[libcamera-devel] [PATCH 2/2] libcamera: Switch to the std::chrono API

Jacopo Mondi jacopo at jmondi.org
Sat Sep 14 10:26:48 CEST 2019


Hi Laurent,

On Sat, Sep 14, 2019 at 03:54:57AM +0300, Laurent Pinchart wrote:
> Replace the clock_gettime()-based API with durations expressed as
> integers with the std::chrono API.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
>  include/libcamera/timer.h               | 12 +++++----
>  src/cam/capture.cpp                     | 15 +++++------
>  src/cam/capture.h                       |  3 ++-
>  src/libcamera/event_dispatcher_poll.cpp | 22 ++++++-----------
>  src/libcamera/include/log.h             |  7 ++++--
>  src/libcamera/log.cpp                   | 20 +++------------
>  src/libcamera/timer.cpp                 | 33 +++++++++++++++----------
>  test/event-dispatcher.cpp               | 13 +++++-----
>  test/timer.cpp                          | 17 +++++++------
>  9 files changed, 67 insertions(+), 75 deletions(-)
>
> diff --git a/include/libcamera/timer.h b/include/libcamera/timer.h
> index f47b6a58404f..476ae45f1e53 100644
> --- a/include/libcamera/timer.h
> +++ b/include/libcamera/timer.h
> @@ -7,6 +7,7 @@
>  #ifndef __LIBCAMERA_TIMER_H__
>  #define __LIBCAMERA_TIMER_H__
>
> +#include <chrono>
>  #include <cstdint>
>
>  #include <libcamera/object.h>
> @@ -22,12 +23,13 @@ public:
>  	Timer(Object *parent = nullptr);
>  	~Timer();
>
> -	void start(unsigned int msec);
> +	void start(unsigned int msec) { start(std::chrono::milliseconds(msec)); }
> +	void start(std::chrono::milliseconds interval);
>  	void stop();
>  	bool isRunning() const;
>
> -	unsigned int interval() const { return interval_; }
> -	uint64_t deadline() const { return deadline_; }
> +	std::chrono::milliseconds interval() const { return interval_; }
> +	std::chrono::steady_clock::time_point deadline() const { return deadline_; }

I wonder if the type definitions you added to utils (timepoint, clock,
duration) aren't better suited for this header so that applications could
use them (with proper namespacing indeed).

