Function GetSingleProcBlockerStatusData

src/backend/storage/lmgr/lock.c:4451–4537

Accumulate data about one possibly-blocked proc for GetBlockerStatusData */

/* Accumulate data about one possibly-blocked proc for GetBlockerStatusData */
static void
GetSingleProcBlockerStatusData(PGPROC *blocked_proc, BlockedProcsData *data)
{
	LOCK	   *theLock = blocked_proc->waitLock;
	BlockedProcData *bproc;
	SHM_QUEUE  *procLocks;
	PROCLOCK   *proclock;
	PROC_QUEUE *waitQueue;
	PGPROC	   *proc;
	int			queue_size;
	int			i;

	/* Nothing to do if this proc is not blocked */
	if (theLock == NULL)
		return;

	/* Set up a procs[] element */
	bproc = &data->procs[data->nprocs++];
	bproc->pid = blocked_proc->pid;
	bproc->first_lock = data->nlocks;
	bproc->first_waiter = data->npids;

	/*
	 * We may ignore the proc's fast-path arrays, since nothing in those could
	 * be related to a contended lock.
	 */

	/* Collect all PROCLOCKs associated with theLock */
	procLocks = &(theLock->procLocks);
	proclock = (PROCLOCK *) SHMQueueNext(procLocks, procLocks,
										 offsetof(PROCLOCK, lockLink));
	while (proclock)
	{
		PGPROC	   *proc = proclock->tag.myProc;
		LOCK	   *lock = proclock->tag.myLock;
		LockInstanceData *instance;

		if (data->nlocks >= data->maxlocks)
		{
			data->maxlocks += MaxBackends;
			data->locks = (LockInstanceData *)
				repalloc(data->locks, sizeof(LockInstanceData) * data->maxlocks);
		}

		instance = &data->locks[data->nlocks];
		memcpy(&instance->locktag, &lock->tag, sizeof(LOCKTAG));
		instance->holdMask = proclock->holdMask;
		if (proc->waitLock == lock)
			instance->waitLockMode = proc->waitLockMode;
		else
			instance->waitLockMode = NoLock;
		instance->backend = proc->backendId;
		instance->lxid = proc->lxid;
		instance->pid = proc->pid;
		instance->leaderPid = proclock->groupLeader->pid;
		instance->fastpath = false;
		data->nlocks++;