/*
* StrategyShmemSize
*
* estimate the size of shared memory used by the freelist-related structures.
*
* Note: for somewhat historical reasons, the buffer lookup hashtable size
* is also determined here.
*/
Size
StrategyShmemSize(void)
{
Size size = 0;
/* size of lookup hash table ... see comment in StrategyInitialize */
size = add_size(size, BufTableShmemSize(NBuffers + NUM_BUFFER_PARTITIONS));
/* size of the shared replacement strategy control block */
size = add_size(size, MAXALIGN(sizeof(BufferStrategyControl)));
return size;
}
/*
* StrategyShmemSize
*
* estimate the size of shared memory used by the freelist-related structures.
*
* Note: for somewhat historical reasons, the buffer lookup hashtable size
* is also determined here.
*/
Size
StrategyShmemSize(void)
{
Size size = 0;
/* size of lookup hash table */
size = add_size(size, BufTableShmemSize(NBuffers));
/* size of the shared replacement strategy control block */
size = add_size(size, MAXALIGN(sizeof(BufferStrategyControl)));
return size;
}
/*
* StrategyShmemSize
*
* estimate the size of shared memory used by the freelist-related structures.
*/
int
StrategyShmemSize(void)
{
/* A1out list can hold 50% of NBuffers, per Johnson and Shasha */
int nCDBs = NBuffers + NBuffers / 2;
int size = 0;
/* size of CDB lookup hash table */
size += BufTableShmemSize(nCDBs);
/* size of the shared replacement strategy control block */
size += MAXALIGN(sizeof(BufferStrategyControl));
/* size of the CDB directory */
size += MAXALIGN(nCDBs * sizeof(BufferStrategyCDB));
return size;
}
