Module: Msf::Exploit::Retry

Defined in:
lib/msf/core/exploit/retry.rb

Instance Method Summary collapse

Instance Method Details

#retry_until_truthy(timeout:) ⇒ Object

Retry the block until it returns a truthy value. Each iteration attempt will be performed with an exponential backoff. If the timeout period surpasses, nil is returned.

Parameters:

  • Integer

    timeout the number of seconds to wait before the operation times out

Returns:

  • the truthy value of the block is returned or nil if it timed out



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# File 'lib/msf/core/exploit/retry.rb', line 8

def retry_until_truthy(timeout:)
  start_time = Process.clock_gettime(Process::CLOCK_MONOTONIC, :second)
  ending_time = start_time + timeout
  retry_count = 0
  while Process.clock_gettime(Process::CLOCK_MONOTONIC, :second) < ending_time
    result = yield
    return result if result

    retry_count += 1
    remaining_time_budget = ending_time - Process.clock_gettime(Process::CLOCK_MONOTONIC, :second)
    break if remaining_time_budget <= 0

    delay = 2**retry_count
    if delay >= remaining_time_budget
      delay = remaining_time_budget
      vprint_status("Final attempt. Sleeping for the remaining #{delay} seconds out of total timeout #{timeout}")
    else
      vprint_status("Sleeping for #{delay} seconds before attempting again")
    end

    sleep delay
  end

  nil
end