| Module | MonitorMixin |
| In: |
monitor.rb
|
Adds monitor functionality to an arbitrary object by mixing the module with include. For example:
require 'monitor.rb'
buf = []
buf.extend(MonitorMixin)
empty_cond = buf.new_cond
# consumer
Thread.start do
loop do
buf.synchronize do
empty_cond.wait_while { buf.empty? }
print buf.shift
end
end
end
# producer
while line = ARGF.gets
buf.synchronize do
buf.push(line)
empty_cond.signal
end
end
The consumer thread waits for the producer thread to push a line to buf while buf.empty?, and the producer thread (main thread) reads a line from ARGF and push it to buf, then call empty_cond.signal.
# File monitor.rb, line 173 def self.extend_object(obj) super(obj) obj.instance_eval {mon_initialize()} end
Enters exclusive section.
# File monitor.rb, line 200 def mon_enter Thread.critical = true mon_acquire(@mon_entering_queue) @mon_count += 1 Thread.critical = false end
Leaves exclusive section.
# File monitor.rb, line 210 def mon_exit mon_check_owner Thread.critical = true @mon_count -= 1 if @mon_count == 0 mon_release end Thread.critical = false Thread.pass end
Enters exclusive section and executes the block. Leaves the exclusive section automatically when the block exits. See example under MonitorMixin.
# File monitor.rb, line 226 def mon_synchronize mon_enter begin yield ensure mon_exit end end
Attempts to enter exclusive section. Returns false if lock fails.
# File monitor.rb, line 181 def mon_try_enter result = false Thread.critical = true if @mon_owner.nil? @mon_owner = Thread.current end if @mon_owner == Thread.current @mon_count += 1 result = true end Thread.critical = false return result end