Book Image

OpenCL Programming by Example

Book Image

OpenCL Programming by Example

Overview of this book

Research in parallel programming has been a mainstream topic for a decade, and will continue to be so for many decades to come. Many parallel programming standards and frameworks exist, but only take into account one type of hardware architecture. Today computing platforms come with many heterogeneous devices. OpenCL provides royalty free standard to program heterogeneous hardware. This guide offers you a compact coverage of all the major topics of OpenCL programming. It explains optimization techniques and strategies in-depth, using illustrative examples and also provides case studies from diverse fields. Beginners and advanced application developers will find this book very useful. Beginning with the discussion of the OpenCL models, this book explores their architectural view, programming interfaces and primitives. It slowly demystifies the process of identifying the data and task parallelism in diverse algorithms. It presents examples from different domains to show how the problems within different domains can be solved more efficiently using OpenCL. You will learn about parallel sorting, histogram generation, JPEG compression, linear and parabolic regression and k-nearest neighborhood, a clustering algorithm in pattern recognition. Following on from this, optimization strategies are explained with matrix multiplication examples. You will also learn how to do an interoperation of OpenGL and OpenCL. "OpenCL Programming by Example" explains OpenCL in the simplest possible language, which beginners will find it easy to understand. Developers and programmers from different domains who want to achieve acceleration for their applications will find this book very useful.
Table of Contents (18 chapters)
OpenCL Programming by Example
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

OpenCL event synchronization models


In OpenCL, the command queues are used to submit work to a device and each work or task can be associated with an event object. The queuing of the command takes place in-order or as the program flow occurs. But when the commands are dequeued the tasks can execute in-order or out-of-order. In ordered execution one does not need an explicit synchronization that means the next command is executed only when the previous one has completed its execution. But in the case of out-of-order execution, there is a need for synchronization. The OpenCL provides this framework for synchronization. Synchronization is needed in the case of multiple command queues also. The user might want to divide his work load across multiple devices, and the running dynamics of each device may be different. So it becomes necessary to do synchronization. Let us discuss some models for queuing commands in OpenCL.

No synchronization needed

This is the simplest form of OpenCL programming....