Re: [ros-dev] [ros-diffs] [gedmurphy] 69650: The c++ bool is 1 byte, not 4. Thanks Thomas

[David Quintana (gigaherz)]

SOME*

On 3 November 2015 at 13:36, David Quintana (gigaherz)
[e-mail] wrote:
> The common computers never work with bits in memory. All the common
> operations work at LEAST in bytes, and often in larger units, so
> working with bits requires extra logic. Booleans are most commonly
> stored as 1 byte because of that.
>
> It is possible that come machines do use 1 bit, but they would
> probably be specialized chips such as embedded microcontrollers.
>
> On 3 November 2015 at 12:57, Javier Agustìn Fernàndez Arroyo
> [e-mail] wrote:
> > i thought it was 1 bit, not 1 byte... thanks for correcting my mistake :)
> >
> > On Tue, Nov 3, 2015 at 10:00 AM, Thomas Faber [e-mail]
> > wrote:
> > > It makes a difference because m_RefreshPending was initialized to 0 by
> > > the constructor, but the three bytes behind it were not, so the first
> > > cmpxchg could fail.
> > > Plus of course if someone decided to add another bool or a char array
> > > or whatever at the end, that would get overwritten.
> > >
> > > On 2015-11-03 00:21, Timo Kreuzer wrote:
> > > > In fact in this case it wouldn't make a difference, since the bool would
> > > > be converted to a LONG. But using TRUE/FALSE seems to be appropriate
> > > > here.
> > > >
> > > > Am 22.10.2015 um 19:37 schrieb [e-mail]:
> > > > > Author: gedmurphy
> > > > > Date: Thu Oct 22 17:37:51 2015
> > > > > New Revision: 69650
> > > > >
> > > > > URL: http://svn.reactos.org/svn/reactos?rev=69650&view=rev
> > > > > Log:
> > > > > The c++ bool is 1 byte, not 4. Thanks Thomas
> > > > >
> > > > > Modified:
> > > > >      trunk/reactos/dll/win32/devmgr/devmgmt/MainWindow.cpp
> > > > >      trunk/reactos/dll/win32/devmgr/devmgmt/MainWindow.h
> > > > >
> > > > > Modified: trunk/reactos/dll/win32/devmgr/devmgmt/MainWindow.cpp
> > > > > URL:
> > > > > http://svn.reactos.org/svn/reactos/trunk/reactos/dll/win32/devmgr/devmgmt/Ma...
> > > > >
> > > > > ==============================================================================
> > > > > --- trunk/reactos/dll/win32/devmgr/devmgmt/MainWindow.cpp
> > > > > [iso-8859-1] (original)
> > > > > +++ trunk/reactos/dll/win32/devmgr/devmgmt/MainWindow.cpp
> > > > > [iso-8859-1] Thu Oct 22 17:37:51 2015
> > > > > @@ -786,7 +786,7 @@
> > > > >                   // we set a timer to run in 500ms, which should leave
> > > > > enough time for all
> > > > >                   // the messages to come through. Wrap so we don't set
> > > > > multiple timers
> > > > >                   //
> > > > >            if (InterlockedCompareExchange((LONG
> > > > >
> > > > > *)&This->m_RefreshPending, true, false) == false)
> > > > >            if (InterlockedCompareExchange((LONG
> > > > >
> > > > > *)&This->m_RefreshPending, TRUE, FALSE) == FALSE)
> > > > >                   {
> > > > >                       SetTimer(hwnd, REFRESH_TIMER, 500, NULL);
> > > > >                   }
> > > > > @@ -807,7 +807,7 @@
> > > > >                   KillTimer(hwnd, REFRESH_TIMER);
> > > > >               // Allow more change notifications
> > > > >            InterlockedExchange((LONG *)&This->m_RefreshPending,
> > > > >
> > > > > false);
> > > > >            InterlockedExchange((LONG *)&This->m_RefreshPending,
> > > > >
> > > > > FALSE);
> > > > >               }
> > > > >               break;
> > > > >           }
> > > > >
> > > > > Modified: trunk/reactos/dll/win32/devmgr/devmgmt/MainWindow.h
> > > > > URL:
> > > > > http://svn.reactos.org/svn/reactos/trunk/reactos/dll/win32/devmgr/devmgmt/Ma...
> > > > >
> > > > > ==============================================================================
> > > > > --- trunk/reactos/dll/win32/devmgr/devmgmt/MainWindow.h
> > > > > [iso-8859-1] (original)
> > > > > +++ trunk/reactos/dll/win32/devmgr/devmgmt/MainWindow.h
> > > > > [iso-8859-1] Thu Oct 22 17:37:51 2015
> > > > > @@ -17,7 +17,7 @@
> > > > >       HMENU m_hMenu;
> > > > >       HMENU m_hActionMenu;
> > > > >       int m_CmdShow;
> > > > > bool m_RefreshPending;
> > > > >
> > > > > BOOL m_RefreshPending;
> > > > >
> > > > > public:
> > > > >  CDeviceManager(void);
> > >
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> >
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