/********************************************************************
RmuRegisterResources - Registers resources for the Restart Manager.
This should be called rarely because it is expensive to run. Call
functions like RmuAddFile for multiple resources then commit them
as a batch of updates to RmuRegisterResources.
Duplicate resources appear to be handled by Restart Manager.
Only one WM_QUERYENDSESSION is being sent for each top-level window.
********************************************************************/
extern "C" HRESULT DAPI RmuRegisterResources(
__in PRMU_SESSION pSession
)
{
HRESULT hr = S_OK;
DWORD er = ERROR_SUCCESS;
HMODULE hModule = NULL;
PFNRMREGISTERRESOURCES pfnRmRegisterResources = NULL;
AssertSz(vcRmuInitialized, "Restart Manager was not properly initialized.");
::EnterCriticalSection(&pSession->cs);
er = vpfnRmRegisterResources(
pSession->dwSessionHandle,
pSession->cFilenames,
pSession->rgsczFilenames,
pSession->cApplications,
pSession->rgApplications,
pSession->cServiceNames,
pSession->rgsczServiceNames
);
ExitOnWin32Error(er, hr, "Failed to register the resources with the Restart Manager session.");
// Empty the arrays if registered in case additional resources are added later.
ReleaseNullStrArray(pSession->rgsczFilenames, pSession->cFilenames);
ReleaseNullApplicationArray(pSession->rgApplications, pSession->cApplications);
ReleaseNullStrArray(pSession->rgsczServiceNames, pSession->cServiceNames);
LExit:
::LeaveCriticalSection(&pSession->cs);
return hr;
}
/********************************************************************
RmuEndSession - Ends the session.
If the session was joined by RmuJoinSession, any remaining resources
are registered before the session is ended (left).
********************************************************************/
extern "C" HRESULT DAPI RmuEndSession(
__in PRMU_SESSION pSession
)
{
HRESULT hr = S_OK;
DWORD er = ERROR_SUCCESS;
AssertSz(vcRmuInitialized, "Restart Manager was not properly initialized.");
// Make sure all resources are registered if we joined the session.
if (!pSession->fStartedSessionHandle)
{
hr = RmuRegisterResources(pSession);
ExitOnFailure(hr, "Failed to register remaining resources.");
}
er = vpfnRmEndSession(pSession->dwSessionHandle);
ExitOnWin32Error(er, hr, "Failed to end the Restart Manager session.");
LExit:
if (pSession->fInitialized)
{
::DeleteCriticalSection(&pSession->cs);
}
ReleaseNullStrArray(pSession->rgsczFilenames, pSession->cFilenames);
ReleaseNullApplicationArray(pSession->rgApplications, pSession->cApplications);
ReleaseNullStrArray(pSession->rgsczServiceNames, pSession->cServiceNames);
ReleaseNullMem(pSession);
RmuUninitialize();
return hr;
}
void HandleUnlock(
__inout CFGDB_STRUCT *pcdb
)
{
HRESULT hr = S_OK;
FILETIME ftRemote = { };
LPWSTR sczTempRemotePath = NULL;
BOOL fCopyRemoteBack = FALSE;
if (1 < pcdb->dwLockRefCount)
{
ExitFunction1(hr = S_OK);
}
Assert(0 < pcdb->dwLockRefCount);
// Disconnect from database, if it's a connected remote database
if (pcdb->fRemote && NULL != pcdb->psceDb)
{
fCopyRemoteBack = SceDatabaseChanged(pcdb->psceDb);
hr = SceCloseDatabase(pcdb->psceDb);
ExitOnFailure(hr, "Failed to close remote database");
pcdb->psceDb = NULL;
if (fCopyRemoteBack)
{
hr = FileGetTime(pcdb->sczDbPath, NULL, NULL, &ftRemote);
ExitOnFailure(hr, "Failed to get modified time of actual remote %ls", &ftRemote);
// Since DB file wasn't locked, we have to verify that nobody changed it in the meantime.
