vectors

rocThrust Vectors Example

Description

This simple program showcases the usage of the thrust::device_vector and the thrust::host_vector templates.

Application flow

1. A thrust::host_vector<int> is instantiated, its elements are set one-by-one, and the vector is printed to the standard output.
2. The host_vector is resized and it is printed again to the standard output.
3. A thrust::device_vector<int> is instantiated with the aforementioned host_vector. The contents are copied to the device.
4. The device_vector's elements are modified from host code, and it is printed to the standard output.

Key APIs and Concepts

• Thrust's device and host vectors implement RAII-style ownership over device and host memory pointers (similarly to std::vector). The instances are aware of the requested element count, allocate the required amount of memory, and free it upon destruction. When resized, the memory is reallocated if needed.
• Additionally, using device_vector and host_vector simplifies the transfers between device and host memory to a copy assignment.
• It is suggested that developers use device_vector and host_vector instead of explicit invocations to malloc and free functions.

Demonstrated API Calls

rocThrust

• thrust::host_vector::host_vector
• thrust::host_vector::~host_vector
• thrust::host_vector::operator[]
• thrust::host_vector::resize()
• thrust::device_vector::device_vector
• thrust::device_vector::~device_vector
• thrust::device_vector::operator[]