The situation that you describe could happen, but it is quite rare in practice. Usually, I call c functions that do their work and be done, such as BLAS. For s

The situation that you describe could happen, but it is quite rare in practice. Usually, I call c functions that do their work and be done, such as BLAS. For such cases, you can either manually allocate the pointers you pass to c, or temporarily disable the gc. Each thread has its own heap, so gc for one thread does not break anything in other threads