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• problems mounting an external IDE drive via USB in ubuntu

  - by Roy Rico

  I am having a problem connecting a specific IDE drive to my linux box. It's an old drive which I just want to get about 3 GB of files off of. INFO I am trying to connect a 200GB IDE Maxtor Drive, internally and externally... externally: I am using an self powered USB IDE external drive enclosure which I have used to connect various drives, under ubuntu and windows, in the past. The other posts stated it coudl be a problem I think i may have formatted the /dev/sdc partition instead of /dev/sdc1 partition when i originally formatted the drive. internally: I only have one machine left that has an internal IDE interface, and it's got XP on it. I plugged this drive internally into this machine with windows XP and used the ext2/ext3 drivers to mount this drive, but some files have question marks (?) in the file names which is messing up my copy process in windows. I can't delete the files under windows. Ubuntu Linux will not install on my only remaining machine that has IDE controller. I have tried the suggestions in the questions below http://superuser.com/questions/88182/mount-an-external-drive-in-ubuntu http://superuser.com/questions/23210/ubuntu-fails-to-mount-usb-drive it looks like i can see the drive in /proc/partitions $ cat /proc/partitions major minor #blocks name 8 0 78125000 sda 8 1 74894998 sda1 8 2 1 sda2 8 5 3229033 sda5 8 16 199148544 sdb <-- could be my drive? but it's not listed under fdisk -l $ fdisk -l Disk /dev/sda: 80.0 GB, 80000000000 bytes 255 heads, 63 sectors/track, 9726 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0xd0f4738c Device Boot Start End Blocks Id System /dev/sda1 * 1 9324 74894998+ 83 Linux /dev/sda2 9325 9726 3229065 5 Extended /dev/sda5 9325 9726 3229033+ 82 Linux swap / Solaris and here is my log of /var/log/messages. with a bunch of weird output, can someone let me know what that weird output is? Mar 3 19:49:40 mala kernel: [687455.112029] usb 1-7: new high speed USB device using ehci_hcd and address 3 Mar 3 19:49:41 mala kernel: [687455.248576] usb 1-7: configuration #1 chosen from 1 choice Mar 3 19:49:41 mala kernel: [687455.267450] Initializing USB Mass Storage driver... Mar 3 19:49:41 mala kernel: [687455.269180] scsi4 : SCSI emulation for USB Mass Storage devices Mar 3 19:49:41 mala kernel: [687455.269410] usbcore: registered new interface driver usb-storage Mar 3 19:49:41 mala kernel: [687455.269416] USB Mass Storage support registered. Mar 3 19:49:46 mala kernel: [687460.270917] scsi 4:0:0:0: Direct-Access Maxtor 6 Y200P0 YAR4 PQ: 0 ANSI: 2 Mar 3 19:49:46 mala kernel: [687460.271485] sd 4:0:0:0: Attached scsi generic sg2 type 0 Mar 3 19:49:46 mala kernel: [687460.278858] sd 4:0:0:0: [sdb] 398297088 512-byte logical blocks: (203 GB/189 GiB) Mar 3 19:49:46 mala kernel: [687460.280866] sd 4:0:0:0: [sdb] Write Protect is off Mar 3 19:50:16 mala kernel: [687460.283784] sdb: Mar 3 19:50:16 mala kernel: [687491.112020] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:50:47 mala kernel: [687522.120030] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:51:18 mala kernel: [687553.112034] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:51:49 mala kernel: [687584.116025] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:52:02 mala kernel: [687596.170632] type=1505 audit(1267671122.035:31): operation="profile_replace" pid=8426 name=/usr/lib/cups/backend/cups-pdf Mar 3 19:52:02 mala kernel: [687596.171551] type=1505 audit(1267671122.035:32): operation="profile_replace" pid=8426 name=/usr/sbin/cupsd Mar 3 19:52:06 mala kernel: [687600.908056] async/0 D c08145c0 0 7655 2 0x00000000 Mar 3 19:52:06 mala kernel: [687600.908062] e5601d38 00000046 e5774000 c08145c0 e4c2a848 c08145c0 d203973a 0002713d Mar 3 19:52:06 mala kernel: [687600.908072] c08145c0 c08145c0 e4c2a848 c08145c0 00000000 0002713d c08145c0 f0a98c00 Mar 3 19:52:06 mala kernel: [687600.908079] e4c2a5b0 c20125c0 00000002 e5601d80 e5601d44 c056f3be e5601d78 e5601d4c Mar 3 19:52:06 mala kernel: [687600.908087] Call Trace: Mar 3 19:52:06 mala kernel: [687600.908099] [<c056f3be>] io_schedule+0x1e/0x30 Mar 3 19:52:06 mala kernel: [687600.908107] [<c01b2cf5>] sync_page+0x35/0x40 Mar 3 19:52:06 mala kernel: [687600.908111] [<c056f8f7>] __wait_on_bit_lock+0x47/0x90 Mar 3 19:52:06 mala kernel: [687600.908115] [<c01b2cc0>] ? sync_page+0x0/0x40 Mar 3 19:52:06 mala kernel: [687600.908121] [<c020f390>] ? blkdev_readpage+0x0/0x20 Mar 3 19:52:06 mala kernel: [687600.908125] [<c01b2ca9>] __lock_page+0x79/0x80 Mar 3 19:52:06 mala kernel: [687600.908130] [<c015c130>] ? wake_bit_function+0x0/0x50 Mar 3 19:52:06 mala kernel: [687600.908135] [<c01b459f>] read_cache_page_async+0xbf/0xd0 Mar 3 19:52:06 mala kernel: [687600.908139] [<c01b45c2>] read_cache_page+0x12/0x60 Mar 3 19:52:06 mala kernel: [687600.908144] [<c0232dca>] read_dev_sector+0x3a/0x80 Mar 3 19:52:06 mala kernel: [687600.908148] [<c0233d3e>] adfspart_check_ICS+0x1e/0x160 Mar 3 19:52:06 mala kernel: [687600.908152] [<c023339f>] ? disk_name+0xaf/0xc0 Mar 3 19:52:06 mala kernel: [687600.908157] [<c0233d20>] ? adfspart_check_ICS+0x0/0x160 Mar 3 19:52:06 mala kernel: [687600.908161] [<c02334de>] check_partition+0x10e/0x180 Mar 3 19:52:06 mala kernel: [687600.908165] [<c02335f6>] rescan_partitions+0xa6/0x330 Mar 3 19:52:06 mala kernel: [687600.908171] [<c0312472>] ? kobject_get+0x12/0x20 Mar 3 19:52:06 mala kernel: [687600.908175] [<c0312472>] ? kobject_get+0x12/0x20 Mar 3 19:52:06 mala kernel: [687600.908180] [<c039fc43>] ? get_device+0x13/0x20 Mar 3 19:52:06 mala kernel: [687600.908185] [<c03c263f>] ? sd_open+0x5f/0x1b0 Mar 3 19:52:06 mala kernel: [687600.908189] [<c020fda0>] __blkdev_get+0x140/0x310 Mar 3 19:52:06 mala kernel: [687600.908194] [<c020f0ac>] ? bdget+0xec/0x100 Mar 3 19:52:06 mala kernel: [687600.908198] [<c020ff7a>] blkdev_get+0xa/0x10 Mar 3 19:52:06 mala kernel: [687600.908202] [<c0232f30>] register_disk+0x120/0x140 Mar 3 19:52:06 mala kernel: [687600.908207] [<c0308b4d>] ? blk_register_region+0x2d/0x40 Mar 3 19:52:06 mala kernel: [687600.908211] [<c03084f0>] ? exact_match+0x0/0x10 Mar 3 19:52:06 mala kernel: [687600.908216] [<c0308cf0>] add_disk+0x80/0x140 Mar 3 19:52:06 mala kernel: [687600.908221] [<c03084f0>] ? exact_match+0x0/0x10 Mar 3 19:52:06 mala kernel: [687600.908225] [<c0308860>] ? exact_lock+0x0/0x20 Mar 3 19:52:06 mala kernel: [687600.908230] [<c03c53df>] sd_probe_async+0xff/0x1c0

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• HP to Cisco spanning tree root flapping

  - by Tim Brigham

  Per a recent question I recently configured both my HP (2x 2900) and Cisco (1x 3750) hardware to use MSTP for interoperability. I thought this was functional until I applied the change to the third device (HP switch 1 below) at which time the spanning tree root started flapping causing performance issues (5% packet loss) between my two HP switches. I'm not sure why. HP Switch 1 A4 connected to Cisco 1/0/1. HP Switch 2 B2 connected to Cisco 2/0/1. HP Switch 1 A2 connected to HP Switch 2 A1. I'd prefer the Cisco stack to act as the root. EDIT: There is one specific line - 'spanning-tree 1 path-cost 500000' in the HP switch 2 that I didn't add and was preexisting. I'm not sure if it could have the kind of impact that I'm describing. I'm more a security and monitoring guy then networking. EDIT 2: I'm starting to believe the problem lies in the fact that the value for my MST 0 instance on the Cisco is still at the default 32768. I worked up a diagram: This is based on every show command I could find for STP. I'll make this change after hours and see if it helps. Cisco 3750 Config: version 12.2 spanning-tree mode mst spanning-tree extend system-id spanning-tree mst configuration name mstp revision 1 instance 1 vlan 1, 40, 70, 100, 250 spanning-tree mst 1 priority 0 vlan internal allocation policy ascending interface TenGigabitEthernet1/1/1 switchport trunk encapsulation dot1q switchport mode trunk ! interface TenGigabitEthernet2/1/1 switchport trunk encapsulation dot1q switchport mode trunk ! interface Vlan1 no ip address ! interface Vlan100 ip address 192.168.100.253 255.255.255.0 ! Cisco 3750 show spanning tree: show spanning-tree MST0 Spanning tree enabled protocol mstp Root ID Priority 32768 Address 0004.ea84.5f80 Cost 200000 Port 53 (TenGigabitEthernet1/1/1) Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Bridge ID Priority 32768 (priority 32768 sys-id-ext 0) Address a44c.11a6.7c80 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Interface Role Sts Cost Prio.Nbr Type ------------------- ---- --- --------- -------- -------------------------------- Te1/1/1 Root FWD 2000 128.53 P2p MST1 Spanning tree enabled protocol mstp Root ID Priority 1 Address a44c.11a6.7c80 This bridge is the root Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Bridge ID Priority 1 (priority 0 sys-id-ext 1) Address a44c.11a6.7c80 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Interface Role Sts Cost Prio.Nbr Type ------------------- ---- --- --------- -------- -------------------------------- Te1/1/1 Desg FWD 2000 128.53 P2p Cisco 3750 show logging: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to down %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan100, changed state to down %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to up %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan100, changed state to up %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to down %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to up HP Switch 1: ; J9049A Configuration Editor; Created on release #T.13.71 vlan 1 name "DEFAULT_VLAN" untagged 1-8,10,13-16,18-23,A1-A4 ip address 100.100.100.17 255.255.255.0 no untagged 9,11-12,17,24 exit vlan 100 name "192.168.100" untagged 9,11-12,17,24 tagged 1-8,10,13-16,18-23,A1-A4 no ip address exit vlan 21 name "Users_2" tagged 1,A1-A4 no ip address exit vlan 40 name "Cafe" tagged 1,4,7,A1-A4 no ip address exit vlan 250 name "Firewall" tagged 1,4,7,A1-A4 no ip address exit vlan 70 name "DMZ" tagged 1,4,7-8,13,A1-A4 no ip address exit spanning-tree spanning-tree config-name "mstp" spanning-tree config-revision 1 spanning-tree instance 1 vlan 1 40 70 100 250 password manager password operator HP Switch 1 show spanning tree: show spanning-tree Multiple Spanning Tree (MST) Information STP Enabled : Yes Force Version : MSTP-operation IST Mapped VLANs : 2-39,41-69,71-99,101-249,251-4094 Switch MAC Address : 0021f7-126580 Switch Priority : 32768 Max Age : 20 Max Hops : 20 Forward Delay : 15 Topology Change Count : 363,490 Time Since Last Change : 14 hours CST Root MAC Address : 0004ea-845f80 CST Root Priority : 32768 CST Root Path Cost : 200000 CST Root Port : 1 IST Regional Root MAC Address : 0021f7-126580 IST Regional Root Priority : 32768 IST Regional Root Path Cost : 0 IST Remaining Hops : 20 Root Guard Ports : TCN Guard Ports : BPDU Protected Ports : BPDU Filtered Ports : PVST Protected Ports : PVST Filtered Ports : | Prio | Designated Hello Port Type | Cost rity State | Bridge Time PtP Edge ----- --------- + --------- ---- ---------- + ------------- ---- --- ---- A1 | Auto 128 Disabled | A2 10GbE-CX4 | 2000 128 Forwarding | 0021f7-126580 2 Yes No A3 10GbE-CX4 | Auto 128 Disabled | A4 10GbE-SR | Auto 128 Disabled | HP Switch 1 Logging: I removed the date / time fields since they are inaccurate (no NTP configured on these switches) 00839 stp: MSTI 1 Root changed from 0:a44c11-a67c80 to 32768:0021f7-126580 00839 stp: MSTI 1 Root changed from 32768:0021f7-126580 to 0:a44c11-a67c80 00842 stp: MSTI 1 starved for an MSTI Msg Rx on port A4 from 0:a44c11-a67c80 00839 stp: MSTI 1 Root changed from 0:a44c11-a67c80 to 32768:0021f7-126580 00839 stp: MSTI 1 Root changed from 32768:0021f7-126580 to 0:a44c11-a67c80 00839 stp: MSTI 1 Root changed from 0:a44c11-a67c80 to ... HP Switch 2 Configuration: ; J9146A Configuration Editor; Created on release #W.14.49 vlan 1 name "DEFAULT_VLAN" untagged 1,3-17,21-24,A1-A2,B2 ip address 100.100.100.36 255.255.255.0 no untagged 2,18-20,B1 exit vlan 100 name "192.168.100" untagged 2,18-20 tagged 1,3-17,21-24,A1-A2,B1-B2 no ip address exit vlan 21 name "Users_2" tagged 1,A1-A2,B2 no ip address exit vlan 40 name "Cafe" tagged 1,13-14,16,A1-A2,B2 no ip address exit vlan 250 name "Firewall" tagged 1,13-14,16,A1-A2,B2 no ip address exit vlan 70 name "DMZ" tagged 1,13-14,16,A1-A2,B2 no ip address exit logging 192.168.100.18 spanning-tree spanning-tree 1 path-cost 500000 spanning-tree config-name "mstp" spanning-tree config-revision 1 spanning-tree instance 1 vlan 1 40 70 100 250 HP Switch 2 Spanning Tree: show spanning-tree Multiple Spanning Tree (MST) Information STP Enabled : Yes Force Version : MSTP-operation IST Mapped VLANs : 2-39,41-69,71-99,101-249,251-4094 Switch MAC Address : 0024a8-cd6000 Switch Priority : 32768 Max Age : 20 Max Hops : 20 Forward Delay : 15 Topology Change Count : 21,793 Time Since Last Change : 14 hours CST Root MAC Address : 0004ea-845f80 CST Root Priority : 32768 CST Root Path Cost : 200000 CST Root Port : A1 IST Regional Root MAC Address : 0021f7-126580 IST Regional Root Priority : 32768 IST Regional Root Path Cost : 2000 IST Remaining Hops : 19 Root Guard Ports : TCN Guard Ports : BPDU Protected Ports : BPDU Filtered Ports : PVST Protected Ports : PVST Filtered Ports : | Prio | Designated Hello Port Type | Cost rity State | Bridge Time PtP Edge ----- --------- + --------- ---- ---------- + ------------- ---- --- ---- A1 10GbE-CX4 | 2000 128 Forwarding | 0021f7-126580 2 Yes No A2 10GbE-CX4 | Auto 128 Disabled | B1 SFP+SR | 2000 128 Forwarding | 0024a8-cd6000 2 Yes No B2 | Auto 128 Disabled | HP Switch 2 Logging: I removed the date / time fields since they are inaccurate (no NTP configured on these switches) 00839 stp: CST Root changed from 32768:0021f7-126580 to 32768:0004ea-845f80 00839 stp: IST Root changed from 32768:0021f7-126580 to 32768:0024a8-cd6000 00839 stp: CST Root changed from 32768:0004ea-845f80 to 32768:0024a8-cd6000 00839 stp: CST Root changed from 32768:0024a8-cd6000 to 32768:0004ea-845f80 00839 stp: CST Root changed from 32768:0004ea-845f80 to 32768:0024a8-cd6000 00435 ports: port B1 is Blocked by STP 00839 stp: CST Root changed from 32768:0024a8-cd6000 to 32768:0021f7-126580 00839 stp: IST Root changed from 32768:0024a8-cd6000 to 32768:0021f7-126580 00839 stp: CST Root changed from 32768:0021f7-126580 to 32768:0004ea-845f80

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• HttpModule Init method is called several times - why?

