Option rename + minor fixes (#57)

- Set choices of OMNITRACE_BACKEND option - rename OMNITRACE_SHMEM_SIZE_HINT_KB option - rename OMNITRACE_BUFFER_SIZE_KB option - rename OMNITRACE_COMBINE_PERFETTO_TRACES - rename OMNITRACE_BACKEND option - default to OMNITRACE_COLLAPSE_PROCESSES for combining perfetto traces - OMNITRACE_PERFETTO_FILL_POLICY option - fix unused variables due to constexpr in add_critical_trace - rename perfetto config from "track_event" to "omnitrace" - fix build-release.sh + python - handle config file updating OMNITRACE_DL_VERBOSE in omnitrace-dl - rename roctrace.cfg to omnitrace.cfg - accept "on" and "off" for get_sampling_cpus() [ROCm/rocprofiler-systems commit: 346f8cd0bc]
2022-05-10 17:30:45 -05:00
@@ -55,7 +55,7 @@ or exectuable which loads the instrumented libraries normally, e.g.:
 ```

 If you want to re-define certain settings to new default in a binary rewrite, use the `--env` option. This `omnitrace` option
-will set the environment variable to the given value but will not override it. E.g. the default value of `OMNITRACE_BUFFER_SIZE_KB`
+will set the environment variable to the given value but will not override it. E.g. the default value of `OMNITRACE_PERFETTO_BUFFER_SIZE_KB`
 is 1024000 KB (1 GiB):

 ```shell
@@ -64,17 +64,17 @@ omnitrace -o app.inst -- /path/to/app
 ./app.inst
 ```

-Passing `--env OMNITRACE_BUFFER_SIZE_KB=5120000` will change the default value in `app.inst` to 5120000 KiB (5 GiB):
+Passing `--env OMNITRACE_PERFETTO_BUFFER_SIZE_KB=5120000` will change the default value in `app.inst` to 5120000 KiB (5 GiB):

 ```shell
 # defaults to 5 GiB buffer size
-omnitrace -o app.inst --env OMNITRACE_BUFFER_SIZE_KB=5120000 -- /path/to/app
+omnitrace -o app.inst --env OMNITRACE_PERFETTO_BUFFER_SIZE_KB=5120000 -- /path/to/app
 ./app.inst
 ```

 ```shell
 # override default 5 GiB buffer size to 200 MB
-export OMNITRACE_BUFFER_SIZE_KB=200000
+export OMNITRACE_PERFETTO_BUFFER_SIZE_KB=200000
 ./app.inst
 ```

@@ -140,13 +140,13 @@ In a separate window run:
 ```shell
 pkill traced
 traced --background
-perfetto --out ./htrace.out --txt -c ${OMNITRACE_ROOT}/share/roctrace.cfg
+perfetto --out ./htrace.out --txt -c ${OMNITRACE_ROOT}/share/omnitrace.cfg
 ```

 then in the window running the application, configure the omnitrace instrumentation to use the system backend:

 ```shell
-export OMNITRACE_BACKEND=system
+export OMNITRACE_PERFETTO_BACKEND=system
 ```

 for the merge use the `htrace.out`:
