rocm-systems/source/lib/src/library.cpp

// MIT License
//
// Copyright (c) 2022 Advanced Micro Devices, Inc. All Rights Reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

#include "library.hpp"
#include "library/components/fork_gotcha.hpp"
#include "library/components/mpi_gotcha.hpp"
#include "library/config.hpp"
#include "library/critical_trace.hpp"
#include "library/debug.hpp"
#include "library/defines.hpp"
#include "library/gpu.hpp"
#include "library/sampling.hpp"
#include "library/thread_data.hpp"
#include "library/thread_sampler.hpp"
#include "library/timemory.hpp"
#include "timemory/mpl/type_traits.hpp"

#include <mutex>
#include <string_view>

using namespace omnitrace;

namespace
{
std::vector<bool>&
get_interval_data()
{
    static thread_local auto _v = std::vector<bool>{};
    return _v;
}

auto
ensure_finalization(bool _static_init = false)
{
    auto _main_tid = threading::get_id();
    (void) _main_tid;
    if(!_static_init)
    {
        OMNITRACE_DEBUG("[%s]\n", __FUNCTION__);
    }
    else
    {
        OMNITRACE_CONDITIONAL_PRINT(get_debug_env(), "[%s]\n", __FUNCTION__);
        // This environment variable forces the ROCR-Runtime to use polling to wait
        // for signals rather than interrupts. We set this variable to avoid issues with
        // rocm/roctracer hanging when interrupted by the sampler
        //
        // see:
        // https://github.com/ROCm-Developer-Tools/roctracer/issues/22#issuecomment-572814465
        tim::set_env("HSA_ENABLE_INTERRUPT", "0", 0);
    }
    return scope::destructor{ []() { omnitrace_finalize(); } };
}

auto&
get_trace_session()
{
    static std::unique_ptr<perfetto::TracingSession> _session{};
    return _session;
}

auto
is_system_backend()
{
    // if get_backend() returns 'system' or 'all', this is true
    return (get_backend() != "inprocess");
}

auto&
get_instrumentation_bundles()
{
    static thread_local auto& _v =
        instrumentation_bundles::instances().at(threading::get_id());
    return _v;
}

auto&
get_functors()
{
    using functor_t = std::function<void(const char*)>;
    static auto _v =
        std::pair<functor_t, functor_t>{ [](const char*) {}, [](const char*) {} };
    return _v;
}

auto&
get_cpu_cid_parents()
{
    static thread_local auto _v =
        std::unordered_map<uint64_t, std::tuple<uint64_t, uint16_t>>{};
    return _v;
}

using Device = critical_trace::Device;
using Phase  = critical_trace::Phase;
}  // namespace

//======================================================================================//
///
/// \fn void omnitrace_push_trace(const char* name)
/// \brief the "start" function for an instrumentation region
///
//======================================================================================//

extern "C" void
omnitrace_push_trace(const char* name)
{
    // return if not active
    if(get_state() == State::Finalized) return;

    if(get_state() != State::Active && !omnitrace_init_tooling())
    {
        static auto _debug = get_debug_env();
        OMNITRACE_CONDITIONAL_BASIC_PRINT_F(_debug, "%s :: not active. state = %s\n",
                                            name, std::to_string(get_state()).c_str());
        return;
    }

    OMNITRACE_DEBUG("[%s] %s\n", __FUNCTION__, name);

    static auto _sample_rate = std::max<size_t>(get_instrumentation_interval(), 1);
    static thread_local size_t _sample_idx = 0;
    auto                       _enabled    = (_sample_idx++ % _sample_rate == 0);
    get_interval_data().emplace_back(_enabled);
    if(_enabled) get_functors().first(name);
    if(get_use_critical_trace())
    {
        auto     _ts     = comp::wall_clock::record();
        auto     _cid    = get_cpu_cid()++;
        uint16_t _depth  = (get_cpu_cid_stack()->empty())
                               ? get_cpu_cid_stack(0)->size()
                               : get_cpu_cid_stack()->size() - 1;
        auto _parent_cid = (get_cpu_cid_stack()->empty()) ? get_cpu_cid_stack(0)->back()
                                                          : get_cpu_cid_stack()->back();
        get_cpu_cid_parents().emplace(_cid, std::make_tuple(_parent_cid, _depth));
        add_critical_trace<Device::CPU, Phase::BEGIN>(
            threading::get_id(), _cid, 0, _parent_cid, _ts, 0,
            critical_trace::add_hash_id(name), _depth);
    }
}

