Detect If Shutdown In Progress
in [Win32 Kernel]
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From: Hugo gleaves on 17 Feb 2010 15:59 I'm a little surprised at something, it seems there is now way (no Win32 function) to ask windows if a shutdown has been issued. I'd very much like ask the OS this question before I allow an app to call some other functions in a support library. The library updates mapped memory in all sorts of complicated ways. If a process is inside one of these update functions, partway through its work and the OS bluntly kills the app, then the mapped data will be flushed to disk OK but may be corrupt because the update function was interrupted. These functions execute very very rapidly, but there is always a "window" for failure. So I want to put code into these update functions that (in essence) does this: if (OsShutdownInProgress == FALSE) { do the fiddly update logic. } else return(OPERATION_PREVENTED_DUE_TO_OS_SHUTDOWN); This greatly reduces the window, so that in almost all cases we will get a clean failure in the update functions if user's app ignores shutdown and updates the mapped data via our API. But is there such a function? Is there any sort of info struct we can get from Windows, with a flag indicating that a shutdown has been started? Thanks H
From: Kerem Gümrükcü on 17 Feb 2010 16:13 Hi Hugo, you dindt say what kind of application you are running so i will tell you some ways this can be aquired/notfied: WM_QUERYENDSESSION //windowed applications HandlerRoutine Callback Function //console based RegisterServiceCtrlHandlerEx Function //service based Each of them will give you a "callback" whenever windows is shutting down or a session changes. Whenever you get a notification, then set some global flag indicating a shutdown and check the flag before you make any calls,.. You see there are many ways,... ;) regards Kerem -- ----------------------- Beste Grüsse / Best regards / Votre bien devoue Kerem Gümrükcü Latest Project: http://www.pro-it-education.de/software/deviceremover Latest Open-Source Projects: http://entwicklung.junetz.de ----------------------- "Hugogleaves(a)hotmail.com>" <hugh<underbar> schrieb im Newsbeitrag news:3F82C790-8545-4DC8-98A7-970E2193C9CB(a)microsoft.com... > I'm a little surprised at something, it seems there is now way (no Win32 > function) to ask windows if a shutdown has been issued. > > I'd very much like ask the OS this question before I allow an app to call > some other functions in a support library. > > The library updates mapped memory in all sorts of complicated ways. > > If a process is inside one of these update functions, partway through its > work and the OS bluntly kills the app, then the mapped data will be > flushed > to disk OK but may be corrupt because the update function was interrupted. > > These functions execute very very rapidly, but there is always a "window" > for failure. > > So I want to put code into these update functions that (in essence) does > this: > > if (OsShutdownInProgress == FALSE) > { > do the fiddly update logic. > } > else > return(OPERATION_PREVENTED_DUE_TO_OS_SHUTDOWN); > > This greatly reduces the window, so that in almost all cases we will get a > clean failure in the update functions if user's app ignores shutdown and > updates the mapped data via our API. > > But is there such a function? > > Is there any sort of info struct we can get from Windows, with a flag > indicating that a shutdown has been started? > > Thanks > H
From: Hugo gleaves on 17 Feb 2010 17:01 Thanks Kerem I was thinking along similar lines, then I just noticed that GetSystemMetrics can be invoked with SM_SHUTDOWN. This will return non-zero if the system is in the process of shutting down. Unless I'm mistaken, this is just what I need. Thx H "Kerem Gümrükcü" wrote: > Hi Hugo, > > you dindt say what kind of application you are running > so i will tell you some ways this can be aquired/notfied: > > WM_QUERYENDSESSION //windowed applications > HandlerRoutine Callback Function //console based > RegisterServiceCtrlHandlerEx Function //service based > > Each of them will give you a "callback" whenever windows > is shutting down or a session changes. Whenever you get > a notification, then set some global flag indicating a shutdown > and check the flag before you make any calls,.. > > You see there are many ways,... ;) > > regards > > Kerem > > -- > ----------------------- > Beste Grüsse / Best regards / Votre bien devoue > Kerem Gümrükcü > Latest Project: http://www.pro-it-education.de/software/deviceremover > Latest Open-Source Projects: http://entwicklung.junetz.de > ----------------------- > > "Hugogleaves(a)hotmail.com>" <hugh<underbar> schrieb im Newsbeitrag > news:3F82C790-8545-4DC8-98A7-970E2193C9CB(a)microsoft.com... > > I'm