@@ -1,4 +1,4 @@
-# perfetto --out OUTPUT_FILE --txt -c roctrace.cfg
+# perfetto --out OUTPUT_FILE --txt -c omnitrace.cfg
 # 2 minute trace, but can be stopped prematurely.
 duration_ms: 120000
 write_into_file: true
@@ -14,9 +14,6 @@ buffers {

 data_sources {
  config {
-      name: "track_event"
-      track_event_config {
-        enabled_categories: "kernels,omnitrace"
-      }
+      name: "omnitrace"
  }
 }
@@ -120,10 +120,14 @@ build-and-package-python()
    for i in ${PYTHON_VERSIONS}
    do
        conda activate py3.${i}
-        _PYTHON_ENVS="${_PYTHON_ENVS}$(dirname $(dirname $(which python)));"
+        if [ -z "${_PYTHON_ENVS}" ]; then
+            _PYTHON_ENVS="$(dirname $(dirname $(which python)))"
+        else
+            _PYTHON_ENVS="${_PYTHON_ENVS};$(dirname $(dirname $(which python)))"
+        fi
        conda deactivate
    done
-    build-and-package-base ${DIR}-python $@ -DOMNITRACE_USE_PYTHON=ON -DOMNITRACE_BUILD_PYTHON=ON -DOMNITRACE_PYTHON_ENVS=\"${_PYTHON_ENVS}\"
+    build-and-package-base ${DIR}-python $@ -DOMNITRACE_USE_PYTHON=ON -DOMNITRACE_BUILD_PYTHON=ON -DOMNITRACE_PYTHON_ROOT_DIRS=\"${_PYTHON_ENVS}\"
 }

 build-and-package()
@@ -70,8 +70,8 @@ $ omnitrace-avail -S -bd
 |          ENVIRONMENT VARIABLE           |               DESCRIPTION               |
 |-----------------------------------------|-----------------------------------------|
 | OMNITRACE_ADD_SECONDARY                 | Enable/disable components adding sec... |
-| OMNITRACE_BACKEND                       | Specify the perfetto backend to acti... |
-| OMNITRACE_BUFFER_SIZE_KB                | Size of perfetto buffer (in KB)         |
+| OMNITRACE_PERFETTO_BACKEND              | Specify the perfetto backend to acti... |
+| OMNITRACE_PERFETTO_BUFFER_SIZE_KB       | Size of perfetto buffer (in KB)         |
 | OMNITRACE_COLLAPSE_PROCESSES            | Enable/disable combining process-spe... |
 | OMNITRACE_COLLAPSE_THREADS              | Enable/disable combining thread-spec... |
 | OMNITRACE_CONFIG_FILE                   | Configuration file for omnitrace        |
@@ -124,7 +124,7 @@ $ omnitrace-avail -S -bd
 | OMNITRACE_SAMPLING_FREQ                 | Number of software interrupts per se... |
 | OMNITRACE_SCIENTIFIC                    | Set the global numerical reporting t... |
 | OMNITRACE_SETTINGS_DESC                 | Provide descriptions when printing s... |
-| OMNITRACE_SHMEM_SIZE_HINT_KB            | Hint for shared-memory buffer size i... |
+| OMNITRACE_PERFETTO_SHMEM_SIZE_HINT_KB   | Hint for shared-memory buffer size i... |
 | OMNITRACE_SUPPRESS_CONFIG               | Disable processing of setting config... |
 | OMNITRACE_SUPPRESS_PARSING              | Disable parsing environment             |
 | OMNITRACE_TEXT_OUTPUT                   | Write text output files                 |
@@ -67,14 +67,20 @@ get_omnitrace_env()
    return get_env("OMNITRACE_VERBOSE", (_debug) ? 100 : 0);
 }

+inline int
+get_omnitrace_dl_env()
+{
+    return get_env("OMNITRACE_DL_DEBUG", false)
+               ? 100
+               : get_env("OMNITRACE_DL_VERBOSE", get_omnitrace_env());
+}
+
 // environment priority:
 //  - OMNITRACE_DL_DEBUG
 //  - OMNITRACE_DL_VERBOSE
 //  - OMNITRACE_DEBUG
 //  - OMNITRACE_VERBOSE
-int _omnitrace_dl_verbose = get_env("OMNITRACE_DL_DEBUG", false)
-                                ? 100
-                                : get_env("OMNITRACE_DL_VERBOSE", get_omnitrace_env());
+int _omnitrace_dl_verbose = get_omnitrace_dl_env();

 // The docs for dlopen suggest that the combination of RTLD_LOCAL + RTLD_DEEPBIND
 // (when available) helps ensure that the symbols in the instrumentation library
@@ -388,6 +394,7 @@ extern "C"
        {
            dl::get_active() = true;
            dl::get_inited() = true;
+            dl::_omnitrace_dl_verbose = dl::get_omnitrace_dl_env();
        }
    }

@@ -649,13 +649,16 @@ omnitrace_init_tooling_hidden()
        auto shmem_size_hint = get_perfetto_shmem_size_hint();
        auto buffer_size     = get_perfetto_buffer_size();

+        auto _policy =
+            get_perfetto_fill_policy() == "discard"
+                ? perfetto::protos::gen::TraceConfig_BufferConfig_FillPolicy_DISCARD
+                : perfetto::protos::gen::TraceConfig_BufferConfig_FillPolicy_RING_BUFFER;
        auto* buffer_config = cfg.add_buffers();
        buffer_config->set_size_kb(buffer_size);
-        buffer_config->set_fill_policy(
-            perfetto::protos::gen::TraceConfig_BufferConfig_FillPolicy_DISCARD);
+        buffer_config->set_fill_policy(_policy);

        auto* ds_cfg = cfg.add_data_sources()->mutable_config();
-        ds_cfg->set_name("track_event");
+        ds_cfg->set_name("omnitrace");
        ds_cfg->set_track_event_config_raw(track_event_cfg.SerializeAsString());

        args.shmem_size_hint_kb = shmem_size_hint;
@@ -1260,8 +1263,12 @@ omnitrace_finalize_hidden(void)
            else
            {
                // Write the trace into a file.
