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 events and monitoring these events


An event is a cl_event object that forms a medium of communication between the application and the OpenCL implementation. These event objects help in monitoring the OpenCL operations and commands. This monitoring can be of data transfer between the host and the devices and vice versa or either for the execution of the NDRange kernel. In OpenCL, an event is an object that specifies the state of a command queued into the OpenCL command queue. In OpenCL, events can be queried to notify the host that a command has completed its execution on the device. Besides this it can also be used for command synchronization. During command synchronization, a command which is queued for execution will wait on a list of events to complete before executing itself. In all the previous chapters you might have seen the last few parameters common across all the APIs starting with signature clEnqueue*.

clEnqueue*( ***, cl_uint num_events_in_wait_list,const cl_event *event_wait_list...