OpenCL test program (1)

OpenCL test program

책의 예제를 넣어서 실행

책에서 오류가 두군데가 있었다.

(1) ifdef에서 APPLE platform을 확인하는 매크로 정의 오류

== WAS == 

 #ifdef APPLE

 == IS ==

#ifdef __APPLE__

(2) OpenCL의 원칙은 OpenCL에 정보의 크기를 물어서 확인하고 그만큼 공간을 만든뒤에 그 정보를 받아들이는 것인데

     예제에서는 정보를 물어서 공간을 만드는 데 까지는 있지만, 그 이후에 정보를 다시 받아들이는 함수를 호출 하지 않았다.

....

main(...)

{

 ...

  먼저 필요한 공간의 크기를 확인

  error = clGetPlatformIDs(0,    

                             NULL,  

                             &numOfPlatforms

                           );

 if ( error < 0)

  ...

   공간을 확보 하고

   이제 확보된 공간으로 값을 받아온다. 

    error = clGetPlatformIDs(numOfPlatforms,  <== 이 함수를 호출 하는 것을 추가함.

                          platforms,  

                          NULL

                          );

  ...

}

전체 코드는 아래와 같다.

//

//  main.cpp

//  TestOpenCL

//

//  Created by freegear on 2014. 2. 8..

//  Copyright (c) 2014년 freegear. All rights reserved.

//

#include <iostream>

#include <stdio.h>

#include <stdlib.h>

#ifdef __APPLE__

#include <OpenCL/opencl.h>

#else

#include <CL/cl.h>

#endif

void displayPlatformInfo(

                         cl_platform_id id ,

                         cl_platform_info param_name,

                         const char * paramNameAsStr

                         )

{

    

    cl_int error = 0 ;

    size_t paramSize = 0 ;

    

    

    error = clGetPlatformInfo(

                              id,

                              param_name,

                              0,

                              NULL,

                              &paramSize

                              );

    

    char * moreInfo = (char *) alloca(sizeof(char)*paramSize);

    

    error = clGetPlatformInfo(

                              id, /* The platform ID returned by clGetPlatformIDs or can be NULL. 

                                     If platform is NULL, the behavior is implementation-defined.*/

                              param_name, /* An enumeration constant that identifies the platform 

                                             information being queried. It can be one of the following values 

                                             as specified in the table below. */

                              paramSize,  /* Specifies the size in bytes of memory pointed to by param_value. 

                                             This size in bytes must be greater than or equal to size of return type

                                             specified in the table below. */

                              moreInfo,   /* A pointer to memory location where appropriate values for a given 

                                             param_value will be returned. Acceptable param_value values are listed in 

                                             the table below. If param_value is NULL, it is ignored.*/

                              NULL        /* Returns the actual size in bytes of data being queried by param_value. 

                                             If param_value_size_ret is NULL, it is ignored */

                              );

    

    if( error != CL_SUCCESS)

    {

        if ( error == CL_INVALID_PLATFORM)

            perror("Error CL_INVALID_PLATFORM");

        else if (error == CL_INVALID_VALUE)

            perror("Error CL_INVALID_VALUE");

        else

            perror("Unable to find any OpenCL platform information");

        return ;

    }

    

    printf("%s : %s\n" , paramNameAsStr, moreInfo);

    

} // end of displayPlatformInfo

int main(int argc, const char * argv[])

{

    

    // OpenCL 1.2 Data struction

    cl_platform_id * platforms ;

    

    /* OpenCL 1.1 scalar data types */

    cl_uint numOfPlatforms ;

    cl_int  error ;

    

    /* 

        Get the number of platforms

        Remember that for each vendor's SDK installed on the computer,

        the number of available platform also increased.

    */

    

    

    error = clGetPlatformIDs(0, /*

                                 The number of cl_platform_id entries that can be added to platforms.

                                 If platforms is not NULL, the num_entries must be greater than zero. 

                                 */

                             NULL, /* Returns a list of OpenCL platforms found. 

                                      The cl_platform_id values returned in platforms can be used to identify 

                                      a specific OpenCL platform. If platforms argument is NULL, 

                                      this argument is ignored. 

                                      The number of OpenCL platforms returned is the mininum of the value 

                                      specified by num_entries or the number of OpenCL platforms available. */

                             &numOfPlatforms

                                    /* Returns the number of OpenCL platforms available. 

                                       If num_platforms is NULL, this argument is ignored. */

                             );

    if ( error < 0)

    {

        perror("Unable to find any OpenCL platforms");

        exit(1);

    }

    

    // allocate memory for the number of installed platforms

    // alloca(....) occupies some stack space but is

    // automatically freed on return

    

    platforms = (cl_platform_id*) alloca(sizeof(cl_platform_id)*numOfPlatforms);

    

    printf("Number of OpenCL platforms found : %d\n", numOfPlatforms);

    

    

    error = clGetPlatformIDs(numOfPlatforms, /*

                                 The number of cl_platform_id entries that can be added to platforms.

                                 If platforms is not NULL, the num_entries must be greater than zero.

                                 */

                             platforms, /* Returns a list of OpenCL platforms found.

                                    The cl_platform_id values returned in platforms can be used to identify

                                    a specific OpenCL platform. If platforms argument is NULL,

                                    this argument is ignored.

                                    The number of OpenCL platforms returned is the mininum of the value

                                    specified by num_entries or the number of OpenCL platforms available. */

                             NULL

                             /* Returns the number of OpenCL platforms available.

                              If num_platforms is NULL, this argument is ignored. */

                             );

    if ( error < 0)

    {

        perror("Unable to find any OpenCL platforms");

        exit(1);

    }

    // We invoke the API 'clPlatformInfo' twice for each

    // parameter we are trying to extract

    // and we use the return value to create temporary data

    // structure (on the stack) to store

    // the returned information ot the second invocation.

    

    for( cl_uint i = 0 ; i < numOfPlatforms ; ++i)

    {

        displayPlatformInfo( platforms[i],  CL_PLATFORM_PROFILE     , "CL_PLATFORM_PROFILE");

        displayPlatformInfo( platforms[i],  CL_PLATFORM_VERSION     , "CL_PLATFORM_VERSION");

        displayPlatformInfo( platforms[i],  CL_PLATFORM_NAME        , "CL_PLATFORM_NAME");

        displayPlatformInfo( platforms[i],  CL_PLATFORM_VENDOR      , "CL_PLATFORM_VENDOR");

        displayPlatformInfo( platforms[i],  CL_PLATFORM_EXTENSIONS  , "CL_PLATFORM_EXTENSIONS");

        

    }

    

    return 0;

}

실행 결과는 아래와 같다.

Number of OpenCL platforms found : 1

CL_PLATFORM_PROFILE : FULL_PROFILE

CL_PLATFORM_VERSION : OpenCL 1.2 (Aug 24 2013 21:03:27)

CL_PLATFORM_NAME : Apple

CL_PLATFORM_VENDOR : Apple

CL_PLATFORM_EXTENSIONS : cl_APPLE_SetMemObjectDestructor cl_APPLE_ContextLoggingFunctions cl_APPLE_clut cl_APPLE_query_kernel_names cl_APPLE_gl_sharing cl_khr_gl_event