decimals = clockSubsecondPrecision();
const uint64_t total_sec = count_seconds(timestamp.time_since_epoch());
const uint64_t days = total_sec / (60 * 60 * 24);
const uint64_t hours = total_sec / (60 * 60) - days * 24;
const uint64_t minutes = total_sec / 60 - (days * 24 * 60) - hours * 60;
const uint64_t seconds = total_sec - (days * 24 * 60 * 60) - hours * 60 * 60 - minutes * 60;
ostringstream out;
if (days)
out << days << "D ";
out << setfill('0') << setw(2) << hours << ":"
<< setfill('0') << setw(2) << minutes << ":"
<< setfill('0') << setw(2) << seconds << "."
<< setfill('0') << setw(decimals) << (timestamp - seconds_from(total_sec)).time_since_epoch().count() << " [STDY]";
return out.str();
}
std::string FormatTimeSys(const steady_clock::time_point& timestamp)
{
const time_t now_s = ::time(NULL); // get current time in seconds
const steady_clock::time_point now_timestamp = steady_clock::now();
const int64_t delta_us = count_microseconds(timestamp - now_timestamp);
const int64_t delta_s =
static_cast<int64_t>(floor((static_cast<double>(count_microseconds(now_timestamp.time_since_epoch()) % 1000000) + delta_us) / 1000000.0));
const time_t tt = now_s + delta_s;
struct tm tm = SysLocalTime(tt); // in seconds
char tmp_buf[512];
strftime(tmp_buf, 512, "%X.", &tm);
ostringstream out;
out << tmp_buf << setfill('0') << setw(6) << (count_microseconds(timestamp.time_since_epoch()) % 1000000) << " [SYST]";
return out.str();
}
#ifdef ENABLE_STDCXX_SYNC
bool StartThread(CThread& th, ThreadFunc&& f, void* args, const string& name)
#else
bool StartThread(CThread& th, void* (*f) (void*), void* args, const string& name)
#endif
{
ThreadName tn(name);
try
{
#if HAVE_FULL_CXX11 || defined(ENABLE_STDCXX_SYNC)
th = CThread(f, args);
#else
// No move semantics in C++03, therefore using a dedicated function
th.create_thread(f, args);
#endif
}
#if ENABLE_HEAVY_LOGGING
catch (const CThreadException& e)
#else
catch (const CThreadException&)
#endif
{
HLOGC(inlog.Debug, log << name << ": failed to start thread. " << e.what());
return false;
}
return true;
}
} // namespace sync
} // namespace srt
////////////////////////////////////////////////////////////////////////////////
//
// CEvent class
//
////////////////////////////////////////////////////////////////////////////////
srt::sync::CEvent::CEvent()
{
#ifndef _WIN32
m_cond.init();
#endif
}
srt::sync::CEvent::~CEvent()
{
#ifndef _WIN32
m_cond.destroy();
#endif
}
bool srt::sync::CEvent::lock_wait_until(const TimePoint<steady_clock>& tp)
{
UniqueLock lock(m_lock);
return m_cond.wait_until(lock, tp);
}
void srt::sync::CEvent::notify_one()
{
return m_cond.notify_one();
}
void srt::sync::CEvent::notify_all()
{
return m_cond.notify_all();
}
bool srt::sync::CEvent::lock_wait_for(const steady_clock::duration& rel_time)
{
UniqueLock lock(m_lock);
return m_cond.wait_for(lock, rel_time);
}
bool srt::sync::CEvent::wait_for(UniqueLock& lock, const steady_clock::duration& rel_time)
{
return m_cond.wait_for(lock, rel_time);
}
void srt::sync::CEvent::lock_wait()
{
UniqueLock lock(m_lock);
return wait(lock);
}
void srt::sync::CEvent::wait(UniqueLock& lock)
{
return m_cond.wait(lock);
}
namespace srt {
namespace sync {
srt::sync::CEvent g_Sync;
} // namespace sync
} // namespace srt
////////////////////////////////////////////////////////////////////////////////
//
// Timer
//
////////////////////////////////////////////////////////////////////////////////
srt::sync::CTimer::CTimer()
{
}
srt::sync::CTimer::~CTimer()
{
}
bool srt::sync::CTimer::sleep_until(TimePoint<steady_clock> tp)
{
// The class member m_sched_time can be used to interrupt the sleep.
