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  • NFS4 / ZFS: revert ACL to clean/inherited state

    - by Keiichi
    My problem is identical to this Windows question, but pertains NFS4 (Linux) and the underlying ZFS (OpenIndiana) we are using. We have this ZFS shared via NFS4 and CIFS for Linux and Windows users respectively. It would be nice for both user groups to benefit from ACLs, but the one missing puzzle piece goes thusly: Each user has a home, where he sets a top-level, inherited ACL. He can later on refine permissions for the contained files/folders iteratively. Over time, sometimes permissions need to be generalized again to avoid increasing pollution of ACL entries. You can tweak the ACL of every single file if need be to obtain the wanted permissions, but that defeats the purpose of inherited ACLs. So, how can an ACL be completely cleared like in the question linked above? I have found nothing about what a blank, inherited ACL should look like. This usecase simply does not seem to exist. In fact, the solaris chmod manpage clearly states A- Removes all ACEs for current ACL on file and replaces current ACL with new ACL that represents only the current mode of the file. I.e. we get three new ACL entries filled with stuff representing the permission bits, which is rather useless for cleaning up. If I try to manually remove every ACE, on the last one I get chmod A0- <file> chmod: ERROR: Can't remove all ACL entries from a file Which by the way makes me think: and why not? In fact, I really want the whole file-specific ACL gone. The same holds for linux, which enumerates ACEs starting with 1(!), and verbalizes its woes less diligently nfs4_setacl -x 1 <file> Failed setxattr operation: Unknown error 524 So, what is the idea behind ACLs under Solaris/NFS? Can they never be cleaned up? Why does the recursion option for the ACL setting commands pollute all children instead of setting a single ACL and making the children inherit? Is this really the intention of the designers? I can clean up the ACLs using a windows client perfectly well, but am I supposed to tell the linux users they have to switch OS just to consolidate permissions?

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  • Windows Server 2008 R2 Firewall - Interface specific rules

    - by Mehmet Ergut
    I'm trying to define per interface rules, much like it was in Server 2003. We will be replacing our old 2003 server with a new 2008 R2 server. The server runs IIS and SQL Server. It's a dedicated server at the hosting company. We use a OpenVPN connection from the office to access SQL server, RDesktop, FTP and other administrative services. Only http and ssh is listening on the public interface. On the old server running 2003, I was able to define global rules for http and ssh, and allow other services only on the vpn interface. I can't find a way to do the same on 2008 R2. I understand that there is the Network Location Awareness service, firewall rules are applied according to the current network location. But I don't understand the purpose of this on a server. The only close solution I found is to set the scope on the firewall rule and restrict remote ip addresses to the private subnet of the office. But the ports will still be listening on the public interface. So how can I restrict a firewall rule to the connections coming from the vpn interface ? A note on this page states that scoping a rule to an interface does not exist anymore: In earlier versions of Windows, many of these command accepted a parameter called interface. This parameter is not supported in the firewall context in Windows Vista or later versions of Windows. I can't believe that they simply decided to remove a core firewall functionality that every firewall has. There must be a way to restrict a rule to an interface. Any ideas ? I'm still unable to find an adequate solution to my problem. So for now, my workaround is this: Administrative services listen on VPN IP address Firewall rules restrict the scope to the local IP address of VPN Public services listen on all interfaces, no scope restriction on firewall rules This is not optimal, if I change the IP address of the VPN, I need to edit the firewall rules too. It won't be the case if the rules were bound to the interface.

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  • Too many Tunnel Adapter Interfaces

    - by Tomas Lycken
    If I open a command prompt on my machine and type ipconfig /all, I see lots of Tunnel adapter Local Area Connection* 9: Media state . . . . . . . . . . . . . : Media disconnected Connection-specific DNS Sufficx . . . : Description . . . . . . . . . . . . . : Microsoft 6to4 Adapter #5 Physical address. . . . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . . . : No Autoconfiguration Enabled . . . . . . : Yes In fact, they're so many that my "real" adapters are pushed out of the stack, and can't be seen anymore. Is there any flag I can use on ipconfig to hide all virtual interfaces? Or is there some other way around this problem? Since they always say "Media disconnected" I suppose disabling could be an option, but if possible I'd rather not turn any functionality off. I just want to control what output I get from ipconfig. Also, I know these are related to IPv6 stuff. However, most of what I find on google merely states what these are, and that they're harmless - nothing about hiding/removing them.

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  • How can the Private Bytes of a process be significantly less than its effect on the system commit charge?

    - by bacar
    On a 64-bit Windows Server 2003, I can see using taskmgr or process explorer that the total commit charge is around 3.5GB, yet when I sum the Private Bytes consumed by each process (by running pslist -m and adding all values under the Priv column) the total comes in at 1.6GB. I know which process seems to be causing this (sqlservr.exe) as when I kill the process, the commit charge drops dramatically. However the process in question is consuming only ~220MB of Private Bytes yet killing the process drops the commit charge by ~1.6GB. How is this possible? How can the commit charge be so significantly greater than Private Bytes, which should represent the amount of committed memory? If some other factor contributes to the commit charge, what is that factor and how can I view its impact in process explorer? Note: I claim that I understand the difference between reserved and committed memory already: my investigations above relate specifically to Private Bytes which includes only committed memory and excludes reserved memory. the Virtual Size of the process in this case is over 4GB, but this should be irrelevant - Virtual Size in procexp represents reserved, not committed memory, and should not contribute to the commit charge. I'm particularly interested in generalised answers to this question: I'm assuming that if sqlservr.exe can behave in this way, that any process potentially could. Further Investigations I notice that pointing Sysinternals VMMap at this process reports a committed "Private Data" of 1.6GB despite Procexp's reported a Private Bytes of 220MB. This is particularly strange given that the documentation for this field in the "Windows® Sysinternals Administrator's Reference" states that: Private Data memory is memory that is allocated by VirtualAlloc and that is not further handled by the Heap Manager or the .NET runtime, or assigned to the Stack category... VMMap’s definition of “Private Data” is more granular than that of Process Explorer’s “private bytes.” Procexp’s “private bytes” includes all private committed memory belonging to the process. i.e. that VMMap's committed "Private Data" should be smaller than procexp's "Private Bytes". Also, after reading the 'Process committed memory' section of Mark Russinovich's excellent Pushing the Limits of Windows: Virtual Memory, he highlights two cases which won't show up in Private Bytes: File mapping views with copy-on-write semantics (however, according to VMMap there is no significant space allocated to Mapped Files). pagefile-backed virtual memory (however, I tried testlimit with the -l flag as suggested, and no significant memory is consumed by pagefile-backed sections)

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  • Is this iptables NAT exploitable from the external side?

    - by Karma Fusebox
    Could you please have a short look on this simple iptables/NAT-Setup, I believe it has a fairly serious security issue (due to being too simple). On this network there is one internet-connected machine (running Debian Squeeze/2.6.32-5 with iptables 1.4.8) acting as NAT/Gateway for the handful of clients in 192.168/24. The machine has two NICs: eth0: internet-faced eth1: LAN-faced, 192.168.0.1, the default GW for 192.168/24 Routing table is two-NICs-default without manual changes: Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 (externalNet) 0.0.0.0 255.255.252.0 U 0 0 0 eth0 0.0.0.0 (externalGW) 0.0.0.0 UG 0 0 0 eth0 The NAT is then enabled only and merely by these actions, there are no more iptables rules: echo 1 > /proc/sys/net/ipv4/ip_forward /sbin/iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE # (all iptables policies are ACCEPT) This does the job, but I miss several things here which I believe could be a security issue: there is no restriction about allowed source interfaces or source networks at all there is no firewalling part such as: (set policies to DROP) /sbin/iptables -A FORWARD -i eth0 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT /sbin/iptables -A FORWARD -i eth1 -o eth0 -j ACCEPT And thus, the questions of my sleepless nights are: Is this NAT-service available to anyone in the world who sets this machine as his default gateway? I'd say yes it is, because there is nothing indicating that an incoming external connection (via eth0) should be handled any different than an incoming internal connection (via eth1) as long as the output-interface is eth0 - and routing-wise that holds true for both external und internal clients that want to access the internet. So if I am right, anyone could use this machine as open proxy by having his packets NATted here. So please tell me if that's right or why it is not. As a "hotfix" I have added a "-s 192.168.0.0/24" option to the NAT-starting command. I would like to know if not using this option was indeed a security issue or just irrelevant thanks to some mechanism I am not aware of. As the policies are all ACCEPT, there is currently no restriction on forwarding eth1 to eth0 (internal to external). But what are the effective implications of currently NOT having the restriction that only RELATED and ESTABLISHED states are forwarded from eth0 to eth1 (external to internal)? In other words, should I rather change the policies to DROP and apply the two "firewalling" rules I mentioned above or is the lack of them not affecting security? Thanks for clarification!

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  • Why does this service refuse to start on Windows server 2003?

    - by PenguinCoder
    We have a Windows 2003 server with Cebos MQ1 (ver. 7 and ver. GRI) products installed that have been operational for years. After installing Microsoft 2010 C++ Redistributable package needed for other development, the MQ1 GRI service now fails to start. Event logs showed that two additional updates (.NET4 and the 2010 C++ Redistributable SP2) where installed by the redistributable as well. As soon as we discovered the MQ1 service was not starting properly, we removed these three installed packages. However the service still does not start; the dialog that pops up states 'The service started then stopped. '. Event logs when we attempt to start the service show nothing; IE: No errors, crashes, failures, or other information related to this service. Executing the MQ1Serv.exe directly specifies an issue of 'Missing command line operation, must specify install, uninstall and company abbreviation.' sc query MQ1Service(GRI) shows a clean exit for the Win32ExitCode of 0x0. Attempting to reinstall the client or server software gives an error of 'The procedure entry point ReInitializeCriticalSection could not be located in the dynamic link library KERNEL32.dll.' at the 'Registering Libraries' stage. At this point, further research has stated that the required function is in URL.dll and to verify the library is not corrupted. Running an sfc /scannow on the server has replaced a few DLLS; including the URL.DLL to versions from 2005. This actually broke other applications which required a reinstall (one of them being IE 7). After reinstall and updates, url.dll version is 7.0.5730.13 (2009) and Kernel32.dll is version 5.2.3790.4480 (2009). The MQ1 GRI service still will not start, specifying the same error as previous 'Service started then stopped'. Running a disassembler on Kernel32.dll and Url.dll show no functions named ReinitializeCriticalSection. Attempting the reinstall of the MQ1 client and server as well as starting the service again, fails once more. However, setting the compatibility mode on the MQ1 client install exe to 'Windows 95' actually gets the program to install. Setting the compatibility mode on the MQ1 server service does not enable it to start. I have been researching this problem for nearly a week and besides the advice to scan and replace url.dll, have come to no successful conclusions. This service was operational prior to the 2010 C++ install, without any additional parameters or settings. After removing the C++ install and all servicepacks/updates it installed silently, still does not correct the issue of the MQ1 GRI service not starting. Q: Has anyone else run into this or similar issue while attempting to get a service initialized? What have I overlooked or what else can I try in order to get this service started??

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  • Ubuntu + SSL ports + AVAST

    - by jurajvt
    I have an interesting problem with communication via standard SSL ports. Fresh installed Ubuntu 14.04 server + Postfix + Dovecot, SASL authentication provided by Dovecot, self-signed certificate generated trough the Dovecot script mkcert.sh. Redirected ports on ZyWALL USG 200. I can send and receive e-mails from outside with standard ports 25 and 110, but not over 587. I am connecting to my server from machine with Windows 8.1 + VMWare Player + Ubuntu 14.04 Desktop + ssh. On Windows host I have installed Avast! antivirus. When I am trying to telnet from virtual machine to server over 587, it refused connection. But when I turn on Avast! it let me in to message Connected to... Same with nmap. When Avast! is turned on it is show me all SSL ports. When I turned it off, only standard ports appeared. OpenSSL shows me CONNECTED(00000003). But outside virtual machine directly in Windows 8.1 using nmap with zenmap there are not opened SSL ports in both Avast! states. From other external linux machines are problems with touching SSL ports same - refused. I have turned on submission in master.cf and 587 port is correctly listening on 0.0.0.0 in process master.pid which belongs to Postfix. I can telnet, or nmap over port 587 to my domain directly from server. Other ports like 995, 993 are OK on localhost, too. It is true, that I can't send emails via 587 anyway (Avast! turned on/off), but I can see ports opened. It is possible, that I have simply bad certificate and Avast! has right one, so with turned it on I can see opened ports? EDIT: To be more clear, I can't see or using port 587 everywhere from outside (tried Thunderbird, telnet, openssl, nmap, putty, swaks; both from Linux or Windows machines) and that is my problem. It was only by chance that I saw opened ports when Avast! is turned on.