//======================================================================================//
///
/// \fn void omnitrace_pop_trace(const char* name)
/// \brief the "stop" function for an instrumentation region
///
//======================================================================================//

extern "C" void
omnitrace_pop_trace(const char* name)
{
    if(get_state() == State::Active)
    {
        OMNITRACE_DEBUG("[%s] %s\n", __FUNCTION__, name);
        auto& _interval_data = get_interval_data();
        if(!_interval_data.empty())
        {
            if(_interval_data.back()) get_functors().second(name);
            _interval_data.pop_back();
        }
        if(get_use_critical_trace())
        {
            if(get_cpu_cid_stack() && !get_cpu_cid_stack()->empty())
            {
                auto _cid = get_cpu_cid_stack()->back();
                if(get_cpu_cid_parents().find(_cid) != get_cpu_cid_parents().end())
                {
                    uint64_t _parent_cid          = 0;
                    uint16_t _depth               = 0;
                    auto     _ts                  = comp::wall_clock::record();
                    std::tie(_parent_cid, _depth) = get_cpu_cid_parents().at(_cid);
                    add_critical_trace<Device::CPU, Phase::END>(
                        threading::get_id(), _cid, 0, _parent_cid, _ts, _ts,
                        critical_trace::add_hash_id(name), _depth);
                }
            }
        }
    }
    else
    {
        static auto _debug = get_debug_env();
        OMNITRACE_CONDITIONAL_BASIC_PRINT(_debug, "[%s] %s ignored :: not active\n",
                                          __FUNCTION__, name);
    }
}

//======================================================================================//
///
/// \fn void omnitrace_set_env(const char* name, const char* env_val)
/// \brief Sets an initial environment variable
///
//======================================================================================//

extern "C" void
omnitrace_set_env(const char* env_name, const char* env_val)
{
    // just search env to avoid initializing the settings
    OMNITRACE_CONDITIONAL_PRINT(get_debug_env() || get_verbose_env() > 2,
                                "[%s] Setting env: %s=%s\n", __FUNCTION__, env_name,
                                env_val);

    tim::set_env(env_name, env_val, 0);

    OMNITRACE_CONDITIONAL_THROW(
        get_state() >= State::Init &&
            (config::get_is_continuous_integration() || get_debug_env()),
        "%s(\"%s\", \"%s\") called after omnitrace was initialized. state = %s",
        __FUNCTION__, env_name, env_val, std::to_string(get_state()).c_str());
}

//======================================================================================//
///
/// \fn void omnitrace_set_mpi(bool use, bool attached)
/// \brief Configures whether MPI support should be activated
///
//======================================================================================//

namespace
{
bool                  _set_mpi_called        = false;
std::function<void()> _start_gotcha_callback = []() {};
}  // namespace

extern "C" void
omnitrace_set_mpi(bool use, bool attached)
{
    // just search env to avoid initializing the settings
    OMNITRACE_CONDITIONAL_PRINT(get_debug_env() || get_verbose_env() > 2,
                                "[%s] use: %s, attached: %s\n", __FUNCTION__,
                                (use) ? "y" : "n", (attached) ? "y" : "n");

    _set_mpi_called       = true;
    config::is_attached() = attached;

    if(use && !attached &&
       (get_state() == State::PreInit || get_state() == State::DelayedInit))
    {
        tim::set_env("OMNITRACE_USE_PID", "ON", 1);
    }
    else if(!use)
    {
        trait::runtime_enabled<mpi_gotcha_t>::set(false);
    }

    OMNITRACE_CONDITIONAL_THROW(
        get_state() >= State::Init &&
            (config::get_is_continuous_integration() || get_debug_env()),
        "%s(use=%s, attached=%s) called after omnitrace was initialized. state = %s",
        __FUNCTION__, std::to_string(use).c_str(), std::to_string(attached).c_str(),
        std::to_string(get_state()).c_str());

