Search Results

Search found 17317 results on 693 pages for 'memory upgrade'.

Page 611/693 | < Previous Page | 607 608 609 610 611 612 613 614 615 616 617 618  | Next Page >

• iPhone programming - problem with CoreFoundation forking, PLEASE for the love of god help! lol

  - by Tom

  Hello all, I've been working on an iPhone for several months. It's a 2d shooting game akin to the old Smash TV type games. I'm doing everything alone and it has come out well so far, but now I am getting unpredictable crashes which seem to be related to CoreFoundation forking and not exec()ing, as the message THE_PROCESS_HAS_FORKED_AND_YOU_CANNOT_USE_THIS_COREFOUNDATION_FUNCTIONA LITY_YOU_MUST_EXEC__ always shows up somewhere in the debugger. Usually it shows up around a CFRunLoopRunSpecific and is related to either a timer firing or _InitializeTouchTapCount. I cannot figure out exactly what is causing the fork to occur. My main game loop is running on a timer, first updating all the logic and then drawing everything with openGL. There is nothing highly complex or unusual. I understand you cannot make CF calls on the childside of a fork, or access shared memory and things like that. I am not explicitly trying to fork anything. My question is: can anyone tell me what type of activity might cause CoreFoundation to randomly fork like this? I'd really like to finish this game and I don't know how to solve this problem. Thanks for any help.

  Read the article

• Boost.MultiIndex: Are there way to share object between two processes?

  - by Arman

  Hello, I have a Boost.MultiIndex big array about 10Gb. In order to reduce the reading I thought there should be a way to keep the data in the memory and another client programs will be able to read and analyse it. What is the proper way to organize it? The array looks like: struct particleID { int ID;// real ID for particle from Gadget2 file "ID" block unsigned int IDf;// postition in the file particleID(int id,const unsigned int idf):ID(id),IDf(idf){} bool operator<(const particleID& p)const { return ID<p.ID;} unsigned int getByGID()const {return (ID&0x0FFF);}; }; struct ID{}; struct IDf{}; struct IDg{}; typedef multi_index_container< particleID, indexed_by< ordered_unique< tag<IDf>, BOOST_MULTI_INDEX_MEMBER(particleID,unsigned int,IDf)>, ordered_non_unique< tag<ID>,BOOST_MULTI_INDEX_MEMBER(particleID,int,ID)>, ordered_non_unique< tag<IDg>,BOOST_MULTI_INDEX_CONST_MEM_FUN(particleID,unsigned int,getByGID)> > > particlesID_set; Any ideas are welcome. kind regards Arman.

  Read the article

• Getting EXC_BAD_ACCESS without any helpful msg from NSZombieEnabled

  - by nefsu

  Hello guys. I'm a newbie to iphone development and I've been struggling with an EXC_BAD_ACCESS error I got a couple of days ago. I'm basically taking the Stanford iphone class independently and I am trying to pass an array of NSManagedObjects to a TableViewController that's supposed to display them. The application launches in the simulator and displays the data in the tableView but it immediately errors out with an EXC_BAD_ACCESS. I followed instructions here and other places on how to use NSZombieEnabled to identify prematurely released objects but this one comes without any helpful msgs even with NSZombieEnabled. My guess is it must be caused by something trying to access unassigned memory that wasn't released through release/autorelease. Or else it would have been picked up as zombie object like the other errors I have been able to fix. I'm not a c expert but does that mean something like that could happen if I were to declare an object and send it a message without ever instantiating it? I looked through my code to see if I had anything like that and I came up empty. I have the stack trace in the debugger for this but I'm not sure how to make use of it. I'm a little frustrated because I can't use breakpoints in the code to narrow down the problem any further since it seems to happen after the app has finished loading. I thought the app would just stay idle if there was no possible user interaction. Is it failing at the tail end of the load where I can't easy see it or is jut doing stuff in the background after it's done loading. And I would much appreciate any tips on how to read the stacktrace for this. Thanks for the help guys.