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  • UITableViewCell selected subview ghosts

    - by Jonathan Cohen
    Hi all, I'm learning about the iPhone SDK and have an interesting exception with UITableViewCell subview management when a finger is pressed on some rows. The table is used to assign sounds to hand gestures -- swiping the phone in one of 3 directions triggers the sound to play. Selecting a row displays an action sheet with 4 options for sound assignment: left, down, right, and cancel. Sounds can be mapped to one, two, or three directions so any cell can have one of seven states: left, down, right, left and down, left and right, down and right, or left down and right. If a row is mapped to any of these seven states, a corresponding arrow or arrows are displayed within the bounds of the row as a subview. Arrows come and go as they should in a given screen and when scrolling around. However, after scrolling to a new batch of rows, only when I press my finger down on some (but not all) rows, does an arrow magically appear in the selected state background. When I lift my finger off the row, and the action sheet appears, the arrow disappears. After pressing any of the four buttons, I can't replicate this anymore. But it's really disorienting and confusing to see this arrow flash on screen because the selected row isn't assigned to anything. What haven't I thought to look into here? All my table code is pasted below and this is a screencast of the problem: http://www.screencast.com/users/JonathanGCohen/folders/Jing/media/d483fe31-05b5-4c24-ab4d-70de4ff3a0bf Am I managing my subviews wrong or is there a selected state property I'm missing? Something else? Should I have included any more information in this post to make things clearer? Thank you!! #pragma mark - #pragma mark Table - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return ([categories count] > 0) ? [categories count] : 1; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { if ([categories count] == 0) return 0; NSMutableString *key = [categories objectAtIndex:section]; NSMutableArray *nameSection = [categoriesSounds objectForKey:key]; return [nameSection count]; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { NSUInteger section = [indexPath section]; NSUInteger row = [indexPath row]; NSString *key = [categories objectAtIndex:section]; NSArray *nameSection = [categoriesSounds objectForKey:key]; static NSString *SectionsTableIdentifier = @"SectionsTableIdentifier"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier: SectionsTableIdentifier]; NSArray *sound = [categoriesSounds objectForKey:key]; NSString *soundName = [[sound objectAtIndex: row] objectAtIndex: 0]; NSString *soundOfType = [[sound objectAtIndex: row] objectAtIndex: 1]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:SectionsTableIdentifier] autorelease]; } cell.textLabel.text = [[nameSection objectAtIndex:row] objectAtIndex: 0]; NSUInteger soundSection = [[[sound objectAtIndex: row] objectAtIndex: 2] integerValue]; NSUInteger soundRow = [[[sound objectAtIndex: row] objectAtIndex: 3] integerValue]; NSUInteger leftRow = [leftOldIndexPath row]; NSUInteger leftSection = [leftOldIndexPath section]; if (soundRow == leftRow && soundSection == leftSection && leftOldIndexPath !=nil){ [selectedSoundLeftAndDown removeFromSuperview]; [selectedSoundLeftAndRight removeFromSuperview]; [cell.contentView addSubview: selectedSoundLeft]; selectedSoundLeft.frame = CGRectMake(200,8,30,30); } else { [cell.contentView sendSubviewToBack: selectedSoundLeft]; } NSUInteger downRow = [downOldIndexPath row]; NSUInteger downSection = [downOldIndexPath section]; if (soundRow == downRow && soundSection == downSection && downOldIndexPath !=nil){ [selectedSoundLeftAndDown removeFromSuperview]; [selectedSoundDownAndRight removeFromSuperview]; [cell.contentView addSubview: selectedSoundDown]; selectedSoundDown.frame = CGRectMake(200,8,30,30); } else { [cell.contentView sendSubviewToBack: selectedSoundDown]; } NSUInteger rightRow = [rightOldIndexPath row]; NSUInteger rightSection = [rightOldIndexPath section]; if (soundRow == rightRow && soundSection == rightSection && rightOldIndexPath !=nil){ [selectedSoundDownAndRight removeFromSuperview]; [selectedSoundLeftAndRight removeFromSuperview]; [cell.contentView addSubview: selectedSoundRight]; selectedSoundRight.frame = CGRectMake(200,8,30,30); } else { [cell.contentView sendSubviewToBack: selectedSoundRight]; } // combos if (soundRow == leftRow && soundRow == downRow && soundSection == leftSection && soundSection == downSection){ [selectedSoundLeft removeFromSuperview]; [selectedSoundDown removeFromSuperview]; [selectedSoundLeftAndDownAndRight removeFromSuperview]; [cell.contentView addSubview: selectedSoundLeftAndDown]; selectedSoundLeftAndDown.frame = CGRectMake(200,8,30,30); } else { [cell.contentView sendSubviewToBack: selectedSoundLeftAndDown]; } if (soundRow == leftRow && soundRow == rightRow && soundSection == leftSection && soundSection == rightSection){ [selectedSoundLeft removeFromSuperview]; [selectedSoundRight removeFromSuperview]; [selectedSoundLeftAndDownAndRight removeFromSuperview]; [cell.contentView addSubview: selectedSoundLeftAndRight]; selectedSoundLeftAndRight.frame = CGRectMake(200,8,30,30); } else { [cell.contentView sendSubviewToBack: selectedSoundLeftAndRight]; } if (soundRow == downRow && soundRow == rightRow && soundSection == downSection && soundSection == rightSection){ [selectedSoundDown removeFromSuperview]; [selectedSoundRight removeFromSuperview]; [selectedSoundLeftAndDownAndRight removeFromSuperview]; [cell.contentView addSubview: selectedSoundDownAndRight]; selectedSoundDownAndRight.frame = CGRectMake(200,8,30,30); } else { [cell.contentView sendSubviewToBack: selectedSoundDownAndRight]; } if (soundRow == leftRow && soundRow == downRow && soundRow == rightRow && soundSection == leftSection && soundSection == downSection && soundSection == rightSection){ [selectedSoundLeftAndDown removeFromSuperview]; [selectedSoundLeftAndRight removeFromSuperview]; [selectedSoundDownAndRight removeFromSuperview]; [selectedSoundLeft removeFromSuperview]; [selectedSoundDown removeFromSuperview]; [selectedSoundRight removeFromSuperview]; [cell.contentView addSubview: selectedSoundLeftAndDownAndRight]; selectedSoundLeftAndDownAndRight.frame = CGRectMake(200,8,30,30); } else { [cell.contentView sendSubviewToBack: selectedSoundLeftAndDownAndRight]; } [indexPath retain]; return cell; } - (NSMutableString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section { if ([categories count] == 0) return nil; NSMutableString *key = [categories objectAtIndex:section]; if (key == UITableViewIndexSearch) return nil; return key; } - (NSMutableArray *)sectionIndexTitlesForTableView:(UITableView *)tableView { if (isSearching) return nil; return categories; } - (NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath { [table reloadData]; [selectedSoundLeft removeFromSuperview]; [selectedSoundDown removeFromSuperview]; [selectedSoundRight removeFromSuperview]; [selectedSoundLeftAndDown removeFromSuperview]; [selectedSoundLeftAndRight removeFromSuperview]; [selectedSoundDownAndRight removeFromSuperview]; [selectedSoundLeftAndDownAndRight removeFromSuperview]; [search resignFirstResponder]; if (isSearching == YES && [search.text length] != 0 ){ searched = YES; } search.text = @""; isSearching = NO; [tableView reloadData]; [indexPath retain]; [indexPath retain]; return indexPath; } - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { [table reloadData]; selectedIndexPath = indexPath; [table reloadData]; NSInteger section = [indexPath section]; NSInteger row = [indexPath row]; NSString *key = [categories objectAtIndex:section]; NSArray *sound = [categoriesSounds objectForKey:key]; NSString *soundName = [[sound objectAtIndex: row] objectAtIndex: 0]; [indexPath retain]; [indexPath retain]; NSMutableString *title = [NSMutableString stringWithString: @"Assign Gesture for "]; NSMutableString *soundFeedback = [NSMutableString stringWithString: (@"%@", soundName)]; [title appendString: soundFeedback]; UIActionSheet *action = [[UIActionSheet alloc] initWithTitle:(@"%@", title) delegate:self cancelButtonTitle:@"Cancel" destructiveButtonTitle: nil otherButtonTitles:@"Left",@"Down",@"Right",nil]; action.actionSheetStyle = UIActionSheetStyleDefault; [action showInView:self.view]; [action release]; } - (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex{ NSInteger section = [selectedIndexPath section]; NSInteger row = [selectedIndexPath row]; NSString *key = [categories objectAtIndex:section]; NSArray *sound = [categoriesSounds objectForKey:key]; NSString *soundName = [[sound objectAtIndex: row] objectAtIndex: 0]; NSString *soundOfType = [[sound objectAtIndex: row] objectAtIndex: 1]; NSUInteger soundSection = [[[sound objectAtIndex: row] objectAtIndex: 2] integerValue]; NSUInteger soundRow = [[[sound objectAtIndex: row] objectAtIndex: 3] integerValue]; NSLog(@"sound row is %i", soundRow); NSLog(@"sound section is row is %i", soundSection); typedef enum { kLeftButton = 0, kDownButton, kRightButton, kCancelButton } gesture; switch (buttonIndex) { //Left case kLeftButton: showLeft.text = soundName; left = [[NSBundle mainBundle] pathForResource:(@"%@", soundName) ofType:(@"%@", soundOfType)]; AudioServicesCreateSystemSoundID((CFURLRef)[NSURL fileURLWithPath:left], &soundNegZ); AudioServicesPlaySystemSound (soundNegZ); [table deselectRowAtIndexPath:selectedIndexPath animated:YES]; leftIndexSection = [NSNumber numberWithInteger:section]; leftIndexRow = [NSNumber numberWithInteger:row]; NSInteger leftSection = [leftIndexSection integerValue]; NSInteger leftRow = [leftIndexRow integerValue]; NSString *leftKey = [categories objectAtIndex: leftSection]; NSArray *leftSound = [categoriesSounds objectForKey:leftKey]; NSInteger leftSoundSection = [[[leftSound objectAtIndex: leftRow] objectAtIndex: 2] integerValue]; NSInteger leftSoundRow = [[[leftSound objectAtIndex: leftRow] objectAtIndex: 3] integerValue]; leftOldIndexPath = [NSIndexPath indexPathForRow:leftSoundRow inSection:leftSoundSection]; break; //Down case kDownButton: showDown.text = soundName; down = [[NSBundle mainBundle] pathForResource:(@"%@", soundName) ofType:(@"%@", soundOfType)]; AudioServicesCreateSystemSoundID((CFURLRef)[NSURL fileURLWithPath:down], &soundNegX); AudioServicesPlaySystemSound (soundNegX); [table deselectRowAtIndexPath:selectedIndexPath animated:YES]; downIndexSection = [NSNumber numberWithInteger:section]; downIndexRow = [NSNumber numberWithInteger:row]; NSInteger downSection = [downIndexSection integerValue]; NSInteger downRow = [downIndexRow integerValue]; NSString *downKey = [categories objectAtIndex: downSection]; NSArray *downSound = [categoriesSounds objectForKey:downKey]; NSInteger downSoundSection = [[[downSound objectAtIndex: downRow] objectAtIndex: 2] integerValue]; NSInteger downSoundRow = [[[downSound objectAtIndex: downRow] objectAtIndex: 3] integerValue]; downOldIndexPath = [NSIndexPath indexPathForRow:downSoundRow inSection:downSoundSection]; break; //Right case kRightButton: showRight.text = soundName; right = [[NSBundle mainBundle] pathForResource:(@"%@", soundName) ofType:(@"%@", soundOfType)]; AudioServicesCreateSystemSoundID((CFURLRef)[NSURL fileURLWithPath:right], &soundPosX); AudioServicesPlaySystemSound (soundPosX); [table deselectRowAtIndexPath:selectedIndexPath animated:YES]; rightIndexSection = [NSNumber numberWithInteger:section]; rightIndexRow = [NSNumber numberWithInteger:row]; NSInteger rightSection = [rightIndexSection integerValue]; NSInteger rightRow = [rightIndexRow integerValue]; NSString *rightKey = [categories objectAtIndex: rightSection]; NSArray *rightSound = [categoriesSounds objectForKey:rightKey]; NSInteger rightSoundSection = [[[rightSound objectAtIndex: rightRow] objectAtIndex: 2] integerValue]; NSInteger rightSoundRow = [[[rightSound objectAtIndex: rightRow] objectAtIndex: 3] integerValue]; rightOldIndexPath = [NSIndexPath indexPathForRow:rightSoundRow inSection:rightSoundSection]; break; case kCancelButton: [table deselectRowAtIndexPath:selectedIndexPath animated:YES]; break; default: break; } UITableViewCell *viewCell = [table cellForRowAtIndexPath: selectedIndexPath]; NSArray *subviews = viewCell.subviews; for (UIView *cellView in subviews){ cellView.alpha = 1; } [table reloadData]; } - (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSMutableString *)title atIndex:(NSInteger)index { NSMutableString *category = [categories objectAtIndex:index]; if (category == UITableViewIndexSearch) { [tableView setContentOffset:CGPointZero animated:NO]; return NSNotFound; } else return index; }

