Hi Dean, Andrew Thanks for your replies. I will definitely get a test case and send across soon. I apologize for the half-baked and abrupt request. With Regards Vardhan -----Original Message----- From: Dean Anderson [mailto:dean@xxxxxxx] Sent: Thursday, November 06, 2008 11:31 AM To: Vardhan, Sundara (GE Infra, Energy) Cc: Andrew Haley Subject: RE: Spin locks Its nice to have code that compiles when you submit examples. One presumes the experts being queried know how to write correct code themselves; what's not clear is what kind of error you've made, or what kind of error the compiler has made. That's why a test case is necessary. In this case, I suspect that you need to spin on __sync_lock_test_and_set, and make sure that ip is initialized to zero so that some thread can get the lock. http://archives.free.net.ph/message/20080225.121911.0732aa8f.fr.html --Dean On Thu, 6 Nov 2008, Vardhan, Sundara (GE Infra, Energy) wrote: > Hi Andrew > > Thanks for the reply. Please find below a code snippet of the function > that calls the spin lock. Hope this helps > > int gstas( unsigned char *ip ) > #else > int gstas(ip) > unsigned char *ip; > #endif > /* > PURPOSE: To atomically lock a byte. > > DESCRIPTION: This routine is used to atomically lock a lock structure > which is one byte in size. > > */ > { > unsigned char gstas_orig_byte ; > int status = RT_SUCCESS ; > > gstas_orig_byte=__sync_lock_test_and_set(ip,0xff); > if ( 0 != gstas_orig_byte ) > { > status = RT_ERROR ; > } > return( status ) ; > } > > The above function is called by different processes when the product > is in runtime. This function returns error in different processes > during different run cycles. > > Hope this helps. > > With Regards > > Vardhan > > > > -----Original Message----- > From: Andrew Haley [mailto:aph@xxxxxxxxxx] > Sent: Thursday, November 06, 2008 10:03 AM > To: Vardhan, Sundara (GE Infra, Energy) > Cc: gcc ML > Subject: Re: Spin locks > > Vardhan, Sundara (GE Infra, Energy) wrote: > > > I compiled my application with gcc4.2.4 and I keep getting spin lock > > errors. The same application, when compiled with gcc 4.1.1, had no > > issues. I am using -march=pentiumpro as compile option as I am using > > __sync_lock_test_and_set() calls for spin locks. Any reason that these > > > errors should occur when application is compiled with 4.2.4? I would > > very much appreciate your help and advice. > > As usual, we really need an example test case to give you any > meaningful answers. I know that producing test cases can be > difficult, but it is almost always worthwhile. > > Andrew. > > -- Av8 Internet Prepared to pay a premium for better service? www.av8.net faster, more reliable, better service 617 344 9000
