the timer is called twice with a double delay

[Krollik]

Hello!
I have next code:

#include <ecal/ecal.h>
#include <ecal/msg/string/publisher.h>

#include <chrono>
#include <iostream>
#include <string>

const static auto start_time = std::chrono::steady_clock::now();

void my_timer_callback() {  
  const auto elapsed_ms = std::chrono::duration_cast<std::chrono::milliseconds>(
                        std::chrono::steady_clock::now() - start_time)
                        .count();
  std::cout << elapsed_ms << ": timer fired!" << std::endl;
}

int main(int argc, char **argv) {
  eCAL::Initialize("Timer");

  eCAL::CTimer my_timer(1000, my_timer_callback);

  while (eCAL::Ok()) {
    eCAL::Process::SleepMS(100);
  }

  eCAL::Finalize();
}

After launch it, i get next output:

[eCAL][Config] Yaml configuration loaded from "/etc/ecal/ecal.yaml".
0: timer fired!
2000: timer fired!
2000: timer fired!
4000: timer fired!
4000: timer fired!
6000: timer fired!
6000: timer fired!

But expected output is:

[eCAL][Config] Yaml configuration loaded from "/etc/ecal/ecal.yaml".
0: timer fired!
1000: timer fired!
2000: timer fired!
3000: timer fired!
4000: timer fired!
5000: timer fired!
6000: timer fired!

The configuration("/etc/ecal/ecal.yaml") is default.
Ecal version is 6.0.1 and it was built with next params:
cmake \ -DCMAKE_INSTALL_PREFIX=/mnt -DCMAKE_BUILD_TYPE=Release -DECAL_USE_HDF5=ON -DECAL_USE_QT=OFF -DECAL_USE_CURL=OFF -DECAL_BUILD_SAMPLES=OFF -DECAL_BUILD_PY_BINDING=ON -DECAL_INSTALL_SAMPLE_SOURCES=OFF -DCMAKE_PROJECT_TOP_LEVEL_INCLUDES=cmake/submodule_dependencies.cmake -DECAL_THIRDPARTY_BUILD_PROTOBUF=OFF -DECAL_THIRDPARTY_BUILD_CURL=OFF -DECAL_THIRDPARTY_BUILD_HDF5=ON
Base docker image is ubuntu:noble.

CMakeLists.txt is:

cmake_minimum_required(VERSION 3.0)
set(CMAKE_FIND_PACKAGE_PREFER_CONFIG ON)

project(ecal_example)

set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

find_package(eCAL REQUIRED)

add_executable(${PROJECT_NAME} main.cpp)
target_link_libraries(${PROJECT_NAME} eCAL::core)

[KerstinKeller]

On my Windows System it's running as expected. @Peguen can you please check on Ubuntu?

[tamanrasset]

I'm having the same issue on Ubuntu 24.04, and, apparently, it has something to do with timegate synchronization mechanisms.

After some experimenting I found that leaving time/rt empty in /etc/ecal/ecal.yaml :

# Time configuration
time:
  # Time synchronisation interface name (dynamic library)
  # The name will be extended with platform suffix (32|64), debug suffix (d) and platform extension (.dll|.so)
  # Available modules are:
  #   - ecaltime-localtime    local system time without synchronization
  #   - ecaltime-linuxptp     For PTP / gPTP synchronization over ethernet on Linux
  #                           (device configuration in ecaltime.ini)
  rt: ""

solves the problem, as with no synchronization all sleep calls fall back to std::this_thread::sleep_for.

No other configuration of time/rt in /etc/ecal/ecal.yaml and linuxptp/device in /etc/ecal/ecaltime.yaml works correctly, but some produce ever weirder behavior where timer intervals grow in geometric progression.

Can someone please explain the difference between no synchronization, ecaltime-localtime and ecaltime-linuxptp + CLOCK_REALTIME (as linuxptp/device in ecaltime.yaml)? What are the drawbacks if I just leave it empty? I'm planning to use eCAL in local configuration without any time sensitive hardware.