Datum cfs_start_gc(PG_FUNCTION_ARGS)
{
int i = 0;
if (cfs_gc_workers == 0 && pg_atomic_test_set_flag(&cfs_state->gc_started))
{
int j;
BackgroundWorkerHandle** handles;
cfs_stop = true; /* do just one iteration */
cfs_state->max_iterations = 1;
cfs_state->n_workers = PG_GETARG_INT32(0);
handles = (BackgroundWorkerHandle**)palloc(cfs_state->n_workers*sizeof(BackgroundWorkerHandle*));
for (i = 0; i < cfs_state->n_workers; i++) {
BackgroundWorker worker;
MemSet(&worker, 0, sizeof(worker));
sprintf(worker.bgw_name, "cfs-worker-%d", i);
worker.bgw_flags = BGWORKER_SHMEM_ACCESS;
worker.bgw_start_time = BgWorkerStart_ConsistentState;
worker.bgw_restart_time = 1;
worker.bgw_main = cfs_bgworker_main;
worker.bgw_main_arg = Int32GetDatum(i);
if (!RegisterDynamicBackgroundWorker(&worker, &handles[i])) {
break;
}
}
for (j = 0; j < i; j++) {
WaitForBackgroundWorkerShutdown(handles[j]);
}
pfree(handles);
pg_atomic_clear_flag(&cfs_state->gc_started);
}
PG_RETURN_INT32(i);
}
/*
* Starts background worker that will create new partitions,
* waits till it finishes the job and returns the result (new partition oid)
*/
Oid
create_partitions_bg_worker(Oid relid, Datum value, Oid value_type, bool *crashed)
{
BackgroundWorker worker;
BackgroundWorkerHandle *worker_handle;
BgwHandleStatus status;
dsm_segment *segment;
dsm_handle segment_handle;
pid_t pid;
PartitionArgs *args;
Oid child_oid;
TypeCacheEntry *tce;
/* Create a dsm segment for the worker to pass arguments */
segment = dsm_create(sizeof(PartitionArgs), 0);
segment_handle = dsm_segment_handle(segment);
tce = lookup_type_cache(value_type, 0);
/* Fill arguments structure */
args = (PartitionArgs *) dsm_segment_address(segment);
args->dbid = MyDatabaseId;
args->relid = relid;
if (tce->typbyval)
args->value = value;
else
memcpy(&args->value, DatumGetPointer(value), sizeof(args->value));
args->by_val = tce->typbyval;
args->value_type = value_type;
args->result = 0;
/* Initialize worker struct */
worker.bgw_flags = BGWORKER_SHMEM_ACCESS |
BGWORKER_BACKEND_DATABASE_CONNECTION;
worker.bgw_start_time = BgWorkerStart_RecoveryFinished;
worker.bgw_restart_time = BGW_NEVER_RESTART;
worker.bgw_main = bg_worker_main;
worker.bgw_main_arg = Int32GetDatum(segment_handle);
worker.bgw_notify_pid = MyProcPid;
/* Start dynamic worker */
if (!RegisterDynamicBackgroundWorker(&worker, &worker_handle))
{
elog(WARNING, "Unable to create background worker for pg_pathman");
}
status = WaitForBackgroundWorkerStartup(worker_handle, &pid);
if (status == BGWH_POSTMASTER_DIED)
{
ereport(WARNING,
(errmsg("Postmaster died during the pg_pathman background worker process"),
errhint("More details may be available in the server log.")));
}
/* Wait till the worker finishes its job */
status = WaitForBackgroundWorkerShutdown(worker_handle);
*crashed = args->crashed;
child_oid = args->result;
/* Free dsm segment */
dsm_detach(segment);
return child_oid;
}