    _start_gotcha_callback();
}

//======================================================================================//

extern "C" void
omnitrace_init_library()
{
    auto _tid = threading::get_id();
    (void) _tid;

    auto _mode = get_mode();

    get_state() = State::Init;

    // configure the settings
    configure_settings();

    auto _debug_init  = get_debug_init();
    auto _debug_value = get_debug();
    if(_debug_init) config::set_setting_value("OMNITRACE_DEBUG", true);
    scope::destructor _debug_dtor{ [_debug_value, _debug_init]() {
        if(_debug_init) config::set_setting_value("OMNITRACE_DEBUG", _debug_value);
    } };

    OMNITRACE_DEBUG("[%s]\n", __FUNCTION__);

    // below will effectively do:
    //      get_cpu_cid_stack(0)->emplace_back(-1);
    // plus query some env variables
    add_critical_trace<Device::CPU, Phase::NONE>(0, -1, 0, 0, 0, 0, 0, 0);

    if(gpu::device_count() == 0 && get_state() != State::Active)
    {
        OMNITRACE_DEBUG(
            "No HIP devices were found: disabling roctracer and rocm_smi...\n");
        get_use_roctracer() = false;
        get_use_rocm_smi()  = false;
    }

    if(_mode == Mode::Sampling)
    {
        OMNITRACE_CONDITIONAL_PRINT(get_verbose() >= 0,
                                    "Disabling critical trace in %s mode...\n",
                                    std::to_string(_mode).c_str());
        get_use_sampling()       = true;
        get_use_critical_trace() = false;
    }

    tim::trait::runtime_enabled<comp::roctracer>::set(get_use_roctracer());
    tim::trait::runtime_enabled<comp::roctracer_data>::set(get_use_roctracer());

    if(get_instrumentation_interval() < 1) get_instrumentation_interval() = 1;
    get_interval_data().reserve(512);

    if(get_use_kokkosp())
    {
        auto _force = 0;
        if(tim::get_env<std::string>("KOKKOS_PROFILE_LIBRARY") == "libtimemory.so")
            _force = 1;
        tim::set_env("KOKKOS_PROFILE_LIBRARY", "libomnitrace.so", _force);
    }

#if defined(OMNITRACE_USE_ROCTRACER)
    tim::set_env("HSA_TOOLS_LIB", "libomnitrace.so", 0);
#endif
}

//======================================================================================//

extern "C" bool
omnitrace_init_tooling()
{
    static bool _once = false;
    if(get_state() != State::PreInit || get_state() == State::Init || _once) return false;
    _once = true;

    OMNITRACE_CONDITIONAL_THROW(
        get_state() == State::Init,
        "%s called after omnitrace_init_library() was explicitly called", __FUNCTION__);

    OMNITRACE_CONDITIONAL_BASIC_PRINT(get_verbose_env() >= 0,
                                      "Instrumentation mode: %s\n",
                                      std::to_string(config::get_mode()).c_str());

    if(get_verbose_env() >= 0) print_banner();

    omnitrace_init_library();

    OMNITRACE_DEBUG("[%s]\n", __FUNCTION__);

    auto _dtor = scope::destructor{ []() {
        if(get_use_sampling())
        {
            pthread_gotcha::enable_sampling_on_child_threads() = false;
            thread_sampler::setup();
            sampling::setup();
            pthread_gotcha::enable_sampling_on_child_threads() = true;
            sampling::unblock_signals();
        }
        get_main_bundle()->start();
        get_state()= State::Active;  // set to active as very last operation
    } };

    if(get_use_sampling())
    {
        pthread_gotcha::enable_sampling_on_child_threads() = false;
        sampling::block_signals();
    }

    if(!get_use_timemory() && !get_use_perfetto() && !get_use_sampling() &&
       !get_use_rocm_smi())
    {
        get_state() = State::Finalized;
        OMNITRACE_DEBUG("[%s] Both perfetto and timemory are disabled. Setting the state "
                        "to finalized\n",
                        __FUNCTION__);
        return false;
    }

