Class: Datadog::Core::Utils::OnlyOnce

Inherits:
Object
  • Object
show all
Defined in:
lib/datadog/core/utils/only_once.rb

Overview

Helper class to execute something only once such as not repeating warning logs, and instrumenting classes only once.

Thread-safe when used correctly (e.g. be careful of races when lazily initializing instances of this class).

Note: In its current state, this class is not Ractor-safe. In github.com/DataDog/dd-trace-rb/pull/1398#issuecomment-797378810 we have a discussion of alternatives, including an alternative implementation that is Ractor-safe once spent.

Direct Known Subclasses

OnlyOnceSuccessful

Instance Method Summary collapse

Constructor Details

#initialize ⇒ OnlyOnce

Returns a new instance of OnlyOnce.



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# File 'lib/datadog/core/utils/only_once.rb', line 15

def initialize
  @mutex = Mutex.new
  @ran_once = false
end

Instance Method Details

#ran? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/datadog/core/utils/only_once.rb', line 30

def ran?
  @mutex.synchronize { @ran_once }
end

#run ⇒ Object 



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# File 'lib/datadog/core/utils/only_once.rb', line 20

def run
  @mutex.synchronize do
    return if @ran_once

    @ran_once = true

    yield
  end
end