-                if(get_verbose() >= 0) fprintf(stderr, "Done\n");
                ofs.write(&trace_data[0], trace_data.size());
+                if(get_verbose() >= 0) fprintf(stderr, "Done\n");
+                auto _manager = tim::manager::instance();
+                if(_manager)
+                    _manager->add_file_output("protobuf", "perfetto",
+                                              get_perfetto_output_filename());
            }
            ofs.close();
            if(get_verbose() >= 0) fprintf(stderr, "\n");
@@ -118,9 +118,10 @@ add_critical_trace(int64_t _targ_tid, size_t _cpu_cid, size_t _gpu_cid,
            if(_gpu_cid == 0 && _cpu_cid % _update_freq == (_update_freq - 1))
                critical_trace::update(_targ_tid);
        }
+        tim::consume_parameters(_lock);
    }

    tim::consume_parameters(_targ_tid, _cpu_cid, _gpu_cid, _parent_cid, _ts_beg, _ts_val,
-                            _queue, _hash, _depth, _prio);
+                            _queue, _hash, _depth, _prio, num_mutexes);
 }
 }  // namespace omnitrace
@@ -142,7 +142,7 @@ configure_settings(bool _init)
    auto _default_perfetto_v =
        !tim::get_env<bool>("OMNITRACE_USE_TIMEMORY", false, false);

-    auto _system_backend = tim::get_env("OMNITRACE_BACKEND_SYSTEM", false, false);
+    auto _system_backend = tim::get_env("OMNITRACE_PERFETTO_BACKEND_SYSTEM", false, false);

    auto _omnitrace_debug = _config->get<bool>("OMNITRACE_DEBUG");
    if(_omnitrace_debug) tim::set_env("TIMEMORY_DEBUG_SETTINGS", "1", 0);
@@ -220,17 +220,20 @@ configure_settings(bool _init)
        "", "thread_sampling");

    auto _backend = tim::get_env_choice<std::string>(
-        "OMNITRACE_BACKEND",
+        "OMNITRACE_PERFETTO_BACKEND",
        (_system_backend)
-            ? "system"      // if OMNITRACE_BACKEND_SYSTEM is true, default to system.
+            ? "system"      // if OMNITRACE_PERFETTO_BACKEND_SYSTEM is true, default to system.
            : "inprocess",  // Otherwise, default to inprocess
        { "inprocess", "system", "all" }, false);

-    OMNITRACE_CONFIG_SETTING(std::string, "OMNITRACE_BACKEND",
+    OMNITRACE_CONFIG_SETTING(std::string, "OMNITRACE_PERFETTO_BACKEND",
                             "Specify the perfetto backend to activate. Options are: "
                             "'inprocess', 'system', or 'all'",
                             _backend, "perfetto");

+    _config->find("OMNITRACE_PERFETTO_BACKEND")
+        ->second->set_choices({ "inprocess", "system", "all" });
+
    OMNITRACE_CONFIG_SETTING(bool, "OMNITRACE_CRITICAL_TRACE",
                             "Enable generation of the critical trace", false, "backend",
                             "critical_trace");
@@ -280,20 +283,32 @@ configure_settings(bool _init)
        "Include names in serialization of critical trace (mainly for debugging)",
        _omnitrace_debug, "debugging", "critical_trace");

-    OMNITRACE_CONFIG_SETTING(size_t, "OMNITRACE_SHMEM_SIZE_HINT_KB",
+    OMNITRACE_CONFIG_SETTING(size_t, "OMNITRACE_PERFETTO_SHMEM_SIZE_HINT_KB",
                             "Hint for shared-memory buffer size in perfetto (in KB)",
                             40960, "perfetto", "data");

-    OMNITRACE_CONFIG_SETTING(size_t, "OMNITRACE_BUFFER_SIZE_KB",
+    OMNITRACE_CONFIG_SETTING(size_t, "OMNITRACE_PERFETTO_BUFFER_SIZE_KB",
                             "Size of perfetto buffer (in KB)", 1024000, "perfetto",
                             "data");

-    OMNITRACE_CONFIG_SETTING(bool, "OMNITRACE_COMBINE_PERFETTO_TRACES",
-                             "Combine Perfetto traces", true, "perfetto", "data");
+    OMNITRACE_CONFIG_SETTING(bool, "OMNITRACE_PERFETTO_COMBINE_TRACES",
+                             "Combine Perfetto traces. If not explicitly set, it will "
