can't access certain libcudart functions with Python ctypes

Accelerated Computing CUDA CUDA Programming and Performance
1

It seems that certain CUDA functions that are ostensibly in the libcudart library are not accessible via Python ctypes. For example, cudaMalloc appears to be accessible:

[codebox]In [1]: import ctypes

In [2]: libcudart = ctypes.cdll.LoadLibrary(‘libcudart.so’)

In [3]: libcudart.cudaMalloc

Out[3]: <_FuncPtr object at 0xae46d0>[/codebox]

However, other functions like cuCtxAttach are not:

[codebox]In [4]: libcudart.cuCtxAttach

AttributeError Traceback (most recent call last)

(snip)

AttributeError: /usr/lib64/libcudart.so.3: undefined symbol: cuCtxAttach[/codebox]

Does anyone have any idea why this is so?

I’m using CUDA 3.0 and Python 2.6.4 on 64-bit Linux.

2

cuCtxAttach is a driver API function, so it will be in cuda.so, not cudart.so (which is only runtime API functions).