This is the mail archive of the cygwin mailing list for the Cygwin project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: sqlite3: bug with monotone

On May 31 14:19, Warren Young wrote:
> On 5/31/2013 13:58, Warren Young wrote:
> >
> >The SQLite code prefers POSIX advisory locks, but it can fall back to
> >BSD locks if it has to.
> Just to clarify, when I say "POSIX locks" I always mean new style
> fcntl() locks.  There are no calls to lockf() in sqlite3.c.
> >I'm not sure why it doesn't just
> >blindly try the lock.
> On reflection, I'm sure it has something to do with maintaining high
> concurrency.  If it knows its near-future DB file write is going to
> get blocked, it can choose to do something else while the existing
> DB lock holders finish.
> By contrast, SQLite's flock() based locking is documented as being
> much more brute-force, resulting in much lower concurrency.

Makes sense, given that flock is not record but file locking.


Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

Problem reports:
Unsubscribe info:

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]