Any updates on this please? I investigated it little further and realized 
libuv relies on only Critical Section objects to synchronize threads.
I suspect there are problems with that approach.

Now if we use read and write locks as demonstrated in the code below, what 
happens is, a thread enters in a critical section then another thread is 
very likely to go ahead of it and call leave critical section.

As per Microsoft's documentation, 
"If a thread calls *LeaveCriticalSection* when it does not have ownership 
of the specified critical section object, an error occurs that may cause 
another thread using *EnterCriticalSection* 
<http://msdn.microsoft.com/en-us/library/windows/desktop/ms682608(v=vs.85).aspx>
 to wait indefinitely."


On Sunday, November 30, 2014 1:05:29 AM UTC+5:30, Ashish wrote:
>
>
> This little piece of code should keep running forever without any trouble. 
> However, when I ran it at my end it results in deadlock situation.
> I apparently can't see any reason for deadlock. Please can someone have a 
> quick look to ensure I am not doing anything in wrong order here.
> (This is on Windows XP. I am using libuv-v1.0.0. Also, I've set threadpool 
> size to 31 before running the code)
>
>
> #include <uv.h>
>
> uv_work_t gWorkT[31];
> uv_rwlock_t g_rwlLock;
> void rd_wr_locks_in_thread(uv_work_t* work_t)
> {
>     static int value = 0;
>     while(1)
>     {
>         uv_rwlock_rdlock(&g_rwlLock);
>         BOOL isvalueodd = value % 2;
>         uv_rwlock_rdunlock(&g_rwlLock);
>
>         uv_rwlock_wrlock(&g_rwlLock);
>         value ++;
>         uv_rwlock_wrunlock(&g_rwlLock);
>     }
> }
>
> void after_rd_wr_locks_in_thread(uv_work_t* work_t, int status)
> {
> }
>
> int main()
> {
>     loop = uv_default_loop();
>
>     int retval = uv_rwlock_init(&g_rwlLock);
>     if (retval < 0)
>     {
>         printf("\nError initilizing lock");
>         return -1;
>     }
>
>     for (int i=0; i<31; i++)
>     {
>         int RetVal = uv_queue_work(loop, &gWorkT[i], 
> rd_wr_locks_in_thread, after_rd_wr_locks_in_thread);
>     }
>     return uv_run(loop, UV_RUN_DEFAULT);
>
> }
>
>

-- 
You received this message because you are subscribed to the Google Groups 
"libuv" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/libuv.
For more options, visit https://groups.google.com/d/optout.

Reply via email to