    if(get_use_timemory())
    {
        comp::user_global_bundle::global_init();
        std::set<int> _comps{};
        // convert string into set of enumerations
        for(auto&& itr : tim::delimit(tim::settings::global_components()))
            _comps.emplace(tim::runtime::enumerate(itr));
        if(_comps.size() == 1 && _comps.find(TIMEMORY_WALL_CLOCK) != _comps.end())
        {
            // using wall_clock directly is lower overhead than using it via user_bundle
            instrumentation_bundle_t::get_initializer() =
                [](instrumentation_bundle_t& _bundle) {
                    _bundle.initialize<comp::wall_clock>();
                };
        }
        else if(!_comps.empty())
        {
            // use user_bundle for other than wall-clock
            instrumentation_bundle_t::get_initializer() =
                [](instrumentation_bundle_t& _bundle) {
                    _bundle.initialize<comp::user_global_bundle>();
                };
        }
        else
        {
            tim::trait::runtime_enabled<api::omnitrace>::set(false);
        }
    }

    perfetto::TracingInitArgs               args{};
    perfetto::TraceConfig                   cfg{};
    perfetto::protos::gen::TrackEventConfig track_event_cfg{};

    // perfetto initialization
    if(get_use_perfetto())
    {
        // environment settings
        auto shmem_size_hint = get_perfetto_shmem_size_hint();
        auto buffer_size     = get_perfetto_buffer_size();

        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);

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

        args.shmem_size_hint_kb = shmem_size_hint;

        if(get_backend() != "inprocess") args.backends |= perfetto::kSystemBackend;
        if(get_backend() != "system") args.backends |= perfetto::kInProcessBackend;

        perfetto::Tracing::Initialize(args);
        perfetto::TrackEvent::Register();

        (void) get_perfetto_output_filename();
    }

    auto        _exe         = get_exe_name();
    static auto _thread_init = [_exe]() {
        static thread_local auto _thread_setup = [_exe]() {
            if(threading::get_id() > 0)
                threading::set_thread_name(
                    TIMEMORY_JOIN(" ", "Thread", threading::get_id()).c_str());
            thread_data<omnitrace_thread_bundle_t>::construct(
                TIMEMORY_JOIN("", _exe, "/thread-", threading::get_id()),
                quirk::config<quirk::auto_start>{});
            if(get_use_sampling()) sampling::setup();
        };
        static thread_local auto _once = std::once_flag{};
        std::call_once(_once, _thread_setup);
        static thread_local auto _dtor = scope::destructor{ []() {
            if(get_use_sampling()) sampling::shutdown();
            thread_data<omnitrace_thread_bundle_t>::instance()->stop();
        } };
        (void) _dtor;
    };

    // functors for starting and stopping timemory
    static auto _push_timemory = [](const char* name) {
        _thread_init();
        auto& _data = get_instrumentation_bundles();
        // this generates a hash for the raw string array
        auto  _hash   = tim::add_hash_id(tim::string_view_t{ name });
        auto* _bundle = _data.allocator.allocate(1);
        _data.bundles.emplace_back(_bundle);
        _data.allocator.construct(_bundle, _hash);
        _bundle->start();
    };

    static auto _push_perfetto = [](const char* name) {
        _thread_init();
        uint64_t _ts = comp::wall_clock::record();
        TRACE_EVENT_BEGIN("host", perfetto::StaticString(name), _ts);
    };

    static auto _pop_timemory = [](const char* name) {
        auto& _data = get_instrumentation_bundles();
        if(_data.bundles.empty())
        {
            OMNITRACE_DEBUG("[%s] skipped %s :: empty bundle stack\n",
                            "omnitrace_pop_trace", name);
            return;
        }
        _data.bundles.back()->stop();
        _data.allocator.destroy(_data.bundles.back());
        _data.allocator.deallocate(_data.bundles.back(), 1);
        _data.bundles.pop_back();
    };

    static auto _pop_perfetto = [](const char*) {
        uint64_t _ts = comp::wall_clock::record();
        TRACE_EVENT_END("host", _ts);
    };