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  • How can I resolve Hibernate 3's ConstraintViolationException when updating a Persistent Entity's Col

    - by Tim Visher
    I'm trying to discover why two nearly identical class sets are behaving different from Hibernate 3's perspective. I'm fairly new to Hibernate in general and I'm hoping I'm missing something fairly obvious about the mappings or timing issues or something along those lines but I spent the whole day yesterday staring at the two sets and any differences that would lead to one being able to be persisted and the other not completely escaped me. I appologize in advance for the length of this question but it all hinges around some pretty specific implementation details. I have the following class mapped with Annotations and managed by Hibernate 3.? (if the specific specific version turns out to be pertinent, I'll figure out what it is). Java version is 1.6. ... @Embeddable public class JobStateChange implements Comparable<JobStateChange> { @Temporal(TemporalType.TIMESTAMP) @Column(nullable = false) private Date date; @Enumerated(EnumType.STRING) @Column(nullable = false, length = JobState.FIELD_LENGTH) private JobState state; @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "acting_user_id", nullable = false) private User actingUser; public JobStateChange() { } @Override public int compareTo(final JobStateChange o) { return this.date.compareTo(o.date); } @Override public boolean equals(final Object obj) { if (this == obj) { return true; } else if (!(obj instanceof JobStateChange)) { return false; } JobStateChange candidate = (JobStateChange) obj; return this.state == candidate.state && this.actingUser.equals(candidate.getUser()) && this.date.equals(candidate.getDate()); } @Override public int hashCode() { return this.state.hashCode() + this.actingUser.hashCode() + this.date.hashCode(); } } It is mapped as a Hibernate CollectionOfElements in the class Job as follows: ... @Entity @Table( name = "job", uniqueConstraints = { @UniqueConstraint( columnNames = { "agency", //Job Name "payment_type", //Job Name "payment_file", //Job Name "date_of_payment", "payment_control_number", "truck_number" }) }) public class Job implements Serializable { private static final long serialVersionUID = -1131729422634638834L; ... @org.hibernate.annotations.CollectionOfElements @JoinTable(name = "job_state", joinColumns = @JoinColumn(name = "job_id")) @Sort(type = SortType.NATURAL) private final SortedSet<JobStateChange> stateChanges = new TreeSet<JobStateChange>(); ... public void advanceState( final User actor, final Date date) { JobState nextState; LOGGER.debug("Current state of {} is {}.", this, this.getCurrentState()); if (null == this.currentState) { nextState = JobState.BEGINNING; } else { if (!this.isAdvanceable()) { throw new IllegalAdvancementException(this.currentState.illegalAdvancementStateMessage); } if (this.currentState.isDivergent()) { nextState = this.currentState.getNextState(this); } else { nextState = this.currentState.getNextState(); } } JobStateChange stateChange = new JobStateChange(nextState, actor, date); this.setCurrentState(stateChange.getState()); this.stateChanges.add(stateChange); LOGGER.debug("Advanced {} to {}", this, this.getCurrentState()); } private void setCurrentState(final JobState jobState) { this.currentState = jobState; } boolean isAdvanceable() { return this.getCurrentState().isAdvanceable(this); } ... @Override public boolean equals(final Object obj) { if (obj == this) { return true; } else if (!(obj instanceof Job)) { return false; } Job otherJob = (Job) obj; return this.getName().equals(otherJob.getName()) && this.getDateOfPayment().equals(otherJob.getDateOfPayment()) && this.getPaymentControlNumber().equals(otherJob.getPaymentControlNumber()) && this.getTruckNumber().equals(otherJob.getTruckNumber()); } @Override public int hashCode() { return this.getName().hashCode() + this.getDateOfPayment().hashCode() + this.getPaymentControlNumber().hashCode() + this.getTruckNumber().hashCode(); } ... } The purpose of JobStateChange is to record when the Job moves through a series of State Changes that are outline in JobState as enums which know about advancement and decrement rules. The interface used to advance Jobs through a series of states is to call Job.advanceState() with a Date and a User. If the Job is advanceable according to rules coded in the enum, then a new StateChange is added to the SortedSet and everyone's happy. If not, an IllegalAdvancementException is thrown. The DDL this generates is as follows: ... drop table job; drop table job_state; ... create table job ( id bigint generated by default as identity, current_state varchar(25), date_of_payment date not null, beginningCheckNumber varchar(8) not null, item_count integer, agency varchar(10) not null, payment_file varchar(25) not null, payment_type varchar(25) not null, endingCheckNumber varchar(8) not null, payment_control_number varchar(4) not null, truck_number varchar(255) not null, wrapping_system_type varchar(15) not null, printer_id bigint, primary key (id), unique (agency, payment_type, payment_file, date_of_payment, payment_control_number, truck_number) ); create table job_state ( job_id bigint not null, acting_user_id bigint not null, date timestamp not null, state varchar(25) not null, primary key (job_id, acting_user_id, date, state) ); ... alter table job add constraint FK19BBD12FB9D70 foreign key (printer_id) references printer; alter table job_state add constraint FK57C2418FED1F0D21 foreign key (acting_user_id) references app_user; alter table job_state add constraint FK57C2418FABE090B3 foreign key (job_id) references job; ... The database is seeded with the following data prior to running tests ... insert into job (id, agency, payment_type, payment_file, payment_control_number, date_of_payment, beginningCheckNumber, endingCheckNumber, item_count, current_state, printer_id, wrapping_system_type, truck_number) values (-3, 'RRB', 'Monthly', 'Monthly','4501','1998-12-01 08:31:16' , '00000001','00040000', 40000, 'UNASSIGNED', null, 'KERN', '02'); insert into job_state (job_id, acting_user_id, date, state) values (-3, -1, '1998-11-30 08:31:17', 'UNASSIGNED'); ... After the database schema is automatically generated and rebuilt by the Hibernate tool. The following test runs fine up until the call to Session.flush() ... @ContextConfiguration(locations = { "/applicationContext-data.xml", "/applicationContext-service.xml" }) public class JobDaoIntegrationTest extends AbstractTransactionalJUnit4SpringContextTests { @Autowired private JobDao jobDao; @Autowired private SessionFactory sessionFactory; @Autowired private UserService userService; @Autowired private PrinterService printerService; ... @Test public void saveJob_JobAdvancedToAssigned_AllExpectedStateChanges() { //Get an unassigned Job Job job = this.jobDao.getJob(-3L); assertEquals(JobState.UNASSIGNED, job.getCurrentState()); Date advancedToUnassigned = new GregorianCalendar(1998, 10, 30, 8, 31, 17).getTime(); assertEquals(advancedToUnassigned, job.getStateChange(JobState.UNASSIGNED).getDate()); //Satisfy advancement constraints and advance job.setPrinter(this.printerService.getPrinter(-1L)); Date advancedToAssigned = new Date(); job.advanceState( this.userService.getUserByUsername("admin"), advancedToAssigned); assertEquals(JobState.ASSIGNED, job.getCurrentState()); assertEquals(advancedToUnassigned, job.getStateChange(JobState.UNASSIGNED).getDate()); assertEquals(advancedToAssigned, job.getStateChange(JobState.ASSIGNED).getDate()); //Persist to DB this.sessionFactory.getCurrentSession().flush(); ... } ... } The error thrown is SQLCODE=-803, SQLSTATE=23505: could not insert collection rows: [jaci.model.job.Job.stateChanges#-3] org.hibernate.exception.ConstraintViolationException: could not insert collection rows: [jaci.model.job.Job.stateChanges#-3] at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:94) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) at org.hibernate.persister.collection.AbstractCollectionPersister.insertRows(AbstractCollectionPersister.java:1416) at org.hibernate.action.CollectionUpdateAction.execute(CollectionUpdateAction.java:86) at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:170) at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50) at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027) at jaci.dao.JobDaoIntegrationTest.saveJob_JobAdvancedToAssigned_AllExpectedStateChanges(JobDaoIntegrationTest.java:98) at org.springframework.test.context.junit4.SpringTestMethod.invoke(SpringTestMethod.java:160) at org.springframework.test.context.junit4.SpringMethodRoadie.runTestMethod(SpringMethodRoadie.java:233) at org.springframework.test.context.junit4.SpringMethodRoadie$RunBeforesThenTestThenAfters.run(SpringMethodRoadie.java:333) at org.springframework.test.context.junit4.SpringMethodRoadie.runWithRepetitions(SpringMethodRoadie.java:217) at org.springframework.test.context.junit4.SpringMethodRoadie.runTest(SpringMethodRoadie.java:197) at org.springframework.test.context.junit4.SpringMethodRoadie.run(SpringMethodRoadie.java:143) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.invokeTestMethod(SpringJUnit4ClassRunner.java:160) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:97) Caused by: com.ibm.db2.jcc.b.lm: DB2 SQL Error: SQLCODE=-803, SQLSTATE=23505, SQLERRMC=1;ACI_APP.JOB_STATE, DRIVER=3.50.152 at com.ibm.db2.jcc.b.wc.a(wc.java:575) at com.ibm.db2.jcc.b.wc.a(wc.java:57) at com.ibm.db2.jcc.b.wc.a(wc.java:126) at com.ibm.db2.jcc.b.tk.b(tk.java:1593) at com.ibm.db2.jcc.b.tk.c(tk.java:1576) at com.ibm.db2.jcc.t4.db.k(db.java:353) at com.ibm.db2.jcc.t4.db.a(db.java:59) at com.ibm.db2.jcc.t4.t.a(t.java:50) at com.ibm.db2.jcc.t4.tb.b(tb.java:200) at com.ibm.db2.jcc.b.uk.Gb(uk.java:2355) at com.ibm.db2.jcc.b.uk.e(uk.java:3129) at com.ibm.db2.jcc.b.uk.zb(uk.java:568) at com.ibm.db2.jcc.b.uk.executeUpdate(uk.java:551) at org.hibernate.jdbc.NonBatchingBatcher.addToBatch(NonBatchingBatcher.java:46) at org.hibernate.persister.collection.AbstractCollectionPersister.insertRows(AbstractCollectionPersister.java:1389) Therein lies my problem… A nearly identical Class set (in fact, so identical that I've been chomping at the bit to make it a single class that serves both business entities) runs absolutely fine. It is identical except for name. Instead of Job it's Web. Instead of JobStateChange it's WebStateChange. Instead of JobState it's WebState. Both Job and Web's SortedSet of StateChanges are mapped as a Hibernate CollectionOfElements. Both are @Embeddable. Both are SortType.Natural. Both are backed by an Enumeration with some advancement rules in it. And yet when a nearly identical test is run for Web, no issue is discovered and the data flushes fine. For the sake of brevity I won't include all of the Web classes here, but I will include the test and if anyone wants to see the actual sources, I'll include them (just leave a comment). The data seed: insert into web (id, stock_type, pallet, pallet_id, date_received, first_icn, last_icn, shipment_id, current_state) values (-1, 'PF', '0011', 'A', '2008-12-31 08:30:02', '000000001', '000080000', -1, 'UNSTAGED'); insert into web_state (web_id, date, state, acting_user_id) values (-1, '2008-12-31 08:30:03', 'UNSTAGED', -1); The test: ... @ContextConfiguration(locations = { "/applicationContext-data.xml", "/applicationContext-service.xml" }) public class WebDaoIntegrationTest extends AbstractTransactionalJUnit4SpringContextTests { @Autowired private WebDao webDao; @Autowired private UserService userService; @Autowired private SessionFactory sessionFactory; ... @Test public void saveWeb_WebAdvancedToNewState_AllExpectedStateChanges() { Web web = this.webDao.getWeb(-1L); Date advancedToUnstaged = new GregorianCalendar(2008, 11, 31, 8, 30, 3).getTime(); assertEquals(WebState.UNSTAGED, web.getCurrentState()); assertEquals(advancedToUnstaged, web.getState(WebState.UNSTAGED).getDate()); Date advancedToStaged = new Date(); web.advanceState( this.userService.getUserByUsername("admin"), advancedToStaged); this.sessionFactory.getCurrentSession().flush(); web = this.webDao.getWeb(web.getId()); assertEquals( "Web should have moved to STAGED State.", WebState.STAGED, web.getCurrentState()); assertEquals(advancedToUnstaged, web.getState(WebState.UNSTAGED).getDate()); assertEquals(advancedToStaged, web.getState(WebState.STAGED).getDate()); assertNotNull(web.getState(WebState.UNSTAGED)); assertNotNull(web.getState(WebState.STAGED)); } ... } As you can see, I assert that the Web was reconstituted the way I expect, I advance it, flush it to the DB, and then re-get it and verify that the states are as I expect. Everything works perfectly. Not so with Job. A possibly pertinent detail: the reconstitution code works fine if I cease to map JobStateChange.data as a TIMESTAMP and instead as a DATE, and ensure that all of the StateChanges always occur on different Dates. The problem is that this particular business entity can go through many state changes in a single day and so it needs to be sorted by time stamp rather than by date. If I don't do this then I can't sort the StateChanges correctly. That being said, WebStateChange.date is also mapped as a TIMESTAMP and so I again remain absolutely befuddled as to where this error is arising from. I tried to do a fairly thorough job of giving all of the technical details of the implementation but as this particular question is very implementation specific, if I missed anything just let me know in the comments and I'll include it. Thanks so much for your help! UPDATE: Since it turns out to be important to the solution of my problem, I have to include the pertinent bits of the WebStateChange class as well. ... @Embeddable public class WebStateChange implements Comparable<WebStateChange> { @Temporal(TemporalType.TIMESTAMP) @Column(nullable = false) private Date date; @Enumerated(EnumType.STRING) @Column(nullable = false, length = WebState.FIELD_LENGTH) private WebState state; @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "acting_user_id", nullable = false) private User actingUser; ... WebStateChange( final WebState state, final User actingUser, final Date date) { ExceptionUtils.illegalNullArgs(state, actingUser, date); this.state = state; this.actingUser = actingUser; this.date = new Date(date.getTime()); } @Override public int compareTo(final WebStateChange otherStateChange) { return this.date.compareTo(otherStateChange.date); } @Override public boolean equals(final Object candidate) { if (this == candidate) { return true; } else if (!(candidate instanceof WebStateChange)) { return false; } WebStateChange candidateWebState = (WebStateChange) candidate; return this.getState() == candidateWebState.getState() && this.getUser().equals(candidateWebState.getUser()) && this.getDate().equals(candidateWebState.getDate()); } @Override public int hashCode() { return this.getState().hashCode() + this.getUser().hashCode() + this.getDate().hashCode(); } ... }

