DIRECTORYCamelot,YggDID,YggEnvironment,YggInternal;YggLock: CEDAR DEFINITIONS = BEGINLockID: TYPE = YggInternal.LockID;LockSubID: TYPE = YggInternal.LockSubID;nullLockID: LockID = YggInternal.nullLockID;LockMode: TYPE = YggEnvironment.LockMode;MakeLockID: PROC [did: YggDID.DID] RETURNS [lock: LockID];Set: PROC [ trans: YggEnvironment.TransID, lock: LockID, mode: LockMode, wait: BOOL _ FALSE] RETURNS [granted: BOOL];ModeReleasableSet: TYPE = PACKED ARRAY LockMode OF ModeReleasable;ModeReleasable: TYPE = {no, yes} _ no;Release: PROC [trans: YggEnvironment.TransID, lock: LockID,mode: LockMode] RETURNS [released: BOOL];ReleaseTransactionLocks: PROC [trans: YggEnvironment.TransID] RETURNS [numberReleased: INT];Error: ERROR [type: ErrorType];ErrorType: TYPE = {lockUnreleasable, unknown, unknownLock};Failed: ERROR [why: YggEnvironment.LockFailure];TransAborting: ERROR;END.   j  YggLock.mesaCopyright Ó 1985, 1988 by Xerox Corporation.  All rights reserved.Last edited byKK on 18-Dec-81 13:41:01MBrown on January 21, 1983 4:43 pmTaft on September 30, 1982 3:01 pmHauser, May 20, 1985 11:10:09 am PDTBob Hagmann September 16, 1988 12:35:57 pm PDTConstruct the lock identifier for the did/segment/offsetAcquires lock, in lock mode mode, for transaction trans.  If the lock cannot immediately be aquired because a conflicting lock is already setby another transaction, and wait=FALSE, RETURNS FALSE.  If wait=TRUE, waitsuntil the lock can be acquired.! Error {lockUnreleasable, unknown};Releases a lock previously set by the same transaction with this mode.! Error {lockUnreleasable, unknown};Releases all locks previously set by this transaction.{conflict, timeout}Hauser, March 8, 1985 10:38:48 am PSTNodified, added copyright.Êè  ˜ šœ™IcodešœB™B—šœ™Jšœ™Jšœ"™"Jšœ"™"K™$K™.—J˜ šÏk	˜	Jšœ˜Jšœ˜Jšœ˜Jšœ˜J˜ J˜ —Jšœ	œ˜"˜ Jšœœ˜"Jšœœ˜(šœ,˜,J˜ —Jšœ
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