  - by MartinF

  I was creating a http module and while debugging I noticed something which at first (at least) seemed like weird behaviour. When i set a breakpoint in the init method of the httpmodule i can see that the http module init method is being called several times even though i have only started up the website for debugging and made one single request (sometimes it is hit only 1 time, other times as many as 10 times). I know that I should expect several instances of the HttpApplication to be running and for each the http modules will be created, but when i request a single page it should be handled by a single http application object and therefore only fire the events associated once, but still it fires the events several times for each request which makes no sense - other than it must have been added several times within that httpApplication - which means it is the same httpmodule init method which is being called every time and not a new http application being created each time it hits my break point (see my code example at the bottom etc.). What could be going wrong here ? is it because i am debugging and set a breakpoint in the http module? It have noticed that it seems that if i startup the website for debugging and quickly step over the breakpoint in the httpmodule it will only hit the init method once and the same goes for the eventhandler. If I instead let it hang at the breakpoint for a few seconds the init method is being called several times (seems like it depends on how long time i wait before stepping over the breakpoint). Maybe this could be some build in feature to make sure that the httpmodule is initialised and the http application can serve requests , but it also seems like something that could have catastrophic consequences. This could seem logical, as it might be trying to finish the request and since i have set the break point it thinks something have gone wrong and try to call the init method again ? soo it can handle the request ? But is this what is happening and is everything fine (i am just guessing), or is it a real problem ? What i am specially concerned about is that if something makes it hang on the "production/live" server for a few seconds a lot of event handlers are added through the init and therefore each request to the page suddenly fires the eventhandler several times. This behaviour could quickly bring any site down. I have looked at the "original" .net code used for the httpmodules for formsauthentication and the rolemanagermodule etc but my code isnt any different that those modules uses. My code looks like this. public void Init(HttpApplication app) { if (CommunityAuthenticationIntegration.IsEnabled) { FormsAuthenticationModule formsAuthModule = (FormsAuthenticationModule) app.Modules["FormsAuthentication"]; formsAuthModule.Authenticate += new FormsAuthenticationEventHandler(this.OnAuthenticate); } } here is an example how it is done in the RoleManagerModule from the .NET framework public void Init(HttpApplication app) { if (Roles.Enabled) { app.PostAuthenticateRequest += new EventHandler(this.OnEnter); app.EndRequest += new EventHandler(this.OnLeave); } } Do anyone know what is going on? (i just hope someone out there can tell me why this is happening and assure me that everything is perfectly fine) :) UPDATE: I have tried to narrow down the problem and so far i have found that the Init method being called is always on a new object of my http module (contary to what i thought before). I seems that for the first request (when starting up the site) all of the HttpApplication objects being created and its modules are all trying to serve the first request and therefore all hit the eventhandler that is being added. I cant really figure out why this is happening. If i request another page all the HttpApplication's created (and their moduless) will again try to serve the request causing it to hit the eventhandler multiple times. But it also seems that if i then jump back to the first page (or another one) only one HttpApplication will start to take care of the request and everything is as expected - as long as i dont let it hang at a break point. If i let it hang at a breakpoint it begins to create new HttpApplication's objects and starts adding HttpApplications (more than 1) to serve/handle the request (which is already in process of being served by the HttpApplication which is currently stopped at the breakpoint). I guess or hope that it might be some intelligent "behind the scenes" way of helping to distribute and handle load and / or errors. But I have no clue. I hope some out there can assure me that it is perfectly fine and how it is supposed to be?

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• JQuery UI Tabs not working

  - by DFG

  Hi, I am using the exact example below from the JQuery website using its built in tabs functions: <script type="text/javascript"> $(function() { $("#tabs").tabs(); }); </script> <div class="demo"> <div id="tabs"> <ul> <li><a href="#tabs-1">Nunc tincidunt</a></li> <li><a href="#tabs-2">Proin dolor</a></li> <li><a href="#tabs-3">Aenean lacinia</a></li> </ul> <div id="tabs-1"> <p>Proin elit arcu, rutrum commodo, vehicula tempus, commodo a, risus. Curabitur nec arcu. Donec sollicitudin mi sit amet mauris. Nam elementum quam ullamcorper ante. Etiam aliquet massa et lorem. Mauris dapibus lacus auctor risus. Aenean tempor ullamcorper leo. Vivamus sed magna quis ligula eleifend adipiscing. Duis orci. Aliquam sodales tortor vitae ipsum. Aliquam nulla. Duis aliquam molestie erat. Ut et mauris vel pede varius sollicitudin. Sed ut dolor nec orci tincidunt interdum. Phasellus ipsum. Nunc tristique tempus lectus.</p> </div> <div id="tabs-2"> <p>Morbi tincidunt, dui sit amet facilisis feugiat, odio metus gravida ante, ut pharetra massa metus id nunc. Duis scelerisque molestie turpis. Sed fringilla, massa eget luctus malesuada, metus eros molestie lectus, ut tempus eros massa ut dolor. Aenean aliquet fringilla sem. Suspendisse sed ligula in ligula suscipit aliquam. Praesent in eros vestibulum mi adipiscing adipiscing. Morbi facilisis. Curabitur ornare consequat nunc. Aenean vel metus. Ut posuere viverra nulla. Aliquam erat volutpat. Pellentesque convallis. Maecenas feugiat, tellus pellentesque pretium posuere, felis lorem euismod felis, eu ornare leo nisi vel felis. Mauris consectetur tortor et purus.</p> </div> <div id="tabs-3"> <p>Mauris eleifend est et turpis. Duis id erat. Suspendisse potenti. Aliquam vulputate, pede vel vehicula accumsan, mi neque rutrum erat, eu congue orci lorem eget lorem. Vestibulum non ante. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Fusce sodales. Quisque eu urna vel enim commodo pellentesque. Praesent eu risus hendrerit ligula tempus pretium. Curabitur lorem enim, pretium nec, feugiat nec, luctus a, lacus.</p> <p>Duis cursus. Maecenas ligula eros, blandit nec, pharetra at, semper at, magna. Nullam ac lacus. Nulla facilisi. Praesent viverra justo vitae neque. Praesent blandit adipiscing velit. Suspendisse potenti. Donec mattis, pede vel pharetra blandit, magna ligula faucibus eros, id euismod lacus dolor eget odio. Nam scelerisque. Donec non libero sed nulla mattis commodo. Ut sagittis. Donec nisi lectus, feugiat porttitor, tempor ac, tempor vitae, pede. Aenean vehicula velit eu tellus interdum rutrum. Maecenas commodo. Pellentesque nec elit. Fusce in lacus. Vivamus a libero vitae lectus hendrerit hendrerit.</p> </div> </div> </div><!-- End demo --> <div style="display: none;" class="demo-description"> <p>Click tabs to swap between content that is broken into logical sections.</p> </div><!-- End demo-description --> However, when I place the JQuery Accordian plugin anywhere in the tabs-1, tabs-2, or tabs-3 element, it stops working correctly, but it works fine in a normal page that doesn't use Jquery. Or any other Jquery doesn't seem to work as its in any of the tabs DIVs. Any ideas?

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• Hung JVM consuming 100% CPU

  - by Bogdan

  We have a JAVA server running on Sun JRE 6u20 on Linux 32-bit (CentOS). We use the Server Hotspot with CMS collector with the following options (I've only provided the relevant ones): -Xmx896m -Xss128k -XX:NewSize=384M -XX:MaxPermSize=96m -XX:+UseParNewGC -XX:+UseConcMarkSweepGC Sometimes, after running for a while, the JVM seems to slip into a hung state, whereby even though we don't make any requests to the application, the CPU continues to spin at 100% (we have 8 logical CPUs, so it looks like only one CPU does the spinning). In this state the JVM doesn't respond to SIGHUP signals (kill -3) and we can't connect to it normally with jstack. We CAN connect with "jstack -F", but the output is dodgy (we can see lots of NullPointerExceptions from JStack apparently because it wasn't able to 'walk' some stacks). So the "jstack -F" output seems to be useless. We have run a stack dump from "gdb" though, and we were able to match the thread id that spins the CPU (we found that using "top" with a per-thread view - "H" option) with a thread stack that appears in the gdb result and this is how it looks like: Thread 443 (Thread 0x7e5b90 (LWP 26310)): #0 0x0115ebd3 in CompactibleFreeListSpace::block_size(HeapWord const*) const () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #1 0x01160ff9 in CompactibleFreeListSpace::prepare_for_compaction(CompactPoint*) () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #2 0x0123456c in Generation::prepare_for_compaction(CompactPoint*) () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #3 0x01229b2c in GenCollectedHeap::prepare_for_compaction() () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #4 0x0122a7fc in GenMarkSweep::invoke_at_safepoint(int, ReferenceProcessor*, bool) () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #5 0x01186024 in CMSCollector::do_compaction_work(bool) () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #6 0x011859ee in CMSCollector::acquire_control_and_collect(bool, bool) () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #7 0x01185705 in ConcurrentMarkSweepGeneration::collect(bool, bool, unsigned int, bool) () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #8 0x01227f53 in GenCollectedHeap::do_collection(bool, bool, unsigned int, bool, int) () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #9 0x0115c7b5 in GenCollectorPolicy::satisfy_failed_allocation(unsigned int, bool) () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #10 0x0122859c in GenCollectedHeap::satisfy_failed_allocation(unsigned int, bool) () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #11 0x0158a8ce in VM_GenCollectForAllocation::doit() () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #12 0x015987e6 in VM_Operation::evaluate() () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #13 0x01597c93 in VMThread::evaluate_operation(VM_Operation*) () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #14 0x01597f0f in VMThread::loop() () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #15 0x015979f0 in VMThread::run() () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #16 0x0145c24e in java_start(Thread*) () from /usr/java/jdk1.6.0_20/jre/lib/i386/server/libjvm.so #17 0x00ccd46b in start_thread () from /lib/libpthread.so.0 #18 0x00bc2dbe in clone () from /lib/libc.so.6 It seems that a JVM thread is spinning while doing some CMS related work. We have checked the memory usage on the box, there seems to be enough memory available and the system is not swapping. Has anyone come across such a situation? Does it look like a JVM bug? UPDATE I've obtained some more information about this problem (it happened again on a server that has been running for more than 7 days). When the JVM entered the "hung" state it stayed like that for 2 hours until the server was manually restarted. We have obtained a core dump of the process and the gc log. We tried to get a heap dump as well, but "jmap" failed. We tried to use jmap -F but then only a 4Mb file was written before the program aborted with an exception (something about the a memory location not being accessible). So far I think the most interesting information comes from the gc log. It seems that the GC logging stopped as well (possibly at the time when the VM thread went into the long loop): 657501.199: [Full GC (System) 657501.199: [CMS: 400352K->313412K(524288K), 2.4024120 secs] 660634K->313412K(878208K), [CMS Perm : 29455K->29320K(68568K)], 2.4026470 secs] [Times: user=2.39 sys=0.01, real=2.40 secs] 657513.941: [GC 657513.941: [ParNew: 314624K->13999K(353920K), 0.0228180 secs] 628036K->327412K(878208K), 0.0230510 secs] [Times: user=0.08 sys=0.00, real=0.02 secs] 657523.772: [GC 657523.772: [ParNew: 328623K->17110K(353920K), 0.0244910 secs] 642036K->330523K(878208K), 0.0247140 secs] [Times: user=0.08 sys=0.00, real=0.02 secs] 657535.473: [GC 657535.473: [ParNew: 331734K->20282K(353920K), 0.0259480 secs] 645147K->333695K(878208K), 0.0261670 secs] [Times: user=0.11 sys=0.00, real=0.02 secs] .... .... 688346.765: [GC [1 CMS-initial-mark: 485248K(524288K)] 515694K(878208K), 0.0343730 secs] [Times: user=0.03 sys=0.00, real=0.04 secs] 688346.800: [CMS-concurrent-mark-start] 688347.964: [CMS-concurrent-mark: 1.083/1.164 secs] [Times: user=2.52 sys=0.09, real=1.16 secs] 688347.964: [CMS-concurrent-preclean-start] 688347.969: [CMS-concurrent-preclean: 0.004/0.005 secs] [Times: user=0.00 sys=0.01, real=0.01 secs] 688347.969: [CMS-concurrent-abortable-preclean-start] CMS: abort preclean due to time 688352.986: [CMS-concurrent-abortable-preclean: 2.351/5.017 secs] [Times: user=3.83 sys=0.38, real=5.01 secs] 688352.987: [GC[YG occupancy: 297806 K (353920 K)]688352.987: [Rescan (parallel) , 0.1815250 secs]688353.169: [weak refs processing, 0.0312660 secs] [1 CMS-remark: 485248K(524288K)] 783055K(878208K), 0.2131580 secs] [Times: user=1.13 sys =0.00, real=0.22 secs] 688353.201: [CMS-concurrent-sweep-start] 688353.903: [CMS-concurrent-sweep: 0.660/0.702 secs] [Times: user=0.91 sys=0.07, real=0.70 secs] 688353.903: [CMS-concurrent-reset-start] 688353.912: [CMS-concurrent-reset: 0.008/0.008 secs] [Times: user=0.01 sys=0.00, real=0.01 secs] 688354.243: [GC 688354.243: [ParNew: 344928K->30151K(353920K), 0.0305020 secs] 681955K->368044K(878208K), 0.0308880 secs] [Times: user=0.15 sys=0.00, real=0.03 secs] .... .... 688943.029: [GC 688943.029: [ParNew: 336531K->17143K(353920K), 0.0237360 secs] 813250K->494327K(878208K), 0.0241260 secs] [Times: user=0.10 sys=0.00, real=0.03 secs] 688950.620: [GC 688950.620: [ParNew: 331767K->22442K(353920K), 0.0344110 secs] 808951K->499996K(878208K), 0.0347690 secs] [Times: user=0.11 sys=0.00, real=0.04 secs] 688956.596: [GC 688956.596: [ParNew: 337064K->37809K(353920K), 0.0488170 secs] 814618K->515896K(878208K), 0.0491550 secs] [Times: user=0.18 sys=0.04, real=0.05 secs] 688961.470: [GC 688961.471: [ParNew (promotion failed): 352433K->332183K(353920K), 0.1862520 secs]688961.657: [CMS I suspect this problem has something to do with the last line in the log (I've added some "...." in order to skip some lines that were not interesting). The fact that the server stayed in the hung state for 2 hours (probably trying to GC and compact the old generation) seems quite strange to me. Also, the gc log stops suddenly with that message and nothing else gets printed any more, probably because the VM Thread gets into some sort of infinite loop (or something that takes 2+ hours).

