Docs » Autodocs » dos.library » LockRecord
LockRecord -- Locks a portion of a file (V36)
success = LockRecord(fh,offset,length,mode,timeout)
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BOOL LockRecord(BPTR,ULONG,ULONG,ULONG,ULONG)
This locks a portion of a file for exclusive access. Timeout is how
long to wait in ticks (1/50 sec) for the record to be available.
Valid modes are:
REC_EXCLUSIVE
REC_EXCLUSIVE_IMMED
REC_SHARED
REC_SHARED_IMMED
For the IMMED modes, the timeout is ignored.
Record locks are tied to the filehandle used to create them. The
same filehandle can get any number of exclusive locks on the same
record, for example. These are cooperative locks, they only
affect other people calling LockRecord().
fh - File handle for which to lock the record
offset - Record start position
length - Length of record in bytes
mode - Type of lock requester
timeout - Timeout interval in ticks. 0 is legal.
success - Success or failure
In 2.0 through 2.02 (V36), LockRecord() only worked in the ramdisk.
Attempting to lock records on the disk filesystem causes a crash.
This was fixed for V37.
LockRecords(), UnLockRecord(), UnLockRecords()
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