Class: Datadog::Profiling::Collectors::IdleSamplingHelper

Inherits:
Object
  • Object
show all
Defined in:
lib/datadog/profiling/collectors/idle_sampling_helper.rb,
ext/datadog_profiling_native_extension/collectors_idle_sampling_helper.c

Overview

Used by the Collectors::CpuAndWallTimeWorker to gather samples when the Ruby process is idle. Almost all of this class is implemented as native code.

Methods prefixed with native are implemented in ‘collectors_idle_sampling_helper.c`

Defined Under Namespace

Modules: Testing

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ IdleSamplingHelper

Returns a new instance of IdleSamplingHelper.



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# File 'lib/datadog/profiling/collectors/idle_sampling_helper.rb', line 17

def initialize
  @worker_thread = nil
  @start_stop_mutex = Mutex.new
end

Class Method Details

._native_idle_sampling_loop ⇒ Object 



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# File 'ext/datadog_profiling_native_extension/collectors_idle_sampling_helper.c', line 33

static VALUE _native_idle_sampling_loop(DDTRACE_UNUSED VALUE self, VALUE self_instance);

._native_reset ⇒ Object 



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# File 'ext/datadog_profiling_native_extension/collectors_idle_sampling_helper.c', line 37

static VALUE _native_reset(DDTRACE_UNUSED VALUE self, VALUE self_instance);

._native_stop ⇒ Object 



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# File 'ext/datadog_profiling_native_extension/collectors_idle_sampling_helper.c', line 34

static VALUE _native_stop(DDTRACE_UNUSED VALUE self, VALUE self_instance);

Instance Method Details

#start ⇒ Object 



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# File 'lib/datadog/profiling/collectors/idle_sampling_helper.rb', line 22

def start
  @start_stop_mutex.synchronize do
    return if @worker_thread&.alive?

    Datadog.logger.debug { "Starting thread for: #{self}" }

    # The same instance of the IdleSamplingHelper can be reused multiple times, and this resets it back to
    # a pristine state before recreating the worker thread
    self.class._native_reset(self)

    @worker_thread = Thread.new do
      Thread.current.name = self.class.name

      self.class._native_idle_sampling_loop(self)

      Datadog.logger.debug("IdleSamplingHelper thread stopping cleanly")
    rescue Exception => e # rubocop:disable Lint/RescueException
      @failure_exception = e
      Datadog.logger.warn(
        "IdleSamplingHelper thread error. " \
        "Cause: #{e.class.name} #{e.message} Location: #{Array(e.backtrace).first}"
      )
    end
    @worker_thread.name = self.class.name # Repeated from above to make sure thread gets named asap
    @worker_thread.thread_variable_set(:fork_safe, true)
  end

  true
end

#stop ⇒ Object 



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# File 'lib/datadog/profiling/collectors/idle_sampling_helper.rb', line 52

def stop
  @start_stop_mutex.synchronize do
    Datadog.logger.debug("Requesting IdleSamplingHelper thread shut down")

    return unless @worker_thread

    self.class._native_stop(self)

    @worker_thread.join
    @worker_thread = nil
    @failure_exception = nil
  end
end