Method cache_writer

src/jrd/cch.cpp:3018–3156

void BufferControl::cache_writer(BufferControl* bcb)
{
/**************************************
 *
 *	c a c h e _ w r i t e r
 *
 **************************************
 *
 * Functional description
 *	Write dirty pages to database to maintain an adequate supply of free pages.
 *
 **************************************/
	FbLocalStatus status_vector;
	Database* const dbb = bcb->bcb_database;

	try
	{
		UserId user;
		user.setUserName("Cache Writer");

		Jrd::Attachment* const attachment = Jrd::Attachment::create(dbb, nullptr);
		RefPtr<SysStableAttachment> sAtt(FB_NEW SysStableAttachment(attachment));
		attachment->setStable(sAtt);
		attachment->att_filename = dbb->dbb_filename;
		attachment->att_user = &user;

		BackgroundContextHolder tdbb(dbb, attachment, &status_vector, FB_FUNCTION);
		Jrd::Attachment::UseCountHolder use(attachment);

		try
		{
			LCK_init(tdbb, LCK_OWNER_attachment);
			PAG_header(tdbb, true);
			PAG_attachment_id(tdbb);
			TRA_init(attachment);

			Monitoring::publishAttachment(tdbb);

			sAtt->initDone();

			bcb->bcb_flags |= BCB_cache_writer;
			bcb->bcb_flags &= ~BCB_writer_start;

			// Notify our creator that we have started
			bcb->bcb_writer_init.release();

			while (bcb->bcb_flags & BCB_cache_writer)
			{
				bcb->bcb_flags |= BCB_writer_active;
#ifdef CACHE_READER
				SLONG starting_page = -1;
#endif

				if (dbb->dbb_flags & DBB_suspend_bgio)
				{
					EngineCheckout cout(tdbb, FB_FUNCTION);
					bcb->bcb_writer_sem.tryEnter(10);
					continue;