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  • SQL SERVER – Beginning SQL Server: One Step at a Time – SQL Server Magazine

    - by pinaldave
    I am glad to announce that along with SQLAuthority.com, I will be blogging on the prominent site of SQL Server Magazine. My very first blog post there is already live; read here: Beginning SQL Server: One Step at a Time. My association with SQL Server Magazine has been quite long, I have written nearly 7 to 8 SQL Server articles for the print magazine and it has been a great experience. I used to stay in the United States at that time. I moved back to India for good, and during this process, I had put everything on hold for a while. Just like many things, “temporary” things become “permanent” – coming back to SQLMag was on hold for long time. Well, this New Year, things have changed – once again, I am back with my online presence at SQLMag.com. Everybody is a beginner at every task or activity at some point of his/her life: spelling words for the first time; learning how to drive for the first time, etc. No one is perfect at the start of any task, but every human is different. As time passes, we all develop our interests and begin to study our subject of interest. Most of us dream to get a job in the area of our study – however things change as time passes. I recently read somewhere online (I could not find the link again while writing this one) that all the successful people in various areas have never studied in the area in which they are successful. After going through a formal learning process of what we love, we refuse to stop learning, and we finally stop changing career and focus areas. We move, we dare and we progress. IT field is similar to our life. New IT professionals come to this field every day. There are two types of beginners – a) those who are associated with IT field but not familiar with other technologies, and b) those who are absolutely new to the IT field. Learning a new technology is always exciting and overwhelming for enthusiasts. I am working with database (in particular) for SQL Server for more than 7 years but I am still overwhelmed with so many things to learn. I continue to learn and I do not think that I should ever stop doing so. Just like everybody, I want to be in the race and get ahead in learning the technology. For the same, I am always looking for good guidance. I always try to find a good article, blog or book chapter, which can teach me what I really want to learn at this stage in my career and can be immensely helpful. Quite often, I prefer to read the material where the author does not judge me or assume my understanding. I like to read new concepts like a child, who takes his/her first steps of learning without any prior knowledge. Keeping my personal philosophy and preference in mind, I will be blogging on SQL Server Magazine site. I will be blogging on the beginners stuff. I will be blogging for them, who really want to start and make a mark in this area. I will be blogging for all those who have an extreme passion for learning. I am happy that this is a good start for this year. One of my resolutions is to help every beginner. It is totally possible that in future they all will grow and find the same article quite ‘easy‘ – well when that happens, it indicates the success of the article and material! Well, I encourage everybody to read my SQL Server Magazine blog – I will be blogging there frequently on various topics. To begin, we will be talking about performance tuning, and I assure that I will not shy away from other multiple areas. Read my SQL Server Magazine Blog: Beginning SQL Server: One Step at a Time I think the title says it all. Do leave your comments and feedback to indicate your preference of subject and interest. I am going to continue writing on subject, and the aim is of course to help grow in this field. Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Optimization, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology

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  • C#: System.Lazy&lt;T&gt; and the Singleton Design Pattern

    - by James Michael Hare
    So we've all coded a Singleton at one time or another.  It's a really simple pattern and can be a slightly more elegant alternative to global variables.  Make no mistake, Singletons can be abused and are often over-used -- but occasionally you find a Singleton is the most elegant solution. For those of you not familiar with a Singleton, the basic Design Pattern is that a Singleton class is one where there is only ever one instance of the class created.  This means that constructors must be private to avoid users creating their own instances, and a static property (or method in languages without properties) is defined that returns a single static instance. 1: public class Singleton 2: { 3: // the single instance is defined in a static field 4: private static readonly Singleton _instance = new Singleton(); 5:  6: // constructor private so users can't instantiate on their own 7: private Singleton() 8: { 9: } 10:  11: // read-only property that returns the static field 12: public static Singleton Instance 13: { 14: get 15: { 16: return _instance; 17: } 18: } 19: } This is the most basic singleton, notice the key features: Static readonly field that contains the one and only instance. Constructor is private so it can only be called by the class itself. Static property that returns the single instance. Looks like it satisfies, right?  There's just one (potential) problem.  C# gives you no guarantee of when the static field _instance will be created.  This is because the C# standard simply states that classes (which are marked in the IL as BeforeFieldInit) can have their static fields initialized any time before the field is accessed.  This means that they may be initialized on first use, they may be initialized at some other time before, you can't be sure when. So what if you want to guarantee your instance is truly lazy.  That is, that it is only created on first call to Instance?  Well, there's a few ways to do this.  First we'll show the old ways, and then talk about how .Net 4.0's new System.Lazy<T> type can help make the lazy-Singleton cleaner. Obviously, we could take on the lazy construction ourselves, but being that our Singleton may be accessed by many different threads, we'd need to lock it down. 1: public class LazySingleton1 2: { 3: // lock for thread-safety laziness 4: private static readonly object _mutex = new object(); 5:  6: // static field to hold single instance 7: private static LazySingleton1 _instance = null; 8:  9: // property that does some locking and then creates on first call 10: public static LazySingleton1 Instance 11: { 12: get 13: { 14: if (_instance == null) 15: { 16: lock (_mutex) 17: { 18: if (_instance == null) 19: { 20: _instance = new LazySingleton1(); 21: } 22: } 23: } 24:  25: return _instance; 26: } 27: } 28:  29: private LazySingleton1() 30: { 31: } 32: } This is a standard double-check algorithm so that you don't lock if the instance has already been created.  However, because it's possible two threads can go through the first if at the same time the first time back in, you need to check again after the lock is acquired to avoid creating two instances. Pretty straightforward, but ugly as all heck.  Well, you could also take advantage of the C# standard's BeforeFieldInit and define your class with a static constructor.  It need not have a body, just the presence of the static constructor will remove the BeforeFieldInit attribute on the class and guarantee that no fields are initialized until the first static field, property, or method is called.   1: public class LazySingleton2 2: { 3: // because of the static constructor, this won't get created until first use 4: private static readonly LazySingleton2 _instance = new LazySingleton2(); 5:  6: // Returns the singleton instance using lazy-instantiation 7: public static LazySingleton2 Instance 8: { 9: get { return _instance; } 10: } 11:  12: // private to prevent direct instantiation 13: private LazySingleton2() 14: { 15: } 16:  17: // removes BeforeFieldInit on class so static fields not 18: // initialized before they are used 19: static LazySingleton2() 20: { 21: } 22: } Now, while this works perfectly, I hate it.  Why?  Because it's relying on a non-obvious trick of the IL to guarantee laziness.  Just looking at this code, you'd have no idea that it's doing what it's doing.  Worse yet, you may decide that the empty static constructor serves no purpose and delete it (which removes your lazy guarantee).  Worse-worse yet, they may alter the rules around BeforeFieldInit in the future which could change this. So, what do I propose instead?  .Net 4.0 adds the System.Lazy type which guarantees thread-safe lazy-construction.  Using System.Lazy<T>, we get: 1: public class LazySingleton3 2: { 3: // static holder for instance, need to use lambda to construct since constructor private 4: private static readonly Lazy<LazySingleton3> _instance 5: = new Lazy<LazySingleton3>(() => new LazySingleton3()); 6:  7: // private to prevent direct instantiation. 8: private LazySingleton3() 9: { 10: } 11:  12: // accessor for instance 13: public static LazySingleton3 Instance 14: { 15: get 16: { 17: return _instance.Value; 18: } 19: } 20: } Note, you need your lambda to call the private constructor as Lazy's default constructor can only call public constructors of the type passed in (which we can't have by definition of a Singleton).  But, because the lambda is defined inside our type, it has access to the private members so it's perfect. Note how the Lazy<T> makes it obvious what you're doing (lazy construction), instead of relying on an IL generation side-effect.  This way, it's more maintainable.  Lazy<T> has many other uses as well, obviously, but I really love how elegant and readable it makes the lazy Singleton.

