NAME

       clGetDeviceIDs - Obtain the list of devices available on a platform.

       cl_int clGetDeviceIDs(cl_platform_id platform, cl_device_type device_type,
                             cl_uint num_entries, cl_device_id *devices, cl_uint *num_devices);

PARAMETERS

       platform
           Refers to the platform ID returned by clGetPlatformIDs(3clc) or can be NULL. If
           platform is NULL, the behavior is implementation-defined.

       device_type
           A bitfield that identifies the type of OpenCL device. The device_type can be used to
           query specific OpenCL devices or all OpenCL devices available. The valid values for
           device_type are specified in the following table.

           ┌───────────────────────────┬──────────────────────────────────┐
           │cl_device_type             │ Description                      │
           ├───────────────────────────┼──────────────────────────────────┤
           │CL_DEVICE_TYPE_CPU         │ An OpenCL device that is the     │
           │                           │ host processor. The host         │
           │                           │ processor runs the OpenCL        │
           │                           │ implementations and is a single  │
           │                           │ or multi-core CPU.               │
           ├───────────────────────────┼──────────────────────────────────┤
           │CL_DEVICE_TYPE_GPU         │ An OpenCL device that is a GPU.  │
           │                           │ By this we mean that the device  │
           │                           │ can also be used to accelerate a │
           │                           │ 3D API such as OpenGL or         │
           │                           │ DirectX.                         │
           ├───────────────────────────┼──────────────────────────────────┤
           │CL_DEVICE_TYPE_ACCELERATOR │ Dedicated OpenCL accelerators    │
           │                           │ (for example the IBM CELL        │
           │                           │ Blade). These devices            │
           │                           │ communicate with the host        │
           │                           │ processor using a peripheral     │
           │                           │ interconnect such as PCIe.       │
           ├───────────────────────────┼──────────────────────────────────┤
           │CL_DEVICE_TYPE_CUSTOM      │ Dedicated accelerators that do   │
           │                           │ not support programs written in  │
           │                           │ OpenCL C.                        │
           ├───────────────────────────┼──────────────────────────────────┤
           │CL_DEVICE_TYPE_DEFAULT     │ The default OpenCL device in the │
           │                           │ system. The default device       │
           │                           │ cannot be a                      │
           │                           │ CL_DEVICE_TYPE_CUSTOM device.    │
           ├───────────────────────────┼──────────────────────────────────┤
           │CL_DEVICE_TYPE_ALL         │ All OpenCL devices available in  │
           │                           │ the system except                │
           │                           │ CL_DEVICE_TYPE_CUSTOM devices.   │
           └───────────────────────────┴──────────────────────────────────┘

       num_entries
           The number of cl_device_id entries that can be added to devices. If devices is not
           NULL, the num_entries must be greater than zero.

       devices
           A list of OpenCL devices found. The cl_device_id values returned in devices can be
           used to identify a specific OpenCL device. If devices argument is NULL, this argument
           is ignored. The number of OpenCL devices returned is the mininum of the value
           specified by num_entries or the number of OpenCL devices whose type matches
           device_type.

       num_devices
           The number of OpenCL devices available that match device_type. If num_devices is NULL,
           this argument is ignored.

NOTES

       clGetDeviceIDs may return all or a subset of the actual physical devices present in the
       platform and that match device_type.

ERRORS

       clGetDeviceIDs returns CL_SUCCESS if the function is executed successfully. Otherwise it
       returns one of the following:

       •   CL_INVALID_PLATFORM if platform is not a valid platform.

       •   CL_INVALID_DEVICE_TYPE if device_type is not a valid value.

       •   CL_INVALID_VALUE if num_entries is equal to zero and devices is not NULL or if both
           num_devices and devices are NULL.

       •   CL_DEVICE_NOT_FOUND if no OpenCL devices that matched device_type were found.

       •   CL_OUT_OF_RESOURCES if there is a failure to allocate resources required by the OpenCL
           implementation on the device.

       •   CL_OUT_OF_HOST_MEMORY if there is a failure to allocate resources required by the
           OpenCL implementation on the host.

SPECIFICATION

       OpenCL Specification[1]

SEE ALSO

       clGetDeviceInfo(3clc), clGetPlatformIDs(3clc), clCreateContext(3clc), classDiagram(3clc)

AUTHORS

       The Khronos Group

COPYRIGHT

       Copyright © 2007-2011 The Khronos Group Inc.
       Permission is hereby granted, free of charge, to any person obtaining a copy of this
       software and/or associated documentation files (the "Materials"), to deal in the Materials
       without restriction, including without limitation the rights to use, copy, modify, merge,
       publish, distribute, sublicense, and/or sell copies of the Materials, and to permit
       persons to whom the Materials are furnished to do so, subject to the condition that this
       copyright notice and permission notice shall be included in all copies or substantial
       portions of the Materials.

NOTES

        1. OpenCL Specification
           page 35, section 4.2 - Querying Devices