Size
table_block_parallelscan_initialize(Relation rel, ParallelTableScanDesc pscan)
{
ParallelBlockTableScanDesc bpscan = (ParallelBlockTableScanDesc) pscan;
bpscan->base.phs_relid = RelationGetRelid(rel);
bpscan->phs_nblocks = RelationGetNumberOfBlocks(rel);
/* compare phs_syncscan initialization to similar logic in initscan */
bpscan->base.phs_syncscan = synchronize_seqscans &&
!RelationUsesLocalBuffers(rel) &&
bpscan->phs_nblocks > NBuffers / 4;
SpinLockInit(&bpscan->phs_mutex);
bpscan->phs_startblock = InvalidBlockNumber;
pg_atomic_init_u64(&bpscan->phs_nallocated, 0);
return sizeof(ParallelBlockTableScanDescData);
}
static void
test_atomic_uint64(void)
{
pg_atomic_uint64 var;
uint64 expected;
int i;
pg_atomic_init_u64(&var, 0);
if (pg_atomic_read_u64(&var) != 0)
elog(ERROR, "atomic_read_u64() #1 wrong");
pg_atomic_write_u64(&var, 3);
if (pg_atomic_read_u64(&var) != 3)
elog(ERROR, "atomic_read_u64() #2 wrong");
if (pg_atomic_fetch_add_u64(&var, 1) != 3)
elog(ERROR, "atomic_fetch_add_u64() #1 wrong");
if (pg_atomic_fetch_sub_u64(&var, 1) != 4)
elog(ERROR, "atomic_fetch_sub_u64() #1 wrong");
if (pg_atomic_sub_fetch_u64(&var, 3) != 0)
elog(ERROR, "atomic_sub_fetch_u64() #1 wrong");
if (pg_atomic_add_fetch_u64(&var, 10) != 10)
elog(ERROR, "atomic_add_fetch_u64() #1 wrong");
if (pg_atomic_exchange_u64(&var, 5) != 10)
elog(ERROR, "pg_atomic_exchange_u64() #1 wrong");
if (pg_atomic_exchange_u64(&var, 0) != 5)
elog(ERROR, "pg_atomic_exchange_u64() #0 wrong");
/* fail exchange because of old expected */
expected = 10;
if (pg_atomic_compare_exchange_u64(&var, &expected, 1))
elog(ERROR, "atomic_compare_exchange_u64() changed value spuriously");
/* CAS is allowed to fail due to interrupts, try a couple of times */
for (i = 0; i < 100; i++)
{
expected = 0;
if (!pg_atomic_compare_exchange_u64(&var, &expected, 1))
break;
}
if (i == 100)
elog(ERROR, "atomic_compare_exchange_u64() never succeeded");
if (pg_atomic_read_u64(&var) != 1)
elog(ERROR, "atomic_compare_exchange_u64() didn't set value properly");
pg_atomic_write_u64(&var, 0);
/* try setting flagbits */
if (pg_atomic_fetch_or_u64(&var, 1) & 1)
elog(ERROR, "pg_atomic_fetch_or_u64() #1 wrong");
if (!(pg_atomic_fetch_or_u64(&var, 2) & 1))
elog(ERROR, "pg_atomic_fetch_or_u64() #2 wrong");
if (pg_atomic_read_u64(&var) != 3)
elog(ERROR, "invalid result after pg_atomic_fetch_or_u64()");
/* try clearing flagbits */
if ((pg_atomic_fetch_and_u64(&var, ~2) & 3) != 3)
elog(ERROR, "pg_atomic_fetch_and_u64() #1 wrong");
if (pg_atomic_fetch_and_u64(&var, ~1) != 1)
elog(ERROR, "pg_atomic_fetch_and_u64() #2 wrong: is " UINT64_FORMAT,
pg_atomic_read_u64(&var));
/* no bits set anymore */
if (pg_atomic_fetch_and_u64(&var, ~0) != 0)
elog(ERROR, "pg_atomic_fetch_and_u64() #3 wrong");
}
/*
* BackendManagementShmemInit is the callback that is to be called on shared
* memory startup hook. The function sets up the necessary shared memory
* segment for the backend manager.
*/
static void
BackendManagementShmemInit(void)
{
bool alreadyInitialized = false;
/* we may update the shmem, acquire lock exclusively */
LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
backendManagementShmemData =
(BackendManagementShmemData *) ShmemInitStruct(
"Backend Management Shmem",
BackendManagementShmemSize(),
&alreadyInitialized);
if (!alreadyInitialized)
{
int backendIndex = 0;
char *trancheName = "Backend Management Tranche";
#if (PG_VERSION_NUM >= 100000)
NamedLWLockTranche *namedLockTranche =
&backendManagementShmemData->namedLockTranche;
#else
LWLockTranche *lockTranche = &backendManagementShmemData->lockTranche;
#endif
/* start by zeroing out all the memory */
memset(backendManagementShmemData, 0,
BackendManagementShmemSize());
#if (PG_VERSION_NUM >= 100000)
namedLockTranche->trancheId = LWLockNewTrancheId();
LWLockRegisterTranche(namedLockTranche->trancheId, trancheName);
LWLockInitialize(&backendManagementShmemData->lock,
namedLockTranche->trancheId);
#else
backendManagementShmemData->trancheId = LWLockNewTrancheId();
/* we only need a single lock */
lockTranche->array_base = &backendManagementShmemData->lock;
lockTranche->array_stride = sizeof(LWLock);
lockTranche->name = trancheName;
LWLockRegisterTranche(backendManagementShmemData->trancheId, lockTranche);
LWLockInitialize(&backendManagementShmemData->lock,
backendManagementShmemData->trancheId);
#endif
/* start the distributed transaction ids from 1 */
pg_atomic_init_u64(&backendManagementShmemData->nextTransactionNumber, 1);
/*
* We need to init per backend's spinlock before any backend
* starts its execution.
*/
for (backendIndex = 0; backendIndex < MaxBackends; ++backendIndex)
{
SpinLockInit(&backendManagementShmemData->backends[backendIndex].mutex);
}
}
LWLockRelease(AddinShmemInitLock);
if (prev_shmem_startup_hook != NULL)
{
prev_shmem_startup_hook();
}
}