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  • C# 4.0: Named And Optional Arguments

    - by Paulo Morgado
    As part of the co-evolution effort of C# and Visual Basic, C# 4.0 introduces Named and Optional Arguments. First of all, let’s clarify what are arguments and parameters: Method definition parameters are the input variables of the method. Method call arguments are the values provided to the method parameters. In fact, the C# Language Specification states the following on §7.5: The argument list (§7.5.1) of a function member invocation provides actual values or variable references for the parameters of the function member. Given the above definitions, we can state that: Parameters have always been named and still are. Parameters have never been optional and still aren’t. Named Arguments Until now, the way the C# compiler matched method call definition arguments with method parameters was by position. The first argument provides the value for the first parameter, the second argument provides the value for the second parameter, and so on and so on, regardless of the name of the parameters. If a parameter was missing a corresponding argument to provide its value, the compiler would emit a compilation error. For this call: Greeting("Mr.", "Morgado", 42); this method: public void Greeting(string title, string name, int age) will receive as parameters: title: “Mr.” name: “Morgado” age: 42 What this new feature allows is to use the names of the parameters to identify the corresponding arguments in the form: name:value Not all arguments in the argument list must be named. However, all named arguments must be at the end of the argument list. The matching between arguments (and the evaluation of its value) and parameters will be done first by name for the named arguments and than by position for the unnamed arguments. This means that, for this method definition: public static void Method(int first, int second, int third) this call declaration: int i = 0; Method(i, third: i++, second: ++i); will have this code generated by the compiler: int i = 0; int CS$0$0000 = i++; int CS$0$0001 = ++i; Method(i, CS$0$0001, CS$0$0000); which will give the method the following parameter values: first: 2 second: 2 third: 0 Notice the variable names. Although invalid being invalid C# identifiers, they are valid .NET identifiers and thus avoiding collision between user written and compiler generated code. Besides allowing to re-order of the argument list, this feature is very useful for auto-documenting the code, for example, when the argument list is very long or not clear, from the call site, what the arguments are. Optional Arguments Parameters can now have default values: public static void Method(int first, int second = 2, int third = 3) Parameters with default values must be the last in the parameter list and its value is used as the value of the parameter if the corresponding argument is missing from the method call declaration. For this call declaration: int i = 0; Method(i, third: ++i); will have this code generated by the compiler: int i = 0; int CS$0$0000 = ++i; Method(i, 2, CS$0$0000); which will give the method the following parameter values: first: 1 second: 2 third: 1 Because, when method parameters have default values, arguments can be omitted from the call declaration, this might seem like method overloading or a good replacement for it, but it isn’t. Although methods like this: public static StreamReader OpenTextFile( string path, Encoding encoding = null, bool detectEncoding = true, int bufferSize = 1024) allow to have its calls written like this: OpenTextFile("foo.txt", Encoding.UTF8); OpenTextFile("foo.txt", Encoding.UTF8, bufferSize: 4096); OpenTextFile( bufferSize: 4096, path: "foo.txt", detectEncoding: false); The complier handles default values like constant fields taking the value and useing it instead of a reference to the value. So, like with constant fields, methods with parameters with default values are exposed publicly (and remember that internal members might be publicly accessible – InternalsVisibleToAttribute). If such methods are publicly accessible and used by another assembly, those values will be hard coded in the calling code and, if the called assembly has its default values changed, they won’t be assumed by already compiled code. At the first glance, I though that using optional arguments for “bad” written code was great, but the ability to write code like that was just pure evil. But than I realized that, since I use private constant fields, it’s OK to use default parameter values on privately accessed methods.

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  • No, iCloud Isn’t Backing Them All Up: How to Manage Photos on Your iPhone or iPad

    - by Chris Hoffman
    Are the photos you take with your iPhone or iPad backed up in case you lose your device? If you’re just relying on iCloud to manage your important memories, your photos may not be backed up at all. Apple’s iCloud has a photo-syncing feature in the form of “Photo Stream,” but Photo Stream doesn’t actually perform any long-term backups of your photos. iCloud’s Photo Backup Limitations Assuming you’ve set up iCloud on your iPhone or iPad, your device is using a feature called “Photo Stream” to automatically upload the photos you take to your iCloud storage and sync them across your devices. Unfortunately, there are some big limitations here. 1000 Photos: Photo Stream only backs up the latest 1000 photos. Do you have 1500 photos in your Camera Roll folder on your phone? If so, only the latest 1000 photos are stored in your iCloud account online. If you don’t have those photos backed up elsewhere, you’ll lose them when you lose your phone. If you have 1000 photos and take one more, the oldest photo will be removed from your iCloud Photo Stream. 30 Days: Apple also states that photos in your Photo Stream will be automatically deleted after 30 days “to give your devices plenty of time to connect and download them.” Some people report photos aren’t deleted after 30 days, but it’s clear you shouldn’t rely on iCloud for more than 30 days of storage. iCloud Storage Limits: Apple only gives you 5 GB of iCloud storage space for free, and this is shared between backups, documents, and all other iCloud data. This 5 GB can fill up pretty quickly. If your iCloud storage is full and you haven’t purchased any more storage more from Apple, your photos aren’t being backed up. Videos Aren’t Included: Photo Stream doesn’t include videos, so any videos you take aren’t automatically backed up. It’s clear that iCloud’s Photo Stream isn’t designed as a long-term way to store your photos, just a convenient way to access recent photos on all your devices before you back them up for real. iCloud’s Photo Stream is Designed for Desktop Backups If you have a Mac, you can launch iPhoto and enable the Automatic Import option under Photo Stream in its preferences pane. Assuming your Mac is on and connected to the Internet, iPhoto will automatically download photos from your photo stream and make local backups of them on your hard drive. You’ll then have to back up your photos manually so you don’t lose them if your Mac’s hard drive ever fails. If you have a Windows PC, you can install the iCloud Control Panel, which will create a Photo Stream folder on your PC. Your photos will be automatically downloaded to this folder and stored in it. You’ll want to back up your photos so you don’t lose them if your PC’s hard drive ever fails. Photo Stream is clearly designed to be used along with a desktop application. Photo Stream temporarily backs up your photos to iCloud so iPhoto or iCloud Control Panel can download them to your Mac or PC and make a local backup before they’re deleted. You could also use iTunes to sync your photos from your device to your PC or Mac, but we don’t really recommend it — you should never have to use iTunes. How to Actually Back Up All Your Photos Online So Photo Stream is actually pretty inconvenient — or, at least, it’s just a way to temporarily sync photos between your devices without storing them long-term. But what if you actually want to automatically back up your photos online without them being deleted automatically? The solution here is a third-party app that does this for you, offering the automatic photo uploads with long-term storage. There are several good services with apps in the App Store: Dropbox: Dropbox’s Camera Upload feature allows you to automatically upload the photos — and videos — you take to your Dropbox account. They’ll be easily accessible anywhere there’s a Dropbox app and you can get much more free Dropbox storage than you can iCloud storage. Dropbox will never automatically delete your old photos. Google+: Google+ offers photo and video backups with its Auto Upload feature, too. Photos will be stored in your Google+ Photos — formerly Picasa Web Albums — and will be marked as private by default so no one else can view them. Full-size photos will count against your free 15 GB of Google account storage space, but you can also choose to upload an unlimited amount of photos at a smaller resolution. Flickr: The Flickr app is no longer a mess. Flickr offers an Auto Upload feature for uploading full-size photos you take and free Flickr accounts offer a massive 1 TB of storage for you to store your photos. The massive amount of free storage alone makes Flickr worth a look. Use any of these services and you’ll get an online, automatic photo backup solution you can rely on. You’ll get a good chunk of free space, your photos will never be automatically deleted, and you can easily access them from any device. You won’t have to worry about storing local copies of your photos and backing them up manually. Apple should fix this mess and offer a better solution for long-term photo backup, especially considering the limitations aren’t immediately obvious to users. Until they do, third-party apps are ready to step in and take their place. You can also automatically back up your photos to the web on Android with Google+’s Auto Upload or Dropbox’s Camera Upload. Image Credit: Simon Yeo on Flickr     

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  • SQLAuthority News – Why VoIP Service Providers Should Think About NuoDB’s Geo Distribution

    - by Pinal Dave
    You can always tell when someone’s showing off their cool, cutting edge comms technology. They tend to raise their voice a lot. Back in the day they’d announce their gadget leadership to the rest of the herd by shouting into their cellphone. Usually the message was no more urgent than “Hi, I’m on my cellphone!” Now the same types will loudly name-drop a different technology to the rest of the airport lounge. “I’m leveraging the wifi,” a fellow passenger bellowed, the other day, as we filtered through the departure gate. Nobody needed to know that, but the subtext was “look at me everybody”. You can tell the really advanced mobile user – they tend to whisper. Their handset has a microphone (how cool is that!) and they know how to use it. Sometimes these shouty public broadcasters aren’t even connected anyway because the database for their Voice over IP (VoIP) platform can’t cope. This will happen if they are using a traditional SQL model to try and cope with a phone network which has far flung offices and hundreds of mobile employees. That, like shouting into your phone, is just wrong on so many levels. What VoIP needs now is a single, logical database across multiple servers in different geographies. It needs to be updated in real-time and automatically scaled out during times of peak demand. A VoIP system should scale up to handle increased traffic, but just as importantly is must then go back down in the off peak hours. Try this with a MySQL database. It can’t scale easily enough, so it will keep your developers busy. They’ll have spent many hours trying to knit the different databases together. Traditional relational databases can possibly achieve this, at a price. Mind you, you could extend baked bean cans and string to every point on the network and that would be no less elegant. That’s not really following engineering principles though is it? Having said that, most telcos and VoIP systems use a separate, independent solution for each office location, which they link together – loosely.  The more office locations, the more complex and expensive the solution becomes and so the more you spend on maintenance. Ideally, you’d have a fluid system that can automatically shift its shape as the need arises. That’s the point of software isn’t it – it adapts. Otherwise, we might as well return to the old days. A MySQL system isn’t exactly baked bean cans attached by string, but it’s closer in spirit to the old many teethed mechanical beast that was employed in the first type of automated switchboard. NuoBD’s NewSQL is designed to be a single database that works across multiple servers, which can scale easily, and scale on demand. That’s one system that gives high connectivity but no latency, complexity or maintenance issues. MySQL works in some circumstances, but a period of growth isn’t one of them. So as a company moves forward, the MySQL database can’t keep pace. Data storage and data replication errors creep in. Soon the diaspora of offices becomes a problem. Your telephone system isn’t just distributed, it is literally all over the place. Though voice calls are often a software function, some of the old habits of telephony remain. When you call an engineer out, some of them will listen to what you’re asking for and announce that it cannot be done. This is what happens if you ask, say, database engineers familiar with Oracle or Microsoft to fulfill your wish for a low maintenance system built on a single, fluid, scalable database. No can do, they’d say. In fact, I heard one shouting something similar into his VoIP handset at the airport. “I can’t get on the network, Mac. I’m on MySQL.” You can download NuoDB from here. “NuoDB provides the ability to replicate data globally in real-time, which is not available with any other product offering,” states Weeks.  “That alone is remarkable and it works. I’ve seen it. I’ve used it.  I’ve tested it. The ability to deploy NuoDB removes a tremendous burden from our support and engineering teams.” Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: NuoDB

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  • Messaging Systems – Handshaking, Reconciliation and Tracking for Data Transparency

    - by Ahsan Alam
    As many corporations build business partnerships with other organizations, the need to share information becomes necessary. Large amount of data sharing using snail mail, email and/or fax are quickly becoming a thing of the past. More and more organizations are relying heavily on Ftp and/or Web Service to exchange data. Corporations apply wide range of technologies and techniques based on available resources and data transfer needs. Sometimes, it involves simple home-grown applications. Other times, large investments are made on products like BizTalk, TIBCO etc. Complexity of information management also varies significantly from one organizations to another. Some may deal with handful of simple steps to process and manage shared data; whereas others may rely on fairly complex processes with heavy interaction with internal and external systems in order to serve the business needs. It is not surprising that many of these systems end up becoming black boxes over a period of time. Consequently, people and business start to rely more and more on developers and support personnel just to extract simple information adding to the loss of productivity. One of the most important factor in any business is transparency to data irrespective of technology preferences and the complexity of business processes. Not knowing the state of data could become very costly to the business. Being involved in messaging systems for some time now, I have heard the same type of questions over and over again. Did we transmit messages successfully? Did we get responses back? What is the expected turn-around-time? Did the system experience any errors? When one company transmits data to one or more company, it may invoke a set of processes that could complete in matter of seconds, or it could days. As data travels from one organizations to another, the uncertainty grows, and the longer it takes to track uncertain state of the data the costlier it gets for the business, So, in every business scenario, it's extremely important to be aware of the state of the data.   Architects of messaging systems can take several steps to aid with data transparency. Some forms of data handshaking and reconciliation mechanism as well as extensive data tracking can be incorporated into the system to provide clear visibility to the data. What do I mean by handshaking and reconciliation? Some might consider these to be a single concept; however, I like to consider them in two unique categories. Handshaking serves as message receipts or acknowledgment. When one transmits messages to another, the receiver must acknowledge each message by sending immediate responses for each transaction. Whenever we use Web Services, handshaking is often achieved utilizing request/reply pattern. Similarly, if Ftp is used, a receiver can acknowledge by dropping messages for the sender as soon as the files are picked up. These forms of handshaking or acknowledgment informs the message sender and receiver that a successful transaction has occurred. I have mentioned earlier that it could take anywhere from a few seconds to a number of days before shared data is completely processed. In addition, whenever a batched transaction is used, processing time for each data element inside the batch could also vary significantly. So, in order to successfully manage data processing, reconciliation becomes extremely important; otherwise it may result into data loss or in some cases hefty penalty. Reconciliation can be done in many ways. Partner organizations can share and compare ad hoc reports to achieve reconciliation. On the other hand, partners can agree on some type of systematic reconciliation messages. Systems within responsible parties can trigger messages to partners as soon as the data process completes.   Next step in the data transparency is extensive data tracking. Some products such as BizTalk and TIBCO provide built-in functionality for data tracking; however, built-in functionality may not always be adequate. Sometimes additional tracking system (or databases) needs to be built in order monitor all types of data flow including, message transactions, handshaking, reconciliation, system errors and many more. If these types of data are captured, then these can be presented to business users in any forms or fashion. When business users are empowered with such information, then the reliance on developers and support teams decreases dramatically.   In today's collaborative world of information sharing, data transparency is key to the success of every business. The state of business data will constantly change. However, when people have easier access to various states of data, it allows them to make better and quicker decisions. Therefore, I feel that data handshaking, reconciliation and tracking is very important aspect of messaging systems.

