Book Image

Python Parallel Programming Cookbook

By : Zaccone
Book Image

Python Parallel Programming Cookbook

By: Zaccone

Overview of this book

This book will teach you parallel programming techniques using examples in Python and will help you explore the many ways in which you can write code that allows more than one process to happen at once. Starting with introducing you to the world of parallel computing, it moves on to cover the fundamentals in Python. This is followed by exploring the thread-based parallelism model using the Python threading module by synchronizing threads and using locks, mutex, semaphores queues, GIL, and the thread pool. Next you will be taught about process-based parallelism where you will synchronize processes using message passing along with learning about the performance of MPI Python Modules. You will then go on to learn the asynchronous parallel programming model using the Python asyncio module along with handling exceptions. Moving on, you will discover distributed computing with Python, and learn how to install a broker, use Celery Python Module, and create a worker. You will understand anche Pycsp, the Scoop framework, and disk modules in Python. Further on, you will learnGPU programming withPython using the PyCUDA module along with evaluating performance limitations.
Table of Contents (8 chapters)
7
Index

The MapReduce operation with PyCUDA


PyCUDA provides a functionality to perform reduction operations on the GPU. This is possible with the pycuda.reduction.ReductionKernel method:

ReductionKernel(dtype_out, arguments, map_expr ,reduce_expr, 
                name,optional_parameters)  

Here, we note that:

  • dtype_out: This is the output's data type. It must be specified by the numpy.dtype data type.

  • arguments: This is a C argument list of all the parameters involved in the reduction's operation.

  • map_expr: This is a string that represents the mapping operation. Each vector in this expression must be referenced with the variable i.

  • reduce_expr: This is a string that represents the reduction operation. The operands in this expression are indicated by lowercase letters, such as a, b, c, ..., z.

  • name: This is the name associated with ReductionKernel, with which the kernel is compiled.

  • optional_parameters: These are not important in this recipe as they are the compiler's directives.

The method executes...