+                             "default to the value of OMNITRACE_COLLAPSE_PROCESSES",
+                             _config->get<bool>("collapse_processes"), "perfetto",
+                             "data");
+
+    OMNITRACE_CONFIG_SETTING(
+        std::string, "OMNITRACE_PERFETTO_FILL_POLICY",
+        "Behavior when perfetto buffer is full. 'discard' will ignore new entries, "
+        "'ring_buffer' will overwrite old entries",
+        "discard", "perfetto", "data");
+
+    _config->find("OMNITRACE_PERFETTO_FILL_POLICY")
+        ->second->set_choices({ "fill", "discard" });

    OMNITRACE_CONFIG_SETTING(int64_t, "OMNITRACE_CRITICAL_TRACE_COUNT",
                             "Number of critical trace to export (0 == all)", 0, "data",
-                             "critical_trace");
+                             "critical_trace", "omnitrace-critical-trace");

    OMNITRACE_CONFIG_SETTING(uint64_t, "OMNITRACE_CRITICAL_TRACE_BUFFER_COUNT",
                             "Number of critical trace records to store in thread-local "
@@ -423,6 +438,13 @@ configure_settings(bool _init)
    _config->get_global_components() =
        _config->get<std::string>("OMNITRACE_TIMEMORY_COMPONENTS");

+    auto _combine_perfetto_traces = _config->find("OMNITRACE_PERFETTO_COMBINE_TRACES");
+    if(!_combine_perfetto_traces->second->get_environ_updated() &&
+       _combine_perfetto_traces->second->get_config_updated())
+    {
+        _combine_perfetto_traces->second->set(_config->get<bool>("collapse_processes"));
+    }
+
    scope::get_fields()[scope::flat::value]     = _config->get_flat_profile();
    scope::get_fields()[scope::timeline::value] = _config->get_timeline_profile();

@@ -535,9 +557,17 @@ configure_settings(bool _init)
    _config->disable("profiler_components");
    _config->disable("destructor_report");
    _config->disable("stack_clearing");
+    _config->disable("auto_output");
+    _config->disable("file_output");
+    _config->disable("plot_output");
+    _config->disable("dart_output");
+    _config->disable("flamegraph_output");
+    _config->disable("separator_freq");
+    _config->disable("width");
+    _config->disable("max_width");

 #if !defined(TIMEMORY_USE_MPI) || TIMEMORY_USE_MPI == 0
-    _config->disable("OMNITRACE_COMBINE_PERFETTO_TRACES");
+    _config->disable("OMNITRACE_PERFETTO_COMBINE_TRACES");
 #endif
 }

@@ -663,47 +693,8 @@ print_settings()
 {
    if(dmp::rank() > 0) return;

-    static std::set<tim::string_view_t> _sample_options = {
-        "OMNITRACE_SAMPLING_FREQ",     "OMNITRACE_SAMPLING_DELAY",
-        "OMNITRACE_SAMPLING_CPUS",     "OMNITRACE_FLAT_SAMPLING",
-        "OMNITRACE_TIMELINE_SAMPLING", "OMNITRACE_FLAT_SAMPLING",
-        "OMNITRACE_TIMELINE_SAMPLING",
-    };
-    static std::set<tim::string_view_t> _perfetto_options = {
-        "OMNITRACE_OUTPUT_FILE",
-        "OMNITRACE_BACKEND",
-        "OMNITRACE_SHMEM_SIZE_HINT_KB",
-        "OMNITRACE_BUFFER_SIZE_KB",
-    };
-    static std::set<tim::string_view_t> _timemory_options = {
-        "OMNITRACE_ROCTRACER_FLAT_PROFILE", "OMNITRACE_ROCTRACER_TIMELINE_PROFILE"
-    };
    // generic filter for filtering relevant options
-    auto _is_omnitrace_option = [](const auto& _v, const auto& _c) {
-        if(!get_use_roctracer() && _v.find("OMNITRACE_ROCTRACER_") == 0) return false;
-        if(!get_use_critical_trace() && _v.find("OMNITRACE_CRITICAL_TRACE_") == 0)
-            return false;
-        if(!get_use_perfetto() && _perfetto_options.count(_v) > 0) return false;
-        if(!get_use_timemory() && _timemory_options.count(_v) > 0) return false;
-        if(!get_use_sampling() && !get_use_thread_sampling() &&
-           _sample_options.count(_v) > 0)
-            return false;
