CPU async causing crashes on gcc 4.8.1

[FilipeMaia]

See arrayfire/arrayfire-python#75.

[pavanky]

@FilipeMaia What is the gcc version being used on the travis instance ?

[FilipeMaia]

g++-4.8 amd64 4.8.1-2ubuntu1~12.04

[pavanky]

@FilipeMaia We've noticed failures on older versions of gcc. From what I remember gcc-4.8.2 was causing failures but gcc-4.8.4 was working fine.

Is there anyway the gcc version on the travis instance can be upgraded?

[FilipeMaia]

It might be, I'll see if I can get it.

[FilipeMaia]

It could be the gcc version. I couldn't get 4.8.4, but I'm trying 4.9.2 and I have 2 runs and no seg faults yet.

[pavanky]

@FilipeMaia Let me know if it breaks, I can reopen the issue. If not we'll close it as a known problem for older versions of gcc.

[FilipeMaia]

Pretty sure it's a gcc problem. 10 build/runs and no problems with the new gcc. It would be nice to have cmake spit out a warning for such issues.

[pavanky]

@FilipeMaia Thanks for the suggestion.

@shehzan10 any chance we can have a warning based on gcc version < 4.8.4 saying that CPU async fails intermittently and ask the user to turn async off ?

[shehzan10]

Yeah we could probably do that.

[shehzan10]

I'm not entirely sure if ArrayFire built with Async on GCC >= 4.8.4 will run fine on systems with older GCC. Might need to test this one.