>
>  	Signal<Timer *> timeout;
>
> @@ -38,8 +40,8 @@ private:
>  	void registerTimer();
>  	void unregisterTimer();
>
> -	unsigned int interval_;
> -	uint64_t deadline_;
> +	std::chrono::milliseconds interval_;
> +	std::chrono::steady_clock::time_point deadline_;
>  };
>
>  } /* namespace libcamera */
> diff --git a/src/cam/capture.cpp b/src/cam/capture.cpp
> index df9602de4ab8..8a939c622703 100644
> --- a/src/cam/capture.cpp
> +++ b/src/cam/capture.cpp
> @@ -5,6 +5,7 @@
>   * capture.cpp - Cam capture
>   */
>
> +#include <chrono>
>  #include <climits>
>  #include <iomanip>
>  #include <iostream>
> @@ -16,7 +17,7 @@
>  using namespace libcamera;
>
>  Capture::Capture(Camera *camera, CameraConfiguration *config)
> -	: camera_(camera), config_(config), writer_(nullptr), last_(0)
> +	: camera_(camera), config_(config), writer_(nullptr)
>  {
>  }
>
> @@ -135,17 +136,13 @@ int Capture::capture(EventLoop *loop)
>
>  void Capture::requestComplete(Request *request, const std::map<Stream *, Buffer *> &buffers)
>  {
> -	double fps = 0.0;
> -	uint64_t now;
> -
>  	if (request->status() == Request::RequestCancelled)
>  		return;
>
> -	struct timespec time;
> -	clock_gettime(CLOCK_MONOTONIC, &time);
> -	now = time.tv_sec * 1000 + time.tv_nsec / 1000000;
> -	fps = now - last_;
> -	fps = last_ && fps ? 1000.0 / fps : 0.0;
> +	std::chrono::steady_clock::time_point now = std::chrono::steady_clock::now();
> +	double fps = std::chrono::duration_cast<std::chrono::milliseconds>(now - last_).count();
> +	fps = last_ != std::chrono::steady_clock::time_point() && fps
> +	    ? 1000.0 / fps : 0.0;
>  	last_ = now;
>
>  	std::stringstream info;
> diff --git a/src/cam/capture.h b/src/cam/capture.h
> index 1d4a25a84a51..ee0dc4211111 100644
> --- a/src/cam/capture.h
> +++ b/src/cam/capture.h
> @@ -7,6 +7,7 @@
>  #ifndef __CAM_CAPTURE_H__
>  #define __CAM_CAPTURE_H__
>
> +#include <chrono>
>  #include <memory>
>
>  #include <libcamera/camera.h>
> @@ -35,7 +36,7 @@ private:
>
>  	std::map<libcamera::Stream *, std::string> streamName_;
>  	BufferWriter *writer_;
> -	uint64_t last_;
> +	std::chrono::steady_clock::time_point last_;
>  };
>
>  #endif /* __CAM_CAPTURE_H__ */
> diff --git a/src/libcamera/event_dispatcher_poll.cpp b/src/libcamera/event_dispatcher_poll.cpp
> index 281f37bdbb16..51ac5adf2f74 100644
> --- a/src/libcamera/event_dispatcher_poll.cpp
> +++ b/src/libcamera/event_dispatcher_poll.cpp
> @@ -8,6 +8,7 @@
>  #include "event_dispatcher_poll.h"
>
>  #include <algorithm>
> +#include <chrono>
>  #include <iomanip>
>  #include <poll.h>
>  #include <stdint.h>
> @@ -20,6 +21,7 @@
>
>  #include "log.h"
>  #include "thread.h"
> +#include "utils.h"
>
>  /**
>   * \file event_dispatcher_poll.h
> @@ -206,17 +208,12 @@ int EventDispatcherPoll::poll(std::vector<struct pollfd> *pollfds)
>  	struct timespec timeout;
>
>  	if (nextTimer) {
> -		clock_gettime(CLOCK_MONOTONIC, &timeout);
> -		uint64_t now = timeout.tv_sec * 1000000000ULL + timeout.tv_nsec;
> +		utils::time_point now = utils::clock::now();
>
> -		if (nextTimer->deadline() > now) {
> -			uint64_t delta = nextTimer->deadline() - now;
> -			timeout.tv_sec = delta / 1000000000ULL;
> -			timeout.tv_nsec = delta % 1000000000ULL;
> -		} else {
> -			timeout.tv_sec = 0;
> -			timeout.tv_nsec = 0;
> -		}
> +		if (nextTimer->deadline() > now)
> +			timeout = utils::duration_to_timespec(nextTimer->deadline() - now);
> +		else
> +			timeout = { 0, 0 };
>
>  		LOG(Event, Debug)
>  			<< "timeout " << timeout.tv_sec << "."
> @@ -295,10 +292,7 @@ void EventDispatcherPoll::processNotifiers(const std::vector<struct pollfd> &pol
>
>  void EventDispatcherPoll::processTimers()
>  {
> -	struct timespec ts;
> -	uint64_t now;
> -	clock_gettime(CLOCK_MONOTONIC, &ts);
> -	now = ts.tv_sec * 1000000000ULL + ts.tv_nsec;
> +	utils::time_point now = utils::clock::now();
>
>  	while (!timers_.empty()) {
>  		Timer *timer = timers_.front();
> diff --git a/src/libcamera/include/log.h b/src/libcamera/include/log.h
> index 9b203f97e304..ee0b4069bd32 100644
> --- a/src/libcamera/include/log.h
> +++ b/src/libcamera/include/log.h
> @@ -7,8 +7,11 @@
>  #ifndef __LIBCAMERA_LOG_H__
>  #define __LIBCAMERA_LOG_H__
>
> +#include <chrono>
>  #include <sstream>
>
> +#include "utils.h"
> +
>  namespace libcamera {
>
>  enum LogSeverity {
> @@ -60,7 +63,7 @@ public:
>
>  	std::ostream &stream() { return msgStream_; }
>
> -	const struct timespec &timestamp() const { return timestamp_; }
> +	const utils::time_point &timestamp() const { return timestamp_; }
>  	LogSeverity severity() const { return severity_; }
>  	const LogCategory &category() const { return category_; }
>  	const std::string &fileInfo() const { return fileInfo_; }
> @@ -72,7 +75,7 @@ private:
