Function write_buffer

src/jrd/cch.cpp:4714–4860

static int write_buffer(thread_db* tdbb,
						BufferDesc* bdb,
						const PageNumber page,
						const bool write_thru,
						FbStatusVector* const status, const bool write_this_page)
{
/**************************************
 *
 *	w r i t e _ b u f f e r
 *
 **************************************
 *
 * Functional description
 *	Write a dirty buffer.  This may recurse due to
 *	precedence problems.
 *
 * input:  write_this_page
 *		= true if the input page needs to be written
 *			before returning.  (normal case)
 *		= false if the input page is being written
 *			because of precedence.  Only write
 *			one page and return so that the caller
 *			can re-establish the need to write this
 *			page.
 *
 * return: 0 = Write failed.
 *         1 = Page is written.  Page was written by this
 *     		call, or was written by someone else, or the
 *		cache buffer is already reassigned.
 *	   2 = Only possible if write_this_page is false.
 *		This input page is not written.  One
 *		page higher in precedence is written
 *		though.  Probable action: re-establich the
 * 		need to write this page and retry write.
 *
 **************************************/
	SET_TDBB(tdbb);
#ifdef SUPERSERVER_V2
	Database* const dbb = tdbb->getDatabase();
#endif

	bdb->lockIO(tdbb);
	if (bdb->bdb_page != page)
	{
		bdb->unLockIO(tdbb);
		return 1;
	}

	if ((bdb->bdb_flags & BDB_marked) && !(bdb->bdb_flags & BDB_faked))
		BUGCHECK(217);	// msg 217 buffer marked for update

	if (!(bdb->bdb_flags & BDB_dirty) && !(write_thru && bdb->bdb_flags & BDB_db_dirty))
	{
		bdb->unLockIO(tdbb);
		clear_precedence(tdbb, bdb);
		return 1;
	}