PTHREAD_MUTEX_DEFAULT different for cygwin v.s. linux.

Peter Rehley peter@rehley.net
Thu Jun 9 21:25:00 GMT 2005


On Jun 9, 2005, at 8:57 AM, Christopher Faylor wrote:

> On Wed, Jun 08, 2005 at 03:29:46PM -0700, Peter Rehley wrote:
>> On Jun 8, 2005, at 2:59 PM, Thomas E. Zerucha wrote:
>>
>>> I have a problem similar to that of:
>>>
>>> http://sourceware.org/ml/cygwin/2005-05/msg01400.html
>>>
>>> I have an old system that I'm trying to port that uses pthreads, but
>>> doesn't set the attribute, and a non-owner thread will destroy the
>>> thread in a deallocate routine, but this won't happen (it won't
>>> actually destroy the thread).
>>>
>>> The problem is that (in pthread.h) PTHREAD_MUTEX_DEFAULT is .._NORMAL
>>> on linux, the system was originally written for.  It works but
>>> eventually dies when it runs out of threads or mutexes or something
>>> since it can't recycle.  PTHREAD_MUTEX_DEFAULT is .._ERRORCHECK on
>>> cygwin.
>>>
>>> It would be painful to add a whole section to create an attribute
>>> structure just to set this to be the same as linux.
>>
>> If you look at the test case you will see a line that says
>> mutex=PTHREAD_MUTEX_INITIALIZER;
>>
>> This causes the program to use the default (ERRORCHECK) mutex.  To get
>> a normal mutex, you can use mutex=PTHREAD_NORMAL_MUTEX_INITIALIZER_NP;
>>
>> However, in the test case when NORMAL is used, the mutex never gets
>> unlocked because the signal SIG_CHLD doesn't get to the parent.
>
> FWIW, I've changed the default for PTHREAD_MUTEX_INITIALIZER to
> PTHREAD_NORMAL_MUTEX_INITIALIZER_NP in CVS.  Last night I also tried to
> implement handling for interrupting mutexes based on Corinna's
> explanation of what your patch did.
>
Shouldn't PTHREAD_MUTEX_DEFAULT be PTHREAD_MUTEX_NORMAL?

> Both of these changes are in the current snapshot.
And the pthread_mutex_lock is still waiting forever...doesn't process 
the signal.  Looking at the code I think that the pthread_mutex::_lock 
function should be using the cancelable_wait routine in place of the 
WaitForSingleObject.


>
> cgf
>
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>
Enjoy,
Peter
-------------------------------
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