-        const auto npos = std::string::npos;
-        if(_v.find("WIDTH") != npos || _v.find("SEPARATOR_FREQ") != npos ||
-           _v.find("AUTO_OUTPUT") != npos || _v.find("DART_OUTPUT") != npos ||
-           _v.find("FILE_OUTPUT") != npos || _v.find("PLOT_OUTPUT") != npos ||
-           _v.find("FLAMEGRAPH_OUTPUT") != npos)
-            return false;
-        if(!_c.empty())
-        {
-            if(_c.find("omnitrace") != _c.end()) return true;
-            if(_c.find("debugging") != _c.end() && _v.find("DEBUG") != npos) return true;
-            if(_c.find("config") != _c.end()) return true;
-            if(_c.find("dart") != _c.end()) return false;
-            if(_c.find("io") != _c.end() && _v.find("_OUTPUT") != npos) return true;
-            if(_c.find("format") != _c.end()) return true;
-            return false;
-        }
+    auto _is_omnitrace_option = [](const auto& _v, const auto&) {
        return (_v.find("OMNITRACE_") == 0);
    };

@@ -988,14 +979,14 @@ get_critical_trace_per_row()
 size_t
 get_perfetto_shmem_size_hint()
 {
-    static auto _v = get_config()->find("OMNITRACE_SHMEM_SIZE_HINT_KB");
+    static auto _v = get_config()->find("OMNITRACE_PERFETTO_SHMEM_SIZE_HINT_KB");
    return static_cast<tim::tsettings<size_t>&>(*_v->second).get();
 }

 size_t
 get_perfetto_buffer_size()
 {
-    static auto _v = get_config()->find("OMNITRACE_BUFFER_SIZE_KB");
+    static auto _v = get_config()->find("OMNITRACE_PERFETTO_BUFFER_SIZE_KB");
    return static_cast<tim::tsettings<size_t>&>(*_v->second).get();
 }

@@ -1003,13 +994,20 @@ bool
 get_perfetto_combined_traces()
 {
 #if defined(TIMEMORY_USE_MPI) && TIMEMORY_USE_MPI > 0
-    static auto _v = get_config()->find("OMNITRACE_COMBINE_PERFETTO_TRACES");
+    static auto _v = get_config()->find("OMNITRACE_PERFETTO_COMBINE_TRACES");
    return static_cast<tim::tsettings<bool>&>(*_v->second).get();
 #else
    return false;
 #endif
 }

+std::string
+get_perfetto_fill_policy()
+{
+    static auto _v = get_config()->find("OMNITRACE_PERFETTO_FILL_POLICY");
+    return static_cast<tim::tsettings<std::string>&>(*_v->second).get();
+}
+
 uint64_t
 get_critical_trace_update_freq()
 {
@@ -1038,7 +1036,7 @@ std::string&
 get_backend()
 {
    // select inprocess, system, or both (i.e. all)
-    static auto _v = get_config()->find("OMNITRACE_BACKEND");
+    static auto _v = get_config()->find("OMNITRACE_PERFETTO_BACKEND");
    return static_cast<tim::tsettings<std::string>&>(*_v->second).get();
 }

@@ -49,7 +49,7 @@ void
 configure_settings(bool _init = true);

 void
-print_banner(std::ostream& _os = std::cout);
+print_banner(std::ostream& _os = std::cerr);

 void
 print_settings(
@@ -202,6 +202,9 @@ get_perfetto_buffer_size();
 bool
 get_perfetto_combined_traces();

+std::string
+get_perfetto_fill_policy();
+
 uint64_t
 get_critical_trace_update_freq();

@@ -98,9 +98,8 @@ config()
                    _cpu_mhz_pos.emplace_back(_pos + 1);
                    _ifs >> _s;
                    if(!_ifs.good() || !_ifs) break;
-                    OMNITRACE_CONDITIONAL_BASIC_PRINT(get_debug() || get_verbose() > 1,
-                                                      "[%zu] %s %s (pos = %zu)\n", i,
-                                                      _st.c_str(), _s.c_str(), _pos + 1);
+                    OMNITRACE_BASIC_VERBOSE(3, "[%zu] %s %s (pos = %zu)\n", i,
+                                            _st.c_str(), _s.c_str(), _pos + 1);
                    break;
                }
            }
@@ -110,6 +109,12 @@ config()
    _ifs.close();

    auto _enabled_val = get_sampling_cpus();
+    for(auto& itr : _enabled_val)
+        itr = tolower(itr);
+    if(_enabled_val == "off")
+        _enabled_val = "none";
+    else if(_enabled_val == "on")