a little surprised at something, it seems there is now way (no Win32 > > function) to ask windows if a shutdown has been issued. > > > > I'd very much like ask the OS this question before I allow an app to call > > some other functions in a support library. > > > > The library updates mapped memory in all sorts of complicated ways. > > > > If a process is inside one of these update functions, partway through its > > work and the OS bluntly kills the app, then the mapped data will be > > flushed > > to disk OK but may be corrupt because the update function was interrupted. > > > > These functions execute very very rapidly, but there is always a "window" > > for failure. > > > > So I want to put code into these update functions that (in essence) does > > this: > > > > if (OsShutdownInProgress == FALSE) > > { > > do the fiddly update logic. > > } > > else > > return(OPERATION_PREVENTED_DUE_TO_OS_SHUTDOWN); > > > > This greatly reduces the window, so that in almost all cases we will get a > > clean failure in the update functions if user's app ignores shutdown and > > updates the mapped data via our API. > > > > But is there such a function? > > > > Is there any sort of info struct we can get from Windows, with a flag > > indicating that a shutdown has been started? > > > > Thanks > > H > > . >
From: Kerem Gümrükcü on 17 Feb 2010 17:28 Hi, if this is good for you, then take it, but i would use the callbacks because once they have been implemented, they will give you more options on detecting "what" exactly lead windows to a session change, so this is more expandable,... regards K. -- ----------------------- Beste Grüsse / Best regards / Votre bien devoue Kerem Gümrükcü Latest Project: http://www.pro-it-education.de/software/deviceremover Latest Open-Source Projects: http://entwicklung.junetz.de ----------------------- "Hugogleaves(a)hotmail.com>" <hugh<underbar> schrieb im Newsbeitrag news:37BB2C78-E285-4BD1-B771-E125AD95D968(a)microsoft.com... > Thanks Kerem > > I was thinking along similar lines, then I just noticed that > GetSystemMetrics can be invoked with SM_SHUTDOWN. > > This will return non-zero if the system is in the process of shutting > down. > > Unless I'm mistaken, this is just what I need. > > Thx > > H > > > "Kerem Gümrükcü" wrote: > >> Hi Hugo, >> >> you dindt say what kind of application you are running >> so i will tell you some ways this can be aquired/notfied: >> >> WM_QUERYENDSESSION //windowed applications >> HandlerRoutine Callback Function //console based >> RegisterServiceCtrlHandlerEx Function //service based >> >> Each of them will give you a "callback" whenever windows >> is shutting down or a session changes. Whenever you get >> a notification, then set some global flag indicating a shutdown >> and check the flag before you make any calls,.. >> >> You see there are many ways,... ;) >> >> regards >> >> Kerem >> >> -- >> ----------------------- >> Beste Grüsse / Best regards / Votre bien devoue >> Kerem Gümrükcü >> Latest Project: http://www.pro-it-education.de/software/deviceremover >> Latest Open-Source Projects: http://entwicklung.junetz.de >> ----------------------- >> >> "Hugogleaves(a)hotmail.com>" <hugh<underbar> schrieb im Newsbeitrag >> news:3F82C790-8545-4DC8-98A7-970E2193C9CB(a)microsoft.com... >> > I'm a little surprised at something, it seems there is now way (no >> > Win32 >> > function) to ask windows if a shutdown has been issued. >> > >> > I'd very much like ask the OS this question before I allow an app to >> > call >> > some other functions in a support library. >> > >> > The library updates mapped memory in all sorts of complicated ways. >> > >> > If a process is inside one of these update functions, partway through >> > its >> > work and the OS bluntly kills the app, then the mapped data will be >> > flushed >> > to disk OK but may be corrupt because the update function was >> > interrupted. >> > >> > These functions execute very very rapidly, but there is always a >> > "window" >> > for failure. >> > >> > So I want to put code into these update functions that (in essence) >> > does >> > this: >> > >> > if (OsShutdownInProgress == FALSE) >> > { >> > do the fiddly update logic. >> > } >> > else >> > return(OPERATION_PREVENTED_DUE_TO_OS_SHUTDOWN); >> > >> > This greatly reduces the window, so that in almost all cases we will >> > get a >> > clean failure in the update functions if user's app ignores shutdown >> > and >> > updates the mapped data via our API. >> > >> > But is there such a function? >> > >> > Is there any sort of info struct we can get from Windows, with a flag >> > indicating that a shutdown has been started? >> > >> > Thanks >> > H >> >> . >>
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