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Added sync.rb from 1.9.2p290.

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commit 16be3e0a45f652554e36edd198a27aff21f94733 1 parent c12aa45
@brixen brixen authored
Showing with 307 additions and 0 deletions.
  1. +307 −0 lib/19/sync.rb
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307 lib/19/sync.rb
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+#
+# sync.rb - 2 phase lock with counter
+# $Release Version: 1.0$
+# $Revision: 27967 $
+# by Keiju ISHITSUKA(keiju@ishitsuka.com)
+#
+# --
+# Sync_m, Synchronizer_m
+# Usage:
+# obj.extend(Sync_m)
+# or
+# class Foo
+# include Sync_m
+# :
+# end
+#
+# Sync_m#sync_mode
+# Sync_m#sync_locked?, locked?
+# Sync_m#sync_shared?, shared?
+# Sync_m#sync_exclusive?, sync_exclusive?
+# Sync_m#sync_try_lock, try_lock
+# Sync_m#sync_lock, lock
+# Sync_m#sync_unlock, unlock
+#
+# Sync, Synchronizer:
+# Usage:
+# sync = Sync.new
+#
+# Sync#mode
+# Sync#locked?
+# Sync#shared?
+# Sync#exclusive?
+# Sync#try_lock(mode) -- mode = :EX, :SH, :UN
+# Sync#lock(mode) -- mode = :EX, :SH, :UN
+# Sync#unlock
+# Sync#synchronize(mode) {...}
+#
+#
+
+unless defined? Thread
+ raise "Thread not available for this ruby interpreter"
+end
+
+module Sync_m
+ RCS_ID='-$Id: sync.rb 27967 2010-05-23 08:48:44Z nobu $-'
+
+ # lock mode
+ UN = :UN
+ SH = :SH
+ EX = :EX
+
+ # exceptions
+ class Err < StandardError
+ def Err.Fail(*opt)
+ fail self, sprintf(self::Message, *opt)
+ end
+
+ class UnknownLocker < Err
+ Message = "Thread(%s) not locked."
+ def UnknownLocker.Fail(th)
+ super(th.inspect)
+ end
+ end
+
+ class LockModeFailer < Err
+ Message = "Unknown lock mode(%s)"
+ def LockModeFailer.Fail(mode)
+ if mode.id2name
+ mode = id2name
+ end
+ super(mode)
+ end
+ end
+ end
+
+ def Sync_m.define_aliases(cl)
+ cl.module_eval %q{
+ alias locked? sync_locked?
+ alias shared? sync_shared?
+ alias exclusive? sync_exclusive?
+ alias lock sync_lock
+ alias unlock sync_unlock
+ alias try_lock sync_try_lock
+ alias synchronize sync_synchronize
+ }
+ end
+
+ def Sync_m.append_features(cl)
+ super
+ # do nothing for Modules
+ # make aliases for Classes.
+ define_aliases(cl) unless cl.instance_of?(Module)
+ self
+ end
+
+ def Sync_m.extend_object(obj)
+ super
+ obj.sync_extend
+ end
+
+ def sync_extend
+ unless (defined? locked? and
+ defined? shared? and
+ defined? exclusive? and
+ defined? lock and
+ defined? unlock and
+ defined? try_lock and
+ defined? synchronize)
+ Sync_m.define_aliases(singleton_class)
+ end
+ sync_initialize
+ end
+
+ # accessing
+ def sync_locked?
+ sync_mode != UN
+ end
+
+ def sync_shared?
+ sync_mode == SH
+ end
+
+ def sync_exclusive?
+ sync_mode == EX
+ end
+
+ # locking methods.
