- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Hello all;
I have loolked at the Distributed Reader-Writer Mutex by Dmitry Vyukov, look at
http://www.1024cores.net/home/lock-free-algorithms/reader-writer-problem/distributed-reader-writer-mutex
and i have looked at it and i think there is a problem with this method, cause look
at the write lock function:
int distr_rw_mutex_wrlock (distr_rw_mutex_t* mtx)
{
int i;
for (i = 0; i != mtx->proc_count; i += 1)
pthread_rwlock_wrlock(&mtx->cell.mtx);
return 0;
}
What is wrong with it ? suppose two or more writers wants to lock this distributed rwlock
there is a possibility of a deadlock.
So i think you have to use a critical section around the for loop to be able to lock
all the rwlocks at the same time to avoid the deadlock problem..
Am i correct or not ?
Thank you,
Amine Moulay Ramdane.
Link Copied
4 Replies
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
I wrote:
> So i think you have to use a critical section around the for loop to
be able
> to lock
> all the rwlocks at the same time to avoid the deadlock problem..
> to lock
> all the rwlocks at the same time to avoid the deadlock problem..
I mean you have to use a critical section around the for loop to be
able
to lock all the rwlocks atomicly to avoid the deadlock problem..
to lock all the rwlocks atomicly to avoid the deadlock problem..
Thank you,
Amine Moulay Ramdane.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Sorry for my english: i mean atomically.
Thank you,
Amine Moulay Ramdne.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Patricia Shanahan wrote:
> The text explanation on the referenced web page says 'No
additional
> synchronization between writers is required, writers acquire the mutexes
> in the same order (from 0 to P-1), so ownership over mutex 0 basically
> determines who is the "current" writer (all other potential writers are
> parked on mutex 0).'
> synchronization between writers is required, writers acquire the mutexes
> in the same order (from 0 to P-1), so ownership over mutex 0 basically
> determines who is the "current" writer (all other potential writers are
> parked on mutex 0).'
You are absolutly right.
Thank you,
Amine Moulay Ramdane.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Patricia Shanahan wrote:
> The text explanation on the referenced web page says 'No
additional
> synchronization between writers is required, writers acquire the mutexes
> in the same order (from 0 to P-1), so ownership over mutex 0 basically
> determines who is the "current" writer (all other potential writers are
> parked on mutex 0).'
> synchronization between writers is required, writers acquire the mutexes
> in the same order (from 0 to P-1), so ownership over mutex 0 basically
> determines who is the "current" writer (all other potential writers are
> parked on mutex 0).'
You are absolutly right.
Thank you,
Amine Moulay Ramdane.
![](/skins/images/D3C0B914909A6564BBB97F4AD1ED1973/responsive_peak/images/icon_anonymous_message.png)
Reply
Topic Options
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page