topic Re: Amplifier fails with fibers in Software Archive

Amplifier fails with fibers

George_Kotorlis — Tue, 12 May 2009 10:14:54 GMT

Hello,

when using Amplifier with a fiber-based application I get the assertion "stack_region_bottom > stack_region_top" and then a runtime error that terminates the process.

On Vista x64 the "stack_region_top" value will not be modified when calling "SwitchToFiber()" since it does not affect the code execution.

Is it possible to remove this assertion?

Thanks
George

Re: Amplifier fails with fibers

Vladimir_T_Intel — Tue, 12 May 2009 12:10:30 GMT

Hello George,

Is that possible to provide us with a simple test case that would reproduce the problem?

Re: Amplifier fails with fibers

George_Kotorlis — Tue, 12 May 2009 17:29:18 GMT

Here is a small example:

#include 


#define MAX_FIBERS 100


LPVOID fiber[MAX_FIBERS];


void WINAPI FiberProc(LPVOID lpv)

{

for (;;)

SwitchToFiber(fiber[(long)lpv]);

}


void main()

{

fiber[0] = ConvertThreadToFiber(0);


for (long i = 1; i < MAX_FIBERS; ++i)

fiber = CreateFiber(0, FiberProc, (void*)((i + 1) % MAX_FIBERS));


for (;;)

SwitchToFiber(fiber[1]);

}

Compile it for x64 and run it. You will get immediately the assertion.

Re: Amplifier fails with fibers

Vladimir_T_Intel — Tue, 12 May 2009 18:18:54 GMT

Thanks for the code sample, I'll check it soon.

Is that particularly x64 problem? Did you reproduce it on x32 system? Which compiler (VS version) you were using?

Re: Amplifier fails with fibers

George_Kotorlis — Tue, 12 May 2009 18:29:05 GMT

Quoting - Vladimir Tsymbal (Intel)

Thanks for the code sample, I'll check it soon.

Is that particularly x64 problem? Did you reproduce it on x32 system? Which compiler (VS version) you were using?

Yes, the problem occurs only on x64 (I tested on Vista), not on x32 where SwitchToFiber() sets the stack_top value.
The compiler I used was VS2008 Professional.

Re: Amplifier fails with fibers

Vladimir_T_Intel — Wed, 13 May 2009 11:01:19 GMT

Hello George,

I've reproduced the problem exactly on x64 system. Thanks again for submitting it.

We are going to fix it. Unfortunately, the bug fix won't be ready for the very next public release. So, we have to wait further releases.

Re: Amplifier fails with fibers

Vladimir_T_Intel — Mon, 15 Feb 2010 14:56:03 GMT

Just in case this is relevant: the bug was fixed long ago in the Amplifier Update 2. Sorry for the late notification.