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• Erasing and modifying elements in Boost MultiIndex Container

  - by Sarah

  I'm trying to use a Boost MultiIndex container in my simulation. My knowledge of C++ syntax is very weak, and I'm concerned I'm not properly removing an element from the container or deleting it from memory. I also need to modify elements, and I was hoping to confirm the syntax and basic philosophy here too. // main.cpp ... #include <boost/multi_index_container.hpp> #include <boost/multi_index/hashed_index.hpp> #include <boost/multi_index/member.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/mem_fun.hpp> #include <boost/tokenizer.hpp> #include <boost/shared_ptr.hpp> ... #include "Host.h" // class Host, all members private, using get fxns to access using boost::multi_index_container; using namespace boost::multi_index; typedef multi_index_container< boost::shared_ptr< Host >, indexed_by< hashed_unique< const_mem_fun<Host,int,&Host::getID> > // ordered_non_unique< BOOST_MULTI_INDEX_MEM_FUN(Host,int,&Host::getAge) > > // end indexed_by > HostContainer; typedef HostContainer::nth_index<0>::type HostsByID; int main() { ... HostContainer allHosts; Host * newHostPtr; newHostPtr = new Host( t, DOB, idCtr, 0, currentEvents ); allHosts.insert( boost::shared_ptr<Host>(newHostPtr) ); // allHosts gets filled up int randomHostID = 4; int newAge = 50; modifyHost( randomHostID, allHosts, newAge ); killHost( randomHostID, allHosts ); } void killHost( int id, HostContainer & hmap ){ HostsByID::iterator it = hmap.find( id ); cout << "Found host id " << (*it)->getID() << "Attempting to kill. hmap.size() before is " << hmap.size() << " and "; hmap.erase( it ); // Is this really erasing (freeing from mem) the underlying Host object? cout << hmap.size() << " after." << endl; } void modifyHost( int id, HostContainer & hmap, int newAge ){ HostsByID::iterator it = hmap.find( id ); (*it) -> setAge( newAge ); // Not actually the "modify" function for MultiIndex... } My questions are In the MultiIndex container allHosts of shared_ptrs to Host objects, is calling allHosts.erase( it ) on an iterator to the object's shared_ptr enough to delete the object permanently and free it from memory? It appears to be removing the shared_ptr from the container. The allhosts container currently has one functioning index that relies on the host's ID. If I introduce an ordered second index that calls on a member function (Host::getAge()), where the age changes over the course of the simulation, is the index always going to be updated when I refer to it? What is the difference between using the MultiIndex's modify to modify the age of the underlying object versus the approach I show above? I'm vaguely confused about what is assumed/required to be constant in MultiIndex. Thanks in advance. Update Here's my attempt to get the modify syntax working, based on what I see in a related Boost example. struct update_age { update_age():(){} // have no idea what this really does... elicits error void operator() (boost::shared_ptr<Host> ptr) { ptr->incrementAge(); // incrementAge() is a member function of class Host } }; and then in modifyHost, I'd have hmap.modify(it,update_age). Even if by some miracle this turns out to be right, I'd love some kind of explanation of what's going on.

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• Avoiding Agnostic Jagged Array Flattening in Powershell

  - by matejhowell

  Hello, I'm running into an interesting problem in Powershell, and haven't been able to find a solution to it. When I google (and find things like this post), nothing quite as involved as what I'm trying to do comes up, so I thought I'd post the question here. The problem has to do with multidimensional arrays with an outer array length of one. It appears Powershell is very adamant about flattening arrays like @( @('A') ) becomes @( 'A' ). Here is the first snippet (prompt is , btw): > $a = @( @( 'Test' ) ) > $a.gettype().isarray True > $a[0].gettype().isarray False So, I'd like to have $a[0].gettype().isarray be true, so that I can index the value as $a[0][0] (the real world scenario is processing dynamic arrays inside of a loop, and I'd like to get the values as $a[$i][$j], but if the inner item is not recognized as an array but as a string (in my case), you start indexing into the characters of the string, as in $a[0][0] -eq 'T'). I have a couple of long code examples, so I have posted them at the end. And, for reference, this is on Windows 7 Ultimate with PSv2 and PSCX installed. Consider code example 1: I build a simple array manually using the += operator. Intermediate array $w is flattened, and consequently is not added to the final array correctly. I have found solutions online for similar problems, which basically involve putting a comma before the inner array to force the outer array to not flatten, which does work, but again, I'm looking for a solution that can build arrays inside a loop (a jagged array of arrays, processing a CSS file), so if I add the leading comma to the single element array (implemented as intermediate array $y), I'd like to do the same for other arrays (like $z), but that adversely affects how $z is added to the final array. Now consider code example 2: This is closer to the actual problem I am having. When a multidimensional array with one element is returned from a function, it is flattened. It is correct before it leaves the function. And again, these are examples, I'm really trying to process a file without having to know if the function is going to come back with @( @( 'color', 'black') ) or with @( @( 'color', 'black'), @( 'background-color', 'white') ) Has anybody encountered this, and has anybody resolved this? I know I can instantiate framework objects, and I'm assuming everything will be fine if I create an object[], or a list<, or something else similar, but I've been dealing with this for a little bit and something sure seems like there has to be a right way to do this (without having to instantiate true framework objects). Code Example 1 function Display($x, [int]$indent, [string]$title) { if($title -ne '') { write-host "$title`: " -foregroundcolor cyan -nonewline } if(!$x.GetType().IsArray) { write-host "'$x'" -foregroundcolor cyan } else { write-host '' $s = new-object string(' ', $indent) for($i = 0; $i -lt $x.length; $i++) { write-host "$s[$i]: " -nonewline -foregroundcolor cyan Display $x[$i] $($indent+1) } } if($title -ne '') { write-host '' } } ### Start Program $final = @( @( 'a', 'b' ), @('c')) Display $final 0 'Initial Value' ### How do we do this part ??? ########### ## $w = @( @('d', 'e') ) ## $x = @( @('f', 'g'), @('h') ) ## # But now $w is flat, $w.length = 2 ## ## ## # Even if we put a leading comma (,) ## # in front of the array, $y will work ## # but $w will not. This can be a ## # problem inside a loop where you don't ## # know the length of the array, and you ## # need to put a comma in front of ## # single- and multidimensional arrays. ## $y = @( ,@('D', 'E') ) ## $z = @( ,@('F', 'G'), @('H') ) ## ## ## ########################################## $final += $w $final += $x $final += $y $final += $z Display $final 0 'Final Value' ### Desired final value: @( @('a', 'b'), @('c'), @('d', 'e'), @('f', 'g'), @('h'), @('D', 'E'), @('F', 'G'), @('H') ) ### As in the below: # # Initial Value: # [0]: # [0]: 'a' # [1]: 'b' # [1]: # [0]: 'c' # # Final Value: # [0]: # [0]: 'a' # [1]: 'b' # [1]: # [0]: 'c' # [2]: # [0]: 'd' # [1]: 'e' # [3]: # [0]: 'f' # [1]: 'g' # [4]: # [0]: 'h' # [5]: # [0]: 'D' # [1]: 'E' # [6]: # [0]: 'F' # [1]: 'G' # [7]: # [0]: 'H' Code Example 2 function Display($x, [int]$indent, [string]$title) { if($title -ne '') { write-host "$title`: " -foregroundcolor cyan -nonewline } if(!$x.GetType().IsArray) { write-host "'$x'" -foregroundcolor cyan } else { write-host '' $s = new-object string(' ', $indent) for($i = 0; $i -lt $x.length; $i++) { write-host "$s[$i]: " -nonewline -foregroundcolor cyan Display $x[$i] $($indent+1) } } if($title -ne '') { write-host '' } } function funA() { $ret = @() $temp = @(0) $temp[0] = @('p', 'q') $ret += $temp Display $ret 0 'Inside Function A' return $ret } function funB() { $ret = @( ,@('r', 's') ) Display $ret 0 'Inside Function B' return $ret } ### Start Program $z = funA Display $z 0 'Return from Function A' $z = funB Display $z 0 'Return from Function B' ### Desired final value: @( @('p', 'q') ) and same for r,s ### As in the below: # # Inside Function A: # [0]: # [0]: 'p' # [1]: 'q' # # Return from Function A: # [0]: # [0]: 'p' # [1]: 'q' Thanks, Matt

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• ./a.out termniated . Garbage output due to smashing of stack . How to remove this error ?

  - by mekasperasky

  #include <iostream> #include <fstream> #include <cstring> using namespace std; typedef unsigned long int WORD; /* Should be 32-bit = 4 bytes */ #define w 32 /* word size in bits */ #define r 12 /* number of rounds */ #define b 16 /* number of bytes in key */ #define c 4 /* number words in key */ /* c = max(1,ceil(8*b/w)) */ #define t 26 /* size of table S = 2*(r+1) words */ WORD S [t],L[c]; /* expanded key table */ WORD P = 0xb7e15163, Q = 0x9e3779b9; /* magic constants */ /* Rotation operators. x must be unsigned, to get logical right shift*/ #define ROTL(x,y) (((x)<<(y&(w-1))) | ((x)>>(w-(y&(w-1))))) #define ROTR(x,y) (((x)>>(y&(w-1))) | ((x)<<(w-(y&(w-1))))) void RC5_ENCRYPT(WORD *pt, WORD *ct) /* 2 WORD input pt/output ct */ { WORD i, A=pt[0]+S[0], B=pt[1]+S[1]; for (i=1; i<=r; i++) { A = ROTL(A^B,B)+S[2*i]; B = ROTL(B^A,A)+S[2*i+1]; } ct [0] = A ; ct [1] = B ; } void RC5_DECRYPT(WORD *ct, WORD *pt) /* 2 WORD input ct/output pt */ { WORD i, B=ct[1], A=ct[ 0]; for (i=r; i>0; i--) { B = ROTR(B-S [2*i+1],A)^A; A = ROTR(A-S [2*i],B)^B; } pt [1] = B-S [1] ;pt [0] = A-S [0]; } void RC5_SETUP(unsigned char *K) /* secret input key K 0...b-1] */ { WORD i, j, k, u=w/8, A, B, L [c]; /* Initialize L, then S, then mix key into S */ for (i=b-1,L[c-1]=0; i!=-1; i--) L[i/u] = (L[i/u]<<8)+K[ i]; for (S [0]=P,i=1; i<t; i++) S [i] = S [i-1]+Q; for (A=B=i=j=k=0; k<3*t; k++,i=(i+1)%t,j=(j+1)%c) /* 3*t > 3*c */ { A = S[i] = ROTL(S [i]+(A+B),3); B = L[j] = ROTL(L[j]+(A+B),(A+B)); } } void printword(WORD A) { WORD k; for (k=0 ;k<w; k+=8) printf("%c"); } int main() { WORD i, j, k,ptext, pt1 [2], pt2 [2], ct [2] = {0,0}; ifstream in("key1.txt"); ifstream in1("plt.txt"); ofstream out1("cpt.txt"); if(!in) { cout << "Cannot open file.\n"; return 1; } if(!in1) { cout << "Cannot open file.\n"; return 1; } unsigned char key[b]; in >> key; in1 >> pt1[0]; in1 >> pt1[0]; if (sizeof(WORD)!=4) printf("RC5 error: WORD has %d bytes.\n",sizeof(WORD)); RC5_SETUP(key); RC5_ENCRYPT(pt1,ct); printf("\n plaintext "); printword(pt1 [0]); printword(pt1 [1]); printf(" ---> ciphertext "); printword(ct [0]); printword(ct [1]); printf("\n"); RC5_SETUP(key); RC5_DECRYPT(ct,pt2); out1<<ct[0]; out1<<ct[1]; out1 <<"\n"; printf("\n plaintext "); printword(pt1 [0]); printword(pt1 [1]); return 0; } Let the plt.txt file contain 101 100 let the key be 111

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• PHP Form not working IE and Chrome, but fine in FF

  - by RO

  <? if(isset($_POST['accountUser']) && isset($_POST['accountPassword'])) { include("dbase.php"); include("settings.php"); if ($_POST['accountType']=="member") { $database="chatusers"; } else if ($_POST['accountType']=="model") { $database="chatmodels"; } else if ($_POST['accountType']=="studioop") { $database="chatoperators"; } $userExists=false; $result = mysql_query("SELECT id,user,password,status FROM $database WHERE status!='pending' AND status!='rejected' "); while($row = mysql_fetch_array($result)) { $tempUser=$row["user"]; $tempPass=$row["password"]; $tempId=$row["id"]; if ($_POST['accountUser']==$tempUser && md5($_POST['accountPassword'])==$tempPass) { if ($row["status"]=="blocked") { $userExists=true; $errorMsg="Account is blocked, please contact the administrator for more details"; } else { $userExists=true; $currentTime=time(); mysql_query("UPDATE $database SET lastLogIn='$currentTime' WHERE id = '$tempId' LIMIT 1"); setcookie("usertype", $database, time()+3600); setcookie("id", $tempId, time()+3600); header("Location: cp/$database/"); } } } if (!$userExists){ $errorMsg="Wrong Username or password"; } } else if (isset($_GET['from']) && $_GET['from']=="recoverpass"){ $errorMsg="Your new password has been sent to your mail"; } else { $errorMsg="Please complete username and password fields"; } ?> <? include("_main.header.php"); ?> <table width="720" height="200" border="0" align="center" cellpadding="0" cellspacing="0"> <tr> <td align="center" valign="middle"><form action="login.php" method="post" enctype="application/x-www-form-urlencoded" name="form1"> <p>&nbsp;</p> <table width="720" border="0" align="center"> <tr> <td colspan="2"><p align="left"> <span class="error"><?php if ( isset($errorMsg) && $errorMsg!=""){ echo $errorMsg; } ?></span> <br> <br> </p></td> </tr> <tr> <td width="210" align="right" valign="top" class="form_definitions"><div align="right">Username:</div></td> <td align="left" valign="top"><input name="accountUser" type="text" id="accountUser" value="<? echo $_GET[user];?>" size="24" maxlength="24"></td> </tr> <tr> <td align="right" valign="top" class="form_definitions"><div align="right">Password:</div></td> <td align="left" valign="top"><input name="accountPassword" type="password" id="accountPassword2" size="24" maxlength="24"></td> </tr> <tr> <td align="right" valign="top" class="form_definitions"><div align="right">Account type:</div></td> <td align="left" valign="top"> <select name="accountType" id="select"> <option value="member" selected>Member</option> <option value="model">Model</option> <option value="studioop">Studio Operator</option> </select> <div align="left"></div></td> </tr> <tr> <td align="right" valign="top" class="form_definitions">&nbsp;</td> <td align="left" valign="top"> <input type="submit" name="Submit" value="Log In to your account"> <div align="left"></div></td> </tr> <tr> <td align="right" valign="top" class="form_definitions">&nbsp;</td> <td align="left" valign="top"><a href="lostpassword.php" class="left">Lost Password? Press Here!</a></td> </tr> </table> </form></td> </tr> </table> <br> <br> <? include("_main.footer.php"); ?>

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• Signals and threads - good or bad design decision?

