[Spice-devel] [vdagent-win PATCH v5 1/6] Use GetModuleHandle to get some functions from user32 library

[Frediano Ziglio]

> 
> On Mon, Jul 09, 2018 at 09:51:39AM +0100, Frediano Ziglio wrote:
> > The library is surely already loaded as providing clipboard and
> > other utilities we need.
> > Avoid using LoadLibrary that increment the reference so we don't
> > need to call FreeLibrary to cleanly decrement the reference.
> 
> Dunno, feels safer to me to load it explicitly if we need it rather than
> assuming something else will have loaded it.
> 
> Christophe
> 

For such an application is not far from checking if we are using libc on Unix.
I think for win32 applications (on Windows you can have no-win32 applications)
is the second library (first kernel32).

> > 
> > Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> > ---
> >  vdagent/vdagent.cpp | 7 ++-----
> >  1 file changed, 2 insertions(+), 5 deletions(-)
> > 
> > diff --git a/vdagent/vdagent.cpp b/vdagent/vdagent.cpp
> > index 423c3ee..dbf6556 100644
> > --- a/vdagent/vdagent.cpp
> > +++ b/vdagent/vdagent.cpp
> > @@ -125,7 +125,6 @@ private:
> >      static VDAgent* _singleton;
> >      HWND _hwnd;
> >      HWND _hwnd_next_viewer;
> > -    HMODULE _user_lib;
> >      PCLIPBOARD_OP _add_clipboard_listener;
> >      PCLIPBOARD_OP _remove_clipboard_listener;
> >      clipboard_owner_t _clipboard_owner;
> > @@ -183,7 +182,6 @@ VDAgent* VDAgent::get()
> >  VDAgent::VDAgent()
> >      : _hwnd (NULL)
> >      , _hwnd_next_viewer (NULL)
> > -    , _user_lib (NULL)
> >      , _add_clipboard_listener (NULL)
> >      , _remove_clipboard_listener (NULL)
> >      , _clipboard_owner (owner_none)
> > @@ -269,9 +267,9 @@ bool VDAgent::run()
> >          vd_printf("SetProcessShutdownParameters failed %lu",
> >          GetLastError());
> >      }
> >  
> > -    _user_lib = LoadLibrary(L"User32.dll");
> > +    HMODULE _user_lib = GetModuleHandle(L"User32");
> >      if (!_user_lib) {
> > -        vd_printf("LoadLibrary failed %lu", GetLastError());
> > +        vd_printf("GetModuleHandle failed %lu", GetLastError());
> >          return false;
> >      }
> >      _add_clipboard_listener =
> > @@ -342,7 +340,6 @@ bool VDAgent::run()
> >  
> >  void VDAgent::cleanup()
> >  {
> > -    FreeLibrary(_user_lib);
> >      CloseHandle(_vio_serial);
> >  }
> >