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From:Thimble Smith Date:July 28 1999 6:35pm
Subject:Re: Duplicated locking operation.
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At 10:12, 19990728, Scott Hess wrote:
>Just now, I noticed that if you try to aquire a lock that you already have,
>mysql first releases the lock before aquiring it.
>
>Just wanted to double-check that this is how things are _intended_ to work,
>rather than just a happy coincidence.  The documentation does not say.

The docs do say.

|`GET_LOCK(str,timeout)'
|    ...
|    A lock is released when you execute `RELEASE_LOCK()',
|    execute a new `GET_LOCK()' or the thread terminates.
|    ...
|
|        mysql> select GET_LOCK("lock1",10);
|                 -> 1
|         mysql> select GET_LOCK("lock2",10);
|                 -> 1
|         mysql> select RELEASE_LOCK("lock2");
|                  -> 1
|         mysql> select RELEASE_LOCK("lock1");
|                  -> NULL
|
|    Note that the second `RELEASE_LOCK()' call returns `NULL' because
|    the lock `"lock1"' was automatically released by the second
|    `GET_LOCK()' call.

Tim
Thread
Duplicated locking operation.Scott Hess28 Jul
  • Re: Duplicated locking operation.Thimble Smith28 Jul
    • Re: Duplicated locking operation.Paul DuBois28 Jul
  • Re: Duplicated locking operation.Scott Hess28 Jul