diff options
Diffstat (limited to 'lib/weakref.rb')
-rw-r--r-- | lib/weakref.rb | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/lib/weakref.rb b/lib/weakref.rb index a398ebf1fe..bc1b916619 100644 --- a/lib/weakref.rb +++ b/lib/weakref.rb @@ -1,4 +1,11 @@ -# Weak Reference class that does not bother GCing. + +require "delegate" + +# Weak Reference class that does not bother GCing. This allows the +# referenced object to be garbage collected as if nothing else is +# referring to it. Because Weakref inherits from Delegator it passes +# method calls to the object from which it was constructed, so it +# is of the same Duck Type. # # Usage: # foo = Object.new @@ -8,11 +15,9 @@ # p foo.to_s # should be same class # ObjectSpace.garbage_collect # p foo.to_s # should raise exception (recycled) - -require "delegate" - class WeakRef<Delegator + # RefError is raised if an object cannot be referenced by a WeakRef. class RefError<StandardError end @@ -41,6 +46,7 @@ class WeakRef<Delegator end } + # Create a new WeakRef from +orig+. def initialize(orig) @__id = orig.object_id printf "orig: %p\n", @__id @@ -58,6 +64,9 @@ class WeakRef<Delegator super end + # Return the object this WeakRef references. Raise + # RefError if this is impossible. The object is that + # to which method calls are delegated (see Delegator). def __getobj__ unless @@id_rev_map[self.object_id] == @__id Kernel::raise RefError, "Illegal Reference - probably recycled", Kernel::caller(2) @@ -71,6 +80,7 @@ class WeakRef<Delegator def __setobj__(obj) end + # Determine if this Weakref still refers to anything. def weakref_alive? @@id_rev_map[self.object_id] == @__id end |