Function SDW_rollover_to_shadow

src/jrd/sdw.cpp:731–875

bool SDW_rollover_to_shadow(thread_db* tdbb, jrd_file* file, const bool inAst)
{
/**************************************
 *
 *	S D W _ r o l l o v e r _ t o _ s h a d o w
 *
 **************************************
 *
 * Functional description
 *
 **************************************/
	SET_TDBB(tdbb);
	Database* dbb = tdbb->getDatabase();

	PageSpace* pageSpace = dbb->dbb_page_manager.findPageSpace(DB_PAGE_SPACE);
	if (file != pageSpace->file)
		return true;

	SyncLockGuard guard(&dbb->dbb_shadow_sync, SYNC_EXCLUSIVE, "SDW_rollover_to_shadow");

	SLONG sdw_update_flags = SDW_rollover;

	// If our attachment is already purged and an error comes from
	// CCH_fini(), then consider us accessing the shadow exclusively.
	// LCK_update_shadow locking isn't going to work anyway. The below
	// code must be executed for valid active attachments only.

	AutoPtr<Lock> update_lock;

	if (tdbb->getAttachment())
	{
		update_lock = FB_NEW_RPT(*tdbb->getDefaultPool(), 0)
			Lock(tdbb, sizeof(SLONG), LCK_update_shadow);
		update_lock->setKey(-1);

		LCK_lock(tdbb, update_lock, LCK_EX, LCK_NO_WAIT);

		if (update_lock->lck_physical != LCK_EX ||
			file != pageSpace->file || !SDW_lck_update(tdbb, sdw_update_flags))
		{
			LCK_release(tdbb, update_lock);
			LCK_lock(tdbb, update_lock, LCK_SR, LCK_NO_WAIT);
			while (update_lock->lck_physical != LCK_SR)
			{
				if (dbb->dbb_ast_flags & DBB_get_shadows)
					break;
				if ((file != pageSpace->file ) || !dbb->dbb_shadow_lock)
					break;
				LCK_lock(tdbb, update_lock, LCK_SR, LCK_NO_WAIT);
			}

			if (update_lock->lck_physical == LCK_SR)
				LCK_release(tdbb, update_lock);

			return true;
		}
	}
	else