Function CCH_flush

src/jrd/cch.cpp:1181–1295

void CCH_flush(thread_db* tdbb, USHORT flush_flag, TraNumber tra_number)
{
/**************************************
 *
 *	C C H _ f l u s h
 *
 **************************************
 *
 * Functional description
 *	Flush all buffers.  If the release flag is set,
 *	release all locks.
 *
 **************************************/
	SET_TDBB(tdbb);
	Database* dbb = tdbb->getDatabase();

	// note that some of the code for btc_flush()
	// replicates code in the for loop
	// to minimize call overhead -- changes should be made in both places

	if (flush_flag & (FLUSH_TRAN | FLUSH_SYSTEM))
	{
		const ULONG transaction_mask = tra_number ? 1L << (tra_number & (BITS_PER_LONG - 1)) : 0;
		bool sys_only = false;
		if (!transaction_mask && (flush_flag & FLUSH_SYSTEM))
			sys_only = true;

#ifdef SUPERSERVER_V2
		BufferControl* bcb = dbb->dbb_bcb;
		//if (!dbb->dbb_wal && A && B) becomes
		//if (true && A && B) then finally (A && B)
		if (!(dbb->dbb_flags & DBB_force_write) && transaction_mask)
		{
			dbb->dbb_flush_cycle |= transaction_mask;
			if (!(bcb->bcb_flags & BCB_writer_active))
				bcb->bcb_writer_sem.release();
		}
		else
#endif
			flushDirty(tdbb, transaction_mask, sys_only);
	}
	else
		flushAll(tdbb, flush_flag);

	//
	// Check if flush needed
	//
	const int max_unflushed_writes = dbb->dbb_config->getMaxUnflushedWrites();
	const time_t max_unflushed_write_time = dbb->dbb_config->getMaxUnflushedWriteTime();
	bool max_num = (max_unflushed_writes >= 0);
	bool max_time = (max_unflushed_write_time >= 0);

	bool doFlush = false;

	PageSpace* pageSpaceID = dbb->dbb_page_manager.findPageSpace(DB_PAGE_SPACE);
	jrd_file* main_file = pageSpaceID->file;

	// Avoid flush while creating and restoring database