cudaStreamSynchronize vs CudaDeviceSynchronize vs cudaThreadSynchronize CUDA中的屏障同步

cudaStreamSynchronize
vs CudaDeviceSynchronize vs cudaThreadSynchronize

These are all barriers. Barriers prevent code execution beyond the barrier until some condition is met.

cudaDeviceSynchronize() halts
execution in the CPU/host thread (that the cudaDeviceSynchronize was issued in) until the GPU has finished processing all previously requested cuda tasks (kernels, data copies, etc.)

cudaThreadSynchronize() as
you've discovered, is just a deprecated version of

cudaDeviceSynchronize

.
Deprecated just means that it still works for now, but it's recommended not to use it (use cudaDeviceSynchronize instead) and in the future, it may become unsupported. But

cudaThreadSynchronize

()
and

cudaDeviceSynchronize

()
are basically identical.

cudaStreamSynchronize() is
similar to the above two functions, but it prevents further execution in the CPU host thread until the GPU has finished processing all previously requested cuda tasks that
were issued in the referenced stream. So

cudaStreamSynchronize

()
takes a stream id as it's only parameter. cuda tasks issued in other streams may or may not be complete when CPU code execution continues beyond this barrier.