/* ----------------------------------------------------------------
* ExecSeqScanEstimate
*
* estimates the space required to serialize seqscan node.
* ----------------------------------------------------------------
*/
void
ExecSeqScanEstimate(SeqScanState *node,
ParallelContext *pcxt)
{
EState *estate = node->ss.ps.state;
node->pscan_len = heap_parallelscan_estimate(estate->es_snapshot);
shm_toc_estimate_chunk(&pcxt->estimator, node->pscan_len);
shm_toc_estimate_keys(&pcxt->estimator, 1);
}
/* ----------------------------------------------------------------
* ExecIndexOnlyScanEstimate
*
* Compute the amount of space we'll need in the parallel
* query DSM, and inform pcxt->estimator about our needs.
* ----------------------------------------------------------------
*/
void
ExecIndexOnlyScanEstimate(IndexOnlyScanState *node,
ParallelContext *pcxt)
{
EState *estate = node->ss.ps.state;
node->ioss_PscanLen = index_parallelscan_estimate(node->ioss_RelationDesc,
estate->es_snapshot);
shm_toc_estimate_chunk(&pcxt->estimator, node->ioss_PscanLen);
shm_toc_estimate_keys(&pcxt->estimator, 1);
}
/* ----------------------------------------------------------------
* ExecForeignScanEstimate
*
* Informs size of the parallel coordination information, if any
* ----------------------------------------------------------------
*/
void
ExecForeignScanEstimate(ForeignScanState *node, ParallelContext *pcxt)
{
FdwRoutine *fdwroutine = node->fdwroutine;
if (fdwroutine->EstimateDSMForeignScan)
{
node->pscan_len = fdwroutine->EstimateDSMForeignScan(node, pcxt);
shm_toc_estimate_chunk(&pcxt->estimator, node->pscan_len);
shm_toc_estimate_keys(&pcxt->estimator, 1);
}
}
void
ExecCustomScanEstimate(CustomScanState *node, ParallelContext *pcxt)
{
const CustomExecMethods *methods = node->methods;
if (methods->EstimateDSMCustomScan)
{
node->pscan_len = methods->EstimateDSMCustomScan(node, pcxt);
shm_toc_estimate_chunk(&pcxt->estimator, node->pscan_len);
shm_toc_estimate_keys(&pcxt->estimator, 1);
}
}
/* ----------------------------------------------------------------
* ExecBitmapHeapEstimate
*
* estimates the space required to serialize bitmap scan node.
* ----------------------------------------------------------------
*/
void
ExecBitmapHeapEstimate(BitmapHeapScanState *node,
ParallelContext *pcxt)
{
EState *estate = node->ss.ps.state;
node->pscan_len = add_size(offsetof(ParallelBitmapHeapState,
phs_snapshot_data),
EstimateSnapshotSpace(estate->es_snapshot));
shm_toc_estimate_chunk(&pcxt->estimator, node->pscan_len);
shm_toc_estimate_keys(&pcxt->estimator, 1);
}
/* ----------------------------------------------------------------
* ExecSortEstimate
*
* Estimate space required to propagate sort statistics.
* ----------------------------------------------------------------
*/
void
ExecSortEstimate(SortState *node, ParallelContext *pcxt)
{
Size size;
/* don't need this if not instrumenting or no workers */
if (!node->ss.ps.instrument || pcxt->nworkers == 0)
return;
size = mul_size(pcxt->nworkers, sizeof(TuplesortInstrumentation));
size = add_size(size, offsetof(SharedSortInfo, sinstrument));
shm_toc_estimate_chunk(&pcxt->estimator, size);
shm_toc_estimate_keys(&pcxt->estimator, 1);
}
/*
* Set up a dynamic shared memory segment.
*
* We set up a small control region that contains only a test_shm_mq_header,
* plus one region per message queue. There are as many message queues as
* the number of workers, plus one.
*/
static void
setup_dynamic_shared_memory(int64 queue_size, int nworkers,
dsm_segment **segp, test_shm_mq_header **hdrp,
shm_mq **outp, shm_mq **inp)
{
shm_toc_estimator e;
int i;
Size segsize;
dsm_segment *seg;
shm_toc *toc;
test_shm_mq_header *hdr;
/* Ensure a valid queue size. */
if (queue_size < 0 || ((uint64) queue_size) < shm_mq_minimum_size)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("queue size must be at least %zu bytes",
shm_mq_minimum_size)));
if (queue_size != ((Size) queue_size))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("queue size overflows size_t")));
/*
* Estimate how much shared memory we need.
*
* Because the TOC machinery may choose to insert padding of oddly-sized
* requests, we must estimate each chunk separately.
*
* We need one key to register the location of the header, and we need
* nworkers + 1 keys to track the locations of the message queues.
*/
shm_toc_initialize_estimator(&e);
shm_toc_estimate_chunk(&e, sizeof(test_shm_mq_header));
for (i = 0; i <= nworkers; ++i)
shm_toc_estimate_chunk(&e, (Size) queue_size);
shm_toc_estimate_keys(&e, 2 + nworkers);
segsize = shm_toc_estimate(&e);
/* Create the shared memory segment and establish a table of contents. */
seg = dsm_create(shm_toc_estimate(&e), 0);
toc = shm_toc_create(PG_TEST_SHM_MQ_MAGIC, dsm_segment_address(seg),
segsize);
/* Set up the header region. */
hdr = shm_toc_allocate(toc, sizeof(test_shm_mq_header));
SpinLockInit(&hdr->mutex);
hdr->workers_total = nworkers;
hdr->workers_attached = 0;
hdr->workers_ready = 0;
shm_toc_insert(toc, 0, hdr);
/* Set up one message queue per worker, plus one. */
for (i = 0; i <= nworkers; ++i)
{
shm_mq *mq;
mq = shm_mq_create(shm_toc_allocate(toc, (Size) queue_size),
(Size) queue_size);
shm_toc_insert(toc, i + 1, mq);
if (i == 0)
{
/* We send messages to the first queue. */
shm_mq_set_sender(mq, MyProc);
*outp = mq;
}
if (i == nworkers)
{
/* We receive messages from the last queue. */
shm_mq_set_receiver(mq, MyProc);
*inp = mq;
}
}
/* Return results to caller. */
*segp = seg;
*hdrp = hdr;
}