Managing Parallels Service Preferences

Parallels Service preferences is a set of parameters that control its default behaviour. Some of the important parameters are:

• Memory limits for the Parallels Service itself.
• Memory limits and recommended values for virtual machines.
• Virtual network adapter information.
• Default virtual machine directory (the directory where all new virtual machines are created by default).
• Communication security level.

Parallels Service preferences are managed using the PHT_DISP_CONFIG handle which is obtained using the PrlSrv_GetCommonPrefs function. For the complete list of functions provided by the PHT_DISP_CONFIG object, see the Parallels C API Reference guide.

The following sample function demonstrates how to obtain a handle of type PHT_DISP_CONFIG and how to use its functions to retrieve and modify some of the Parallels Service preferences. The function accepts the hServer parameter which is a server handle. For the example on how to obtain a server handle, see Obtaining Server Handle and Logging In.

PRL_RESULT GetSetServicePrefs(PRL_HANDLE hServer)

{

    // Variables for handles.

    PRL_HANDLE hJob = PRL_INVALID_HANDLE;

    PRL_HANDLE hJobResult = PRL_INVALID_HANDLE;

    PRL_HANDLE hDispConfig = PRL_INVALID_HANDLE;

    // Variables for return codes.

    PRL_RESULT ret = PRL_ERR_UNINITIALIZED;

    PRL_RESULT nJobReturnCode = PRL_ERR_UNINITIALIZED;

    // An asynchronous call that obtains a handle

    // of type PHT_DISP_CONFIG.

    hJob = PrlSrv_GetCommonPrefs(hServer);

    // Wait for the job to complete.

    ret = PrlJob_Wait(hJob, 1000);

    if (PRL_FAILED(ret))

    {

        // Handle the error...

        PrlHandle_Free(hJob);

        return -1;

    }

    // Analyze the result of PrlSrv_GetCommonPrefs.

    ret = PrlJob_GetRetCode(hJob, &nJobReturnCode);

    if (PRL_FAILED(ret))

    {

        // Handle the error...

        PrlHandle_Free(hJob);

        return -1;

    }

    // Get the job return code.

    if (PRL_FAILED(nJobReturnCode))

    {

        // Handle the error...

        PrlHandle_Free(hJob);

        return -1;

    }

    // Get job result.

    ret = PrlJob_GetResult(hJob, &hJobResult);

    PrlHandle_Free(hJob);

    if (PRL_FAILED(ret))

    {

        // Handle the error...

        return -1;

    }

    // Get the PHT_DISP_CONFIG handle.

    ret = PrlResult_GetParam(hJobResult, &hDispConfig);

    PrlHandle_Free(hJobResult);

    if (PRL_FAILED(ret))

    {

        // Handle the error...

        return -1;

    }

    // Get the default virtual machine directory.

    char sDefaultDir[1024];

    PRL_UINT32 nBufSize = sizeof(sDefaultDir);

    ret = PrlDispCfg_GetDefaultVmDir(hDispConfig,

                                sDefaultDir, &nBufSize);

    if (PRL_FAILED(ret))

    {

        fprintf(stderr, "Error: %s\n",

            prl_result_to_string(ret));

        PrlHandle_Free(hDispConfig);

        return -1;

    }

    printf("Parallels Service Preferences \n\n");

    printf("Default VM Directory: %s\n", sDefaultDir);

    // Get the recommended virtual machine memory size.

    PRL_UINT32 nMemSize = 0;

    ret = PrlDispCfg_GetRecommendMaxVmMem(hDispConfig, &nMemSize);

    if (PRL_FAILED(ret))

    {

        fprintf(stderr, "Error: %s\n",

            prl_result_to_string(ret));

        PrlHandle_Free(hDispConfig);

        return -1;

    }

    printf("Recommended VM memory size: %d\n", nMemSize);

    // Modify some of the Parallels Service preferences.

    // Begin edit.

    hJob = PrlSrv_CommonPrefsBeginEdit(hServer);

    ret = PrlJob_Wait(hJob, 1000);

    if (PRL_FAILED(ret))

    {

        fprintf(stderr, "Error: %s\n",

            prl_result_to_string(ret));

        PrlHandle_Free(hJob);

        PrlHandle_Free(hDispConfig);

        return -1;            

    }

    // Get the "begin edit" operation success code.

    ret = PrlJob_GetRetCode(hJob, &nJobReturnCode);

    if (PRL_FAILED(ret))

    {

        fprintf(stderr, "Error: %s\n",

            prl_result_to_string(ret));

        PrlHandle_Free(hJob);

        PrlHandle_Free(hDispConfig);

        return -1;            

    }

    if (PRL_FAILED(nJobReturnCode))

    {

        fprintf(stderr, "Error: %s\n",

            prl_result_to_string(nJobReturnCode));

        PrlHandle_Free(hJob);

        PrlHandle_Free(hDispConfig);

        return -1;            

    }

    PrlHandle_Free(hJob);

    // Modify the recommended virtual machine memory size.

    nMemSize = 512;

    ret = PrlDispCfg_SetRecommendMaxVmMem(hDispConfig, nMemSize);

    if (PRL_FAILED(ret))

    {

        fprintf(stderr, "Error: %s\n",

            prl_result_to_string(ret));

        PrlHandle_Free(hDispConfig);

        return -1;

    }

    // Commit the changes.

    hJob = PrlSrv_CommonPrefsCommit(hServer, hDispConfig);

    ret = PrlJob_Wait(hJob, 1000);

    if (PRL_FAILED(ret))

    {

        fprintf(stderr, "Error: %s\n",

            prl_result_to_string(ret));

        PrlHandle_Free(hJob);

        PrlHandle_Free(hDispConfig);

        return -1;            

    }

    ret = PrlJob_GetRetCode(hJob, &nJobReturnCode);

    if (PRL_FAILED(ret))

    {

        fprintf(stderr, "Error: %s\n",

            prl_result_to_string(ret));

        PrlHandle_Free(hJob);

        PrlHandle_Free(hDispConfig);

        return -1;            

    }

    if (PRL_FAILED(nJobReturnCode))

    {

        fprintf(stderr, "Error: %s\n",

            prl_result_to_string(nJobReturnCode));

        PrlHandle_Free(hJob);

        PrlHandle_Free(hDispConfig);

        return -1;            

    }

    printf("The recommended VM memory size changed to: %d\n", nMemSize);

    PrlHandle_Free(hDispConfig);

    return 0;

}