Class: Datadog::Profiling::Collectors::CpuAndWallTimeWorker

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

Overview

Used to trigger the periodic execution of Collectors::ThreadState, which implements all of the sampling logic itself; this class only implements the “when to do it” part. Almost all of this class is implemented as native code.

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

Defined Under Namespace

Modules: Testing

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(gc_profiling_enabled:, no_signals_workaround_enabled:, thread_context_collector:, dynamic_sampling_rate_overhead_target_percentage:, allocation_profiling_enabled:, dynamic_sampling_rate_enabled: true, skip_idle_samples_for_testing: false, idle_sampling_helper: IdleSamplingHelper.new) ⇒ CpuAndWallTimeWorker

Returns a new instance of CpuAndWallTimeWorker.



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# File 'lib/datadog/profiling/collectors/cpu_and_wall_time_worker.rb', line 16

def initialize(
  gc_profiling_enabled:,
  no_signals_workaround_enabled:,
  thread_context_collector:,
  dynamic_sampling_rate_overhead_target_percentage:,
  allocation_profiling_enabled:,
  # **NOTE**: This should only be used for testing; disabling the dynamic sampling rate will increase the
  # profiler overhead!
  dynamic_sampling_rate_enabled: true,
  skip_idle_samples_for_testing: false,
  idle_sampling_helper: IdleSamplingHelper.new
)
  unless dynamic_sampling_rate_enabled
    Datadog.logger.warn(
      'Profiling dynamic sampling rate disabled. This should only be used for testing, and will increase overhead!'
    )
  end

  self.class._native_initialize(
    self,
    thread_context_collector,
    gc_profiling_enabled,
    idle_sampling_helper,
    no_signals_workaround_enabled,
    dynamic_sampling_rate_enabled,
    dynamic_sampling_rate_overhead_target_percentage,
    allocation_profiling_enabled,
    skip_idle_samples_for_testing,
  )
  @worker_thread = nil
  @failure_exception = nil
  @start_stop_mutex = Mutex.new
  @idle_sampling_helper = idle_sampling_helper
  @wait_until_running_mutex = Mutex.new
  @wait_until_running_condition = ConditionVariable.new
end

Class Method Details

._native_allocation_count ⇒ Object 



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# File 'ext/datadog_profiling_native_extension/collectors_cpu_and_wall_time_worker.c', line 218

static VALUE _native_allocation_count(DDTRACE_UNUSED VALUE self);

._native_initialize ⇒ Object 



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# File 'ext/datadog_profiling_native_extension/collectors_cpu_and_wall_time_worker.c', line 174

static VALUE _native_initialize(
  DDTRACE_UNUSED VALUE _self,
  VALUE self_instance,
  VALUE thread_context_collector_instance,
  VALUE gc_profiling_enabled,
  VALUE idle_sampling_helper_instance,
  VALUE no_signals_workaround_enabled,
  VALUE dynamic_sampling_rate_enabled,
  VALUE dynamic_sampling_rate_overhead_target_percentage,
  VALUE allocation_profiling_enabled,
  VALUE skip_idle_samples_for_testing
);

._native_is_running? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'ext/datadog_profiling_native_extension/collectors_cpu_and_wall_time_worker.c', line 199

static VALUE _native_is_running(DDTRACE_UNUSED VALUE self, VALUE instance);

._native_reset_after_fork ⇒ Object 



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# File 'ext/datadog_profiling_native_extension/collectors_cpu_and_wall_time_worker.c', line 210

static VALUE _native_reset_after_fork(DDTRACE_UNUSED VALUE self, VALUE instance);

._native_sampling_loop ⇒ Object 



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# File 'ext/datadog_profiling_native_extension/collectors_cpu_and_wall_time_worker.c', line 187

static VALUE _native_sampling_loop(VALUE self, VALUE instance);

._native_stats ⇒ Object 



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# File 'ext/datadog_profiling_native_extension/collectors_cpu_and_wall_time_worker.c', line 212

static VALUE _native_stats(DDTRACE_UNUSED VALUE self, VALUE instance);

._native_stats_reset_not_thread_safe ⇒ Object 



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# File 'ext/datadog_profiling_native_extension/collectors_cpu_and_wall_time_worker.c', line 213

static VALUE _native_stats_reset_not_thread_safe(DDTRACE_UNUSED VALUE self, VALUE instance);

._native_stop ⇒ Object 



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# File 'ext/datadog_profiling_native_extension/collectors_cpu_and_wall_time_worker.c', line 188

static VALUE _native_stop(DDTRACE_UNUSED VALUE _self, VALUE self_instance, VALUE worker_thread);

Instance Method Details

#reset_after_fork ⇒ Object 



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# File 'lib/datadog/profiling/collectors/cpu_and_wall_time_worker.rb', line 100

def reset_after_fork
  self.class._native_reset_after_fork(self)
end

#start(on_failure_proc: nil) ⇒ Object 



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# File 'lib/datadog/profiling/collectors/cpu_and_wall_time_worker.rb', line 53

def start(on_failure_proc: nil)
  @start_stop_mutex.synchronize do
    return if @worker_thread && @worker_thread.alive?

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

    @idle_sampling_helper.start

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

        self.class._native_sampling_loop(self)

        Datadog.logger.debug('CpuAndWallTimeWorker thread stopping cleanly')
      rescue Exception => e # rubocop:disable Lint/RescueException
        @failure_exception = e
        Datadog.logger.warn(
          'CpuAndWallTimeWorker thread error. ' \
          "Cause: #{e.class.name} #{e.message} Location: #{Array(e.backtrace).first}"
        )
        on_failure_proc&.call
      end
    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

#stats ⇒ Object 



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# File 'lib/datadog/profiling/collectors/cpu_and_wall_time_worker.rb', line 104

def stats
  self.class._native_stats(self)
end

#stats_and_reset_not_thread_safe ⇒ Object 



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# File 'lib/datadog/profiling/collectors/cpu_and_wall_time_worker.rb', line 108

def stats_and_reset_not_thread_safe
  stats = self.stats
  self.class._native_stats_reset_not_thread_safe(self)
  stats
end

#stop ⇒ Object 



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# File 'lib/datadog/profiling/collectors/cpu_and_wall_time_worker.rb', line 84

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

    @idle_sampling_helper.stop

    return unless @worker_thread

    self.class._native_stop(self, @worker_thread)

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

#wait_until_running(timeout_seconds: 5) ⇒ Object

Useful for testing, to e.g. make sure the profiler is running before we start running some code we want to observe



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# File 'lib/datadog/profiling/collectors/cpu_and_wall_time_worker.rb', line 115

def wait_until_running(timeout_seconds: 5)
  @wait_until_running_mutex.synchronize do
    return true if self.class._native_is_running?(self)

    @wait_until_running_condition.wait(@wait_until_running_mutex, timeout_seconds)

    if self.class._native_is_running?(self)
      true
    else
      raise "Timeout waiting for #{self.class.name} to start (waited for #{timeout_seconds} seconds)"
    end
  end
end