  Read the article

• "QFontEngine(Win) GetTextMetrics failed ()" error on 64-bit Windows

  - by David Murdoch

  I'll add 500 of my own rep as a bounty when SO lets me. I'm using wkhtmltopdf to convert HTML web pages to PDFs. This works perfectly on my 32-bit dev server [unfortunately, I can't ship my machine :-p ]. However, when I deploy to the web application's 64-bit server the following errors are displayed: C:\>wkhtmltopdf http://www.google.com google.pdf Loading pages (1/5) QFontEngine::loadEngine: GetTextMetrics failed () ] 10% QFontEngineWin: GetTextMetrics failed () QFontEngineWin: GetTextMetrics failed () QFontEngine::loadEngine: GetTextMetrics failed () QFontEngineWin: GetTextMetrics failed () QFontEngineWin: GetTextMetrics failed () QFontEngineWin: GetTextMetrics failed () QFontEngine::loadEngine: GetTextMetrics failed () ] 36% QFontEngineWin: GetTextMetrics failed () QFontEngineWin: GetTextMetrics failed () // ...etc.... and the PDF is created and saved... just WITHOUT text. All form-fields, images, borders, tables, divs, spans, ps, etc are rendered accurately...just void of any text at all. Server information: Windows edition: Windows Server Standard Service Pack 2 Processor: Intel Xeon E5410 @ 2.33GHz 2.33 GHz Memory: 8.00 GB System type: 64-bit Operating System Can anyone give me a clue as to what is happening and how I can fix this? Also, I wasn't sure what to tag/title this question with...so if you can think of better tags/title comment them or edit the question. :-)

  Read the article

• STLport crash (race condition, Darwin only?)

  - by Jonas Byström

  When I run STLport on Darwin I get a strange crash. (Haven't seen it anywhere else than on Mac, but exactly same thing crash on both i686 and PowerPC.) This is what it looks like in gdb: Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: 13 at address: 0x0000000000000000 [Switching to process 21097] 0x000000010120f47c in stlp_std::__node_alloc_impl::_M_allocate () It may be some setting in STLport, I noticed that Mac.h and MacOSX.h seemed far behind on features. I also know that it it must be some type of race condition, since it doesn't occur just by calling this method (implicity called). The crash happens mainly when I push the system, running 10 simultaneous threads that do a lot of string handling. Other theories I come up with have to do with compiler flags (configure script) and g++ 4.2 bugs (seems like 4.4.3 isn't on Mac yet with Objective-C support, which I need to link with). HELP!!! :) Edit: I run unit tests, which do all sorts of things. This problem arise when I start 10 threads that push the system; and it always comes down to std::string::append which eventually boils down to _M_allocate. Since I can't even get a descent dump of the code that's causing the problem, I figure I'm doing something bad. Could it be so since it's trying to execute at instruction pointer 0x000...000? Are dynlibs built as DLLs in Windows with a jump table? Could it perhaps be that such a jump table has been overwritten for some reason? That would probably explain this behavior. (The code is huge, if I run out of other ideas, I'll post a minimum crashing sample here.)

  Read the article

• Per-pixel per-component alpha blending in Windows

  - by Crend King

  I have a 24-bit bitmaps with R, G, B color channels and a 24-bit bitmap with R, G, B alpha channels. I want to alpha blend the first bitmap to a HDC in GDI or RenderTarget in Direct2D with the alpha channels respectively. For example, suppose for one pixel, the bitmap color is (192, 192, 192), the HDC color is (0, 255, 255) and the alpha channels are (30, 40, 50). The final HDC color should be (22, 245, 242). I know I can BitBlt the HDC to a memory HDC first, do alpha blending by manually calculating the color of each pixel and finally BitBlt back. I just want to avoid the additional blitting and leave APIs do their job (faster since they are in kernel space). The first idea comes to my mind is to split the source bitmap into 3 red-only, green-only and blue-only 8-bit bitmaps, do normal alpha blending, then composite the 3 output bitmaps into the HDC. But I don't find a way to do the splitting and composition natively in Windows (would Direct2D layer help?). Also, the splitting and compositing may require many additional copying. The performance overhead would be too high. Or maybe do the alpha blending in 3 passes. Each pass apply the blending for one channel, while maintaining the other 2 unchanged. Thanks for any comment. EDIT: I found this question, and the answer should be good reference to this problem. However, besides AC_SRC_OVER, there is no other blending operation supported. Why don't Microsoft improve their API?