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  • SQL SERVER – Solution – Puzzle – SELECT * vs SELECT COUNT(*)

    - by pinaldave
    Earlier I have published Puzzle Why SELECT * throws an error but SELECT COUNT(*) does not. This question have received many interesting comments. Let us go over few of the answers, which are valid. Before I start the same, let me acknowledge Rob Farley who has not only answered correctly very first but also started interesting conversation in the same thread. The usual question will be what is the right answer. I would like to point to official Microsoft Connect Items which discusses the same. RGarvao https://connect.microsoft.com/SQLServer/feedback/details/671475/select-test-where-exists-select tiberiu utan http://connect.microsoft.com/SQLServer/feedback/details/338532/count-returns-a-value-1 Rob Farley count(*) is about counting rows, not a particular column. It doesn’t even look to see what columns are available, it’ll just count the rows, which in the case of a missing FROM clause, is 1. “select *” is designed to return columns, and therefore barfs if there are none available. Even more odd is this one: select ‘blah’ where exists (select *) You might be surprised at the results… Koushik The engine performs a “Constant scan” for Count(*) where as in the case of “SELECT *” the engine is trying to perform either Index/Cluster/Table scans. amikolaj When you query ‘select * from sometable’, SQL replaces * with the current schema of that table. With out a source for the schema, SQL throws an error. so when you query ‘select count(*)’, you are counting the one row. * is just a constant to SQL here. Check out the execution plan. Like the description states – ‘Scan an internal table of constants.’ You could do ‘select COUNT(‘my name is adam and this is my answer’)’ and get the same answer. Netra Acharya SELECT * Here, * represents all columns from a table. So it always looks for a table (As we know, there should be FROM clause before specifying table name). So, it throws an error whenever this condition is not satisfied. SELECT COUNT(*) Here, COUNT is a Function. So it is not mandetory to provide a table. Check it out this: DECLARE @cnt INT SET @cnt = COUNT(*) SELECT @cnt SET @cnt = COUNT(‘x’) SELECT @cnt Naveen Select 1 / Select ‘*’ will return 1/* as expected. Select Count(1)/Count(*) will return the count of result set of select statement. Count(1)/Count(*) will have one 1/* for each row in the result set of select statement. Select 1 or Select ‘*’ result set will contain only 1 result. so count is 1. Where as “Select *” is a sysntax which expects the table or equauivalent to table (table functions, etc..). It is like compilation error for that query. Ramesh Hi Friends, Count is an aggregate function and it expects the rows (list of records) for a specified single column or whole rows for *. So, when we use ‘select *’ it definitely give and error because ‘*’ is meant to have all the fields but there is not any table and without table it can only raise an error. So, in the case of ‘Select Count(*)’, there will be an error as a record in the count function so you will get the result as ’1'. Try using : Select COUNT(‘RAMESH’) and think there is an error ‘Must specify table to select from.’ in place of ‘RAMESH’ Pinal : If i am wrong then please clarify this. Sachin Nandanwar Any aggregate function expects a constant or a column name as an expression. DO NOT be confused with * in an aggregate function.The aggregate function does not treat it as a column name or a set of column names but a constant value, as * is a key word in SQL. You can replace any value instead of * for the COUNT function.Ex Select COUNT(5) will result as 1. The error resulting from select * is obvious it expects an object where it can extract the result set. I sincerely thank you all for wonderful conversation, I personally enjoyed it and I am sure all of you have the same feeling. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: CodeProject, Pinal Dave, PostADay, Readers Contribution, Readers Question, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQLServer, T SQL, Technology

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  • Team Leaders & Authors - Manage and Report Workflow using "Print an Outline" in UPK

    - by [email protected]
    Did you know you can "print an outline?" You can print any outline or portion of an outline. Why might you want to "print an outline" in UPK... Have you ever wondered how many topics you have recorded, how many of your topics are ready for review, or even better, how many topics are complete! Do you need to report your project status to management? Maybe you just like to have a copy of your outline to refer to during development. Included in this output is the outline structure as well as the layout defined in the Details View of the Outline Editor. To print an outline, you must open either a module or section in the Outline Editor. A set of default data columns is automatically included in the output; however, you can configure which columns you want to appear in the report by switching to the Details view and customizing the columns. (To learn more about customizing your columns refer to the Add and Remove Columns section of the Content Development.pdf guide) To print an outline from the Outline Editor: 1. Open a module or section document in the Outline Editor. 2. Expand the documents to display the details that you want included in the report. 3. On the File menu, choose Print and use the toolbar icons to print, view, or save the report to a file. Personally, I opt to save my outline in Microsoft Excel. Using the delivered features of Microsoft Excel you can add columns of information, such as development notes, to your outline or you can graph and chart your Project status. As mentioned above you can configure what columns you want to appear in the outline. When utilizing the Print an Outline feature in conjunction with the Managing Workflow features of the UPK Multi-user instance you as a Team Lead or Author can better report project status. Read more about Managing Workflow below. Managing Workflow: The Properties toolpane contains special properties that allow authors to track document status or State as well as assign Document Ownership. Assign Content State The State property is an editable property for communicating the status of a document. This is particularly helpful when collaborating with other authors in a development team. Authors can assign a state to documents from the master list defined by the administrator. The default list of States includes (blank), Not Started, Draft, In Review, and Final. Administrators can customize the list by adding, deleting or renaming the values. To assign a State value to a document: 1. Make sure you are working online. 2. Display the Properties toolpane. 3. Select the document(s) to which you want to assign a state. Note: You can select multiple documents using the standard Windows selection keys (CTRL+click and SHIFT+click). 4. In the Workflow category, click in the State cell. 5. Select a value from the list. Assign Document Ownership In many enterprises, multiple authors often work together developing content in a team environment. Team leaders typically handle large projects by assigning specific development responsibilities to authors. The Owner property allows team leaders and authors to assign documents to themselves and other authors to track who is responsible for a specific document. You view and change document assignments for a document using the Owner property in the Properties toolpane. To assign a document owner: 1. Make sure you are working online. 2. On the View menu, choose Properties. 3. Select the document(s) to which you want to assign document responsibility. Note: You can select multiple documents using the standard Windows selection keys (CTRL+click and SHIFT+click). 4. In the Workflow category, click in the Owner cell. 5. Select a name from the list. Is anyone out there already using this feature? Share your ideas with the group. Those of you new to this feature, give it a test drive and let us know what you think. - Kathryn Lustenberger, Oracle UPK & Tutor Outbound Product Management

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  • Lync Server 2010

    - by ManojDhobale
    Microsoft Lync Server 2010 communications software and its client software, such as Microsoft Lync 2010, enable your users to connect in new ways and to stay connected, regardless of their physical location. Lync 2010 and Lync Server 2010 bring together the different ways that people communicate in a single client interface, are deployed as a unified platform, and are administered through a single management infrastructure. Workload Description IM and presence Instant messaging (IM) and presence help your users find and communicate with one another efficiently and effectively. IM provides an instant messaging platform with conversation history, and supports public IM connectivity with users of public IM networks such as MSN/Windows Live, Yahoo!, and AOL. Presence establishes and displays a user’s personal availability and willingness to communicate through the use of common states such as Available or Busy. This rich presence information enables other users to immediately make effective communication choices. Conferencing Lync Server includes support for IM conferencing, audio conferencing, web conferencing, video conferencing, and application sharing, for both scheduled and impromptu meetings. All these meeting types are supported with a single client. Lync Server also supports dial-in conferencing so that users of public switched telephone network (PSTN) phones can participate in the audio portion of conferences. Conferences can seamlessly change and grow in real time. For example, a single conference can start as just instant messages between a few users, and escalate to an audio conference with desktop sharing and a larger audience instantly, easily, and without interrupting the conversation flow. Enterprise Voice Enterprise Voice is the Voice over Internet Protocol (VoIP) offering in Lync Server 2010. It delivers a voice option to enhance or replace traditional private branch exchange (PBX) systems. In addition to the complete telephony capabilities of an IP PBX, Enterprise Voice is integrated with rich presence, IM, collaboration, and meetings. Features such as call answer, hold, resume, transfer, forward and divert are supported directly, while personalized speed dialing keys are replaced by Contacts lists, and automatic intercom is replaced with IM. Enterprise Voice supports high availability through call admission control (CAC), branch office survivability, and extended options for data resiliency. Support for remote users You can provide full Lync Server functionality for users who are currently outside your organization’s firewalls by deploying servers called Edge Servers to provide a connection for these remote users. These remote users can connect to conferences by using a personal computer with Lync 2010 installed, the phone, or a web interface. Deploying Edge Servers also enables you to federate with partner or vendor organizations. A federated relationship enables your users to put federated users on their Contacts lists, exchange presence information and instant messages with these users, and invite them to audio calls, video calls, and conferences. Integration with other products Lync Server integrates with several other products to provide additional benefits to your users and administrators. Meeting tools are integrated into Outlook 2010 to enable organizers to schedule a meeting or start an impromptu conference with a single click and make it just as easy for attendees to join. Presence information is integrated into Outlook 2010 and SharePoint 2010. Exchange Unified Messaging (UM) provides several integration features. Users can see if they have new voice mail within Lync 2010. They can click a play button in the Outlook message to hear the audio voice mail, or view a transcription of the voice mail in the notification message. Simple deployment To help you plan and deploy your servers and clients, Lync Server provides the Microsoft Lync Server 2010, Planning Tool and the Topology Builder. Lync Server 2010, Planning Tool is a wizard that interactively asks you a series of questions about your organization, the Lync Server features you want to enable, and your capacity planning needs. Then, it creates a recommended deployment topology based on your answers, and produces several forms of output to aid your planning and installation. Topology Builder is an installation component of Lync Server 2010. You use Topology Builder to create, adjust and publish your planned topology. It also validates your topology before you begin server installations. When you install Lync Server on individual servers, the installation program deploys the server as directed in the topology. Simple management After you deploy Lync Server, it offers the following powerful and streamlined management tools: Active Directory for its user information, which eliminates the need for separate user and policy databases. Microsoft Lync Server 2010 Control Panel, a new web-based graphical user interface for administrators. With this web-based UI, Lync Server administrators can manage their systems from anywhere on the corporate network, without needing specialized management software installed on their computers. Lync Server Management Shell command-line management tool, which is based on the Windows PowerShell command-line interface. It provides a rich command set for administration of all aspects of the product, and enables Lync Server administrators to automate repetitive tasks using a familiar tool. While the IM and presence features are automatically installed in every Lync Server deployment, you can choose whether to deploy conferencing, Enterprise Voice, and remote user access, to tailor your deployment to your organization’s needs.

