Compaq AAQ2G1FTK - page 263

Sharing Files and Locking Records
8.3 Ensuring Successful File Sharing
Legend
3Second stream is denied access to the file because the first stream intends
to write, while the second stream specifies read-only sharing.
4Second stream is denied access to the file because the second stream
intends to write, while the first stream specifies read-only sharing.
5No sharing; second will create new file version with OPEN OUTPUT.
On Tru64 UNIX, Table 8–2 shows the validand invalid OPEN ALLOWING
combinations between first and subsequent access streams. The table assumes no
file protection violations on the first stream.
Table8–2 File-Sharing Options (Tru64UNIX)
FIRST STREAM SUBSEQUENT STREAM
Open mode:
Allowing: UPDATE ALL UPDATE READERS UPDATE NONE INPUT ALL INPUT READERS INPUT NONE
UPDATE
ALL G5 2G5 2
UPDATE
READERS 6 3,4 2 G 5 2
UPDATE
NONE 1 1,3 1,2 1 1,3 1,2
INPUT
ALL GG 2GG 2
INPUT
READERS 77 2GG 2
INPUT
NONE 1 1 1,2 1 1 1,2
Legend
UPDATE OPEN EXTEND or OPENI-O
INPUT OPEN INPUT
OUTPUT OPEN OUTPUT
ALL ALLOWING ALL or ALLOWING UPDATERSor ALLOWING WRITERS
READERS ALLOWING READERS
NONE ALLOWING NO OTHERS
GSecond stream successfully opens and file sharing is granted.
1Second stream is denied access to the file because the first stream requires
exclusive access (the first stream specified NO OTHERS).
2Second stream is denied access to the file because the second stream
requires exclusive access (the second stream specified NO OTHERS).
3Second stream is denied access to the file because the first stream intends
to write, while the second stream specifies read-only sharing.
4Second stream is denied access to the file because the second stream
intends to write, while the first stream specifies read-only sharing.
5No sharing; second will create new file version with OPEN OUTPUT.
Sharing Files and Locking Records 8–11