  Read the article

• RegistryKey ValueCount/SubKeyCount wrong

  - by Mark J Miller

  I am trying to query the following registry key values: HKLM\SOFTWARE\Microsoft\MSSQLServer\Client\SharedMemoryOn HKLM\SOFTWARE\Microsoft\MSSQLServer\Client\SuperSocketNetLib\ProtocolOrder But depending on which machine I'm running the program the query returns null. When I debug on my local machine and I inspect the value for ValueCount for: HKLM\SOFTWARE\Microsoft\MSSQLServer\Client HKLM\SOFTWARE\Microsoft\MSSQLServer\Client\SuperSocketNetLib The count is 0 and OpenSubKey returns null. I am a domain admin, in the local administrators group and have added the following to my app.manifest: <requestedExecutionLevel level="requireAdministrator" uiAccess="false" /> Any idea why? private static void ValidateSqlClientSettings() { Console.WriteLine("\r\n/////////////// LOCAL SQL CLIENT PROTOCOLS ////////////////"); RegistryKey keyHKLM = Registry.LocalMachine; ///TODO: nullreferenceexception - connect to remote machine and find out why RegistryKey sqlClientKey = keyHKLM.OpenSubKey(@"SOFTWARE\Microsoft\MSSQLServer\Client"); if (sqlClientKey == null) { WriteLine2Console(@"WARNING: unable to read registry key '{0}\SOFTWARE\Microsoft\MSSQLServer\Client'", ConsoleColor.Yellow); } var cliKeyNames = from k in sqlClientKey.GetSubKeyNames() where k == "SuperSocketNetLib" select k; ///TODO: find out why these values are always missing (even if I can see them in regedit) Console.Write("Shared Memory Disabled (cliconfg): "); if (Convert.ToBoolean(sqlClientKey.GetValue("SharedMemoryOn"))) WriteLine2Console("FAILED", ConsoleColor.Red); else if(sqlClientKey.GetValue("SharedMemoryOn") == null) WriteLine2Console(String.Format("WARNING - unable to read '{0}\\SharedMemoryOn'", sqlClientKey.Name), ConsoleColor.Yellow); else WriteLine2Console("PASS", ConsoleColor.Green); Console.Write("Client Protocol Order (cliconfg - tcp first): "); foreach (string cliKey in cliKeyNames) { RegistryKey subKey = sqlClientKey.OpenSubKey(cliKey); object order = subKey.GetValue("ProtocolOrder"); if (order != null && order.ToString().StartsWith("tcp") == false) { WriteLine2Console("FAILED", ConsoleColor.Red); } else if (order == null) { WriteLine2Console(String.Format("WARNING - unable to read '{0}\\ProtocolOrder'", subKey.Name), ConsoleColor.Yellow); } else { WriteLine2Console("PASS", ConsoleColor.Green); } subKey.Close(); } sqlClientKey.Close(); keyHKLM.Close(); }

  Read the article

• Help! I've learned jQuery... now I want to learn JavaScript

  - by Derek Adair

  I am a self-taught web developer/programmer. I started out about two years ago by learning how to make simple dynamic websites with HTML/CSS/PHP. Then I started dabbling with animation... Enter jQuery I've become quite proficient with jQuery over the last year and I've even started making my own plugins. I've spent most of my effort learning how to beautify websites with fancy effects and what not. Upon tackling my first full-blown application, I realized how under-developed my knowledge of JavaScript actually is. jQuery has allowed me to rely on its framework so heavily that I rarely use any interesting functions, techniques, or whatever that are 'native' to the JavaScript language. For example: I have a basic understanding of what a closure is... but I am unsure where this technique can actually benefit me. Although as I understand it, that's what my jQuery plugins do with (function ($){//plugin code here})(jQuery). I've seen many posts/blogs/whatever about memory leaks and circular references which is concerning. I'm frustrated because I can wrap my head around the basic concepts of what these are just by reading the articles, but I'm finding that the deeper I go the more I don't understand. The vocabulary alone is burdensome. Let alone how to actually use these techniques/functions/language features. I am trying to figure out what I don't know I'm looking to gather any advice, techniques, articles, books, videos, snippets, examples, potential pitfalls... really anything you have regarding application development with JavaScript/jQuery.

  Read the article

• Beginning 3.2+ iPhone development

  - by Dinah

  I'm interested in learning Objective C for iPhone development. This is a topic which I realize has been covered to death. The qualifying difference is: I'd like to start learning beginning with the latest version (the most recent iPhone OS as of May, 2010 is ver. 3.2 and 4 beta is also out). I'd like to not have to wade through or unlearn legacy information. Using the links I've found throughout related topics on Stack Overflow, I'll read a blog post or tutorial which will say one thing, but then the comments will say, "this is different now in version xyz." For example, I've found this a few times regarding memory management/garbage collection. I assume that Apple's "getting started" doc.s will have the most recent info but many SO posts have said that those are not the most clear. The Stanford iPhone course looks great, but how do I know if it still applies to the most recent versions? Where should one start learning Objective C for iPhone development starting with version 3.2 or later without having as much exposure to legacy information?