  - by Jens

  I have to write a program that performs highly computationally intensive calculations. The program might run for several days. The calculation can be separated easily in different threads without the need of shared data. I want a GUI or a web service that informs me of the current status. My current design uses BOOST::signals2 and BOOST::thread. It compiles and so far works as expected. If a thread finished one iteration and new data is available it calls a signal which is connected to a slot in the GUI class. My question(s): Is this combination of signals and threads a wise idea? I another forum somebody advised someone else not to "go down this road". Are there potential deadly pitfalls nearby that I failed to see? Is my expectation realistic that it will be "easy" to use my GUI class to provide a web interface or a QT, a VTK or a whatever window? Is there a more clever alternative (like other boost libs) that I overlooked? following code compiles with g++ -Wall -o main -lboost_thread-mt <filename>.cpp code follows: #include <boost/signals2.hpp> #include <boost/thread.hpp> #include <boost/bind.hpp> #include <iostream> #include <iterator> #include <string> using std::cout; using std::cerr; using std::string; /** * Called when a CalcThread finished a new bunch of data. */ boost::signals2::signal<void(string)> signal_new_data; /** * The whole data will be stored here. */ class DataCollector { typedef boost::mutex::scoped_lock scoped_lock; boost::mutex mutex; public: /** * Called by CalcThreads call the to store their data. */ void push(const string &s, const string &caller_name) { scoped_lock lock(mutex); _data.push_back(s); signal_new_data(caller_name); } /** * Output everything collected so far to std::out. */ void out() { typedef std::vector<string>::const_iterator iter; for (iter i = _data.begin(); i != _data.end(); ++i) cout << " " << *i << "\n"; } private: std::vector<string> _data; }; /** * Several of those can calculate stuff. * No data sharing needed. */ struct CalcThread { CalcThread(string name, DataCollector &datcol) : _name(name), _datcol(datcol) { } /** * Expensive algorithms will be implemented here. * @param num_results how many data sets are to be calculated by this thread. */ void operator()(int num_results) { for (int i = 1; i <= num_results; ++i) { std::stringstream s; s << "["; if (i == num_results) s << "LAST "; s << "DATA " << i << " from thread " << _name << "]"; _datcol.push(s.str(), _name); } } private: string _name; DataCollector &_datcol; }; /** * Maybe some VTK or QT or both will be used someday. */ class GuiClass { public: GuiClass(DataCollector &datcol) : _datcol(datcol) { } /** * If the GUI wants to present or at least count the data collected so far. * @param caller_name is the name of the thread whose data is new. */ void slot_data_changed(string caller_name) const { cout << "GuiClass knows: new data from " << caller_name << std::endl; } private: DataCollector & _datcol; }; int main() { DataCollector datcol; GuiClass mc(datcol); signal_new_data.connect(boost::bind(&GuiClass::slot_data_changed, &mc, _1)); CalcThread r1("A", datcol), r2("B", datcol), r3("C", datcol), r4("D", datcol), r5("E", datcol); boost::thread t1(r1, 3); boost::thread t2(r2, 1); boost::thread t3(r3, 2); boost::thread t4(r4, 2); boost::thread t5(r5, 3); t1.join(); t2.join(); t3.join(); t4.join(); t5.join(); datcol.out(); cout << "\nDone" << std::endl; return 0; }

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• problems mounting an external IDE drive via USB in ubuntu

  - by Roy Rico

  I am having a problem connecting a specific IDE drive to my linux box. It's an old drive which I just want to get about 3 GB of files off of. INFO I am trying to connect a 200GB IDE Maxtor Drive, internally and externally... externally: I am using an self powered USB IDE external drive enclosure which I have used to connect various drives, under ubuntu and windows, in the past. The other posts stated it coudl be a problem I think i may have formatted the /dev/sdc partition instead of /dev/sdc1 partition when i originally formatted the drive. internally: I only have one machine left that has an internal IDE interface, and it's got XP on it. I plugged this drive internally into this machine with windows XP and used the ext2/ext3 drivers to mount this drive, but some files have question marks (?) in the file names which is messing up my copy process in windows. I can't delete the files under windows. Ubuntu Linux will not install on my only remaining machine that has IDE controller. I have tried the suggestions in the questions below http://superuser.com/questions/88182/mount-an-external-drive-in-ubuntu http://superuser.com/questions/23210/ubuntu-fails-to-mount-usb-drive it looks like i can see the drive in /proc/partitions $ cat /proc/partitions major minor #blocks name 8 0 78125000 sda 8 1 74894998 sda1 8 2 1 sda2 8 5 3229033 sda5 8 16 199148544 sdb <-- could be my drive? but it's not listed under fdisk -l $ fdisk -l Disk /dev/sda: 80.0 GB, 80000000000 bytes 255 heads, 63 sectors/track, 9726 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0xd0f4738c Device Boot Start End Blocks Id System /dev/sda1 * 1 9324 74894998+ 83 Linux /dev/sda2 9325 9726 3229065 5 Extended /dev/sda5 9325 9726 3229033+ 82 Linux swap / Solaris and here is my log of /var/log/messages. with a bunch of weird output, can someone let me know what that weird output is? Mar 3 19:49:40 mala kernel: [687455.112029] usb 1-7: new high speed USB device using ehci_hcd and address 3 Mar 3 19:49:41 mala kernel: [687455.248576] usb 1-7: configuration #1 chosen from 1 choice Mar 3 19:49:41 mala kernel: [687455.267450] Initializing USB Mass Storage driver... Mar 3 19:49:41 mala kernel: [687455.269180] scsi4 : SCSI emulation for USB Mass Storage devices Mar 3 19:49:41 mala kernel: [687455.269410] usbcore: registered new interface driver usb-storage Mar 3 19:49:41 mala kernel: [687455.269416] USB Mass Storage support registered. Mar 3 19:49:46 mala kernel: [687460.270917] scsi 4:0:0:0: Direct-Access Maxtor 6 Y200P0 YAR4 PQ: 0 ANSI: 2 Mar 3 19:49:46 mala kernel: [687460.271485] sd 4:0:0:0: Attached scsi generic sg2 type 0 Mar 3 19:49:46 mala kernel: [687460.278858] sd 4:0:0:0: [sdb] 398297088 512-byte logical blocks: (203 GB/189 GiB) Mar 3 19:49:46 mala kernel: [687460.280866] sd 4:0:0:0: [sdb] Write Protect is off Mar 3 19:50:16 mala kernel: [687460.283784] sdb: Mar 3 19:50:16 mala kernel: [687491.112020] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:50:47 mala kernel: [687522.120030] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:51:18 mala kernel: [687553.112034] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:51:49 mala kernel: [687584.116025] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:52:02 mala kernel: [687596.170632] type=1505 audit(1267671122.035:31): operation="profile_replace" pid=8426 name=/usr/lib/cups/backend/cups-pdf Mar 3 19:52:02 mala kernel: [687596.171551] type=1505 audit(1267671122.035:32): operation="profile_replace" pid=8426 name=/usr/sbin/cupsd Mar 3 19:52:06 mala kernel: [687600.908056] async/0 D c08145c0 0 7655 2 0x00000000 Mar 3 19:52:06 mala kernel: [687600.908062] e5601d38 00000046 e5774000 c08145c0 e4c2a848 c08145c0 d203973a 0002713d Mar 3 19:52:06 mala kernel: [687600.908072] c08145c0 c08145c0 e4c2a848 c08145c0 00000000 0002713d c08145c0 f0a98c00 Mar 3 19:52:06 mala kernel: [687600.908079] e4c2a5b0 c20125c0 00000002 e5601d80 e5601d44 c056f3be e5601d78 e5601d4c Mar 3 19:52:06 mala kernel: [687600.908087] Call Trace: Mar 3 19:52:06 mala kernel: [687600.908099] [<c056f3be>] io_schedule+0x1e/0x30 Mar 3 19:52:06 mala kernel: [687600.908107] [<c01b2cf5>] sync_page+0x35/0x40 Mar 3 19:52:06 mala kernel: [687600.908111] [<c056f8f7>] __wait_on_bit_lock+0x47/0x90 Mar 3 19:52:06 mala kernel: [687600.908115] [<c01b2cc0>] ? sync_page+0x0/0x40 Mar 3 19:52:06 mala kernel: [687600.908121] [<c020f390>] ? blkdev_readpage+0x0/0x20 Mar 3 19:52:06 mala kernel: [687600.908125] [<c01b2ca9>] __lock_page+0x79/0x80 Mar 3 19:52:06 mala kernel: [687600.908130] [<c015c130>] ? wake_bit_function+0x0/0x50 Mar 3 19:52:06 mala kernel: [687600.908135] [<c01b459f>] read_cache_page_async+0xbf/0xd0 Mar 3 19:52:06 mala kernel: [687600.908139] [<c01b45c2>] read_cache_page+0x12/0x60 Mar 3 19:52:06 mala kernel: [687600.908144] [<c0232dca>] read_dev_sector+0x3a/0x80 Mar 3 19:52:06 mala kernel: [687600.908148] [<c0233d3e>] adfspart_check_ICS+0x1e/0x160 Mar 3 19:52:06 mala kernel: [687600.908152] [<c023339f>] ? disk_name+0xaf/0xc0 Mar 3 19:52:06 mala kernel: [687600.908157] [<c0233d20>] ? adfspart_check_ICS+0x0/0x160 Mar 3 19:52:06 mala kernel: [687600.908161] [<c02334de>] check_partition+0x10e/0x180 Mar 3 19:52:06 mala kernel: [687600.908165] [<c02335f6>] rescan_partitions+0xa6/0x330 Mar 3 19:52:06 mala kernel: [687600.908171] [<c0312472>] ? kobject_get+0x12/0x20 Mar 3 19:52:06 mala kernel: [687600.908175] [<c0312472>] ? kobject_get+0x12/0x20 Mar 3 19:52:06 mala kernel: [687600.908180] [<c039fc43>] ? get_device+0x13/0x20 Mar 3 19:52:06 mala kernel: [687600.908185] [<c03c263f>] ? sd_open+0x5f/0x1b0 Mar 3 19:52:06 mala kernel: [687600.908189] [<c020fda0>] __blkdev_get+0x140/0x310 Mar 3 19:52:06 mala kernel: [687600.908194] [<c020f0ac>] ? bdget+0xec/0x100 Mar 3 19:52:06 mala kernel: [687600.908198] [<c020ff7a>] blkdev_get+0xa/0x10 Mar 3 19:52:06 mala kernel: [687600.908202] [<c0232f30>] register_disk+0x120/0x140 Mar 3 19:52:06 mala kernel: [687600.908207] [<c0308b4d>] ? blk_register_region+0x2d/0x40 Mar 3 19:52:06 mala kernel: [687600.908211] [<c03084f0>] ? exact_match+0x0/0x10 Mar 3 19:52:06 mala kernel: [687600.908216] [<c0308cf0>] add_disk+0x80/0x140 Mar 3 19:52:06 mala kernel: [687600.908221] [<c03084f0>] ? exact_match+0x0/0x10 Mar 3 19:52:06 mala kernel: [687600.908225] [<c0308860>] ? exact_lock+0x0/0x20 Mar 3 19:52:06 mala kernel: [687600.908230] [<c03c53df>] sd_probe_async+0xff/0x1c0

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• Build Environment setup - Using .net, java, hudson, and ruby - Could really use a critique

  - by Jeff D

  I'm trying to figure out the best way to stitch together a fast, repeatable, unbreakable build process for the following environment. I've got a plan for how to do it, but I'd really appreciate a critique. (I'd also appreciate some sample code, but more on that later) Ecosystem - Logical: Website - asp.net MVC 2, .net 3.5, Visual Studio 2010. IIS 6, Facebook iframe application application. This website/facebook app uses a few services. An internal search api, an internal read/write api, facebook, and an IP geolocation service. More details on these below Internal search api - .net, restful, built using old school .ashx handlers. The api uses lucene, and a sql server database behind the scenes. My project won't touch the lucene code, but does potentially touch the database and the web services. internal read/write api - java, restful, running on Tomcat Facebook web services A mocking site that emulates the internal read/write api, and parts of the facebook api Hudson - Runs unit tests on checkin, and creates some installers that behave inconsistently. Ecosystem - Physical: All of these machines can talk to one another, except for Hudson. Hudson can't see any of the target machines. So code must be pulled, rather than pushed. (Security thing) 1. Web Server - Holds the website, and the read/write api. (The api itself writes to a replicated sql server environment). 2. Search Server - Houses the search api. 3. Hudson Server - Does not have permissions to push to any environment. They have to pull. 4. Lucene Server 5. Database Server Problem I've been trying to set this site up to run in a stress environment, but the number of setup steps, the amount of time it takes to update a component, the black-box nature of the current installers, and the time it takes to generate data into the test system is absolutely destroying my productivity. I tweak one setting, have to redeploy, restart in a certain order, resetup some of the settings, and rebuild test data. Errors result in headscratching, and then basically starting over. Very bad. This problem is complicated further by my stress testing. I need to be able to turn on and off different external components, so that I can effectively determine the scalability of each piece. I've got strategies in place for how to do that for each dependency, but it further complicates my setup strategy, because now each component has 2 options. A mock version, or a real version. Configurations everywhere must be updated accordingly. Goals Fast - I want to drop this from a 20 minute exercise when things go perfectly, to a 3 minute one Stupid simple - I want to tell the environment what to do with as few commands as possible, and not have to remember how to stitch the environments together Repeatable - I want the script to be idempotent. Kind of a corollary to the Stupid Simple thing. The Plan So Far Here's what I've come up with so far, and what I've come looking for feedback on: Use VisualStudio's new web.config transformations to permit easily altering configs based on envrionment. This solution isn't really sufficient though. I will leave web.config set up to let the site run locally, but when deploying elsewhere, I have as many as 6 different possible outputs for the stress environment alone (because of the mocks of the various dependencies), let alone the settings for prod, QA, and dev. Each of these would then require it's own setup, or a setup that would then post-process the configs. So I'm currently leaning toward just having the dev version, and a version that converts key configuration values into a ruby string interpolation syntax. ({#VAR_NAME} kinda thing) Create a ruby script for each server that is essentially a bootstrapping script. That is to say, it will do nothing but load the ruby code that does the 'real' work from hudson/subversion, so that the script's functionality can evolve with the application, making it easy to build the site at any point in time by reference the appropriate version of the script. So in a nutshell, this script loads another script, and runs it. The 'real' ruby script will then accept commandline parameters that describe how the environment should look. From there, 1 configuration file can be used, and ruby will download the current installers, run them, post-process the configs, restart IIS/Tomcat, and kick off any data setup code that is needed. So that's it. I'm in a real time crunch to get this site stress-tested, so any feedback that you think could abbreviate the time this might take would be appreciated. That includes a shameless request for sample ruby code. I've not gotten too much further than puts "Hello World". :-) Just guidance would be helpful. Is this something that Rake would be useful for? How would you recommend I write tests for this animal? (I use interfaces and automocking frameworks to mock out things like http requests in .net. With ducktyping, it seems that this might be easier, but I don't know how to tell my code to use a fake duck in test, but a real one in practice) Thanks all. Sorry for such such a long-winded, open-ended question.

