1.1 --- a/PrivateQueue.c	Wed Jun 22 16:55:10 2011 +0200
     1.2 +++ b/PrivateQueue.c	Wed Jun 22 18:49:17 2011 +0200
     1.3 @@ -39,18 +39,23 @@
     1.4  
     1.5  void
     1.6  enlargePrivQ( PrivQueueStruc *Q )
     1.7 - { int    oldSize, newSize;
     1.8 + { size_t    oldSize, newSize;
     1.9     void **oldStartOfData;
    1.10  
    1.11 -   oldSize           = Q->endOfData - Q->startOfData;
    1.12 +   oldSize           = Q->endOfData - Q->startOfData + 1;
    1.13     newSize           = 2 * oldSize;
    1.14     oldStartOfData = Q->startOfData;
    1.15 -   Q->startOfData = VMS__malloc( newSize * sizeof(void *) );
    1.16 -   memcpy(Q->startOfData, oldStartOfData, oldSize * sizeof(void *));
    1.17 +   Q->startOfData = VMS__malloc( newSize * sizeof(void*));
    1.18 +   //copy second half
    1.19 +   size_t secondHalfSize = Q->endOfData - Q->extractPos + 1;
    1.20 +   memcpy(Q->startOfData,Q->extractPos, secondHalfSize * sizeof(void*));
    1.21 +   //copy first half
    1.22 +   memcpy(Q->startOfData + secondHalfSize, oldStartOfData, 
    1.23 +                        (oldSize-secondHalfSize) * sizeof(void*));
    1.24     VMS__free(oldStartOfData);
    1.25     
    1.26 -   Q->extractPos  = &(Q->startOfData[0]); //side by side == empty
    1.27 -   Q->insertPos   = &(Q->startOfData[1]); // so start pos's have to be
    1.28 +   Q->extractPos  = Q->startOfData;
    1.29 +   Q->insertPos   = Q->startOfData + oldSize - 1;
    1.30     Q->endOfData   = &(Q->startOfData[newSize - 1]);
    1.31   }
    1.32  
    1.33 @@ -106,28 +111,28 @@
    1.34  void
    1.35  writePrivQ( void * in, PrivQueueStruc* Q )
    1.36   {
    1.37 -   void **startOfData = Q->startOfData;
    1.38 -   void **endOfData   = Q->endOfData;
    1.39 -   
    1.40 -   void **insertPos  = Q->insertPos;
    1.41 -   void **extractPos = Q->extractPos;
    1.42 +   while(1){
    1.43 +       void **startOfData = Q->startOfData;
    1.44 +       void **endOfData   = Q->endOfData;
    1.45  
    1.46 -tryAgain:
    1.47 -      //Full? (insert is just below extract when full)
    1.48 -   if( extractPos - insertPos != 1 &&
    1.49 -       !(insertPos == endOfData && extractPos == startOfData))
    1.50 -    { *(Q->insertPos) = in;   //insert before move
    1.51 -      if( insertPos == endOfData ) //write new pos exactly once, correctly
    1.52 -       { Q->insertPos = startOfData;
    1.53 -       }
    1.54 -      else
    1.55 -       { Q->insertPos++;
    1.56 -       }
    1.57 -      return;
    1.58 -    }
    1.59 -      //Q is full
    1.60 -   enlargePrivQ( Q );
    1.61 -   goto tryAgain;
    1.62 +       void **insertPos  = Q->insertPos;
    1.63 +       void **extractPos = Q->extractPos;
    1.64 +
    1.65 +          //Full? (insert is just below extract when full)
    1.66 +       if( extractPos - insertPos != 1 &&
    1.67 +           !(insertPos == endOfData && extractPos == startOfData))
    1.68 +        { *(Q->insertPos) = in;   //insert before move
    1.69 +          if( insertPos == endOfData ) //write new pos exactly once, correctly
    1.70 +           { Q->insertPos = startOfData;
    1.71 +           }
    1.72 +          else
    1.73 +           { Q->insertPos++;
    1.74 +           }
    1.75 +          return;
    1.76 +        }
    1.77 +          //Q is full
    1.78 +       enlargePrivQ( Q );
    1.79 +   }
    1.80   }
    1.81  
    1.82  
    1.83 @@ -164,30 +169,30 @@
    1.84  void
    1.85  pushPrivQ( void * in, PrivQueueStruc* Q )
    1.86   {
    1.87 -   void **startOfData = Q->startOfData;
    1.88 -   void **endOfData   = Q->endOfData;
    1.89 +   while(1){
    1.90 +       void **startOfData = Q->startOfData;
    1.91 +       void **endOfData   = Q->endOfData;
    1.92  
    1.93 -   void **insertPos  = Q->insertPos;
    1.94 -   void **extractPos = Q->extractPos;
    1.95 +       void **insertPos  = Q->insertPos;
    1.96 +       void **extractPos = Q->extractPos;
    1.97  
    1.98 -tryAgain:
    1.99 -      //Full? (insert is just below extract when full)
   1.100 -   if( extractPos - insertPos != 1 &&
   1.101 -       !(insertPos == endOfData && extractPos == startOfData))
   1.102 -    {    //insert -- but go backwards, inserting at read position then
   1.103 -         // move read pos backwards
   1.104 -      *(Q->extractPos) = in;
   1.105 -      if( extractPos == startOfData ) //write new pos exactly once, correctly
   1.106 -       { Q->extractPos = endOfData;   //can't overrun then fix it 'cause
   1.107 -       }                              // other thread might read bad pos
   1.108 -      else
   1.109 -       { Q->extractPos--;
   1.110 -       }
   1.111 -      return;
   1.112 -    }
   1.113 -      //Q is full
   1.114 -   enlargePrivQ( Q );
   1.115 -   goto tryAgain;
   1.116 +          //Full? (insert is just below extract when full)
   1.117 +       if( extractPos - insertPos != 1 &&
   1.118 +           !(insertPos == endOfData && extractPos == startOfData))
   1.119 +        {    //insert -- but go backwards, inserting at read position then
   1.120 +             // move read pos backwards
   1.121 +          *(Q->extractPos) = in;
   1.122 +          if( extractPos == startOfData ) //write new pos exactly once, correctly
   1.123 +           { Q->extractPos = endOfData;   //can't overrun then fix it 'cause
   1.124 +           }                              // other thread might read bad pos
   1.125 +          else
   1.126 +           { Q->extractPos--;
   1.127 +           }
   1.128 +          return;
   1.129 +        }
   1.130 +          //Q is full
   1.131 +       enlargePrivQ( Q );
   1.132 +   }
   1.133   }
   1.134  
   1.135  void