Host Backends

Like the device system, we can also control the host system which applies to untagged, or "raw" types like thrust::host_vector::iterator, std::vector::iterators, and raw pointers. We can use this feature to parallelize Thrust algorithms on host types such as thrust::host_vector with a parallel backend like OpenMP.

The host system backend is selected via the THRUST_HOST_SYSTEM macro:

$ nvcc -Xcompiler -fopenmp -DTHRUST_HOST_SYSTEM=THRUST_HOST_SYSTEM_OMP my_program.cu -lgomp

By default, THRUST_HOST_SYSTEM is set to THRUST_HOST_SYSTEM_CPP. It can be set to any one of

• THRUST_HOST_SYSTEM_CPP
• THRUST_HOST_SYSTEM_OMP
• THRUST_HOST_SYSTEM_TBB

Currently, the implementation of all host systems' memories are interoperable.