doc/mcc/gc/gc_operations.tex

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   5 \section{Garbage collection algorithm}
   6
   7 \subsection{Operations on the roots}
   8
   9 The $\ms{minor\_roots}$ array contains pointers to blocks in the major heap that \emph{may} contain
  10 pointers into the minor heap.  The \thmtitle{Root invariant}~\ref{invariant:roots} requires that
  11 the root bit $R$ is set in the header of each block in $\ms{minor\_roots}$.
  12
  13 The $\ms{clear\_minor\_root}$ function deletes all entries in $\ms{minor\_roots}$, clearing the root
  14 bits $R$ in the process.
  15
  16 \subsection{The mark phase}
  17
  18 The
  19
  20 \subsection{Garbage collection}
  21
  22 The garbage collector is called with five parameters:
  23
  24 \begin{enumerate}
  25 \item the process context $\ms{contextp}$,
  26 \item the number of heap bytes requested $\ms{req\_bytes}$,
  27 \item the number of free entries in the pointer table requested $\ms{req\_pointers}$,
  28 \item an array of values of the machine registers $\ms{regs}$,
  29 \item and a bitmask of indicating which registers contain pointers.
  30 \end{enumerate}
  31
  32 The $\ms{normalize}$ function converts the value of each register that contain a pointer to its
  33 corresponding index in the pointer table.  The $\ms{denormalize}$ function does the reverse.
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