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Inside Macintosh: OpenDoc Class Reference /
Part 1 - Classes and Methods / ODLinkSource


Lock

The Lock method locks this link-source object, ensuring exclusive access to its content storage unit.

ODBoolean Lock (in ODULong wait, 
                out ODLinkKey key);
wait
The time interval to wait for access to be granted.
key
If access is granted, a valid link key; otherwise an undefined, invalid key.
return value
kODTrue if access is granted, otherwise kODFalse.
DISCUSSION
To ensure thread-safe access, you must call this method to acquire a valid link key before you write the link data. This method grants exclusive access to this link-source object's content; nested calls to the Lock method deny access.

The wait parameter specifies the time you are willing to wait for access to be granted. A value of 0 means no wait and is the only value accepted on the Mac OS platform. If the wait argument is nonzero and the lock cannot be granted, the Lock method returns kODFalse immediately. Other platforms may accept other values with platform-dependent meanings.

While your part has this link-source object locked, you must pass the key returned in the key output parameter to all methods that access or modify this link-source object, such as the Clear, ContentUpdated, and GetContentStorageUnit methods. When you are finished modifying this link-source object, you must pass the key to the Unlock method to unlock the link-source object.

EXCEPTIONS
kODErrBrokenLink
Internal error; this link-source object disconnected from its destinations.
SEE ALSO
The ODLinkKey type (page 924).
The ODLinkSource::Clear method (page 376).
The ODLinkSource::ContentUpdated method (page 378).
The ODLinkSource::GetContentStorageUnit method (page 380).
The ODLinkSource::Unlock method (page 388).
"Manipulating Links" on page 380 in OpenDoc Programmer's Guide.
"Updating a Link at the Source" on page 386 in OpenDoc Programmer's Guide.


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© Apple Computer, Inc.
17 JUL 1996




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