mmdevapi: Use InitOnce to initialize audio drivers.

[Andrew Eikum]

Signed-off-by: Andrew Eikum <aeikum at codeweavers.com>

On Fri, Feb 17, 2017 at 09:34:25AM +0100, Sebastian Lackner wrote:
> Signed-off-by: Sebastian Lackner <sebastian at fds-team.de>
> ---
> 
> For https://bugs.winehq.org/show_bug.cgi?id=42463.
> 
>  dlls/mmdevapi/main.c |    8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/dlls/mmdevapi/main.c b/dlls/mmdevapi/main.c
> index 110c8028c76..42467580d77 100644
> --- a/dlls/mmdevapi/main.c
> +++ b/dlls/mmdevapi/main.c
> @@ -109,7 +109,7 @@ static BOOL load_driver(const WCHAR *name, DriverFuncs *driver)
>      return TRUE;
>  }
>  
> -static BOOL init_driver(void)
> +static BOOL WINAPI init_driver(INIT_ONCE *once, void *param, void **context)
>  {
>      static const WCHAR drv_value[] = {'A','u','d','i','o',0};
>  
> @@ -120,9 +120,6 @@ static BOOL init_driver(void)
>      HKEY key;
>      WCHAR reg_list[256], *p, *next, *driver_list = default_list;
>  
> -    if(drvs.module)
> -        return TRUE;
> -
>      if(RegOpenKeyW(HKEY_CURRENT_USER, drv_keyW, &key) == ERROR_SUCCESS){
>          DWORD size = sizeof(reg_list);
>  
> @@ -276,10 +273,11 @@ static IClassFactoryImpl MMDEVAPI_CF[] = {
>  
>  HRESULT WINAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, LPVOID *ppv)
>  {
> +    static INIT_ONCE init_once = INIT_ONCE_STATIC_INIT;
>      unsigned int i = 0;
>      TRACE("(%s, %s, %p)\n", debugstr_guid(rclsid), debugstr_guid(riid), ppv);
>  
> -    if(!init_driver()){
> +    if(!InitOnceExecuteOnce(&init_once, init_driver, NULL, NULL)) {
>          ERR("Driver initialization failed\n");
>          return E_FAIL;
>      }
> -- 
> 2.11.0
> 
>