class BBS::Background

Work a board does in a thread of its own, out of the callers’ way: an index loaded at boot, a catalog refreshed every hour. An error is logged (BBS.log) and the work tried again after a pause that doubles up to max_retry seconds, so a service that is down for an hour costs a few log lines, not a crashed board or a busy loop. Start one with BBS.background:

BBS.background('index') { wiki.load_index }                 # once, until it succeeds
BBS.background('catalog refresh', every: 3600) { library.refresh }

Constants

MAX_RETRY: The longest pause between retries, by default, in seconds.
RETRY_AFTER: Seconds before the first retry, by default.

Public Class Methods

new (name, every: nil, retry_after: RETRY_AFTER, max_retry: MAX_RETRY, &work)

Source

# File lib/bbs/background.rb, line 20
def initialize(name, every: nil, retry_after: RETRY_AFTER, max_retry: MAX_RETRY, &work)
  @name        = name
  @every       = every
  @retry_after = retry_after
  @max_retry   = max_retry
  @work        = work
end

Prepares the work; see BBS.background for the arguments.

Public Instance Methods

run ()

Source

# File lib/bbs/background.rb, line 39
def run
  delay = @retry_after
  loop do
    @work.call
    return unless @every

    delay = @retry_after
    sleep @every
  rescue StandardError => e
    delay = failed(e, delay)
  end
end

Runs the work in the calling thread: once until it succeeds, or forever every every seconds. Returns when a single run succeeded.

start ()

Source

# File lib/bbs/background.rb, line 30
def start
  Thread.new { run }.tap do |thread|
    thread.name = "bbs: #{@name}"
    thread.report_on_exception = false
  end
end

Starts the work in a new Thread named after it and returns the Thread.