mirror of
https://github.com/ruby/ruby.git
synced 2022-11-09 12:17:21 -05:00
51e6d9061d
strings. [ruby-dev:22695] * lib/weakref.rb (WeakRef::initialize): set up @__id before calling "super". * lib/delegate.rb (Delegator::initialize): preserve singleton_method_added method [ruby-dev:22685] * lib/delegate.rb (Delegator::initialize): use Kernel::raise instead of mere raise. [ruby-dev:22681] git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@5565 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
83 lines
1.9 KiB
Ruby
83 lines
1.9 KiB
Ruby
# Weak Reference class that does not bother GCing.
|
|
#
|
|
# Usage:
|
|
# foo = Object.new
|
|
# foo = Object.new
|
|
# p foo.to_s # original's class
|
|
# foo = WeakRef.new(foo)
|
|
# p foo.to_s # should be same class
|
|
# ObjectSpace.garbage_collect
|
|
# p foo.to_s # should raise exception (recycled)
|
|
|
|
require "delegate"
|
|
|
|
class WeakRef<Delegator
|
|
|
|
class RefError<StandardError
|
|
end
|
|
|
|
@@id_map = {} # obj -> [ref,...]
|
|
@@id_rev_map = {} # ref -> obj
|
|
@@final = lambda{|id|
|
|
__old_status = Thread.critical
|
|
Thread.critical = true
|
|
begin
|
|
rids = @@id_map[id]
|
|
if rids
|
|
for rid in rids
|
|
@@id_rev_map.delete(rid)
|
|
end
|
|
@@id_map.delete(id)
|
|
end
|
|
rid = @@id_rev_map[id]
|
|
if rid
|
|
@@id_rev_map.delete(id)
|
|
@@id_map[rid].delete(id)
|
|
@@id_map.delete(rid) if @@id_map[rid].empty?
|
|
end
|
|
ensure
|
|
Thread.critical = __old_status
|
|
end
|
|
}
|
|
|
|
def initialize(orig)
|
|
@__id = orig.object_id
|
|
ObjectSpace.define_finalizer orig, @@final
|
|
ObjectSpace.define_finalizer self, @@final
|
|
__old_status = Thread.critical
|
|
begin
|
|
Thread.critical = true
|
|
@@id_map[@__id] = [] unless @@id_map[@__id]
|
|
ensure
|
|
Thread.critical = __old_status
|
|
end
|
|
@@id_map[@__id].push self.object_id
|
|
@@id_rev_map[self.object_id] = @__id
|
|
super
|
|
end
|
|
|
|
def __getobj__
|
|
unless @@id_rev_map[self.object_id] == @__id
|
|
Kernel::raise RefError, "Illegal Reference - probably recycled", Kernel::caller(2)
|
|
end
|
|
begin
|
|
ObjectSpace._id2ref(@__id)
|
|
rescue RangeError
|
|
Kernel::raise RefError, "Illegal Reference - probably recycled", Kernel::caller(2)
|
|
end
|
|
end
|
|
|
|
def weakref_alive?
|
|
@@id_rev_map[self.object_id] == @__id
|
|
end
|
|
end
|
|
|
|
if __FILE__ == $0
|
|
require 'thread'
|
|
foo = Object.new
|
|
p foo.to_s # original's class
|
|
foo = WeakRef.new(foo)
|
|
p foo.to_s # should be same class
|
|
ObjectSpace.garbage_collect
|
|
p foo.to_s # should raise exception (recycled)
|
|
end
|