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• EC2 instance suddenly refusing SSH connections and won't respond to ping

  - by Chris

  My instance was running fine and this morning I was able to access a Ruby on Rails app hosted on it. An hour later I suddenly wasn't able to access my site, my SSH connection attempts were refused and the server wasn't even responding to ping. I didn't change anything on my system during that hour and reboots aren't fixing it. I've never had any problems connecting or pinging the system before. Can someone please help? This is on my production system! OS: CentOS 5 AMI ID: ami-10b55379 Type: m1.small [] ~% ssh -v *****@meeteor.com OpenSSH_5.2p1, OpenSSL 0.9.8l 5 Nov 2009 debug1: Reading configuration data /etc/ssh_config debug1: Connecting to meeteor.com [184.73.235.191] port 22. debug1: connect to address 184.73.235.191 port 22: Connection refused ssh: connect to host meeteor.com port 22: Connection refused [] ~% ping meeteor.com PING meeteor.com (184.73.235.191): 56 data bytes Request timeout for icmp_seq 0 Request timeout for icmp_seq 1 Request timeout for icmp_seq 2 ^C --- meeteor.com ping statistics --- 4 packets transmitted, 0 packets received, 100.0% packet loss [] ~% ========= System Log ========= Restarting system. Linux version 2.6.16-xenU ([email protected]) (gcc version 4.0.1 20050727 (Red Hat 4.0.1-5)) #1 SMP Mon May 28 03:41:49 SAST 2007 BIOS-provided physical RAM map: Xen: 0000000000000000 - 000000006a400000 (usable) 980MB HIGHMEM available. 727MB LOWMEM available. NX (Execute Disable) protection: active IRQ lockup detection disabled Built 1 zonelists Kernel command line: root=/dev/sda1 ro 4 Enabling fast FPU save and restore... done. Enabling unmasked SIMD FPU exception support... done. Initializing CPU#0 PID hash table entries: 4096 (order: 12, 65536 bytes) Xen reported: 2599.998 MHz processor. Dentry cache hash table entries: 131072 (order: 7, 524288 bytes) Inode-cache hash table entries: 65536 (order: 6, 262144 bytes) Software IO TLB disabled vmalloc area: ee000000-f53fe000, maxmem 2d7fe000 Memory: 1718700k/1748992k available (1958k kernel code, 20948k reserved, 620k data, 144k init, 1003528k highmem) Checking if this processor honours the WP bit even in supervisor mode... Ok. Calibrating delay using timer specific routine.. 5202.30 BogoMIPS (lpj=26011526) Mount-cache hash table entries: 512 CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line) CPU: L2 Cache: 1024K (64 bytes/line) Checking 'hlt' instruction... OK. Brought up 1 CPUs migration_cost=0 Grant table initialized NET: Registered protocol family 16 Brought up 1 CPUs xen_mem: Initialising balloon driver. highmem bounce pool size: 64 pages VFS: Disk quotas dquot_6.5.1 Dquot-cache hash table entries: 1024 (order 0, 4096 bytes) Initializing Cryptographic API io scheduler noop registered io scheduler anticipatory registered (default) io scheduler deadline registered io scheduler cfq registered i8042.c: No controller found. RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize Xen virtual console successfully installed as tty1 Event-channel device installed. netfront: Initialising virtual ethernet driver. mice: PS/2 mouse device common for all mice md: md driver 0.90.3 MAX_MD_DEVS=256, MD_SB_DISKS=27 md: bitmap version 4.39 NET: Registered protocol family 2 Registering block device major 8 IP route cache hash table entries: 65536 (order: 6, 262144 bytes) TCP established hash table entries: 262144 (order: 9, 2097152 bytes) TCP bind hash table entries: 65536 (order: 7, 524288 bytes) TCP: Hash tables configured (established 262144 bind 65536) TCP reno registered TCP bic registered NET: Registered protocol family 1 NET: Registered protocol family 17 NET: Registered protocol family 15 Using IPI No-Shortcut mode md: Autodetecting RAID arrays. md: autorun ... md: ... autorun DONE. kjournald starting. Commit interval 5 seconds EXT3-fs: mounted filesystem with ordered data mode. VFS: Mounted root (ext3 filesystem) readonly. Freeing unused kernel memory: 144k freed *************************************************************** *************************************************************** ** WARNING: Currently emulating unsupported memory accesses ** ** in /lib/tls glibc libraries. The emulation is ** ** slow. To ensure full performance you should ** ** install a 'xen-friendly' (nosegneg) version of ** ** the library, or disable tls support by executing ** ** the following as root: ** ** mv /lib/tls /lib/tls.disabled ** ** Offending process: init (pid=1) ** *************************************************************** *************************************************************** Pausing... 5Pausing... 4Pausing... 3Pausing... 2Pausing... 1Continuing... INIT: version 2.86 booting Welcome to CentOS release 5.4 (Final) Press 'I' to enter interactive startup. Setting clock : Fri Oct 1 14:35:26 EDT 2010 [ OK ] Starting udev: [ OK ] Setting hostname localhost.localdomain: [ OK ] No devices found Setting up Logical Volume Management: [ OK ] Checking filesystems Checking all file systems. [/sbin/fsck.ext3 (1) -- /] fsck.ext3 -a /dev/sda1 /dev/sda1: clean, 275424/1310720 files, 1161123/2621440 blocks [ OK ] Remounting root filesystem in read-write mode: [ OK ] Mounting local filesystems: [ OK ] Enabling local filesystem quotas: [ OK ] Enabling /etc/fstab swaps: [ OK ] INIT: Entering runlevel: 4 Entering non-interactive startup Starting background readahead: [ OK ] Applying ip6tables firewall rules: modprobe: FATAL: Module ip6_tables not found. ip6tables-restore v1.3.5: ip6tables-restore: unable to initializetable 'filter' Error occurred at line: 3 Try `ip6tables-restore -h' or 'ip6tables-restore --help' for more information. [FAILED] Applying iptables firewall rules: [ OK ] Loading additional iptables modules: ip_conntrack_netbios_ns [ OK ] Bringing up loopback interface: [ OK ] Bringing up interface eth0: Determining IP information for eth0... done. [ OK ] Starting auditd: [FAILED] Starting irqbalance: [ OK ] Starting portmap: [ OK ] FATAL: Module lockd not found. Starting NFS statd: [ OK ] Starting RPC idmapd: FATAL: Module sunrpc not found. FATAL: Error running install command for sunrpc Error: RPC MTAB does not exist. Starting system message bus: [ OK ] Starting Bluetooth services:[ OK ] [ OK ] Can't open RFCOMM control socket: Address family not supported by protocol Mounting other filesystems: [ OK ] Starting PC/SC smart card daemon (pcscd): [ OK ] Starting hidd: Can't open HIDP control socket: Address family not supported by protocol [FAILED] Starting autofs: Starting automount: automount: test mount forbidden or incorrect kernel protocol version, kernel protocol version 5.00 or above required. [FAILED] [FAILED] Starting sshd: [ OK ] Starting cups: [ OK ] Starting sendmail: [ OK ] Starting sm-client: [ OK ] Starting console mouse services: no console device found[FAILED] Starting crond: [ OK ] Starting xfs: [ OK ] Starting anacron: [ OK ] Starting atd: [ OK ] % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 390 100 390 0 0 58130 0 --:--:-- --:--:-- --:--:-- 58130 100 390 100 390 0 0 56984 0 --:--:-- --:--:-- --:--:-- 0 Starting yum-updatesd: [ OK ] Starting Avahi daemon... [ OK ] Starting HAL daemon: [ OK ] Starting OSSEC: [ OK ] Starting smartd: [ OK ] c CentOS release 5.4 (Final) Kernel 2.6.16-xenU on an i686 domU-12-31-39-00-C4-97 login: INIT: Id "2" respawning too fast: disabled for 5 minutes INIT: Id "3" respawning too fast: disabled for 5 minutes INIT: Id "4" respawning too fast: disabled for 5 minutes INIT: Id "5" respawning too fast: disabled for 5 minutes INIT: Id "6" respawning too fast: disabled for 5 minutes

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• C# Generic Arrays and math operations on it

  - by msedi

  Hello, I'm currently involved in a project where I have very large image volumes. This volumes have to processed very fast (adding, subtracting, thresholding, and so on). Additionally most of the volume are so large that they event don't fit into the memory of the system. For that reason I have created an abstract volume class (VoxelVolume) that host the volume and image data and overloads the operators so that it's possible to perform the regular mathematical operations on volumes. Thereby two more questions opened up which I will put into stackoverflow into two additional threads. Here is my first question. My volume is implemented in a way that it only can contain float array data, but most of the containing data is from an UInt16 image source. Only operations on the volume can create float array images. When I started implementing such a volume the class looked like following: public abstract class VoxelVolume<T> { ... } but then I realized that overloading the operators or return values would get more complicated. An example would be: public abstract class VoxelVolume<T> { ... public static VoxelVolume<T> Import<T>(param string[] files) { } } also adding two overloading operators would be more complicated: ... public static VoxelVolume<T> operator+(VoxelVolume<T> A, VoxelVolume<T> B) { ... } Let's assume I can overcome the problems described above, nevertheless I have different types of arrays that contain the image data. Since I have fixed my type in the volumes to float the is no problem and I can do an unsafe operation when adding the contents of two image volume arrays. I have read a few threads here and had a look around the web, but found no real good explanation of what to do when I want to add two arrays of different types in a fast way. Unfortunately every math operation on generics is not possible, since C# is not able to calculate the size of the underlying data type. Of course there might by a way around this problem by using C++/CLR, but currently everything I have done so far, runs in 32bit and 64bit without having to do a thing. Switching to C++/CLR seemed to me (pleased correct me if I'm wrong) that I'm bound to a certain platform (32bit) and I have to compile two assemblies when I let the application run on another platform (64bit). Is this true? So asked shortly: How is it possible to add two arrays of two different types in a fast way. Is it true that the developers of C# haven't thought about this. Switching to a different language (C# - C++) seems not to be an option. I realize that simply performing this operation float []A = new float[]{1,2,3}; byte []B = new byte[]{1,2,3}; float []C = A+B; is not possible and unnecessary although it would be nice if it would work. My solution I was trying was following: public static class ArrayExt { public static unsafe TResult[] Add<T1, T2, TResult>(T1 []A, T2 []B) { // Assume the length of both arrays is equal TResult[] result = new TResult[A.Length]; GCHandle h1 = GCHandle.Alloc (A, Pinned); GCHandle h2 = GCHandle.Alloc (B, Pinned); GCHandle hR = GCHandle.Alloc (C, Pinned); void *ptrA = h1.ToPointer(); void *ptrB = h2.ToPointer(); void *ptrR = hR.ToPointer(); for (int i=0; i<A.Length; i++) { *((TResult *)ptrR) = (TResult *)((T1)*ptrA + (T2)*ptrB)); } h1.Free(); h2.Free(); hR.Free(); return result; } } Please excuse if the code above is not quite correct, I wrote it without using an C# editor. Is such a solution a shown above thinkable? Please feel free to ask if I made a mistake or described some things incompletely. Thanks for your help Martin

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• Printing an array in a method, from a different class?

  - by O.Lodhi

  Hello All, I'm a fairly inexperienced programmer, and i'm currently working on a Console Application project. It's basically a little 'mathematics game'; the application generates two random numbers, that have either been added, subtracted, multiplied or divided against each other randomly. The answer is shown on screen and the user has to pick from the menu which is the right mathematical operator, once the correct answer is picked the application then displays on screen how long it took for the user in milliseconds to input the correct answer. Now I want to save the times of the players in an array that can be called up later with all the scores. I need to include a method in this programme and I figured a method to save the times into an array would be suitable. I seem to have stumbled across a little problem though. I'm not quite sure what's wrong: using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace Mathgame { class Program { } class arrayclass { public static void saveInArray(int duration) { int[] TopTenScores = {000,1000,2000,3000,4000,5000,6000,7000,8000,9000}; if (duration < 1000) { duration = TopTenScores[000]; } else if ((duration >= 1000) && (duration <= 1999)) { duration = TopTenScores[1000]; } else if ((duration >= 2000) && (duration <= 2999)) { duration = TopTenScores[2000]; } else if ((duration >= 3000) && (duration <= 3999)) { duration = TopTenScores[3000]; } else if ((duration >= 4000) && (duration <= 4999)) { duration = TopTenScores[4000]; } else if ((duration >= 5000) && (duration <= 5999)) { duration = TopTenScores[5000]; } else if ((duration >= 6000) && (duration <= 6999)) { duration = TopTenScores[6000]; } else if ((duration >= 7000) && (duration <= 7999)) { duration = TopTenScores[7000]; } else if ((duration >= 8000) && (duration <= 8999)) { duration = TopTenScores[8000]; } else if ((duration >= 9000) && (duration <= 9999)) { duration = TopTenScores[9000]; } Console.WriteLine(TopTenScores); } static void Main(string[] args) { int intInput, num1, num2, incorrect, array1; float answer; string input; System.Random randNum = new System.Random(); Console.WriteLine("Welcome to the Maths game!"); Console.WriteLine("(Apologies for the glitchiness!)"); Console.WriteLine(); Console.WriteLine("Please choose from the following options:"); Console.WriteLine(); retry: Console.WriteLine("1 - Test your Maths against the clock!"); Console.WriteLine("2 - Exit the application."); Console.WriteLine("3 - Top scores"); Console.WriteLine(); input = Console.ReadLine(); intInput = int.Parse(input); if (intInput == 1) { goto start; } else if (intInput == 2) { goto fin; } else if (intInput == 3) { array1 = array1.saveInArray; goto retry; } Now, in the last 'else if' statement in the code, you can see my variable array1 trying to call the method, but no matter what I do I keep getting errors. This is the only error I have at the moment, but I have a feeling soon as I resolve that error, another will come up. For now i'm just determined to get past this error: 'int' does not contain a definition for 'saveInArray' and no extension method 'saveInArray' accepting a first argument of type 'int' could be found (are you missing a using directive or an assembly reference?). Any help would be kindly appreciated, apologies in advanced for my ugly written code! And thank you to any help that I receive! Regards, Omar.

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• Searching a set of data with multiple terms using Linq

  - by Cj Anderson

  I'm in the process of moving from ADO.NET to Linq. The application is a directory search program to look people up. The users are allowed to type the search criteria into a single textbox. They can separate each term with a space, or wrap a phrase in quotes such as "park place" to indicate that it is one term. Behind the scenes the data comes from a XML file that has about 90,000 records in it and is about 65 megs. I load the data into a DataTable and then use the .Select method with a SQL query to perform the searches. The query I pass is built from the search terms the user passed. I split the string from the textbox into an array using a regular expression that will split everything into a separate element that has a space in it. However if there are quotes around a phrase, that becomes it's own element in the array. I then end up with a single dimension array with x number of elements, which I iterate over to build a long query. I then build the search expression below: query = query & _ "((userid LIKE '" & tempstr & "%') OR " & _ "(nickname LIKE '" & tempstr & "%') OR " & _ "(lastname LIKE '" & tempstr & "%') OR " & _ "(firstname LIKE '" & tempstr & "%') OR " & _ "(department LIKE '" & tempstr & "%') OR " & _ "(telephoneNumber LIKE '" & tempstr & "%') OR " & _ "(email LIKE '" & tempstr & "%') OR " & _ "(Office LIKE '" & tempstr & "%'))" Each term will have a set of the above query. If there is more than one term, I put an AND in between, and build another query like above with the next term. I'm not sure how to do this in Linq. So far, I've got the XML file loading correctly. I'm able to search it with specific criteria, but I'm not sure how to best implement the search over multiple terms. 'this works but far too simple to get the job done Dim results = From c In m_DataSet...<Users> _ Where c.<userid>.Value = "XXXX" _ Select c The above code also doesn't use the LIKE operator either. So partial matches don't work. It looks like what I'd want to use is the .Startswith but that appears to be only in Linq2SQL. Any guidance would be appreciated. I'm new to Linq, so I might be missing a simple way to do this. The XML file looks like so: <?xml version="1.0" standalone="yes"?> <theusers> <Users> <userid>person1</userid> <nickname></nickname> <lastname></lastname> <firstname></firstname> <department></department> <telephoneNumber></telephoneNumber> <email></email> </Users> <Users> <userid>person2</userid> <nickname></nickname> <lastname></lastname> <firstname></firstname> <department></department> <telephoneNumber></telephoneNumber> <email></email> </Users>

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• How to diagnose failing 6Gbps SATA connection?

  - by whitequark

  I have a Samsung RC530 notebook and OCZ Vertex-3 6Gbps SATA SSD working in AHCI mode. # dmesg | grep DMI SAMSUNG ELECTRONICS CO., LTD. RC530/RC730/RC530/RC730, BIOS 03WD.M008.20110927.PSA 09/27/2011 # lspci -nn 00:1f.2 SATA controller [0106]: Intel Corporation 6 Series/C200 Series Chipset Family 6 port SATA AHCI Controller [8086:1c03] (rev 04) # sdparm -a /dev/sda /dev/sda: ATA OCZ-VERTEX3 2.15 At the boot, the following messages are present in dmesg (I am running Debian wheezy @ Linux 3.2.8): # dmesg | grep -iE '(ata|ahci)' [ 5.179783] ahci 0000:00:1f.2: version 3.0 [ 5.179802] ahci 0000:00:1f.2: PCI INT B -> GSI 19 (level, low) -> IRQ 19 [ 5.179864] ahci 0000:00:1f.2: irq 42 for MSI/MSI-X [ 5.195424] ahci 0000:00:1f.2: AHCI 0001.0300 32 slots 6 ports 6 Gbps 0x5 impl SATA mode [ 5.195429] ahci 0000:00:1f.2: flags: 64bit ncq sntf pm led clo pio slum part ems apst [ 5.195436] ahci 0000:00:1f.2: setting latency timer to 64 [ 5.204035] scsi0 : ahci [ 5.204301] scsi1 : ahci [ 5.204447] scsi2 : ahci [ 5.204592] scsi3 : ahci [ 5.204682] scsi4 : ahci [ 5.204799] scsi5 : ahci [ 5.204917] ata1: SATA max UDMA/133 abar m2048@0xf7c06000 port 0xf7c06100 irq 42 [ 5.204920] ata2: DUMMY [ 5.204923] ata3: SATA max UDMA/133 abar m2048@0xf7c06000 port 0xf7c06200 irq 42 [ 5.204924] ata4: DUMMY [ 5.204926] ata5: DUMMY [ 5.204927] ata6: DUMMY [ 5.523039] ata3: SATA link up 1.5 Gbps (SStatus 113 SControl 300) [ 5.525911] ata3.00: ATAPI: TSSTcorp CDDVDW SN-208BB, SC00, max UDMA/100 [ 5.531006] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300) [ 5.533703] ata3.00: configured for UDMA/100 [ 5.542790] ata1.00: ATA-8: OCZ-VERTEX3, 2.15, max UDMA/133 [ 5.542800] ata1.00: 117231408 sectors, multi 16: LBA48 NCQ (depth 31/32), AA [ 5.552751] ata1.00: configured for UDMA/133 [ 5.553050] scsi 0:0:0:0: Direct-Access ATA OCZ-VERTEX3 2.15 PQ: 0 ANSI: 5 [ 5.559621] scsi 2:0:0:0: CD-ROM TSSTcorp CDDVDW SN-208BB SC00 PQ: 0 ANSI: 5 [ 5.564059] sd 0:0:0:0: [sda] 117231408 512-byte logical blocks: (60.0 GB/55.8 GiB) [ 5.564127] sd 0:0:0:0: [sda] Write Protect is off [ 5.564131] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00 [ 5.564158] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 5.564582] sda: sda1 [ 5.564810] sd 0:0:0:0: [sda] Attached SCSI disk [ 5.572006] sr0: scsi3-mmc drive: 16x/24x writer dvd-ram cd/rw xa/form2 cdda tray [ 5.572010] cdrom: Uniform CD-ROM driver Revision: 3.20 [ 5.572189] sr 2:0:0:0: Attached scsi CD-ROM sr0 [ 6.717181] ata1.00: exception Emask 0x50 SAct 0x1 SErr 0x280900 action 0x6 frozen [ 6.717238] ata1.00: irq_stat 0x08000000, interface fatal error [ 6.717291] ata1: SError: { UnrecovData HostInt 10B8B BadCRC } [ 6.717342] ata1.00: failed command: READ FPDMA QUEUED [ 6.717395] ata1.00: cmd 60/50:00:20:39:58/00:00:00:00:00/40 tag 0 ncq 40960 in [ 6.717396] res 40/00:00:20:39:58/00:00:00:00:00/40 Emask 0x50 (ATA bus error) [ 6.717503] ata1.00: status: { DRDY } [ 6.717553] ata1: hard resetting link [ 7.033417] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300) [ 7.055234] ata1.00: configured for UDMA/133 [ 7.055262] ata1: EH complete [ 7.147280] ata1.00: exception Emask 0x10 SAct 0xf8 SErr 0x280100 action 0x6 frozen [ 7.147340] ata1.00: irq_stat 0x08000000, interface fatal error [ 7.147393] ata1: SError: { UnrecovData 10B8B BadCRC } [ 7.147460] ata1.00: failed command: READ FPDMA QUEUED [ 7.147529] ata1.00: cmd 60/08:18:88:17:41/00:00:02:00:00/40 tag 3 ncq 4096 in [ 7.147531] res 40/00:38:50:99:64/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.147691] ata1.00: status: { DRDY } [ 7.147754] ata1.00: failed command: READ FPDMA QUEUED [ 7.147821] ata1.00: cmd 60/00:20:f8:42:4c/01:00:02:00:00/40 tag 4 ncq 131072 in [ 7.147822] res 40/00:38:50:99:64/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.147977] ata1.00: status: { DRDY } [ 7.148036] ata1.00: failed command: READ FPDMA QUEUED [ 7.148100] ata1.00: cmd 60/50:28:f8:43:4c/00:00:02:00:00/40 tag 5 ncq 40960 in [ 7.148101] res 40/00:38:50:99:64/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.148255] ata1.00: status: { DRDY } [ 7.148315] ata1.00: failed command: READ FPDMA QUEUED [ 7.148379] ata1.00: cmd 60/00:30:50:98:64/01:00:02:00:00/40 tag 6 ncq 131072 in [ 7.148380] res 40/00:38:50:99:64/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.148534] ata1.00: status: { DRDY } [ 7.148593] ata1.00: failed command: READ FPDMA QUEUED [ 7.148657] ata1.00: cmd 60/00:38:50:99:64/01:00:02:00:00/40 tag 7 ncq 131072 in [ 7.148658] res 40/00:38:50:99:64/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.148813] ata1.00: status: { DRDY } [ 7.148875] ata1: hard resetting link [ 7.464842] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300) [ 7.486794] ata1.00: configured for UDMA/133 [ 7.486822] ata1: EH complete [ 7.546395] ata1.00: exception Emask 0x10 SAct 0x2f SErr 0x280100 action 0x6 frozen [ 7.546470] ata1.00: irq_stat 0x08000000, interface fatal error [ 7.546531] ata1: SError: { UnrecovData 10B8B BadCRC } [ 7.546588] ata1.00: failed command: READ FPDMA QUEUED [ 7.546648] ata1.00: cmd 60/00:00:e0:4b:61/01:00:02:00:00/40 tag 0 ncq 131072 in [ 7.546649] res 40/00:28:e0:4c:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.546794] ata1.00: status: { DRDY } [ 7.546847] ata1.00: failed command: READ FPDMA QUEUED [ 7.546906] ata1.00: cmd 60/00:08:90:2f:48/01:00:02:00:00/40 tag 1 ncq 131072 in [ 7.546907] res 40/00:28:e0:4c:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.547053] ata1.00: status: { DRDY } [ 7.547106] ata1.00: failed command: READ FPDMA QUEUED [ 7.547165] ata1.00: cmd 60/00:10:90:30:48/01:00:02:00:00/40 tag 2 ncq 131072 in [ 7.547166] res 40/00:28:e0:4c:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.547310] ata1.00: status: { DRDY } [ 7.547363] ata1.00: failed command: READ FPDMA QUEUED [ 7.547422] ata1.00: cmd 60/00:18:50:c7:64/01:00:02:00:00/40 tag 3 ncq 131072 in [ 7.547423] res 40/00:28:e0:4c:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.547568] ata1.00: status: { DRDY } [ 7.547621] ata1.00: failed command: READ FPDMA QUEUED [ 7.547681] ata1.00: cmd 60/00:28:e0:4c:61/01:00:02:00:00/40 tag 5 ncq 131072 in [ 7.547682] res 40/00:28:e0:4c:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.547825] ata1.00: status: { DRDY } [ 7.547882] ata1: hard resetting link [ 7.864408] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300) [ 7.886351] ata1.00: configured for UDMA/133 [ 7.886375] ata1: EH complete [ 7.890012] ata1: limiting SATA link speed to 3.0 Gbps [ 7.890016] ata1.00: exception Emask 0x10 SAct 0x7 SErr 0x280100 action 0x6 frozen [ 7.890093] ata1.00: irq_stat 0x08000000, interface fatal error [ 7.890152] ata1: SError: { UnrecovData 10B8B BadCRC } [ 7.890210] ata1.00: failed command: READ FPDMA QUEUED [ 7.890272] ata1.00: cmd 60/00:00:90:33:48/01:00:02:00:00/40 tag 0 ncq 131072 in [ 7.890273] res 40/00:10:e0:4f:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.890418] ata1.00: status: { DRDY } [ 7.890472] ata1.00: failed command: READ FPDMA QUEUED [ 7.890530] ata1.00: cmd 60/00:08:90:34:48/01:00:02:00:00/40 tag 1 ncq 131072 in [ 7.890531] res 40/00:10:e0:4f:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.890672] ata1.00: status: { DRDY } [ 7.890724] ata1.00: failed command: READ FPDMA QUEUED [ 7.890781] ata1.00: cmd 60/78:10:e0:4f:61/00:00:02:00:00/40 tag 2 ncq 61440 in [ 7.890782] res 40/00:10:e0:4f:61/00:00:02:00:00/40 Emask 0x10 (ATA bus error) [ 7.890925] ata1.00: status: { DRDY } [ 7.890981] ata1: hard resetting link [ 8.208021] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 320) [ 8.230100] ata1.00: configured for UDMA/133 [ 8.230124] ata1: EH complete Looks like the SATA interface tries to use 6Gbps link, then fails miserably and Linux fallbacks to 3Gbps. This is somewhat fine for me, as the system boots successfully each time and works under high load (cd linux-3.2.8; make -j16). I've also ran memtest86+ and it did not find any errors. What concerns me more is that Grub sometimes takes a long time to load the images and/or fails to load itself completely. The error is consistent and is probablistic: that is, each time I boot I have a certain chance to fail. Actually, I have a slight suspiction on the cause of the failure. Look at the cabling: What kind of engineer does it this way? Nah. Even 1Gbps Ethernet hardly tolerates cables bent over a small angle, and there you have 6Gbps SATA. How cound I determine and fix the cause of errors and/or switch the link to 3Gbps mode permanently?

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• C++ destructor seems to be called 'early'

  - by suicideducky

  Please see the "edit" section for the updated information. Sorry for yet another C++ dtor question... However I can't seem to find one exactly like mine as all the others are assigning to STL containers (that will delete objects itself) whereas mine is to an array of pointers. So I have the following code fragment #include<iostream> class Block{ public: int x, y, z; int type; Block(){ x=1; y=2; z=3; type=-1; } }; template <class T> class Octree{ T* children[8]; public: ~Octree(){ for( int i=0; i<8; i++){ std::cout << "del:" << i << std::endl; delete children[i]; } } Octree(){ for( int i=0; i<8; i++ ) children[i] = new T; } // place newchild in array at [i] void set_child(int i, T* newchild){ children[i] = newchild; } // return child at [i] T* get_child(int i){ return children[i]; } // place newchild at [i] and return the old [i] T* swap_child(int i, T* newchild){ T* p = children[i]; children[i] = newchild; return p; } }; int main(){ Octree< Octree<Block> > here; std::cout << "nothing seems to have broken" << std::endl; } Looking through the output I notice that the destructor is being called many times before I think it should (as Octree is still in scope), the end of the output also shows: del:0 del:0 del:1 del:2 del:3 Process returned -1073741819 (0xC0000005) execution time : 1.685 s Press any key to continue. For some reason the destructor is going through the same point in the loop twice (0) and then dying. All of this occures before the "nothing seems to have gone wrong" line which I expected before any dtor was called. Thanks in advance :) EDIT The code I posted has some things removed that I thought were unnecessary but after copying and compiling the code I pasted I no longer get the error. What I removed was other integer attributes of the code. Here is the origional: #include<iostream> class Block{ public: int x, y, z; int type; Block(){ x=1; y=2; z=3; type=-1; } Block(int xx, int yy, int zz, int ty){ x=xx; y=yy; z=zz; type=ty; } Block(int xx, int yy, int zz){ x=xx; y=yy; z=zz; type=0; } }; template <class T> class Octree{ int x, y, z; int size; T* children[8]; public: ~Octree(){ for( int i=0; i<8; i++){ std::cout << "del:" << i << std::endl; delete children[i]; } } Octree(int xx, int yy, int zz, int size){ x=xx; y=yy; z=zz; size=size; for( int i=0; i<8; i++ ) children[i] = new T; } Octree(){ Octree(0, 0, 0, 10); } // place newchild in array at [i] void set_child(int i, T* newchild){ children[i] = newchild; } // return child at [i] T* get_child(int i){ return children[i]; } // place newchild at [i] and return the old [i] T* swap_child(int i, T* newchild){ T* p = children[i]; children[i] = newchild; return p; } }; int main(){ Octree< Octree<Block> > here; std::cout << "nothing seems to have broken" << std::endl; } Also, as for the problems with set_child, get_child and swap_child leading to possible memory leaks this will be solved as a wrapper class will either use get before set or use swap to get the old child and write this out to disk before freeing the memory itself. I am glad that it is not my memory management failing but rather another error. I have not made a copy and/or assignment operator yet as I was just testing the block tree out, I will almost certainly make them all private very soon. This version spits out -1073741819. Thank you all for your suggestions and I apologise for highjacking my own thread :$

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• Using a boost::fusion::map in boost::spirit::karma

  - by user1097105

  I am using boost spirit to parse some text files into a data structure and now I am beginning to generate text from this data structure (using spirit karma). One attempt at a data structure is a boost::fusion::map (as suggested in an answer to this question). But although I can use boost::spirit::qi::parse() and get data in it easily, when I tried to generate text from it using karma, I failed. Below is my attempt (look especially at the "map_data" type). After some reading and playing around with other fusion types, I found boost::fusion::vector and BOOST_FUSION_DEFINE_ASSOC_STRUCT. I succeeded to generate output with both of them, but they don't seem ideal: in vector you cannot access a member using a name (it is like a tuple) -- and in the other solution, I don't think I need both ways (member name and key type) to access the members. #include <iostream> #include <string> #include <boost/spirit/include/karma.hpp> #include <boost/fusion/include/map.hpp> #include <boost/fusion/include/make_map.hpp> #include <boost/fusion/include/vector.hpp> #include <boost/fusion/include/as_vector.hpp> #include <boost/fusion/include/transform.hpp> struct sb_key; struct id_key; using boost::fusion::pair; typedef boost::fusion::map < pair<sb_key, int> , pair<id_key, unsigned long> > map_data; typedef boost::fusion::vector < int, unsigned long > vector_data; #include <boost/fusion/include/define_assoc_struct.hpp> BOOST_FUSION_DEFINE_ASSOC_STRUCT( (), assocstruct_data, (int, a, sb_key) (unsigned long, b, id_key)) namespace karma = boost::spirit::karma; template <typename X> std::string to_string ( const X& data ) { std::string generated; std::back_insert_iterator<std::string> sink(generated); karma::generate_delimited ( sink, karma::int_ << karma::ulong_, karma::space, data ); return generated; } int main() { map_data d1(boost::fusion::make_map<sb_key, id_key>(234, 35314988526ul)); vector_data d2(boost::fusion::make_vector(234, 35314988526ul)); assocstruct_data d3(234,35314988526ul); std::cout << "map_data as_vector: " << boost::fusion::as_vector(d1) << std::endl; //std::cout << "map_data to_string: " << to_string(d1) << std::endl; //*FAIL No 1* std::cout << "at_key (sb_key): " << boost::fusion::at_key<sb_key>(d1) << boost::fusion::at_c<0>(d1) << std::endl << std::endl; std::cout << "vector_data: " << d2 << std::endl; std::cout << "vector_data to_string: " << to_string(d2) << std::endl << std::endl; std::cout << "assoc_struct as_vector: " << boost::fusion::as_vector(d3) << std::endl; std::cout << "assoc_struct to_string: " << to_string(d3) << std::endl; std::cout << "at_key (sb_key): " << boost::fusion::at_key<sb_key>(d3) << d3.a << boost::fusion::at_c<0>(d3) << std::endl; return 0; } Including the commented line gives lots of pages of compilation errors, among which notably something like: no known conversion for argument 1 from ‘boost::fusion::pair’ to ‘double’ no known conversion for argument 1 from ‘boost::fusion::pair’ to ‘float’ Might it be that to_string needs the values of the map_data, and not the pairs? Though I am not good with templates, I tried to get a vector from a map using transform in the following way template <typename P> struct take_second { typename P::second_type operator() (P p) { return p.second; } }; // ... inside main() pair <char, int> ff(32); std::cout << "take_second (expect 32): " << take_second<pair<char,int>>()(ff) << std::endl; std::cout << "transform map_data and to_string: " << to_string(boost::fusion::transform(d1, take_second<>())); //*FAIL No 2* But I don't know what types am I supposed to give when instantiating take_second and anyway I think there must be an easier way to get (iterate over) the values of a map (is there?) If you answer this question, please also give your opinion on whether using an ASSOC_STRUCT or a map is better.

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• Parse a text file into multiple text file

  - by Vijay Kumar Singh

  I want to get multiple file by parsing a input file Through Java. The Input file contains many fasta format of thousands of protein sequence and I want to generate raw format(i.e., without any comma semicolon and without any extra symbol like "", "[", "]" etc) of each protein sequence. A fasta sequence starts form "" symbol followed by description of protein and then sequence of protein. For example ? lcl|NC_000001.10_cdsid_XP_003403591.1 [gene=LOC100652771] [protein=hypothetical protein LOC100652771] [protein_id=XP_003403591.1] [location=join(12190..12227,12595..12721,13403..13639)] MSESINFSHNLGQLLSPPRCVVMPGMPFPSIRSPELQKTTADLDHTLVSVPSVAESLHHPEITFLTAFCL PSFTRSRPLPDRQLHHCLALCPSFALPAGDGVCHGPGLQGSCYKGETQESVESRVLPGPRHRH Like above formate the input file contains 1000s of protein sequence. I have to generate thousands of raw file containing only individual protein sequence without any special symbol or gaps. I have developed the code for it in Java but out put is : Cannot open a file followed by cannot find file. Please help me to solve my problem. Regards Vijay Kumar Garg Varanasi Bharat (India) The code is /*Java code to convert FASTA format to a raw format*/ import java.io.*; import java.util.*; import java.util.regex.*; import java.io.FileInputStream; // java package for using regular expression public class Arrayren { public static void main(String args[]) throws IOException { String a[]=new String[1000]; String b[][] =new String[1000][1000]; /*open the id file*/ try { File f = new File ("input.txt"); //opening the text document containing genbank ids FileInputStream fis = new FileInputStream("input.txt"); //Reading the file contents through inputstream BufferedInputStream bis = new BufferedInputStream(fis); // Writing the contents to a buffered stream DataInputStream dis = new DataInputStream(bis); //Method for reading Java Standard data types String inputline; String line; String separator = System.getProperty("line.separator"); // reads a line till next line operator is found int i=0; while ((inputline=dis.readLine()) != null) { i++; a[i]=inputline; a[i]=a[i].replaceAll(separator,""); //replaces unwanted patterns like /n with space a[i]=a[i].trim(); // trims out if any space is available a[i]=a[i]+".txt"; //takes the file name into an array try // to handle run time error /*take the sequence in to an array*/ { BufferedReader in = new BufferedReader (new FileReader(a[i])); String inline = null; int j=0; while((inline=in.readLine()) != null) { j++; b[i][j]=inline; Pattern q=Pattern.compile(">"); //Compiling the regular expression Matcher n=q.matcher(inline); //creates the matcher for the above pattern if(n.find()) { /*appending the comment line*/ b[i][j]=b[i][j].replaceAll(">gi",""); //identify the pattern and replace it with a space b[i][j]=b[i][j].replaceAll("[a-zA-Z]",""); b[i][j]=b[i][j].replaceAll("|",""); b[i][j]=b[i][j].replaceAll("\\d{1,15}",""); b[i][j]=b[i][j].replaceAll(".",""); b[i][j]=b[i][j].replaceAll("_",""); b[i][j]=b[i][j].replaceAll("\\(",""); b[i][j]=b[i][j].replaceAll("\\)",""); } /*printing the sequence in to a text file*/ b[i][j]=b[i][j].replaceAll(separator,""); b[i][j]=b[i][j].trim(); // trims out if any space is available File create = new File(inputline+"R.txt"); try { if(!create.exists()) { create.createNewFile(); // creates a new file } else { System.out.println("file already exists"); } } catch(IOException e) // to catch the exception and print the error if cannot open a file { System.err.println("cannot create a file"); } BufferedWriter outt = new BufferedWriter(new FileWriter(inputline+"R.txt", true)); outt.write(b[i][j]); // printing the contents to a text file outt.close(); // closing the text file System.out.println(b[i][j]); } } catch(Exception e) { System.out.println("cannot open a file"); } } } catch(Exception ex) // catch the exception and prints the error if cannot find file { System.out.println("cannot find file "); } } } If you provide me correct it will be much easier to understand.

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• How to make my robot move in a rectangular path along the black tape?

  - by Sahat

  I am working on a robot, it's part of the summer robotics workshop in our college. We are using C-STAMP micro controllers by A-WIT. I was able to make it move, turn left, turn right, move backward. I have even managed to make it go along the black tape using a contrast sensor. I send the robot at 30-45 degrees toward the black tape on the table and it aligns itself and starts to move along the black tape. It jerks a little, probably due to my programming logic below, it's running a while loop and constantly checking if statements, so it ends up trying to turn left and right every few milliseconds, which explains the jerking part. But it's okay, it works, not as smooth as I want it to work but it works! Problem is that I can't make my robot go into a rectangular path of the black tape. As soon as it reaches the corner it just keeps going straight instead of making a left/right turn. Here's my attempt. The following code is just part of the code. My 2 sensors are located right underneath the robot, next to the front wheel, almost at the floor level. It has "index" value ranging from 0 to 8. I believe it's 8 when you have a lot of light coming into the sensor , and 0 when it's nearly pitch black. So when the robot moves into the black-tape-zone, the index value drops, and based on that I have an if-statement telling my robot to either turn left or right. To avoid confusion I didn't post the entire source code, but only the logical part responsible for the movement of my robot along the black tape. while(1) { // don't worry about these. // 10 and 9 represent Sensor's PIN location on the motherboard V = ANALOGIN(10, 1, 0, 0, 0); V2 = ANALOGIN(9, 1, 0, 0, 0); // i got this "formula" from the example in my Manual. // V stands for voltage of the sensor. // it gives me the index value of the sensor. 0 = darkest, 8 = lightest. index = ((-(V - 5) / 5) * 8 + 0.5); index2 = ((-(V2 - 5) / 5) * 8 + 0.5); // i've tweaked the position of the sensors so index > 7 is just right number. // the robot will move anywhere on the table just fine with index > 7. // as soon as it drops to or below 7 (i.e. finds black tape), the robot will // either turn left or right and then go forward. // lp & rp represent left-wheel pin and right-wheel pin, 1 means run forever. // if i change it from 1 to 100, it will go forward for 100ms. if (index > 7 && index2 > 7) goForward(lp, rp, 1); if (index <= 7) { turnLeft(lp, rp, 1); goForward(lp, rp, 1); // this is the tricky part. i've added this code last minute // trying to make my robot turn, but i didn't work. if (index > 4) { turnLeft(lp, rp, 1); goForward(lp, rp, 1); } } else if (index2 <= 7) { turnRight(lp, rp, 1); goForward(lp, rp, 1); // this is also the last minute addition. it's same code as above // but it's for the 2nd sensor. if (index2 > 4) { turnRight(lp, rp, 1); goForward(lp, rp, 1); } } I've spent the entire day trying to figure it out. I've pretty much exhausted all avenues. Asking for the solution on stackoverflow is my very last option now. Thanks in advance! If you have any questions about the code, let me know, but comments should be self-explanatory.

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• Alternate way to create a clone of a UNIX System

  - by Spirit

  THE STORY: (If you don't like to read much, down below is the question :) ) Where I work we have two HP RP2470 servers same hardware same number of hard drives same everything :). One of them is a production server and runs HP-UX 11.00. The poor ba***rd hasn't been turned off for years and now I have to make a clone of it on the other server - just in case, for redundancy. The problem is simple (or not simple) as I have to make the the other server exactly the same. However the old version of OS (UX 11.00 is a history now) and the old software running on it, have made my task almost impossible. On the production server there is also a cloning/recover utility Ignite-UX. I tried many times to create a recovery tape with it. Then when I load the tape on the backup server, it succeeds with the loading of the tape (no errors no warnings) but on the next restart it fails to load the OS :S and drops into HP`s ISL prompt. --- THE QUESTION: Is there an alternate way to create a clone of the Unix System? The environment is: 1. 2x HP RP2470 Servers (non-Intel), same hardware, same number od HDDs (two each of them) same everything. 2. OS running: HP-UX 11.00 The production server has to be cloned without downtime - sadly :( as I hope that they will reconsider on this one For example (like on Windows platforms), if you try to copy an entire HDD with Windows inside on another HDD, and then put that HDD on another PC it will still work, as long as the hardware is the same. Can I do something like that with a Unix system? Can I somehow COPY the contents of the entire HDD, put those on another HDD, and then just load the HDD into the other server? (If you haven't read the story the servers are exactly the same) Will it work? Can it be done with ordinary commands like cp or dump or something like that? Does any one have a similar experience? --- UPDATE: 26.01.2012 NOTE: The update is related to "The Story". If you haven't read that part then you can skip this update. This is just a short update on the recover logs from the Ignite Tape.. someone with more exp. might notice something.. ... --- READING CONTENTS OF THE IGNITE TAPE --- --- OUTPUT OMITED --- ... ... x ./configure3, 413696 bytes, 808 tape blocks x ./monitor_bpr, 20480 bytes, 40 tape blocks * Download_mini-system: Complete * Loading_software: Begin * Installing boot area on disk. * Enabling swap areas. * Backing up LVM configuration for "vg00". * Processing the archive source (Recovery Archive). * Wed Jan 25 15:27:32 EST 2012: Starting archive load of the source (Recovery Archive). * Positioning the tape (/dev/rmt/0mn). * Archive extraction from tape is beginning. Please wait. * Wed Jan 25 15:39:52 EST 2012: Completed archive load of the source (Recovery Archive). * Executing user specified script: "/opt/ignite/data/scripts/os_arch_post_l". * Running in recovery mode (os_arch_post_l). * Running the ioinit command ("/sbin/ioinit -c") * Creating device files via the insf command. insf: Installing special files for sdisk instance 0 address 0/0/1/1.15.0 insf: Installing special files for sdisk instance 1 address 0/0/2/0.1.0 insf: Installing special files for sdisk instance 2 address 0/0/2/1.15.0 insf: Installing special files for stape instance 0 address 0/0/1/0.3.0 insf: Installing special files for btlan instance 0 address 0/0/0/0 insf: Installing special files for btlan instance 1 address 0/2/0/0 insf: Installing special files for pseudo driver dlpi insf: Installing special files for pseudo driver kepd insf: Installing special files for pseudo driver framebuf insf: Installing special files for pseudo driver sad * Running "/opt/upgrade/bin/tlinstall -v" and correcting transition link permissions. * Constructing the bootconf file. * Setting primary boot path to "0/0/1/1.15.0". * Executing: "/var/adm/sw/products/PHSS_20146/pfiles/iux_postload". * Executing: "/var/adm/sw/products/PHSS_25982/pfiles/iux_postload". NOTE: tlinstall is searching filesystem - please be patient NOTE: Successfully completed * Loading_software: Complete * Build_Kernel: Begin NOTE: Since the /stand/vmunix kernel is already in place, the kernel will not be re-built. Note that no mod_kernel directives will be processed. * Build_Kernel: Complete * Boot_From_Client_Disk: Begin * Rebooting machine as expected. NOTE: Rebooting system. sync'ing disks (0 buffers to flush): 0 buffers not flushed 0 buffers still dirty Closing open logical volumes... Done Console reset done. Boot device reset done. ********** VIRTUAL FRONT PANEL ********** System Boot detected ***************************************** LEDs: RUN ATTENTION FAULT REMOTE POWER FLASH OFF OFF ON ON LED State: Running non-OS code. (i.e. Boot or Diagnostics) ... ... ... --- SERVER IS PERFORMING POST SEQUENCE HERE --- --- OUTPUT OMITED --- ... ... ... ***************************************** ************ EARLY BOOT VFP ************* End of early boot detected ***************************************** Firmware Version 43.50 Duplex Console IO Dependent Code (IODC) revision 1 ------------------------------------------------------------------------------ (c) Copyright 1995-2002, Hewlett-Packard Company, All rights reserved ------------------------------------------------------------------------------ Processor Speed State CoProcessor State Cache Size Number State Inst Data --------- -------- --------------------- ----------------- ------------ 0 650 MHz Active Functional 750 KB 1.5 MB 1 650 MHz Idle Functional 750 KB 1.5 MB Central Bus Speed (in MHz) : 120 Available Memory : 2097152 KB Good Memory Required : 16140 KB Primary boot path: 0/0/1/1.15 Alternate boot path: 0/0/2/1.15 Console path: 0/0/4/1.643 Keyboard path: 0/0/4/0.0 Processor is starting autoboot process. To discontinue, press any key within 10 seconds. 10 seconds expired. Proceeding... Trying Primary Boot Path ------------------------ Booting... Boot IO Dependent Code (IODC) revision 1 HARD Booted. ISL Revision A.00.38 OCT 26, 1994 ISL booting hpux ISL>

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• Update table rows in a non-sequential way using the output of a php script

  - by moviemaniac

  Good evening everybody, this is my very first question and I hope I've done my search in stack's archive at best!!! I need to monitor several devices by querying theyr mysql database and gather some informations. Then these informations are presented to the operator in an html table. I have wrote a php script wich loads devices from a multidimensional array, loops through the array and gather data and create the table. The table structure is the following: <table id="monitoring" class="rt cf"> <thead class="cf"> <tr> <th>Device</th> <th>Company</th> <th>Data1</th> <th>Data2</th> <th>Data3</th> <th>Data4</th> <th>Data5</th> <th>Data6</th> <th>Data7</th> <th>Data8</th> <th>Data9</th> </tr> </thead> <tbody> <tr id="Device1"> <td>Devide 1 name</td> <td>xx</td> <td><img src="/path_to_images/ajax_loader.gif" width="24px" /></td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> </tr> <tr id="Device2"> <td>Devide 1 name</td> <td>xx</td> <td><img src="/path_to_images/ajax_loader.gif" width="24px" /></td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> </tr> <tr id="DeviceN"> <td>Devide 1 name</td> <td>xx</td> <td><img src="/path_to_images/ajax_loader.gif" width="24px" /></td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> </tr> </tbody> </table> The above table is directly populated when I first load the page; then, with a very simple function, i update this table every minute without reloading the page: <script> var auto_refresh = setInterval( function() { jQuery("#monitoring").load('/overview.php').fadeIn("slow"); var UpdateTime= new Date(); var StrUpdateTime; StrUpdateTime= ('0' + UpdateTime.getHours()).slice(-2) + ':' + ('0' + UpdateTime.getMinutes()).slice(-2) + ':' + ('0' + UpdateTime.getSeconds()).slice(-2); jQuery("#progress").text("Updated on: " + StrUpdateTime); }, 60000); </script> The above code runs in a wordpress environment. It comes out that when devices are too much and internet connection is not that fast, the script times out, even if i dramatically increase the timeout period. So it is impossible even to load the page the first time... Therefore I would like to change my code so that I can handle each row as a single entity, with its own refresh period. So when the user first loads the page, he sees n rows (one per device) with the ajax loader image... then an update cycle should start independently for each row, so that the user sees data gathered from each database... then ajax loader when the script is trying to retrieve data, then the gathered data once it has been collected or an error message stating that it is not possible to gather data since hour xx:yy:zz. So rows updating should be somewhat independent from the others, like if each row updating was a single closed process. So that rows updating is not done sequentially from the first row to the last. I hope I've sufficiently detailed my problem. Currently I feel like I am at a dead-end. Could someone please show me somewhere to start from?

