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)
<gigaherz(a)gmail.com> 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
>  <elhoir(a)gmail.com> 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 <thomas.faber(a)reactos.org>
> > 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 gedmurphy(a)svn.reactos.org:
> >> >> 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/M…
> >> >>
> >> >>
> ==============================================================================
> >> >> --- 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/M…
> >> >>
> >> >>
> ==============================================================================
> >> >> --- 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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