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  • Create Orchard Module in a Separate Project

    - by Steve Michelotti
    The Orchard Project is a new OOS Microsoft project that is being developed up on CodePlex. From the Orchard home page on CodePlex, it states “Orchard project is focused on delivering a .NET-based CMS application that will allow users to rapidly create content-driven Websites, and an extensibility framework that will allow developers and customizers to provide additional functionality through modules and themes.” The Orchard Project site contains additional information including documentation and walkthroughs. The ability to create a composite solution based on a collection of modules is a compelling feature. In Orchard, these modules can just be created as simple MVC Areas or they can also be created inside of stand-alone web application projects.  The walkthrough for writing an Orchard module that is available on the Orchard site uses a simple Area that is created inside of the host application. It is based on the Orchard MIX presentation. This walkthrough does an effective job introducing various Orchard concepts such as hooking into the navigation system, theme/layout system, content types, and more.  However, creating an Orchard module in a separate project does not seem to be concisely documented anywhere. Orchard ships with several module OOTB that are in separate assemblies – but again, it’s not well documented how to get started building one from scratch. The following are the steps I took to successfully get an Orchard module in a separate project up and running. Step 1 – Download the OrchardIIS.zip file from the Orchard Release page. Unzip and open up the solution. Step 2 – Add your project to the solution. I named my project “Orchard.Widget” and used and “MVC 2 Empty Web Application” project type. Make sure you put the physical path inside the “Modules” sub-folder to the main project like this: At this point the solution should look like: Step 3 – Add assembly references to Orchard.dll and Orchard.Core.dll. Step 4 – Add a controller and view.  I’ll just create a Hello World controller and view. Notice I created the view as a partial view (*.ascx). Also add the [Themed] attribute to the top of the HomeController class just like the normal Orchard walk through shows it. Step 5 – Add Module.txt to the project root. The is a very important step. Orchard will not recognize your module without this text file present.  It can contain just the name of your module: name: Widget Step 6 – Add Routes.cs. Notice I’ve given an area name of “Orchard.Widget” on lines 26 and 33. 1: using System; 2: using System.Collections.Generic; 3: using System.Web.Mvc; 4: using System.Web.Routing; 5: using Orchard.Mvc.Routes; 6:   7: namespace Orchard.Widget 8: { 9: public class Routes : IRouteProvider 10: { 11: public void GetRoutes(ICollection<RouteDescriptor> routes) 12: { 13: foreach (var routeDescriptor in GetRoutes()) 14: { 15: routes.Add(routeDescriptor); 16: } 17: } 18:   19: public IEnumerable<RouteDescriptor> GetRoutes() 20: { 21: return new[] { 22: new RouteDescriptor { 23: Route = new Route( 24: "Widget/{controller}/{action}/{id}", 25: new RouteValueDictionary { 26: {"area", "Orchard.Widget"}, 27: {"controller", "Home"}, 28: {"action", "Index"}, 29: {"id", ""} 30: }, 31: new RouteValueDictionary(), 32: new RouteValueDictionary { 33: {"area", "Orchard.Widget"} 34: }, 35: new MvcRouteHandler()) 36: } 37: }; 38: } 39: } 40: } Step 7 – Add MainMenu.cs. This will make sure that an item appears in the main menu called “Widget” which points to the module. 1: using System; 2: using Orchard.UI.Navigation; 3:   4: namespace Orchard.Widget 5: { 6: public class MainMenu : INavigationProvider 7: { 8: public void GetNavigation(NavigationBuilder builder) 9: { 10: builder.Add(menu => menu.Add("Widget", item => item.Action("Index", "Home", new 11: { 12: area = "Orchard.Widget" 13: }))); 14: } 15:   16: public string MenuName 17: { 18: get { return "main"; } 19: } 20: } 21: } Step 8 – Clean up web.config. By default Visual Studio adds numerous sections to the web.config. The sections that can be removed are: appSettings, connectionStrings, authentication, membership, profile, and roleManager. Step 9 – Delete Global.asax. This project will ultimately be running from inside the Orchard host so this “sub-site” should not have its own Global.asax.   Now you’re ready the run the app.  When you first run it, the “Widget” menu item will appear in the main menu because of the MainMenu.cs file we added: We can then click the “Widget” link in the main menu to send us over to our view:   Packaging From start to finish, it’s a relatively painless experience but it could be better. For example, a Visual Studio project template that encapsulates aspects from this blog post would definitely make it a lot easier to get up and running with creating an Orchard module.  Another aspect I found interesting is that if you read the first paragraph of the walkthrough, it says, “You can also develop modules as separate projects, to be packaged and shared with other users of Orchard CMS (the packaging story is still to be defined, along with marketplaces for sharing modules).” In particular, I will be extremely curious to see how the “packaging story” evolves. The first thing that comes to mind for me is: what if we explored MvcContrib Portable Areas as a potential mechanism for this packaging? This would certainly make things easy since all artifacts (aspx, aspx, images, css, javascript) are all wrapped up into a single assembly. Granted, Orchard does have its own infrastructure for layouts and themes but it seems like integrating portable areas into this pipeline would not be a difficult undertaking. Maybe that’ll be the next research task. :)

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  • 3 Ways to Make Steam Even Faster

    - by Chris Hoffman
    Have you ever noticed how slow Steam’s built-in web browser can be? Do you struggle with slow download speeds? Or is Steam just slow in general? These tips will help you speed it up. Steam isn’t a game itself, so there are no 3D settings to change to achieve maximum performance. But there are some things you can do to speed it up dramatically. Speed Up the Steam Web Browser Steam’s built-in web browser — used in both the Steam store and in Steam’s in-game overlay to provide a web browser you can quickly use within games – can be frustratingly slow on many systems. Rather than the typical speed we’ve come to expect from Chrome, Firefox, or even Internet Explorer, Steam seems to struggle. When you click a link or go to a new page, there’s a noticeable delay before the new page appears — something that doesn’t happen in desktop browsers. Many people seem to have made peace with this slowness, accepting that Steam’s built-in browser is just bad. However, there’s a trick that will eliminate this delay on many systems and make the Steam web browser fast. This problem seems to arise from an incompatibility with the Automatically Detect Proxy Settings option, which is enabled by default on Windows. This is a compatibility option that very few people should actually need, so it’s safe to disable it. To disable this option, open the Internet Options dialog — press the Windows key to access the Start menu or Start screen, type Internet Options, and click the Internet Options shortcut. Select the Connections tab in the Internet Options window and click the LAN settings button. Uncheck the Automatically detect settings option here, then click OK to save your settings. If you experienced a significant delay every time a web page loaded in Steam’s web browser, it should now be gone. In the unlikely event that you encounter some sort of problem with your network connection, you could always re-enable this option. Increase Steam’s Game Download Speed Steam attempts to automatically select the nearest download server to your location. However, it may not always select the ideal download server. Or, in the case of high-traffic events like big seasonal sales and huge game launches, you may benefit from selecting a less-congested server. To do this, open Steam’s settings by clicking the Steam menu in Steam and selecting Settings. Click over to the Downloads tab and select the closest download server from the Download Region box. You should also ensure that Steam’s download bandwidth isn’t limited from here. You may want to restart Steam and see if your download speeds improve after changing this setting. In some cases, the closest server might not be the fastest. One a bit farther away could be faster if your local server is more congested, for example. Steam once provided information about content server load, which allowed you to select a regional server that wasn’t under high-load, but this information no longer seems to be available. Steam still provides a page that shows you the amount of download activity happening in different regions, including statistics about the difference in download speeds in different US states, but this information isn’t as useful. Accelerate Steam and Your Games One way to speed up all your games — and Steam itself —  is by getting a solid-state drive and installing Steam to it. Steam allows you to easily move your Steam folder — at C:\Program Files (x86)\Steam by default — to another hard drive. Just move it like you would any other folder. You can then launch the Steam.exe program as if you had never moved Steam’s files. Steam also allows you to configure multiple game library folders. This means that you can set up a Steam library folder on a solid-state drive and one on your larger magnetic hard drive. Install your most frequently played games to the solid-state drive for maximum speed and your less frequently played ones to the slower magnetic hard drive to save SSD space. To set up additional library folders, open Steam’s Settings window and click the Downloads tab. You’ll find the Steam Library Folders option here. Click the Add Library Folder button and create a new game library on another hard drive. When you install a game in Steam, you’ll be asked which library folder you want to install it to. With the proxy compatibility option disabled, the correct download server chosen, and Steam installed to a fast SSD, it should be a speed demon. There’s not much more you can do to speed up Steam, short of upgrading other hardware like your computer’s CPU. Image Credit: Andrew Nash on Flickr     

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  • Subterranean IL: Constructor constraints

    - by Simon Cooper
    The constructor generic constraint is a slightly wierd one. The ECMA specification simply states that it: constrains [the type] to being a concrete reference type (i.e., not abstract) that has a public constructor taking no arguments (the default constructor), or to being a value type. There seems to be no reference within the spec to how you actually create an instance of a generic type with such a constraint. In non-generic methods, the normal way of creating an instance of a class is quite different to initializing an instance of a value type. For a reference type, you use newobj: newobj instance void IncrementableClass::.ctor() and for value types, you need to use initobj: .locals init ( valuetype IncrementableStruct s1 ) ldloca 0 initobj IncrementableStruct But, for a generic method, we need a consistent method that would work equally well for reference or value types. Activator.CreateInstance<T> To solve this problem the CLR designers could have chosen to create something similar to the constrained. prefix; if T is a value type, call initobj, and if it is a reference type, call newobj instance void !!0::.ctor(). However, this solution is much more heavyweight than constrained callvirt. The newobj call is encoded in the assembly using a simple reference to a row in a metadata table. This encoding is no longer valid for a call to !!0::.ctor(), as different constructor methods occupy different rows in the metadata tables. Furthermore, constructors aren't virtual, so we would have to somehow do a dynamic lookup to the correct method at runtime without using a MethodTable, something which is completely new to the CLR. Trying to do this in IL results in the following verification error: newobj instance void !!0::.ctor() [IL]: Error: Unable to resolve token. This is where Activator.CreateInstance<T> comes in. We can call this method to return us a new T, and make the whole issue Somebody Else's Problem. CreateInstance does all the dynamic method lookup for us, and returns us a new instance of the correct reference or value type (strangely enough, Activator.CreateInstance<T> does not itself have a .ctor constraint on its generic parameter): .method private static !!0 CreateInstance<.ctor T>() { call !!0 [mscorlib]System.Activator::CreateInstance<!!0>() ret } Going further: compiler enhancements Although this method works perfectly well for solving the problem, the C# compiler goes one step further. If you decompile the C# version of the CreateInstance method above: private static T CreateInstance() where T : new() { return new T(); } what you actually get is this (edited slightly for space & clarity): .method private static !!T CreateInstance<.ctor T>() { .locals init ( [0] !!T CS$0$0000, [1] !!T CS$0$0001 ) DetectValueType: ldloca.s 0 initobj !!T ldloc.0 box !!T brfalse.s CreateInstance CreateValueType: ldloca.s 1 initobj !!T ldloc.1 ret CreateInstance: call !!0 [mscorlib]System.Activator::CreateInstance<T>() ret } What on earth is going on here? Looking closer, it's actually quite a clever performance optimization around value types. So, lets dissect this code to see what it does. The CreateValueType and CreateInstance sections should be fairly self-explanatory; using initobj for value types, and Activator.CreateInstance for reference types. How does the DetectValueType section work? First, the stack transition for value types: ldloca.s 0 // &[!!T(uninitialized)] initobj !!T // ldloc.0 // !!T box !!T // O[!!T] brfalse.s // branch not taken When the brfalse.s is hit, the top stack entry is a non-null reference to a boxed !!T, so execution continues to to the CreateValueType section. What about when !!T is a reference type? Remember, the 'default' value of an object reference (type O) is zero, or null. ldloca.s 0 // &[!!T(null)] initobj !!T // ldloc.0 // null box !!T // null brfalse.s // branch taken Because box on a reference type is a no-op, the top of the stack at the brfalse.s is null, and so the branch to CreateInstance is taken. For reference types, Activator.CreateInstance is called which does the full dynamic lookup using reflection. For value types, a simple initobj is called, which is far faster, and also eliminates the unboxing that Activator.CreateInstance has to perform for value types. However, this is strictly a performance optimization; Activator.CreateInstance<T> works for value types as well as reference types. Next... That concludes the initial premise of the Subterranean IL series; to cover the details of generic methods and generic code in IL. I've got a few other ideas about where to go next; however, if anyone has any itching questions, suggestions, or things you've always wondered about IL, do let me know.