// Refer to Timer::interrupt().
enterCS(m_event.mutex());
m_tsSchedTime = tp;
leaveCS(m_event.mutex());
#if USE_BUSY_WAITING
#if defined(_WIN32)
// 10 ms on Windows: bad accuracy of timers
const steady_clock::duration
td_threshold = milliseconds_from(10);
#else
// 1 ms on non-Windows platforms
const steady_clock::duration
td_threshold = milliseconds_from(1);
#endif
#endif // USE_BUSY_WAITING
TimePoint<steady_clock> cur_tp = steady_clock::now();
while (cur_tp < m_tsSchedTime)
{
#if USE_BUSY_WAITING
steady_clock::duration td_wait = m_tsSchedTime - cur_tp;
if (td_wait <= 2 * td_threshold)
break;
td_wait -= td_threshold;
m_event.lock_wait_for(td_wait);
#else
m_event.lock_wait_until(m_tsSchedTime);
#endif // USE_BUSY_WAITING
cur_tp = steady_clock::now();
}
#if USE_BUSY_WAITING
while (cur_tp < m_tsSchedTime)
{
#ifdef IA32
__asm__ volatile ("pause; rep; nop; nop; nop; nop; nop;");
#elif IA64
__asm__ volatile ("nop 0; nop 0; nop 0; nop 0; nop 0;");
#elif AMD64
__asm__ volatile ("nop; nop; nop; nop; nop;");
#elif defined(_WIN32) && !defined(__MINGW32__)
__nop();
__nop();
__nop();
__nop();
__nop();
#endif
cur_tp = steady_clock::now();
}
#endif // USE_BUSY_WAITING
return cur_tp >= m_tsSchedTime;
}
void srt::sync::CTimer::interrupt()
{
UniqueLock lck(m_event.mutex());
m_tsSchedTime = steady_clock::now();
m_event.notify_all();
}
void srt::sync::CTimer::tick()
{
m_event.notify_one();
}
void srt::sync::CGlobEvent::triggerEvent()
{
return g_Sync.notify_one();
}
bool srt::sync::CGlobEvent::waitForEvent()
{
return g_Sync.lock_wait_for(milliseconds_from(10));
}
////////////////////////////////////////////////////////////////////////////////
//
// Random
//
////////////////////////////////////////////////////////////////////////////////
namespace srt
{
#if HAVE_CXX11
static std::mt19937& randomGen()
{
static std::random_device s_RandomDevice;
static std::mt19937 s_GenMT19937(s_RandomDevice());
return s_GenMT19937;
}
#elif defined(_WIN32) && defined(__MINGW32__)
static void initRandSeed()
{
const int64_t seed = sync::steady_clock::now().time_since_epoch().count();
srand((unsigned int) seed);
}
static pthread_once_t s_InitRandSeedOnce = PTHREAD_ONCE_INIT;
#else
static unsigned int genRandSeed()
{
// Duration::count() does not depend on any global objects,
// therefore it is preferred over count_microseconds(..).
const int64_t seed = sync::steady_clock::now().time_since_epoch().count();
return (unsigned int) seed;
}
static unsigned int* getRandSeed()
{
static unsigned int s_uRandSeed = genRandSeed();
return &s_uRandSeed;
}
#endif
}
int srt::sync::genRandomInt(int minVal, int maxVal)
{
// This Meyers singleton initialization is thread-safe since C++11, but is not thread-safe in C++03.
// A mutex to protect simultaneous access to the random device.
// Thread-local storage could be used here instead to store the seed / random device.
// However the generator is not used often (Initial Socket ID, Initial sequence number, FileCC),
// so sharing a single seed among threads should not impact the performance.
static sync::Mutex s_mtxRandomDevice;
sync::ScopedLock lck(s_mtxRandomDevice);
#if HAVE_CXX11
uniform_int_distribution<> dis(minVal, maxVal);
return dis(randomGen());
#else
#if defined(__MINGW32__)
// No rand_r(..) for MinGW.
pthread_once(&s_InitRandSeedOnce, initRandSeed);
// rand() returns a pseudo-random integer in the range 0 to RAND_MAX inclusive
// (i.e., the mathematical range [0, RAND_MAX]).
// Therefore, rand_0_1 belongs to [0.0, 1.0].
const double rand_0_1 = double(rand()) / RAND_MAX;
#else // not __MINGW32__
// rand_r(..) returns a pseudo-random integer in the range 0 to RAND_MAX inclusive
// (i.e., the mathematical range [0, RAND_MAX]).
// Therefore, rand_0_1 belongs to [0.0, 1.0].
const double rand_0_1 = double(rand_r(getRandSeed())) / RAND_MAX;
#endif
// Map onto [minVal, maxVal].
// Note. There is a minuscule probablity to get maxVal+1 as the result.
// So we have to use long long to handle cases when maxVal = INT32_MAX.
// Also we must check 'res' does not exceed maxVal,
// which may happen if rand_0_1 = 1, even though the chances are low.
const long long llMaxVal = maxVal;
const int res = minVal + static_cast<int>((llMaxVal + 1 - minVal) * rand_0_1);
return min(res, maxVal);
#endif // HAVE_CXX11
}