[vdr] ringbuffer broken?

[Ludwig Nussel <ludwig.nussel@gmx.de>]

Hi,

cRingBufferLinear beheaves strangely. The attached test program
creates a cRingBufferLinear of size 100 and margin 10 an then tries
to fill it completely, get everything and fill it again. I'd expect
to be able to put 100 bytes inside but that doesn't work. It fills
up to 89 (i.e. size-margin-1 does that make any sense?). After
beeing depleted and refilled it doesn't allow Get() anymore:

put 25 lost 0
put 25 lost 0
put 25 lost 0
put 14 lost 11
got 89 at 0x8077012
got 0 at (nil)
put 25 lost 0
put 25 lost 0
put 25 lost 0
put 14 lost 11
put 0 lost 25
got 0 at (nil)


Shouldn't the buffer fill up to 100? I'd expect 'margin' to only
affect Get(), i.e. block it until the specified number of bytes is
available.

cu
Ludwig

-- 
(o_  Ludwig.Nussel@gmx.de
//\  PGP Key ID: FF8135CE
V_/_ ICQ:        52166811
#include "tools.h"
#include "ringbuffer.h"

cRingBufferLinear rb(100, 10, true);

void putbuffer(int count)
{
  uchar buf[25] = {0};
  for(; count; --count)
  {
    int ret = rb.Put(buf, sizeof(buf));
    printf("put %d lost %d\n", ret, sizeof(buf)-ret);
  }
}

void consumebuffer()
{
  while(1)
  {
    int count = 0;
    uchar* p = rb.Get(count);
    printf("got %d at %p\n", count, p);
    if(!p) break;
    rb.Del(count);
  }
}

int main(void)
{
  putbuffer(4);

  consumebuffer();

  putbuffer(5);

  consumebuffer();

  return 0;
}

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