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

Getting information about cl_event


Let's understand the cl_event object in more detail. Every object in OpenCL has a mechanism to get information about itself. A user can query its associated context, its command queue, its status of execution or the type of the command it is associated with. Similar to clGetContextInfo, clGetDevicenfo, and so on. The function is defined as follows:

cl_int clGetEventInfo (cl_event event,cl_event_info param_name,size_t param_value_size,void *param_value,size_t *param_value_size_ret);

This function returns the information as requested in param_name for the event object. The following bullet list describes the objects used in the preceding code:

  • event: It specifies the cl_event object being queried.

  • param_name: It specifies the information to query and is of type cl_event_info. The following table lists out the different enumerations of cl_event_info, which can be queried and returned in param_value.

The param_value, param_value_size, and param_value_size_ret objects...