>  	std::ostringstream msgStream_;
>  	const LogCategory &category_;
>  	LogSeverity severity_;
> -	struct timespec timestamp_;
> +	utils::time_point timestamp_;
>  	std::string fileInfo_;
>  };
>
> diff --git a/src/libcamera/log.cpp b/src/libcamera/log.cpp
> index 91f7c3ee5157..51f9f86b4c44 100644
> --- a/src/libcamera/log.cpp
> +++ b/src/libcamera/log.cpp
> @@ -11,7 +11,6 @@
>  #include <cstdlib>
>  #include <ctime>
>  #include <fstream>
> -#include <iomanip>
>  #include <iostream>
>  #include <list>
>  #include <string.h>
> @@ -78,17 +77,6 @@ static int log_severity_to_syslog(LogSeverity severity)
>  	}
>  }
>
> -static std::string log_timespec_to_string(const struct timespec &timestamp)
> -{
> -	std::ostringstream ossTimestamp;
> -	ossTimestamp.fill('0');
> -	ossTimestamp << "[" << timestamp.tv_sec / (60 * 60) << ":"
> -		     << std::setw(2) << (timestamp.tv_sec / 60) % 60 << ":"
> -		     << std::setw(2) << timestamp.tv_sec % 60 << "."
> -		     << std::setw(9) << timestamp.tv_nsec << "]";
> -	return ossTimestamp.str();
> -}
> -
>  static const char *log_severity_name(LogSeverity severity)
>  {
>  	static const char *const names[] = {
> @@ -216,10 +204,10 @@ void LogOutput::writeSyslog(const LogMessage &msg)
>
>  void LogOutput::writeStream(const LogMessage &msg)
>  {
> -	std::string str = std::string(log_timespec_to_string(msg.timestamp()) +
> -	      		  log_severity_name(msg.severity()) + " " +
> +	std::string str = "[" + utils::time_point_to_string(msg.timestamp()) +
> +			  "]" + log_severity_name(msg.severity()) + " " +
>  			  msg.category().name() + " " + msg.fileInfo() + " " +
> -			  msg.msg());
> +			  msg.msg();
>  	stream_->write(str.c_str(), str.size());
>  	stream_->flush();
>  }
> @@ -777,7 +765,7 @@ LogMessage::LogMessage(LogMessage &&other)
>  void LogMessage::init(const char *fileName, unsigned int line)
>  {
>  	/* Log the timestamp, severity and file information. */
> -	clock_gettime(CLOCK_MONOTONIC, &timestamp_);
> +	timestamp_ = utils::clock::now();
>
>  	std::ostringstream ossFileInfo;
>  	ossFileInfo << utils::basename(fileName) << ":" << line;
> diff --git a/src/libcamera/timer.cpp b/src/libcamera/timer.cpp
> index c61d77e5128f..fe47a348cff9 100644
> --- a/src/libcamera/timer.cpp
> +++ b/src/libcamera/timer.cpp
> @@ -7,7 +7,7 @@
>
>  #include <libcamera/timer.h>
>
> -#include <time.h>
> +#include <chrono>
>
>  #include <libcamera/camera_manager.h>
>  #include <libcamera/event_dispatcher.h>
> @@ -15,6 +15,7 @@
>  #include "log.h"
>  #include "message.h"
>  #include "thread.h"
> +#include "utils.h"
>
>  /**
>   * \file timer.h
> @@ -42,7 +43,7 @@ LOG_DEFINE_CATEGORY(Timer)
>   * \param[in] parent The parent Object
>   */
>  Timer::Timer(Object *parent)
> -	: Object(parent), interval_(0), deadline_(0)
> +	: Object(parent)
>  {
>  }
>
> @@ -52,22 +53,28 @@ Timer::~Timer()
>  }
>
>  /**
> + * \fn Timer::start(unsigned int msec)
>   * \brief Start or restart the timer with a timeout of \a msec
>   * \param[in] msec The timer duration in milliseconds
>   *
>   * If the timer is already running it will be stopped and restarted.
>   */
> -void Timer::start(unsigned int msec)
> -{
> -	struct timespec tp;
> -	clock_gettime(CLOCK_MONOTONIC, &tp);
>
> -	interval_ = msec;
> -	deadline_ = tp.tv_sec * 1000000000ULL + tp.tv_nsec + msec * 1000000ULL;
> +/**
> + * \brief Start or restart the timer with a timeout of \a interval
> + * \param[in] interval The timer duration in milliseconds
> + *
> + * If the timer is already running it will be stopped and restarted.
> + */
> +void Timer::start(std::chrono::milliseconds interval)
> +{
> +	interval_ = interval;
> +	deadline_ = utils::clock::now() + interval;
>
>  	LOG(Timer, Debug)
>  		<< "Starting timer " << this << " with interval "
> -		<< msec << ": deadline " << deadline_;
> +		<< interval.count() << ": deadline "
> +		<< utils::time_point_to_string(deadline_);
>
>  	registerTimer();
>  }
> @@ -84,7 +91,7 @@ void Timer::stop()
>  {
>  	unregisterTimer();
>
> -	deadline_ = 0;
> +	deadline_ = utils::time_point();
>  }
>
>  void Timer::registerTimer()
> @@ -103,7 +110,7 @@ void Timer::unregisterTimer()
>   */
>  bool Timer::isRunning() const
>  {
> -	return deadline_ != 0;
> +	return deadline_ != utils::time_point();
>  }
>
>  /**
> @@ -115,7 +122,7 @@ bool Timer::isRunning() const
>  /**
>   * \fn Timer::deadline()
>   * \brief Retrieve the timer deadline
> - * \return The timer deadline in nanoseconds
> + * \return The timer deadline
>   */
>
>  /**
> @@ -128,7 +135,7 @@ bool Timer::isRunning() const
>  void Timer::message(Message *msg)
>  {
>  	if (msg->type() == Message::ThreadMoveMessage) {
> -		if (deadline_) {
> +		if (deadline_ != utils::time_point()) {

