Method ThreadStatus

src/Common/ThreadStatus.cpp:79–131

ThreadStatus::ThreadStatus()
    : thread_id{getThreadId()}
{
    last_rusage = std::make_unique<RUsageCounters>();

    memory_tracker.setDescription("(for thread)");
    log = &Poco::Logger::get("ThreadStatus");

    current_thread = this;

    /// NOTE: It is important not to do any non-trivial actions (like updating ProfileEvents or logging) before ThreadStatus is created
    /// Otherwise it could lead to SIGSEGV due to current_thread dereferencing

    /// Will set alternative signal stack to provide diagnostics for stack overflow errors.
    /// If not already installed for current thread.
    /// Sanitizer makes larger stack usage and also it's incompatible with alternative stack by default (it sets up and relies on its own).
#if !defined(SANITIZER) && !defined(ARCADIA_BUILD)
    if (!has_alt_stack)
    {
        /// Don't repeat tries even if not installed successfully.
        has_alt_stack = true;

        /// We have to call 'sigaltstack' before first 'sigaction'. (It does not work other way, for unknown reason).
        stack_t altstack_description{};
        altstack_description.ss_sp = alt_stack.getData();
        altstack_description.ss_flags = 0;
        altstack_description.ss_size = alt_stack.getSize();

        if (0 != sigaltstack(&altstack_description, nullptr))
        {
            LOG_WARNING(log, "Cannot set alternative signal stack for thread, {}", errnoToString(errno));
        }
        else
        {
            /// Obtain existing sigaction and modify it by adding a flag.
            struct sigaction action{};
            if (0 != sigaction(SIGSEGV, nullptr, &action))
            {
                LOG_WARNING(log, "Cannot obtain previous signal action to set alternative signal stack for thread, {}", errnoToString(errno));
            }
            else if (!(action.sa_flags & SA_ONSTACK))
            {
                action.sa_flags |= SA_ONSTACK;

                if (0 != sigaction(SIGSEGV, &action, nullptr))
                {
                    LOG_WARNING(log, "Cannot set action with alternative signal stack for thread, {}", errnoToString(errno));
                }
            }
        }
    }
#endif
}

ThreadStatus::~ThreadStatus()
{