Hi, > When you commented out the INCREF on the datat, did you also comment > out PyArray_Set_BASE? If not, that may have been causing the problem. > If you set the base without INCREF'ing the data, then numpy will > DECREF that data when python goes to gc the array. Now you've lost a > reference, and if it went to zero, python then tries to gc an object > that's still in scope.
Ah - yes - you are right. Commenting out the Base line removes the segfault. Just for my own sake I'm going to summarize, often repeating what you've said above: Given this line: arr = PyArray_NewFromDescr(&PyArray_Type, 1, dt, 1, &size, NULL, <void *>ptr, 0, <object>NULL) The array now points into the memory at `ptr`. The memory at `ptr` needs to stay around for as long as I want to use the array. In my example, as you've pointed out, I passed in `data`, from which I got `ptr`, and `data` therefore exists in the surrounding scope, and will support `ptr`, at least in the surrounding scope. When I add: PyArray_Set_BASE(arr, data) this _borrows_ a reference to the object `data`, and stores it in the array. When the array is garbage collected, `data` is DECREF'd so that `data` in the surrounding scope has been busted by the DECREF on array garbage collection. However, if I had created `data` in the original 'make_1d_array` function, rather than passing it in, I'd need to do as I have done, which is INCREF the data so that it does not get garbage collected when I leave the function scope, and PyArray_Set_BASE so that the array knows to DECREF `data` and allow garbage collection when it goes out of scope. I don't know whether that is clear, but it was my best shot... Cheers, Matthew _______________________________________________ Cython-dev mailing list Cython-dev@codespeak.net http://codespeak.net/mailman/listinfo/cython-dev
