Class: Cond::ThreadLocal

Inherits:
Object
  • Object
show all
Includes:
SymbolGenerator
Defined in:
lib/cond/thread_local.rb

Overview

Thread-local variable.

Class Method Summary collapse

Instance Method Summary collapse

Methods included from SymbolGenerator

gensym, recycle, track

Constructor Details

#initialize(&default) ⇒ ThreadLocal

If value is called before value= then the result of &default is used.

&default normally creates a new object, otherwise the returned object will be shared across threads.



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# File 'lib/cond/thread_local.rb', line 16

def initialize(&default)
  @name = gensym
  @accessed = gensym
  @default = default
end

Class Method Details

.accessor_module(name, subclass = self, &block) ⇒ Object 



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# File 'lib/cond/thread_local.rb', line 51

def accessor_module(name, subclass = self, &block)
  var = subclass.new(&block)
  Module.new {
    define_method(name) {
      var.value
    }
    define_method("#{name}=") { |value|
      var.value = value
    }
  }
end

.reader_module(name, subclass = self, &block) ⇒ Object 



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# File 'lib/cond/thread_local.rb', line 63

def reader_module(name, subclass = self, &block)
  accessor_module(name, subclass, &block).instance_eval {
    remove_method "#{name}="
    self
  }
end

Instance Method Details

#clear(&default) ⇒ Object

Reset to just-initialized state for all threads.



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# File 'lib/cond/thread_local.rb', line 25

def clear(&default)
  Thread.exclusive {
    @default = default
    Thread.list.each { |thread|
      thread[@accessed] = nil
      thread[@name] = nil
    }
  }
end

#value ⇒ Object 



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# File 'lib/cond/thread_local.rb', line 35

def value
  unless Thread.current[@accessed]
    if @default
      Thread.current[@name] = @default.call
    end
    Thread.current[@accessed] = true
  end
  Thread.current[@name]
end

#value=(value) ⇒ Object 



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# File 'lib/cond/thread_local.rb', line 45

def value=(value)
  Thread.current[@accessed] = true
  Thread.current[@name] = value
end