include/lang/FIFOT.h

   1 /*
   2         SuperCollider real time audio synthesis system
   3     Copyright (c) 2002 James McCartney. All rights reserved.
   4         http://www.audiosynth.com
   5
   6     This program is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with this program; if not, write to the Free Software
  18     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
  19 */
  20 /*
  21
  22 A Fifo for sending/receiving some type of object.
  23
  24 */
  25
  26 #ifndef _FIFOT_
  27 #define _FIFOT_
  28
  29 #include "SCBase.h"
  30
  31 template <class T, int N> class FIFOT
  32 {
  33 public:
  34         FIFOT()
  35                         : mMask(N-1), mReadHead(0), mWriteHead(0)
  36                 {
  37                 }
  38         void MakeEmpty() { mReadHead = mWriteHead; }
  39         bool IsEmpty() { return mReadHead == mWriteHead; }
  40         int CanGet() {
  41                 int diff = mWriteHead - mReadHead;
  42                 return diff >= 0 ? diff : N - diff;
  43         }
  44         int CanPut() { return N-1-CanGet(); }
  45
  46         int NextPos(int inPos) { return (inPos + 1) & mMask; }
  47
  48         bool Put(const T& inItem)
  49                 {
  50                         long next = NextPos(mWriteHead);
  51                         if (next == mReadHead) return false; // fifo is full
  52                         mItems[next] = inItem;
  53                         mWriteHead = next;
  54                         return true;
  55                 }
  56
  57         bool Get(T& outItem) // get next and advance
  58                 {
  59                         if (IsEmpty()) return false;
  60                         long next = NextPos(mReadHead);
  61                         outItem = mItems[next];
  62                         mReadHead = next;
  63                         return true;
  64                 }
  65         void DebugDump()
  66                 {
  67                         post("FIFO N %d  mMask %d  mReadHead %d  mWriteHead%d\n",
  68                                 N, mMask, mReadHead, mWriteHead);
  69                 }
  70
  71 private:
  72         long mMask;
  73         volatile long mReadHead, mWriteHead;// mReclaimHead;
  74         T mItems[N];
  75 };
  76
  77 #endif