summaryrefslogtreecommitdiff
path: root/lib/monitor.rb
diff options
context:
space:
mode:
authormatz <matz@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>1999-08-13 05:45:20 +0000
committermatz <matz@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>1999-08-13 05:45:20 +0000
commit65a5162550f58047974793cdc8067a970b2435c0 (patch)
tree082bb7d5568f3b2e36e3fe166e9f3039394fcf44 /lib/monitor.rb
parentfcd020c83028f5610d382e85a2df00223e12bd7e (diff)
1.4.0
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@520 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'lib/monitor.rb')
-rw-r--r--lib/monitor.rb229
1 files changed, 229 insertions, 0 deletions
diff --git a/lib/monitor.rb b/lib/monitor.rb
new file mode 100644
index 0000000..75d9c35
--- /dev/null
+++ b/lib/monitor.rb
@@ -0,0 +1,229 @@
+=begin
+
+monitor.rb
+Author: Shugo Maeda <shugo@netlab.co.jp>
+Version: 1.2.1
+
+USAGE:
+
+ foo = Foo.new
+ foo.extend(MonitorMixin)
+ cond = foo.new_cond
+
+ thread1:
+ foo.synchronize {
+ ...
+ cond.wait_until { foo.done? }
+ ...
+ }
+
+ thread2:
+ foo.synchronize {
+ foo.do_something
+ cond.signal
+ }
+
+=end
+
+module MonitorMixin
+ module Accessible
+ protected
+ attr_accessor :mon_owner, :mon_count
+ attr_reader :mon_entering_queue, :mon_waiting_queue
+ end
+
+ module Initializable
+ protected
+ def mon_initialize
+ @mon_owner = nil
+ @mon_count = 0
+ @mon_entering_queue = []
+ @mon_waiting_queue = []
+ end
+ end
+
+ class ConditionVariable
+ class Timeout < Exception; end
+
+ include Accessible
+
+ def wait(timeout = nil)
+ if @monitor.mon_owner != Thread.current
+ raise ThreadError, "current thread not owner"
+ end
+
+ Thread.critical = true
+ count = @monitor.mon_count
+ @monitor.mon_count = 0
+ @monitor.mon_owner = nil
+ if @monitor.mon_waiting_queue.empty?
+ t = @monitor.mon_entering_queue.shift
+ else
+ t = @monitor.mon_waiting_queue.shift
+ end
+ t.wakeup if t
+ @waiters.push(Thread.current)
+
+ if timeout
+ t = Thread.current
+ timeout_thread = Thread.start {
+ sleep(timeout)
+ t.raise(Timeout.new)
+ }
+ end
+ begin
+ Thread.stop
+ rescue Timeout
+ @waiters.delete(Thread.current)
+ ensure
+ if timeout && timeout_thread.alive?
+ Thread.kill(timeout_thread)
+ end
+ end
+
+ Thread.critical = true
+ while @monitor.mon_owner &&
+ @monitor.mon_owner != Thread.current
+ @monitor.mon_waiting_queue.push(Thread.current)
+ Thread.stop
+ Thread.critical = true
+ end
+ @monitor.mon_owner = Thread.current
+ @monitor.mon_count = count
+ Thread.critical = false
+ end
+
+ def wait_while
+ while yield
+ wait
+ end
+ end
+
+ def wait_until
+ until yield
+ wait
+ end
+ end
+
+ def signal
+ if @monitor.mon_owner != Thread.current
+ raise ThreadError, "current thread not owner"
+ end
+ Thread.critical = true
+ t = @waiters.shift
+ t.wakeup if t
+ Thread.critical = false
+ Thread.pass
+ end
+
+ def broadcast
+ if @monitor.mon_owner != Thread.current
+ raise ThreadError, "current thread not owner"
+ end
+ Thread.critical = true
+ for t in @waiters
+ t.wakeup
+ end
+ @waiters.clear
+ Thread.critical = false
+ Thread.pass
+ end
+
+ def count_waiters
+ return @waiters.length
+ end
+
+ private
+ def initialize(monitor)
+ @monitor = monitor
+ @waiters = []
+ end
+ end
+
+ include Accessible
+ include Initializable
+ extend Initializable
+
+ def self.extend_object(obj)
+ super(obj)
+ obj.mon_initialize
+ end
+
+ def try_mon_enter
+ result = false
+ Thread.critical = true
+ if mon_owner.nil?
+ self.mon_owner = Thread.current
+ end
+ if mon_owner == Thread.current
+ self.mon_count += 1
+ result = true
+ end
+ Thread.critical = false
+ return result
+ end
+
+ def mon_enter
+ Thread.critical = true
+ while mon_owner != nil && mon_owner != Thread.current
+ mon_entering_queue.push(Thread.current)
+ Thread.stop
+ Thread.critical = true
+ end
+ self.mon_owner = Thread.current
+ self.mon_count += 1
+ Thread.critical = false
+ end
+
+ def mon_exit
+ if mon_owner != Thread.current
+ raise ThreadError, "current thread not owner"
+ end
+ Thread.critical = true
+ self.mon_count -= 1
+ if mon_count == 0
+ self.mon_owner = nil
+ if mon_waiting_queue.empty?
+ t = mon_entering_queue.shift
+ else
+ t = mon_waiting_queue.shift
+ end
+ end
+ t.wakeup if t
+ Thread.critical = false
+ Thread.pass
+ end
+
+ def mon_synchronize
+ mon_enter
+ begin
+ yield
+ ensure
+ mon_exit
+ end
+ end
+ alias synchronize mon_synchronize
+
+ def new_cond
+ return ConditionVariable.new(self)
+ end
+
+private
+ def initialize(*args)
+ super
+ mon_initialize
+ end
+end
+
+class Monitor
+ include MonitorMixin
+ alias try_enter try_mon_enter
+ alias enter mon_enter
+ alias exit mon_exit
+ alias owner mon_owner
+end
+
+# Local variables:
+# mode: Ruby
+# tab-width: 8
+# End: