thunk

3 definitions found

thunk - WordNet (r) 2.1 (2005) :

  thunk
      n 1: a dull hollow sound; "the basketball made a thunk as it hit
           the rim"

thunk - Free On-line Dictionary of Computing (26 May 2007) :

  thunk
  
     <programming> /thuhnk/ 1. "A piece of coding which provides an
     address", according to P. Z. Ingerman, who invented thunks in
     1961 as a way of binding actual parameters to their formal
     definitions in ALGOL 60 procedure calls.  If a procedure
     is called with an expression in the place of a formal parameter
     , the compiler generates a thunk which computes the
     expression and leaves the address of the result in some
     standard location.
  
     2. The term was later generalised to mean an expression,
     frozen together with its environment (variable values), for
     later evaluation if and when needed (similar to a
     "closure").  The process of unfreezing these thunks is
     called "forcing".
  
     3. A stubroutine, in an overlay programming environment,
     that loads and jumps to the correct overlay.
  
     Compare trampoline.
  
     There are a couple of onomatopoeic myths circulating about the
     origin of this term.  The most common is that it is the sound
     made by data hitting the stack; another holds that the sound
     is that of the data hitting an accumulator.  Yet another
     suggests that it is the sound of the expression being unfrozen
     at argument-evaluation time.  In fact, according to the
     inventors, it was coined after they realised (in the wee hours
     after hours of discussion) that the type of an argument in
     ALGOL 60 could be figured out in advance with a little
     compile-time thought, simplifying the evaluation machinery.
     In other words, it had "already been thought of"; thus it was
     christened a "thunk", which is "the past tense of "think" at
     two in the morning".
  
     4. (Microsoft Windows programming) universal thunk,
     generic thunk, flat thunk.
  
     [Jargon File]
  
     (1997-10-11)
  

thunk - Jargon File (4.4.4, 14 Aug 2003) :

  thunk
   /thuhnk/, n.
  
     1. [obs.]"A piece of coding which provides an address:", according to
     P. Z. Ingerman, who invented thunks in 1961 as a way of binding
  actual
     parameters to their formal definitions in Algol-60 procedure calls.
  If
     a procedure is called with an expression in the place of a formal
     parameter, the compiler generates a thunk which computes the
     expression and leaves the address of the result in some standard
     location.
  
     2. Later generalized into: an expression, frozen together with its
     environment, for later evaluation if and when needed (similar to what
     in techspeak is called a closure). The process of unfreezing these
     thunks is called forcing.
  
     3. A stubroutine, in an overlay programming environment, that loads
     and jumps to the correct overlay. Compare trampoline.
  
     4. Microsoft and IBM have both defined, in their Intel-based systems,
     a "16-bit environment" (with bletcherous segment registers and 64K
     address limits) and a "32-bit environment" (with flat addressing and
     semi-real memory management). The two environments can both be
  running
     on the same computer and OS (thanks to what is called, in the
     Microsoft world, WOW which stands for Windows On Windows). MS and IBM
     have both decided that the process of getting from 16- to 32-bit and
     vice versa is called a "thunk"; for Windows 95, there is even a tool
     THUNK.EXE called a "thunk compiler".
  
     5. A person or activity scheduled in a thunklike manner. "It occurred
     to me the other day that I am rather accurately modeled by a thunk --
     I frequently need to be forced to completion.:" -- paraphrased from a
     plan file.
  
     Historical note: There are a couple of onomatopoeic myths circulating
     about the origin of this term. The most common is that it is the
  sound
     made by data hitting the stack; another holds that the sound is that
     of the data hitting an accumulator. Yet another suggests that it is
     the sound of the expression being unfrozen at argument-evaluation
     time. In fact, according to the inventors, it was coined after they
     realized (in the wee hours after hours of discussion) that the type
  of
     an argument in Algol-60 could be figured out in advance with a little
     compile-time thought, simplifying the evaluation machinery. In other
     words, it had `already been thought of'; thus it was christened a
     thunk, which is "the past tense of `think' at two in the morning".