    if(get_use_perfetto() && get_use_timemory())
    {
        get_functors().first = [](const char* name) {
            _push_perfetto(name);
            _push_timemory(name);
        };
        get_functors().second = [](const char* name) {
            _pop_timemory(name);
            _pop_perfetto(name);
        };
    }
    else if(get_use_perfetto())
    {
        get_functors().first  = _push_perfetto;
        get_functors().second = _pop_perfetto;
    }
    else if(get_use_timemory())
    {
        get_functors().first  = _push_timemory;
        get_functors().second = _pop_timemory;
    }

    if(get_use_perfetto() && !is_system_backend())
    {
#if defined(CUSTOM_DATA_SOURCE)
        // Add the following:
        perfetto::DataSourceDescriptor dsd{};
        dsd.set_name("com.example.custom_data_source");
        CustomDataSource::Register(dsd);
        auto* ds_cfg = cfg.add_data_sources()->mutable_config();
        ds_cfg->set_name("com.example.custom_data_source");
        CustomDataSource::Trace([](CustomDataSource::TraceContext ctx) {
            auto packet = ctx.NewTracePacket();
            packet->set_timestamp(perfetto::TrackEvent::GetTraceTimeNs());
            packet->set_for_testing()->set_str("Hello world!");
            PRINT_HERE("%s", "Trace");
        });
#endif
        auto& tracing_session = get_trace_session();
        tracing_session       = perfetto::Tracing::NewTrace();
        tracing_session->Setup(cfg);
        tracing_session->StartBlocking();
    }

    // if static objects are destroyed in the inverse order of when they are
    // created this should ensure that finalization is called before perfetto
    // ends the tracing session
    static auto _ensure_finalization = ensure_finalization();

    if(dmp::rank() == 0 && get_verbose() >= 0) fprintf(stderr, "\n");

    return true;
}

//======================================================================================//

extern "C" void
omnitrace_init(const char* _mode, bool _is_binary_rewrite, const char* _argv0)
{
    // always the first
    std::atexit(&omnitrace_finalize);

    OMNITRACE_CONDITIONAL_BASIC_PRINT(
        get_debug_env() || get_verbose_env() > 2,
        "[%s] mode: %s | is binary rewrite: %s | command: %s\n", __FUNCTION__, _mode,
        (_is_binary_rewrite) ? "y" : "n", _argv0);

    tim::set_env("OMNITRACE_MODE", _mode, 0);
    config::is_binary_rewrite() = _is_binary_rewrite;

    // default to KokkosP enabled when sampling, otherwise default to off
    tim::set_env("OMNITRACE_USE_KOKKOSP", (get_mode() == Mode::Sampling) ? "ON" : "OFF",
                 0);

    if(!_set_mpi_called)
    {
        _start_gotcha_callback = []() { get_gotcha_bundle()->start(); };
    }
    else
    {
        get_gotcha_bundle()->start();
    }
}

//======================================================================================//

extern "C" void
omnitrace_finalize(void)
{
    // return if not active
    if(get_state() != State::Active)
    {
        OMNITRACE_DEBUG_F("State = %s. Finalization skipped\n",
                          std::to_string(get_state()).c_str());
        return;
    }

    pthread_gotcha::enable_sampling_on_child_threads() = false;

    auto _debug_init  = get_debug_finalize();
    auto _debug_value = get_debug();
    if(_debug_init) config::set_setting_value("OMNITRACE_DEBUG", true);
    scope::destructor _debug_dtor{ [_debug_value, _debug_init]() {
        if(_debug_init) config::set_setting_value("OMNITRACE_DEBUG", _debug_value);
    } };

    OMNITRACE_DEBUG("[%s]\n", __FUNCTION__);

    auto& _thread_bundle = thread_data<omnitrace_thread_bundle_t>::instance();
    if(_thread_bundle) _thread_bundle->stop();

    if(dmp::rank() == 0 && get_verbose() >= 0) fprintf(stderr, "\n");
    if(get_verbose_env() > 0) config::print_settings();

    get_state() = State::Finalized;

    if(get_use_sampling())
    {
        OMNITRACE_DEBUG("[%s] Shutting down sampling...\n", __FUNCTION__);
        sampling::shutdown();
        sampling::block_signals();
    }