+        _enabled_val = "all";
    if(_enabled_val != "none" && _enabled_val != "all")
    {
        auto _enabled = tim::delimit(_enabled_val, ",; \t");
@@ -145,9 +150,19 @@ config()
            }
        }
    }
+    else if(_enabled_val == "all")
+    {
+        for(size_t i = 0; i < _ncpu; ++i)
+            enabled_cpu_frequencies.emplace(i);
+    }
+    else if(_enabled_val == "none")
+    {
+        enabled_cpu_frequencies.clear();
+    }
    cpu_frequencies.resize(_ncpu);
    cpu_mhz_pos = _cpu_mhz_pos;
-    ifs         = std::make_unique<std::ifstream>("/proc/cpuinfo", std::ifstream::binary);
+    if(!enabled_cpu_frequencies.empty())
+        ifs = std::make_unique<std::ifstream>("/proc/cpuinfo", std::ifstream::binary);
 }

 void
@@ -166,11 +181,9 @@ sample()
    };

    auto _ts = tim::get_clock_real_now<size_t, std::nano>();
-    for(int64_t i = 0; i < ncpu; ++i)
+    for(const auto& itr : enabled_cpu_frequencies)
    {
-        if(!enabled_cpu_frequencies.empty() && enabled_cpu_frequencies.count(i) == 0)
-            continue;
-        cpu_frequencies.at(i).emplace_back(_ts, _read_cpu_freq(i));
+        cpu_frequencies.at(itr).emplace_back(_ts, _read_cpu_freq(itr));
    }
 }

@@ -93,6 +93,8 @@ sampler::poll(std::atomic<State>* _state, nsec_t _interval, promise_t* _ready)
    {
        std::this_thread::sleep_until(_now);
        if(_state->load() != State::Active) continue;
+        if(get_state() == State::Finalized) break;
+        if(get_state() != State::Active) continue;
        get_sampler_is_sampling().store(true);
        for(auto& itr : instances)
            itr->sample();
@@ -100,6 +102,8 @@ sampler::poll(std::atomic<State>* _state, nsec_t _interval, promise_t* _ready)
        while(_now < std::chrono::steady_clock::now())
            _now += _interval;
    }
+    // ensure this is always false
+    get_sampler_is_sampling().store(false);

    OMNITRACE_CONDITIONAL_BASIC_PRINT(get_debug(),
                                      "Thread sampler polling completed...\n");
@@ -165,30 +169,44 @@ sampler::setup()
 void
 sampler::shutdown()
 {
+    // set the local sampler state to finalized
+    set_state(State::Finalized);
+
+    // shutdown all components
    for(auto& itr : instances)
        itr->shutdown();

    auto& _thread = get_thread();
    if(_thread)
    {
-        set_state(State::Finalized);
+        size_t           _nitr     = 0;
+        constexpr size_t _nitr_max = 100;
+        uint64_t         _freq     = (1.0 / get_thread_sampling_freq()) * 1.0e3;
+
+        // wait until the sampler is no longer sampling
+        std::this_thread::sleep_for(msec_t{ _freq });
        while(get_sampler_is_sampling().load())
-        {}
+        {
+            if(_nitr++ > _nitr_max) break;
+        }
+
+        // during CI, throw an error if polling_finished is not valid
+        OMNITRACE_CI_THROW(!polling_finished, "polling_finished is not valid\n");
        if(polling_finished)
        {
-            auto     _fut  = polling_finished->get_future();
-            uint64_t _freq = (1.0 / get_thread_sampling_freq()) * 1.0e3;
+            // wait for the thread to finish
+            auto _fut = polling_finished->get_future();
            _fut.wait_for(msec_t{ 10 * _freq });
            _thread->join();
        }
        else
        {
-            uint64_t _freq = (1.0 / get_thread_sampling_freq()) * 1.0e3;
+            // cancel the thread and detach
            std::this_thread::sleep_for(msec_t{ 10 * _freq });
            pthread_cancel(_thread->native_handle());
            _thread->detach();
        }
-        _thread          = std::unique_ptr<std::thread>{};
+        _thread          = std::unique_ptr<std::thread>{ nullptr };
        polling_finished = std::unique_ptr<promise_t>{};
    }