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  • Oracle Social Network Developer Challenge: Bezzotech

    - by Kellsey Ruppel
    Originally posted by Jake Kuramoto on The Apps Lab blog. I’ve covered all the entries we had for the Oracle Social Network Developer Challenge, the winners, Dimitri and Martin, HarQen, TEAM Informatics and John Sim from Fishbowl Solutions, and today, I’m giving you bonus coverage. Friend of the ‘Lab, Bex Huff (@bex) from Bezzotech (@bezzotech), had an interesting OpenWorld. He rebounded from an allergic reaction to finish his entry, Honey Badger, only to have his other OpenWorld commitments make him unable to present his work. Still, he did a bunch of work, and I want to make sure everyone knows about the Honey Badger. If you’re wondering about the name, it’s a meme; “honey badger don’t care.” Bex tackled a common problem with social tools by adding game mechanics to create an incentive for people to keep their profiles updated. He used a Hot-or-Not style comparison app that poses expertise questions and awards a badge to the winner. Questions are based on whatever attributes the business wants to emphasize. The goal is to find the mavens in an organization, give them praise and recognition, ideally creating incentive for everyone to raise their games. In his own words: There is a real information quality problem in social networks. In last year’s keynote, Larry Elison demonstrated how to use the social network to track down resources that have the skill sets needed for specific projects. But how well would that work in real life? People usually update that information with the basic profile information, but they rarely update their profiles with latest news items, projects, customers, or skills. It’s a pain. Or, put another way, when was the last time you updated your LinkedIn profile? Enter the Honey Badger! This is a example of a comparator app that gamifies the way people keep their profiles updated, which ensures higher quality data in the social network. An administrator comes up with a series of important questions: Who is a better communicator? Who is a better Java programmer? Who is a better team player? And people would have a space in their profile to give a justification as to why they have these skills. The second part of the app is the comparator. It randomly shows two people, their names, and their justification for why they have these skills. You will click on one of them to “vote” for them, then on the next page you will see the results from the previous match, and get 2 new people to vote on. Anybody with a winning score wins a “Honey Badge” to be displayed on their profile page, which proudly states that their peers agree that this person has those skills. Once a badge is won, it will be jealously guarded. The longer your go without updating your profile, the more likely it is that you will lose your badge. This “loss aversion” is well known in psychology, and is a strong incentive for people to keep their profiles up to date. If a user sees their rank drop from 90% to 60%, they will find the time to update their justification! Unfortunately, during the hackathon we were not allowed to modify the schema to allow for additional fields such as “justification.” So this hack is limited to just the one basic question: who is the bigger Honey Badger? Here are some shots of the Honey Badger application: #gallery-1 { margin: auto; } #gallery-1 .gallery-item { float: left; margin-top: 10px; text-align: center; width: 33%; } #gallery-1 img { border: 2px solid #cfcfcf; } #gallery-1 .gallery-caption { margin-left: 0; } Thanks to Bex and everyone for participating in our challenge. Despite very little time to promote this event, we had a great turnout and creative and useful entries. The amount of work required to put together these final entries was significant, especially during a conference, and the judges and all of us involved were impressed at how much work everyone was able to do. Congrats to everyone, pat yourselves on the back. Stay tuned if you’re interested in challenges like these. We’ll likely be running similar events in the not-so-distant future.

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  • How do I prove or disprove "god" objects are wrong?

    - by honestduane
    Problem Summary: Long story short, I inherited a code base and an development team I am not allowed to replace and the use of God Objects is a big issue. Going forward, I want to have us re-factor things but I am getting push-back from the teams who want to do everything with God Objects "because its easier" and this means I would not be allowed to re-factor. I pushed back citing my years of dev experience, that I'm the new boss who was hired to know these things, etc, and so did the third party offshore companies account sales rep, and this is now at the executive level and my meeting is tomorrow and I want to go in with a lot of technical ammo to advocate best practices because I feel it will be cheaper in the long run (And I personally feel that is what the third party is worried about) for the company. My issue is from a technical level, I know its good long term but I'm having trouble with the ultra short term and 6 months term, and while its something I "know" I cant prove it with references and cited resources outside of one person (Robert C. Martin, aka Uncle Bob), as that is what I am being asked to do as I have been told having data from one person and only one person (Robert C Martin) is not good enough of an argument. Question: What are some resources I can cite directly (Title, year published, page number, quote) by well known experts in the field that explicitly say this use of "God" Objects/Classes/Systems is bad (or good, since we are looking for the most technically valid solution)? Research I have already done: I have a number of books here and I have searched their indexes for the use of the words "god object" and "god class". I found that oddly its almost never used and the copy of the GoF book I have for example, never uses it (At least according to the index in front of me) but I have found it in 2 books per the below, but I want more I can use. I checked the Wikipedia page for "God Object" and its currently a stub with little reference links so although I personally agree with that it says, It doesn't have much I can use in an environment where personal experience is not considered valid. The book cited is also considered too old to be valid by the people I am debating these technical points with as the argument they are making is that "it was once thought to be bad but nobody could prove it, and now modern software says "god" objects are good to use". I personally believe that this statement is incorrect, but I want to prove the truth, whatever it is. In Robert C Martin's "Agile Principles, Patterns, and Practices in C#" (ISBN: 0-13-185725-8, hardcover) where on page 266 it states "Everybody knows that god classes are a bad idea. We don't want to concentrate all the intelligence of a system into a single object or a single function. One of the goals of OOD is the partitioning and distribution of behavior into many classes and many function." -- And then goes on to say sometimes its better to use God Classes anyway sometimes (Citing micro-controllers as an example). In Robert C Martin's "Clean Code: A Handbook of Agile Software Craftsmanship" page 136 (And only this page) talks about the "God class" and calls it out as a prime example of a violation of the "classes should be small" rule he uses to promote the Single Responsibility Principle" starting on on page 138. The problem I have is all my references and citations come from the same person (Robert C. Martin), and am from the same single person/source. I am being told that because he is just one guy, my desire to not use "God Classes" is invalid and not accepted as a standard best practice in the software industry. Is this true? Am I doing things wrong from a technical perspective by trying to keep to the teaching of Uncle Bob? God Objects and Object Oriented Programming and Design: The more I think of this the more I think this is more something you learn when you study OOP and its never explicitly called out; Its implicit to good design is my thinking (Feel free to correct me, please, as I want to learn), The problem is I "know" this, but but not everybody does, so in this case its not considered a valid argument because I am effectively calling it out as universal truth when in fact most people are statistically ignorant of it since statistically most people are not programmers. Conclusion: I am at a loss on what to search for to get the best additional results to cite, since they are making a technical claim and I want to know the truth and be able to prove it with citations like a real engineer/scientist, even if I am biased against god objects due to my personal experience with code that used them. Any assistance or citations would be deeply appreciated.

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  • Red Gate in the Community

    - by Nick Harrison
    Much has been said recently about Red Gate's community involvement and commitment to the DotNet community. Much of this has been unduly negative. Before you start throwing stones and spewing obscenities, consider some additional facts: Red Gate's software is actually very good. I have worked on many projects where Red Gate's software was instrumental in finishing successfully. Red Gate is VERY good to the community. I have spoken at many user groups and code camps where Red Gate has been a sponsor. Red Gate consistently offers up money to pay for the venue or food, and they will often give away licenses as door prizes. There are many such community events that would not take place without Red Gate's support. All I have ever seen them ask for is to have their products mentioned or be listed as a sponsor. They don't insist on anyone following a specific script. They don't monitor how their products are showcased. They let their products speak for themselves. Red Gate sponsors the Simple Talk web site. I publish there regularly. Red Gate has never exerted editorial pressure on me. No one has ever told me we can't publish this unless you mention Red Gate products. No one has ever said, you need to say nice things about Red Gate products in order to be published. They have told me, "you need to make this less academic, so you don't alienate too many readers. "You need to actually write an introduction so people will know what you are talking about". "You need to write this so that someone who isn't a reflection nut will follow what you are trying to say." In short, they have been good editors worried about the quality of the content and what the readers are likely to be interested in. For me personally, Red Gate and Simple Talk have both been excellent to work with. As for the developer outrage… I am a little embarrassed by so much of the response that I am seeing. So much of the complaints remind me of little children whining "but you promised" Semantics aside. A promise is just a promise. It's not like they "pinky sweared". Sadly no amount name calling or "double dog daring" will change the economics of the situation. Red Gate is not a multibillion dollar corporation. They are a mid size company doing the best they can. Without a doubt, their pockets are not as deep as Microsoft's. I honestly believe that they did try to make the "freemium" model work. Sadly it did not. I have no doubt that they intended for it to work and that they tried to make it work. I also have no doubt that they labored over making this decision. This could not have been an easy decision to make. Many people are gleefully proclaiming a massive backlash against Red Gate swearing off their wonderful products and promising to bash them at every opportunity from now on. This is childish behavior that does not represent professionals. This type of behavior is more in line with bullies in the school yard than professionals in a professional community. Now for my own prediction… This back lash against Red Gate is not likely to last very long. We will all realize that we still need their products. We may look around for alternatives, but realize that they really do have the best in class for every product that they produce, and that they really are not exorbitantly priced. We will see them sponsoring Code Camps and User Groups and be reminded, "hey this isn't such a bad company". On the other hand, software shops like Red Gate, will remember this back lash and give a second thought to supporting open source projects. They will worry about getting involved when an individual wants to turn over control for a product that they developed but can no longer support alone. Who wants to run the risk of not being able to follow through on their best intentions. In the end we may all suffer, even the toddlers among us throwing the temper tantrum, "BUT YOU PROMISED!" Disclaimer Before anyone asks or jumps to conclusions, I do not get paid by Red Gate to say any of this. I have often written about their products, and I have long thought that they are a wonderful company with amazing products. If they ever open an office in the SE United States, I will be one of the first to apply.

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  • .NET 4: &ldquo;Slim&rdquo;-style performance boost!

    - by Vitus
    RTM version of .NET 4 and Visual Studio 2010 is available, and now we can do some test with it. Parallel Extensions is one of the most valuable part of .NET 4.0. It’s a set of good tools for easily consuming multicore hardware power. And it also contains some “upgraded” sync primitives – Slim-version. For example, it include updated variant of widely known ManualResetEvent. For people, who don’t know about it: you can sync concurrency execution of some pieces of code with this sync primitive. Instance of ManualResetEvent can be in 2 states: signaled and non-signaled. Transition between it possible by Set() and Reset() methods call. Some shortly explanation: Thread 1 Thread 2 Time mre.Reset(); mre.WaitOne(); //code execution 0 //wating //code execution 1 //wating //code execution 2 //wating //code execution 3 //wating mre.Set(); 4 //code execution //… 5 Upgraded version of this primitive is ManualResetEventSlim. The idea in decreasing performance cost in case, when only 1 thread use it. Main concept in the “hybrid sync schema”, which can be done as following:   internal sealed class SimpleHybridLock : IDisposable { private Int32 m_waiters = 0; private AutoResetEvent m_waiterLock = new AutoResetEvent(false);   public void Enter() { if (Interlocked.Increment(ref m_waiters) == 1) return; m_waiterLock.WaitOne(); }   public void Leave() { if (Interlocked.Decrement(ref m_waiters) == 0) return; m_waiterLock.Set(); }   public void Dispose() { m_waiterLock.Dispose(); } } It’s a sample from Jeffry Richter’s book “CLR via C#”, 3rd edition. Primitive SimpleHybridLock have two public methods: Enter() and Leave(). You can put your concurrency-critical code between calls of these methods, and it would executed in only one thread at the moment. Code is really simple: first thread, called Enter(), increase counter. Second thread also increase counter, and suspend while m_waiterLock is not signaled. So, if we don’t have concurrent access to our lock, “heavy” methods WaitOne() and Set() will not called. It’s can give some performance bonus. ManualResetEvent use the similar idea. Of course, it have more “smart” technics inside, like a checking of recursive calls, and so on. I want to know a real difference between classic ManualResetEvent realization, and new –Slim. I wrote a simple “benchmark”: class Program { static void Main(string[] args) { ManualResetEventSlim mres = new ManualResetEventSlim(false); ManualResetEventSlim mres2 = new ManualResetEventSlim(false);   ManualResetEvent mre = new ManualResetEvent(false);   long total = 0; int COUNT = 50;   for (int i = 0; i < COUNT; i++) { mres2.Reset(); Stopwatch sw = Stopwatch.StartNew();   ThreadPool.QueueUserWorkItem((obj) => { //Method(mres, true); Method2(mre, true); mres2.Set(); }); //Method(mres, false); Method2(mre, false);   mres2.Wait(); sw.Stop();   Console.WriteLine("Pass {0}: {1} ms", i, sw.ElapsedMilliseconds); total += sw.ElapsedMilliseconds; }   Console.WriteLine(); Console.WriteLine("==============================="); Console.WriteLine("Done in average=" + total / (double)COUNT); Console.ReadLine(); }   private static void Method(ManualResetEventSlim mre, bool value) { for (int i = 0; i < 9000000; i++) { if (value) { mre.Set(); } else { mre.Reset(); } } }   private static void Method2(ManualResetEvent mre, bool value) { for (int i = 0; i < 9000000; i++) { if (value) { mre.Set(); } else { mre.Reset(); } } } } I use 2 concurrent thread (the main thread and one from thread pool) for setting and resetting ManualResetEvents, and try to run test COUNT times, and calculate average execution time. Here is the results (I get it on my dual core notebook with T7250 CPU and Windows 7 x64): ManualResetEvent ManualResetEventSlim Difference is obvious and serious – in 10 times! So, I think preferable way is using ManualResetEventSlim, because not always on calling Set() and Reset() will be called “heavy” methods for working with Windows kernel-mode objects. It’s a small and nice improvement! ;)

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