    OMNITRACE_DEBUG("[%s] Stopping gotcha bundle...\n", __FUNCTION__);
    // stop the gotcha bundle
    if(get_gotcha_bundle())
    {
        get_gotcha_bundle()->stop();
        get_gotcha_bundle().reset();
    }

    pthread_gotcha::shutdown();
    thread_sampler::shutdown();

    OMNITRACE_DEBUG("[%s] Shutting down roctracer...\n", __FUNCTION__);
    // ensure that threads running roctracer callbacks shutdown
    comp::roctracer::shutdown();

    if(dmp::rank() == 0) fprintf(stderr, "\n");

    OMNITRACE_DEBUG("[%s] Stopping main bundle...\n", __FUNCTION__);
    // stop the main bundle and report the high-level metrics
    if(get_main_bundle())
    {
        get_main_bundle()->stop();
        std::string _msg = JOIN("", *get_main_bundle());
        auto        _pos = _msg.find(">>>  ");
        if(_pos != std::string::npos) _msg = _msg.substr(_pos + 5);
        OMNITRACE_PRINT("%s\n", _msg.c_str());
        get_main_bundle().reset();
    }

    int _threadpool_verbose = (get_debug()) ? 4 : -1;
    tasking::get_roctracer_thread_pool().set_verbose(_threadpool_verbose);
    tasking::get_critical_trace_thread_pool().set_verbose(_threadpool_verbose);

    // join extra thread(s) used by roctracer
    OMNITRACE_DEBUG("[%s] waiting for all roctracer tasks to complete...\n",
                    __FUNCTION__);
    tasking::get_roctracer_task_group().join();

    // print out thread-data if they are not still running
    // if they are still running (e.g. thread-pool still alive), the
    // thread-specific data will be wrong if try to stop them from
    // the main thread.
    OMNITRACE_DEBUG("[%s] Destroying thread bundle data...\n", __FUNCTION__);
    for(auto& itr : thread_data<omnitrace_thread_bundle_t>::instances())
    {
        if(itr && itr->get<comp::wall_clock>() &&
           !itr->get<comp::wall_clock>()->get_is_running())
        {
            std::string _msg = JOIN("", *itr);
            auto        _pos = _msg.find(">>>  ");
            if(_pos != std::string::npos) _msg = _msg.substr(_pos + 5);
            OMNITRACE_CONDITIONAL_PRINT(get_verbose() >= 0, "%s\n", _msg.c_str());
        }
    }

    // ensure that all the MT instances are flushed
    OMNITRACE_DEBUG("[%s] Stopping and destroying instrumentation bundles...\n",
                    __FUNCTION__);
    for(auto& itr : instrumentation_bundles::instances())
    {
        while(!itr.bundles.empty())
        {
            itr.bundles.back()->stop();
            itr.bundles.back()->pop();
            itr.allocator.destroy(itr.bundles.back());
            itr.allocator.deallocate(itr.bundles.back(), 1);
            itr.bundles.pop_back();
        }
    }

    // ensure that all the MT instances are flushed
    if(get_use_sampling())
    {
        OMNITRACE_DEBUG("[%s] Post-processing the sampling backtraces...\n",
                        __FUNCTION__);
        for(size_t i = 0; i < max_supported_threads; ++i)
        {
            sampling::backtrace::post_process(i);
            sampling::get_sampler(i).reset();
        }
    }

    if(get_use_critical_trace() || (get_use_rocm_smi() && get_use_roctracer()))
    {
        OMNITRACE_DEBUG("[%s] Generating the critical trace...\n", __FUNCTION__);
        // increase the thread-pool size
        tasking::get_critical_trace_thread_pool().initialize_threadpool(
            get_critical_trace_num_threads());

        for(size_t i = 0; i < max_supported_threads; ++i)
        {
            using critical_trace_hash_data =
                thread_data<critical_trace::hash_ids, critical_trace::id>;

            if(critical_trace_hash_data::instances().at(i))
                critical_trace::add_hash_id(*critical_trace_hash_data::instances().at(i));
        }

        for(size_t i = 0; i < max_supported_threads; ++i)
        {
            using critical_trace_chain_data = thread_data<critical_trace::call_chain>;

            if(critical_trace_chain_data::instances().at(i))
                critical_trace::update(i);  // launch update task
        }
    }

    thread_sampler::post_process();

    if(get_use_critical_trace())
    {
        OMNITRACE_DEBUG("[%s] Generating the critical trace...\n", __FUNCTION__);
        // increase the thread-pool size
        tasking::get_critical_trace_thread_pool().initialize_threadpool(
            get_critical_trace_num_threads());