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• What is the MVC version of this code?

  - by Ian Boyd

  i'm trying to wrap my head around how to enterprise up my code: taking a simple routine and splitting it up into 5 or 6 methods in 3 or 4 classes. i quickly came up three simple examples of code how i currently write it. Could someone please convert these into an MVC/MVP obfuscated version? Example 1: The last name is mandatory. Color the text box red if nothing is entered. Color it green if stuff is entered: private void txtLastname_TextChanged(object sender, EventArgs e) { //Lastname mandatory. //Color pinkish if nothing entered. Greenish if entered. if (txtLastname.Text.Trim() == "") { //Lastname is required, color pinkish txtLastname.BackColor = ControlBad; } else { //Lastname entered, remove the coloring txtLastname.BackColor = ControlGood; } } Example 2: The first name is optional, but try to get it. We'll add a bluish tint to this "try to get" field: private void txtFirstname_TextChanged(object sender, EventArgs e) { //Firstname can be blank. //Hint them that they should *try* to get it with a bluish color. //If they do enter stuff: it better be not all spaces. if (txtFirstname.Text == "") { //Nothing there, hint it blue txtFirstname.BackColor = ControlRequired; } else if (txtFirstname.Text.Trim() == "") { //They entered spaces - bad user! txtFirstname.BackColor = ControlBad; } else { //Entered stuff, remove coloring txtFirstname.BackColor = SystemColors.Window; } } Example 3 The age is totally optional. If an age is entered, it better be valid: private void txtAge_TextChanged(object sender, EventArgs e) { //Age is optional, but if entered it better be valid int nAge = 0; if (Int32.TryParse(txtAge.Text, out nAge)) { //Valid integer entered if (nAge < 0) { //Negative age? i don't think so txtAge.BackColor = ControlBad; } else { //Valid age entered, remove coloring txtAge.BackColor = SystemColors.Window; } } else { //Whatever is in there: it's *not* a valid integer, if (txtAge.Text == "") { //Blank is okay txtAge.BackColor = SystemColors.Window; } else { //Not a valid age, bad user txtAge.BackColor = ControlBad; } } } Every time i see MVC code, it looks almost like random splitting of code into different methods, classes, and files. i've not been able to determine a reason or pattern to their madness. Without any understanding of they why it's being one some way, it makes no sense. And using the words model, view, controller and presenter, like i'm supposed to know what that means, doesn't help. The model is your data. The view shows data on screen. The controller is used to carry out the users actions And oranges taste orangy. Here's my attempt at splitting things up in order to make the code more difficult to follow. Is this anywhere close to MVC? private void txtFirstname_TextChanged(object sender, EventArgs e) { FirstnameTextChangedHandler(sender, e); } private void FirstnameTextChangedHandler(sender, e) { string firstname = GetFirstname(); Color firstnameTextBoxColor = GetFirstnameTextBoxColor(firstname); SetFirstNameTextBoxColor(firstnameTextBoxColor); } private string GetFirstname() { return txtFirstname.Text; } private Color GetFirstnameTextBoxColor(string firstname) { //Firstname can be blank. //Hint them that they should *try* to get it with a bluish color. //If they do enter stuff: it better be not all spaces. if (firstname == "") { //Nothing there, hint it blue return GetControlRequiredColor(); } else if (firstname.Trim() == "") { //They entered spaces - bad user! return GetControlBadColor(); } else { //Entered stuff, remove coloring return GetControlDefaultColor(); } } private Color GetControlRequiredColor() { return ControlRequired; } private Color GetControlBadColor() { return ControlBad; } private Color GetControlGoodColor() { return ControlGood; } //am i doin it rite i've obfuscated the code, but it's still altogether. The next step in the MVC obfuscation, i gather, is to hide the code in 3 or 4 different files. It's that next step that i don't understand. What is the logical separation of which functions are moved into what other classes? Can someone translate my 3 simple examples above into full fledged MVC obfuscation? Edit: Not ASP/ASP.NET/Online. Pretend it's on a desktop, handheld, surface, kiosk. And pretend it's language agnostic.

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• Inheritance Mapping Strategies with Entity Framework Code First CTP5: Part 3 – Table per Concrete Type (TPC) and Choosing Strategy Guidelines

  - by mortezam

  This is the third (and last) post in a series that explains different approaches to map an inheritance hierarchy with EF Code First. I've described these strategies in previous posts: Part 1 – Table per Hierarchy (TPH) Part 2 – Table per Type (TPT)In today’s blog post I am going to discuss Table per Concrete Type (TPC) which completes the inheritance mapping strategies supported by EF Code First. At the end of this post I will provide some guidelines to choose an inheritance strategy mainly based on what we've learned in this series. TPC and Entity Framework in the Past Table per Concrete type is somehow the simplest approach suggested, yet using TPC with EF is one of those concepts that has not been covered very well so far and I've seen in some resources that it was even discouraged. The reason for that is just because Entity Data Model Designer in VS2010 doesn't support TPC (even though the EF runtime does). That basically means if you are following EF's Database-First or Model-First approaches then configuring TPC requires manually writing XML in the EDMX file which is not considered to be a fun practice. Well, no more. You'll see that with Code First, creating TPC is perfectly possible with fluent API just like other strategies and you don't need to avoid TPC due to the lack of designer support as you would probably do in other EF approaches. Table per Concrete Type (TPC)In Table per Concrete type (aka Table per Concrete class) we use exactly one table for each (nonabstract) class. All properties of a class, including inherited properties, can be mapped to columns of this table, as shown in the following figure: As you can see, the SQL schema is not aware of the inheritance; effectively, we’ve mapped two unrelated tables to a more expressive class structure. If the base class was concrete, then an additional table would be needed to hold instances of that class. I have to emphasize that there is no relationship between the database tables, except for the fact that they share some similar columns. TPC Implementation in Code First Just like the TPT implementation, we need to specify a separate table for each of the subclasses. We also need to tell Code First that we want all of the inherited properties to be mapped as part of this table. In CTP5, there is a new helper method on EntityMappingConfiguration class called MapInheritedProperties that exactly does this for us. Here is the complete object model as well as the fluent API to create a TPC mapping: public abstract class BillingDetail {     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } }          public class BankAccount : BillingDetail {     public string BankName { get; set; }     public string Swift { get; set; } }          public class CreditCard : BillingDetail {     public int CardType { get; set; }     public string ExpiryMonth { get; set; }     public string ExpiryYear { get; set; } }      public class InheritanceMappingContext : DbContext {     public DbSet<BillingDetail> BillingDetails { get; set; }              protected override void OnModelCreating(ModelBuilder modelBuilder)     {         modelBuilder.Entity<BankAccount>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("BankAccounts");         });         modelBuilder.Entity<CreditCard>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("CreditCards");         });                 } } The Importance of EntityMappingConfiguration ClassAs a side note, it worth mentioning that EntityMappingConfiguration class turns out to be a key type for inheritance mapping in Code First. Here is an snapshot of this class: namespace System.Data.Entity.ModelConfiguration.Configuration.Mapping {     public class EntityMappingConfiguration<TEntityType> where TEntityType : class     {         public ValueConditionConfiguration Requires(string discriminator);         public void ToTable(string tableName);         public void MapInheritedProperties();     } } As you have seen so far, we used its Requires method to customize TPH. We also used its ToTable method to create a TPT and now we are using its MapInheritedProperties along with ToTable method to create our TPC mapping. TPC Configuration is Not Done Yet!We are not quite done with our TPC configuration and there is more into this story even though the fluent API we saw perfectly created a TPC mapping for us in the database. To see why, let's start working with our object model. For example, the following code creates two new objects of BankAccount and CreditCard types and tries to add them to the database: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount();     CreditCard creditCard = new CreditCard() { CardType = 1 };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Running this code throws an InvalidOperationException with this message: The changes to the database were committed successfully, but an error occurred while updating the object context. The ObjectContext might be in an inconsistent state. Inner exception message: AcceptChanges cannot continue because the object's key values conflict with another object in the ObjectStateManager. Make sure that the key values are unique before calling AcceptChanges. The reason we got this exception is because DbContext.SaveChanges() internally invokes SaveChanges method of its internal ObjectContext. ObjectContext's SaveChanges method on its turn by default calls AcceptAllChanges after it has performed the database modifications. AcceptAllChanges method merely iterates over all entries in ObjectStateManager and invokes AcceptChanges on each of them. Since the entities are in Added state, AcceptChanges method replaces their temporary EntityKey with a regular EntityKey based on the primary key values (i.e. BillingDetailId) that come back from the database and that's where the problem occurs since both the entities have been assigned the same value for their primary key by the database (i.e. on both BillingDetailId = 1) and the problem is that ObjectStateManager cannot track objects of the same type (i.e. BillingDetail) with the same EntityKey value hence it throws. If you take a closer look at the TPC's SQL schema above, you'll see why the database generated the same values for the primary keys: the BillingDetailId column in both BankAccounts and CreditCards table has been marked as identity. How to Solve The Identity Problem in TPC As you saw, using SQL Server’s int identity columns doesn't work very well together with TPC since there will be duplicate entity keys when inserting in subclasses tables with all having the same identity seed. Therefore, to solve this, either a spread seed (where each table has its own initial seed value) will be needed, or a mechanism other than SQL Server’s int identity should be used. Some other RDBMSes have other mechanisms allowing a sequence (identity) to be shared by multiple tables, and something similar can be achieved with GUID keys in SQL Server. While using GUID keys, or int identity keys with different starting seeds will solve the problem but yet another solution would be to completely switch off identity on the primary key property. As a result, we need to take the responsibility of providing unique keys when inserting records to the database. We will go with this solution since it works regardless of which database engine is used. Switching Off Identity in Code First We can switch off identity simply by placing DatabaseGenerated attribute on the primary key property and pass DatabaseGenerationOption.None to its constructor. DatabaseGenerated attribute is a new data annotation which has been added to System.ComponentModel.DataAnnotations namespace in CTP5: public abstract class BillingDetail {     [DatabaseGenerated(DatabaseGenerationOption.None)]     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } } As always, we can achieve the same result by using fluent API, if you prefer that: modelBuilder.Entity<BillingDetail>()             .Property(p => p.BillingDetailId)             .HasDatabaseGenerationOption(DatabaseGenerationOption.None); Working With The Object Model Our TPC mapping is ready and we can try adding new records to the database. But, like I said, now we need to take care of providing unique keys when creating new objects: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount()      {          BillingDetailId = 1                          };     CreditCard creditCard = new CreditCard()      {          BillingDetailId = 2,         CardType = 1     };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Polymorphic Associations with TPC is Problematic The main problem with this approach is that it doesn’t support Polymorphic Associations very well. After all, in the database, associations are represented as foreign key relationships and in TPC, the subclasses are all mapped to different tables so a polymorphic association to their base class (abstract BillingDetail in our example) cannot be represented as a simple foreign key relationship. For example, consider the the domain model we introduced here where User has a polymorphic association with BillingDetail. This would be problematic in our TPC Schema, because if User has a many-to-one relationship with BillingDetail, the Users table would need a single foreign key column, which would have to refer both concrete subclass tables. This isn’t possible with regular foreign key constraints. Schema Evolution with TPC is Complex A further conceptual problem with this mapping strategy is that several different columns, of different tables, share exactly the same semantics. This makes schema evolution more complex. For example, a change to a base class property results in changes to multiple columns. It also makes it much more difficult to implement database integrity constraints that apply to all subclasses. Generated SQLLet's examine SQL output for polymorphic queries in TPC mapping. For example, consider this polymorphic query for all BillingDetails and the resulting SQL statements that being executed in the database: var query = from b in context.BillingDetails select b; Just like the SQL query generated by TPT mapping, the CASE statements that you see in the beginning of the query is merely to ensure columns that are irrelevant for a particular row have NULL values in the returning flattened table. (e.g. BankName for a row that represents a CreditCard type). TPC's SQL Queries are Union Based As you can see in the above screenshot, the first SELECT uses a FROM-clause subquery (which is selected with a red rectangle) to retrieve all instances of BillingDetails from all concrete class tables. The tables are combined with a UNION operator, and a literal (in this case, 0 and 1) is inserted into the intermediate result; (look at the lines highlighted in yellow.) EF reads this to instantiate the correct class given the data from a particular row. A union requires that the queries that are combined, project over the same columns; hence, EF has to pad and fill up nonexistent columns with NULL. This query will really perform well since here we can let the database optimizer find the best execution plan to combine rows from several tables. There is also no Joins involved so it has a better performance than the SQL queries generated by TPT where a Join is required between the base and subclasses tables. Choosing Strategy GuidelinesBefore we get into this discussion, I want to emphasize that there is no one single "best strategy fits all scenarios" exists. As you saw, each of the approaches have their own advantages and drawbacks. Here are some rules of thumb to identify the best strategy in a particular scenario: If you don’t require polymorphic associations or queries, lean toward TPC—in other words, if you never or rarely query for BillingDetails and you have no class that has an association to BillingDetail base class. I recommend TPC (only) for the top level of your class hierarchy, where polymorphism isn’t usually required, and when modification of the base class in the future is unlikely. If you do require polymorphic associations or queries, and subclasses declare relatively few properties (particularly if the main difference between subclasses is in their behavior), lean toward TPH. Your goal is to minimize the number of nullable columns and to convince yourself (and your DBA) that a denormalized schema won’t create problems in the long run. If you do require polymorphic associations or queries, and subclasses declare many properties (subclasses differ mainly by the data they hold), lean toward TPT. Or, depending on the width and depth of your inheritance hierarchy and the possible cost of joins versus unions, use TPC. By default, choose TPH only for simple problems. For more complex cases (or when you’re overruled by a data modeler insisting on the importance of nullability constraints and normalization), you should consider the TPT strategy. But at that point, ask yourself whether it may not be better to remodel inheritance as delegation in the object model (delegation is a way of making composition as powerful for reuse as inheritance). Complex inheritance is often best avoided for all sorts of reasons unrelated to persistence or ORM. EF acts as a buffer between the domain and relational models, but that doesn’t mean you can ignore persistence concerns when designing your classes. SummaryIn this series, we focused on one of the main structural aspect of the object/relational paradigm mismatch which is inheritance and discussed how EF solve this problem as an ORM solution. We learned about the three well-known inheritance mapping strategies and their implementations in EF Code First. Hopefully it gives you a better insight about the mapping of inheritance hierarchies as well as choosing the best strategy for your particular scenario. Happy New Year and Happy Code-Firsting! References ADO.NET team blog Java Persistence with Hibernate book a { color: #5A99FF; } a:visited { color: #5A99FF; } .title { padding-bottom: 5px; font-family: Segoe UI; font-size: 11pt; font-weight: bold; padding-top: 15px; } .code, .typeName { font-family: consolas; } .typeName { color: #2b91af; } .padTop5 { padding-top: 5px; } .padTop10 { padding-top: 10px; } .exception { background-color: #f0f0f0; font-style: italic; padding-bottom: 5px; padding-left: 5px; padding-top: 5px; padding-right: 5px; }

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