Nit:
isRunning() ?

Thanks
   j

>  			unregisterTimer();
>  			invokeMethod(&Timer::registerTimer);
>  		}
> diff --git a/test/event-dispatcher.cpp b/test/event-dispatcher.cpp
> index f243ec39bc28..9f9cf17818f2 100644
> --- a/test/event-dispatcher.cpp
> +++ b/test/event-dispatcher.cpp
> @@ -5,6 +5,7 @@
>   * event-dispatcher.cpp - Event dispatcher test
>   */
>
> +#include <chrono>
>  #include <iostream>
>  #include <signal.h>
>  #include <sys/time.h>
> @@ -47,8 +48,7 @@ protected:
>  		Timer timer;
>
>  		/* Event processing interruption by signal. */
> -		struct timespec start;
> -		clock_gettime(CLOCK_MONOTONIC, &start);
> +		std::chrono::steady_clock::time_point start = std::chrono::steady_clock::now();
>
>  		timer.start(1000);
>
> @@ -59,12 +59,11 @@ protected:
>
>  		dispatcher->processEvents();
>
> -		struct timespec stop;
> -		clock_gettime(CLOCK_MONOTONIC, &stop);
> -		int duration = (stop.tv_sec - start.tv_sec) * 1000;
> -		duration += (stop.tv_nsec - start.tv_nsec) / 1000000;
> +		std::chrono::steady_clock::time_point stop = std::chrono::steady_clock::now();
> +		std::chrono::steady_clock::duration duration = stop - start;
> +		int msecs = std::chrono::duration_cast<std::chrono::milliseconds>(duration).count();
>
> -		if (abs(duration - 1000) > 50) {
> +		if (abs(msecs - 1000) > 50) {
>  			cout << "Event processing restart test failed" << endl;
>  			return TestFail;
>  		}
> diff --git a/test/timer.cpp b/test/timer.cpp
> index c30709d4109a..af922cb371cd 100644
> --- a/test/timer.cpp
> +++ b/test/timer.cpp
> @@ -5,6 +5,7 @@
>   * timer.cpp - Timer test
>   */
>
> +#include <chrono>
>  #include <iostream>
>
>  #include <libcamera/event_dispatcher.h>
> @@ -28,28 +29,28 @@ public:
>  	void start(int msec)
>  	{
>  		interval_ = msec;
> -		clock_gettime(CLOCK_MONOTONIC, &start_);
> -		expiration_ = { 0, 0 };
> +		start_ = std::chrono::steady_clock::now();
> +		expiration_ = std::chrono::steady_clock::time_point();
>
>  		Timer::start(msec);
>  	}
>
>  	int jitter()
>  	{
> -		int duration = (expiration_.tv_sec - start_.tv_sec) * 1000;
> -		duration += (expiration_.tv_nsec - start_.tv_nsec) / 1000000;
> -		return abs(duration - interval_);
> +		std::chrono::steady_clock::duration duration = expiration_ - start_;
> +		int msecs = std::chrono::duration_cast<std::chrono::milliseconds>(duration).count();
> +		return abs(msecs - interval_);
>  	}
>
>  private:
>  	void timeoutHandler(Timer *timer)
>  	{
> -		clock_gettime(CLOCK_MONOTONIC, &expiration_);
> +		expiration_ = std::chrono::steady_clock::now();
>  	}
>
>  	int interval_;
> -	struct timespec start_;
> -	struct timespec expiration_;
> +	std::chrono::steady_clock::time_point start_;
> +	std::chrono::steady_clock::time_point expiration_;
>  };
>
>  class TimerTest : public Test
> --
> Regards,
>
> Laurent Pinchart
>
> _______________________________________________
> libcamera-devel mailing list
> libcamera-devel at lists.libcamera.org
> https://lists.libcamera.org/listinfo/libcamera-devel
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