// Do it once before we try uploading to the remote (because uploading could be a lengthy operation on a slow connection to remote path)
if (0 != ::CompareFileTime(&ftRemote, &pcdb->ftBeforeModify))
{
hr = HRESULT_FROM_WIN32(ERROR_LOCK_VIOLATION);
ExitOnFailure(hr, "database %ls was modified (before copy), we can't overwrite it!", pcdb->sczDbPath);
}
// Get it on the volume first which may take time
// TODO: in some cases such as crashes or connection lost to network remote,
// we'll leave a file behind here. We need a feature to look for and cleanup old files.
hr = PathConcat(pcdb->sczDbDir, pcdb->sczGuid, &sczTempRemotePath);
ExitOnFailure(hr, "Failed to get temp path in remote directory");
hr = FileEnsureCopy(pcdb->sczDbCopiedPath, sczTempRemotePath, TRUE);
ExitOnFailure(hr, "Failed to copy remote database back to remote location (from %ls to %ls) due to changes", pcdb->sczDbCopiedPath, pcdb->sczDbPath);
// Now do it again after the upload right before we do the actual move
hr = FileGetTime(pcdb->sczDbPath, NULL, NULL, &ftRemote);
ExitOnFailure(hr, "Failed to get modified time of original remote (again) %ls", &ftRemote);
if (0 != ::CompareFileTime(&ftRemote, &pcdb->ftBeforeModify))
{
hr = HRESULT_FROM_WIN32(ERROR_LOCK_VIOLATION);
ExitOnFailure(hr, "database %ls was modified (after copy), we can't overwrite it!", pcdb->sczDbPath);
}
// Use MoveFile to ensure it's done as an atomic operation, so remote can never be left not existing.
// There is a tiny chance we're reverting someone else's changes here if some other machine just moved the file between
// the last timestamp check and this MoveFile call. I don't believe there is a way to fix that (we could open a lock on the file,
// but then we can't use atomic MoveFile() API, meaning we could leave a partial file around in some cases, a HUGE no-no)
// However, inadvertently overwriting a just-written db file is not a problem - Autosync on all machines will notice the fact
// that the DB changed, re-sync it, at which time we will try again to re-propagate the changes.
if (!::MoveFileExW(sczTempRemotePath, pcdb->sczDbPath, MOVEFILE_REPLACE_EXISTING | MOVEFILE_WRITE_THROUGH))
{
ExitWithLastError(hr, "Failed to move uploaded database path back to original remote location %ls", pcdb->sczDbPath);
}
}
if (pcdb->fUpdateLastModified)
{
hr = FileGetTime(pcdb->sczDbCopiedPath, NULL, NULL, &pcdb->ftLastModified);
if (E_FILENOTFOUND == hr || E_NOTFOUND == hr)
{
hr = S_OK;
}
ExitOnFailure(hr, "Failed to get modified time of copied db: %ls", pcdb->sczDbCopiedPath);
}
hr = FileEnsureDelete(pcdb->sczDbCopiedPath);
ExitOnFailure(hr, "Failed to delete copied remote database from %ls", pcdb->sczDbCopiedPath);
ReleaseNullStr(pcdb->sczDbCopiedPath);
}
for (DWORD i = 0; i < pcdb->cStreamsToDelete; ++i)
{
DeleteStream(pcdb->rgsczStreamsToDelete[i]);
}
ReleaseNullStrArray(pcdb->rgsczStreamsToDelete, pcdb->cStreamsToDelete);
pcdb->fUpdateLastModified = FALSE;
LExit:
--pcdb->dwLockRefCount;
::LeaveCriticalSection(&pcdb->cs);
if (FAILED(hr) && sczTempRemotePath)
{
// In case we left a temp file around, try to delete it before exiting (ignoring failure)
FileEnsureDelete(sczTempRemotePath);
}
ReleaseStr(sczTempRemotePath);
}