        // make sure outstanding hash tasks completed before compute
        OMNITRACE_PRINT("[%s] waiting for all critical trace tasks to complete...\n",
                        __FUNCTION__);
        tasking::get_critical_trace_task_group().join();

        // launch compute task
        OMNITRACE_PRINT("[%s] launching critical trace compute task...\n", __FUNCTION__);
        critical_trace::compute();
    }

    tasking::get_critical_trace_task_group().join();

    bool _perfetto_output_error = false;
    if(get_use_perfetto() && !is_system_backend())
    {
        if(get_verbose() >= 0) fprintf(stderr, "\n");
        if(get_verbose() >= 0 || get_debug())
            fprintf(stderr, "[%s]|%i> Flushing perfetto...\n", __FUNCTION__, dmp::rank());

        // Make sure the last event is closed for this example.
        perfetto::TrackEvent::Flush();

        auto& tracing_session = get_trace_session();
        OMNITRACE_DEBUG("[%s] Stopping the blocking perfetto trace sessions...\n",
                        __FUNCTION__);
        tracing_session->StopBlocking();

        OMNITRACE_DEBUG("[%s] Getting the trace data...\n", __FUNCTION__);
        std::vector<char> trace_data{ tracing_session->ReadTraceBlocking() };

        if(trace_data.empty())
        {
            fprintf(stderr,
                    "[%s]> trace data is empty. File '%s' will not be written...\n",
                    __FUNCTION__, get_perfetto_output_filename().c_str());
            return;
        }
        // Write the trace into a file.
        if(get_verbose() >= 0)
            fprintf(stderr, "[%s]|%i> Outputting '%s' (%.2f KB / %.2f MB / %.2f GB)... ",
                    __FUNCTION__, dmp::rank(), get_perfetto_output_filename().c_str(),
                    static_cast<double>(trace_data.size()) / units::KB,
                    static_cast<double>(trace_data.size()) / units::MB,
                    static_cast<double>(trace_data.size()) / units::GB);
        std::ofstream ofs{};
        if(!tim::filepath::open(ofs, get_perfetto_output_filename(),
                                std::ios::out | std::ios::binary))
        {
            fprintf(stderr, "\n[%s]> Error opening '%s'...\n", __FUNCTION__,
                    get_perfetto_output_filename().c_str());
            _perfetto_output_error = true;
        }
        else
        {
            // Write the trace into a file.
            if(get_verbose() >= 0) fprintf(stderr, "Done\n");
            ofs.write(&trace_data[0], trace_data.size());
        }
        ofs.close();
        if(get_verbose() >= 0) fprintf(stderr, "\n");
    }

    // these should be destroyed before timemory is finalized, especially the
    // roctracer thread-pool
    OMNITRACE_DEBUG("[%s] Destroying the thread pools...\n", __FUNCTION__);
    tasking::get_roctracer_thread_pool().destroy_threadpool();
    tasking::get_critical_trace_thread_pool().destroy_threadpool();

    if(get_use_sampling())
        static_cast<tim::tsettings<bool>*>(
            tim::settings::instance()->find("OMNITRACE_DEBUG")->second.get())
            ->set(false);

    OMNITRACE_DEBUG("[%s] Finalizing timemory...\n", __FUNCTION__);
    tim::timemory_finalize();
    OMNITRACE_DEBUG("[%s] Finalizing timemory... Done\n", __FUNCTION__);

    if(_perfetto_output_error)
    {
        OMNITRACE_THROW("Error opening perfetto output file: %s",
                        get_perfetto_output_filename().c_str());
    }
}

//======================================================================================//

namespace
{
// if static objects are destroyed randomly (relatively uncommon behavior)
// this might call finalization before perfetto ends the tracing session
// but static variable in omnitrace_init_tooling is more likely
auto _ensure_finalization = ensure_finalization(true);
}  // namespace