+ def sync_try_lock(mode = EX)
+ return unlock if mode == UN
+ @sync_mutex.synchronize do
+ ret = sync_try_lock_sub(mode)
+ end
+ ret
+ end
+
+ def sync_lock(m = EX)
+ return unlock if m == UN
+
+ while true
+ @sync_mutex.synchronize do
+ if sync_try_lock_sub(m)
+ return self
+ else
+ if sync_sh_locker[Thread.current]
+ sync_upgrade_waiting.push [Thread.current, sync_sh_locker[Thread.current]]
+ sync_sh_locker.delete(Thread.current)
+ else
+ sync_waiting.push Thread.current
+ end
+ @sync_mutex.sleep
+ end
+ end
+ end
+ self
+ end
+
+ def sync_unlock(m = EX)
+ wakeup_threads = []
+ @sync_mutex.synchronize do
+ if sync_mode == UN
+ Err::UnknownLocker.Fail(Thread.current)
+ end
+
+ m = sync_mode if m == EX and sync_mode == SH
+
+ runnable = false
+ case m
+ when UN
+ Err::UnknownLocker.Fail(Thread.current)
+
+ when EX
+ if sync_ex_locker == Thread.current
+ if (self.sync_ex_count = sync_ex_count - 1) == 0
+ self.sync_ex_locker = nil
+ if sync_sh_locker.include?(Thread.current)
+ self.sync_mode = SH
+ else
+ self.sync_mode = UN
+ end
+ runnable = true
+ end
+ else
+ Err::UnknownLocker.Fail(Thread.current)
+ end
+
+ when SH
+ if (count = sync_sh_locker[Thread.current]).nil?
+ Err::UnknownLocker.Fail(Thread.current)
+ else
+ if (sync_sh_locker[Thread.current] = count - 1) == 0
+ sync_sh_locker.delete(Thread.current)
+ if sync_sh_locker.empty? and sync_ex_count == 0
+ self.sync_mode = UN
+ runnable = true
+ end
+ end
+ end
+ end
+
+ if runnable
+ if sync_upgrade_waiting.size > 0
+ th, count = sync_upgrade_waiting.shift
+ sync_sh_locker[th] = count
+ th.wakeup
+ wakeup_threads.push th
+ else
+ wait = sync_waiting
+ self.sync_waiting = []
+ for th in wait
+ th.wakeup
+ wakeup_threads.push th
+ end
+ end
+ end
+ end
+ for th in wakeup_threads
+ th.run
+ end
+ self
+ end
+
+ def sync_synchronize(mode = EX)
+ sync_lock(mode)
+ begin
+ yield
+ ensure
+ sync_unlock
+ end
+ end
+
+ attr_accessor :sync_mode
+
+ attr_accessor :sync_waiting
+ attr_accessor :sync_upgrade_waiting
+ attr_accessor :sync_sh_locker
+ attr_accessor :sync_ex_locker
+ attr_accessor :sync_ex_count
+
+ def sync_inspect
+ sync_iv = instance_variables.select{|iv| /^@sync_/ =~ iv.id2name}.collect{|iv| iv.id2name + '=' + instance_eval(iv.id2name).inspect}.join(",")
+ print "<#{self.class}.extend Sync_m: #{inspect}, <Sync_m: #{sync_iv}>"
+ end
+
+ private
+
+ def sync_initialize
+ @sync_mode = UN
+ @sync_waiting = []
+ @sync_upgrade_waiting = []
+ @sync_sh_locker = Hash.new
+ @sync_ex_locker = nil
+ @sync_ex_count = 0
+
+ @sync_mutex = Mutex.new
+ end
+
+ def initialize(*args)
+ super
+ sync_initialize
+ end
+
+ def sync_try_lock_sub(m)
+ case m
+ when SH
+ case sync_mode
+ when UN
+ self.sync_mode = m
+ sync_sh_locker[Thread.current] = 1
+ ret = true
+ when SH
+ count = 0 unless count = sync_sh_locker[Thread.current]
+ sync_sh_locker[Thread.current] = count + 1
+ ret = true
+ when EX
+ # in EX mode, lock will upgrade to EX lock
+ if sync_ex_locker == Thread.current
+ self.sync_ex_count = sync_ex_count + 1
+ ret = true
+ else
+ ret = false
+ end
+ end
+ when EX
+ if sync_mode == UN or
+ sync_mode == SH && sync_sh_locker.size == 1 && sync_sh_locker.include?(Thread.current)
+ self.sync_mode = m
+ self.sync_ex_locker = Thread.current
+ self.sync_ex_count = 1
+ ret = true
+ elsif sync_mode == EX && sync_ex_locker == Thread.current
+ self.sync_ex_count = sync_ex_count + 1
+ ret = true
+ else
+ ret = false
+ end
+ else
+ Err::LockModeFailer.Fail mode
+ end
+ return ret
+ end
+end
+Synchronizer_m = Sync_m
+
+class Sync
+ include Sync_m
+end
+Synchronizer = Sync
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