From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ross Johnson <rpj@ise.canberra.edu.au>
To: "Phil Frisbie, Jr." <phil@hawksoft.com>
Cc: "pthreads-win32@sourceware.cygnus.com" <pthreads-win32@sourceware.cygnus.com>
Subject: Re: Thread local storage problem, and fix
Date: Wed, 22 Aug 2001 22:46:00 -0000
Message-id: <3B8498BF.B7EAE71A@ise.canberra.edu.au>
References: <3B83FF1D.DDB30CB0@hawksoft.com>
X-SW-Source: 2001/msg00117.html

Hi,

I've added your change to the current CVS repository version.

Thanks.
Ross

"Phil Frisbie, Jr." wrote:
> 
> While converting the simple per thread error storage in HawkNL over to POSIX and
> native Windows thread local storage, I came across some problems. I store a
> HawkNL error code for the thread, and if it is a Winsock error I set the error
> to NL_SOCKET_ERROR so the application can retrieve the real error code. But
> Winsock errors seemed to be cleared whenever pthread_getspecific() was called.
> They were also cleared by calling the native Windows TlsGetValue().
> 
> So, I looked at the Pthreads-win32 source code for pthread_getspecific(), and
> found this:
> 
> void *
> pthread_getspecific (pthread_key_t key)
> {
>   int lasterror = GetLastError();
> 
>   void *ptr = TlsGetValue (key->key);
> 
>   SetLastError( lasterror );
> 
>   return ptr;
> }
> 
> I guess someone already found out TlsGetValue() clears out the last error, but
> they did not know it also clears out the last Winsock error. The fix is to
> change the code to:
> 
> void *
> pthread_getspecific (pthread_key_t key)
> {
>   int lasterror = GetLastError();
>   int lastWSAerror = WSAGetLastError();
> 
>   void *ptr = TlsGetValue (key->key);
> 
>   SetLastError( lasterror );
>   WSASetLastError( lastWSAerror );
> 
>   return ptr;
> }
> 
> I have added a work around to HawkNL until this gets fixed.
> 
> Phil Frisbie, Jr.
> Lead Developer, Hawk Software
> http://www.hawksoft.com

-- 
+-------------------------+---+
| Ross Johnson            |   | "Come down off the cross
| Management & Technology |___|  We can use the wood" - Tom Waits
| Building 11                 |
| University of Canberra      | eMail: rpj@ise.canberra.edu.au
| ACT    2601                 | WWW:  
http://public.ise.canberra.edu.au/~rpj/
| AUSTRALIA                   |
+-----------------------------+