MMProgRef - RIFF Compound Files and Elements - Sharing and Access

Reprint Courtesy of International Business Machines Corporation, © International Business Machines Corporation

Multimedia Programming Reference

Introduction What's New... MCI Functions High-Level Macro Service Functions Subsystem Messages Notification Messages MCI Command Messages String Commands Memory Playlist Commands Graphic Button Control Secondary Window Functions MMIO Functions MMIO Messages CODEC Messages DIVE Functions Real-Time MIDI Functions SPI Functions Data Stream State Table SMH Messages DDCMD Messages VSD Commands SHD Messages SHC Messages Data Types Types of MIDI Messages Multimedia Specification Overview Resource Interchange File Format Multimedia File Formats RIFF Compound Files and Elements - Sharing and Access Return Codes Notices Glossary

The following tables show the relationship between sharing and accessing RIFF compound files (CF) and elements within those files, both within the current process and between processes.

Access and Sharing Modes

An A indicates that the function is allowed. Both the access and sharing values must be A for the open to work. For example, in the CF Open - CF Open of the same process, if the first CF Open is RO - DW, then the next CF Open must be RO - DW. Any access other than RO fails. Any sharing other than DW also will fail.

Access Modes

• RO - READ ONLY
• WO - WRITE ONLY
• RW - READ and WRITE

Sharing Modes

• DR - DENY READ
• DW - DENY WRITE
• DN - DENY NONE
• EX - EXCLUSIVE (DENY ALL)

Element Opened Again (Any Process)

Element Opened	Access			Sharing
	RO	WO	RW	DR	DW	DN	EX
RO - DR	X	A	X	X	A	A	X
RO - DW	A	X	X	X	A	A	X
RO - DN	A	A	A	X	A	A	X
RO - EX	X	X	X	X	X	X	X
RW - DR	X	A	X	X	X	A	X
RW - DW	A	X	X	X	X	A	X
RW - DN	A	A	A	X	X	A	X
RW - EX	X	X	X	X	X	X	X
RO - DR	X	A	X	A	X	A	X
RO - DW	A	X	X	A	X	A	X
RO - DN	A	A	A	A	X	A	X
RO - EX	X	X	X	X	X	X	X

Elements Opened (Same Process)

CF Opened	Access			Sharing
	RO	WO	RW	DR	DW	DN	EX
RO - DR	A	X	X	A	A	A	A
RO - DW	A	X	X	A	A	A	A
RO - DN	A	X	X	A	A	A	A
RO - EX	A	X	X	A	A	A	A
RW - DR	A	A	A	A	A	A	A
RW - DW	A	A	A	A	A	A	A
RW - DN	A	A	A	A	A	A	A
RW - EX	A	A	A	A	A	A	A
RO - DR	X	A	X	A	A	A	A
RO - DW	X	A	X	A	A	A	A
RO - DN	X	A	X	A	A	A	A
RO - EX	X	A	X	A	A	A	A

Fully Qualified Element Open

CF Opened	Access			Sharing
	RO	WO	RW	DR	DW	DN	EX
RW - DN	A	A	A	A	A	A	A

CF Opened Again (Same Process)

CF Opened	Access			Sharing
	RO	WO	RW	DR	DW	DN	EX
RO - DR	X	X	X	X	X	X	X
RO - DW	A	X	X	X	A	X	X
RO - DN	A	X	X	X	X	A	X
RO - EX	X	X	X	X	X	X	X
RW - DR	X	X	X	X	X	X	X
RW - DW	X	X	X	X	X	X	X
RW - DN	X	X	A	X	X	A	X
RW - EX	X	X	X	X	X	X	X
RO - DR	X	A	X	A	X	X	X
RO - DW	X	X	X	X	X	X	X
RO - DN	X	A	X	X	X	A	X
RO - EX	X	X	X	X	X	X	X

Element Opened (Different Process)

CF Opened	Access			Sharing
	RO	WO	RW	DR	DW	DN	EX
RO - DR	X	A	X	X	A	A	X
RO - DW	A	X	X	X	A	A	X
RO - DN	A	A	A	X	X	A	X
RO - EX	X	X	X	X	X	X	X
RW - DR	X	A	X	X	X	A	X
RW - DW	A	X	X	X	X	A	X
RW - DN	A	A	A	X	X	A	X
RW - EX	X	X	X	X	X	X	X
RO - DR	X	A	X	A	X	A	X
RO - DW	A	X	X	A	X	A	X
RO - DN	A	A	A	X	X	A	X
RO - EX	X	X	X	X	X	X	X

CF Opened Again (Different Process)

CF Opened	Access			Sharing
	RO	WO	RW	DR	DW	DN	EX
RO - DR	X	A	X	X	A	A	X
RO - DW	A	X	X	X	A	A	X
RO - DN	A	A	A	X	A	A	X
RO - EX	X	X	X	X	X	X	X
RW - DR	X	A	X	X	X	A	X
RW - DW	A	X	X	X	X	A	X
RW - DN	A	A	A	X	X	A	X
RW - EX	X	X	X	X	X	X	X
RO - DR	X	A	X	A	X	A	X
RO - DW	A	X	X	A	X	A	X
RO - DN	A	A	A	A	X	A	X
RO - EX	X	X	X	X	X	X	X