  Read the article

• Mapping issue with multi-field primary keys using hibernate/JPA annotations

  - by Derek Clarkson

  Hi all, I'm stuck with a database which is using multi-field primary keys. I have a situation where I have a master and details table, where the details table's primary key contains fields which are also the foreign key's the the master table. Like this: Master primary key fields: master_pk_1 Details primary key fields: master_pk_1 details_pk_2 details_pk_3 In the Master class we define the hibernate/JPA annotations like this: @Id @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "idGenerator") @Column(name = "master_pk_1") private long masterPk1; @OneToMany(cascade=CascadeType.ALL) @JoinColumn(name = "master_pk_1", referencedColumnName = "master_pk_1") private List<Details> details = new ArrayList<Details>(); And in the details class I have defined the id and back reference like this: @EmbeddedId @AttributeOverrides( { @AttributeOverride( name = "masterPk1", column = @Column(name = "master_pk_1")), @AttributeOverride(name = "detailsPk2", column = @Column(name = "details_pk_2")), @AttributeOverride(name = "detailsPk2", column = @Column(name = "details_pk_2")) }) private DetailsPrimaryKey detailsPrimaryKey = new DetailsPrimaryKey(); @ManyToOne @JoinColumn(name = "master_pk_1", referencedColumnName = "master_pk_1", insertable=false) private Master master; The goal of all of this was that I could create a new master, add some details to it, and when saved, JPA/Hibernate would generate the new id for master in the masterPk1 field, and automatically pass it down to the details records, storing it in the matching masterPk1 field in the DetailsPrimaryKey class. At least that's what the documentation I've been looking at implies. What actually happens is that hibernate appears to corectly create and update the records in the database, but not pass the key to the details classes in memory. Instead I have to manually set it myself. I also found that without the insertable=true added to the back reference to master, that hibernate would create sql that had the master_pk_1 field listed twice in the insert statement, resulting in the database throwing an exception. My question is simply is this arrangement of annotations correct? or is there a better way of doing it?

  Read the article

• What are the primitive Forth operators?

  - by Barry Brown

  I'm interested in implementing a Forth system, just so I can get some experience building a simple VM and runtime. When starting in Forth, one typically learns about the stack and its operators (DROP, DUP, SWAP, etc.) first, so it's natural to think of these as being among the primitive operators. But they're not. Each of them can be broken down into operators that directly manipulate memory and the stack pointers. Later one learns about store (!) and fetch (@) which can be used to implement DUP, SWAP, and so forth (ha!). So what are the primitive operators? Which ones must be implemented directly in the runtime environment from which all others can be built? I'm not interested in high-performance; I want something that I (and others) can learn from. Operator optimization can come later. (Yes, I'm aware that I can start with a Turing machine and go from there. That's a bit extreme.) Edit: What I'm aiming for is akin to bootstrapping an operating system or a new compiler. What do I need do implement, at minimum, so that I can construct the rest of the system out of those primitive building blocks? I won't implement this on bare hardware; as an educational exercise, I'd write my own minimal VM.

  Read the article

• error while loadin applet in web application

  - by pallavi

  I want to run my applet on web application, but i got some error which i mentioned below please help me to get out of this problem ============================================================================================= Java Plug-in 1.7.0 Using JRE version 1.7.0-ea-b116 Java HotSpot(TM) Client VM User home directory = C:\Users\HONEY c: clear console window f: finalize objects on finalization queue g: garbage collect h: display this help message l: dump classloader list m: print memory usage o: trigger logging q: hide console r: reload policy configuration s: dump system and deployment properties t: dump thread list v: dump thread stack x: clear classloader cache 0-5: set trace level to java.lang.RuntimeException: java.lang.NoClassDefFoundError: mp3$1 at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source) at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source) at java.lang.Thread.run(Unknown Source) Caused by: java.lang.NoClassDefFoundError: mp3$1 at mp3.(mp3.java:93) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) at java.lang.reflect.Constructor.newInstance(Unknown Source) at java.lang.Class.newInstance0(Unknown Source) at java.lang.Class.newInstance(Unknown Source) at sun.plugin2.applet.Plugin2Manager$12.run(Unknown Source) at java.awt.event.InvocationEvent.dispatch(Unknown Source) at java.awt.EventQueue.dispatchEvent(Unknown Source) at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.run(Unknown Source) Caused by: java.lang.ClassNotFoundException: mp3$1 at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source) at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source) at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source) at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) ... 16 more Caused by: java.io.IOException: open HTTP connection failed:http://viscous10.webng.com/mp3/mp3$1.class at sun.plugin2.applet.Applet2ClassLoader.getBytes(Unknown Source) at sun.plugin2.applet.Applet2ClassLoader.access$000(Unknown Source) at sun.plugin2.applet.Applet2ClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) ... 21 more Exception: java.lang.RuntimeException: java.lang.NoClassDefFoundError: mp3$1 ========================================================================================== but it happens only if i run applet with events and in simple applet i never occurred thanx

  Read the article

• Using graphical ActiveX (COM) controls in WinForms project

  - by alex

  I have a collection (set) of ActiveX controls. I recieved them from our vendor company. I created a wrappers for them using tlbimp.exe and aximp.exe. All non-graphical controls work good. All graphical controls don't react on some methods. When I call their methods I get: TargetInvocativeException (InnerException is null). or Attempt to read/write protected memory. Our vendor company assure that their graphical activex controls work good. But they don't provide support service, so I have to find solution of my problem alone. And some more, All graphical activex controls don't react on mouseclick or any other mouse manipulations. But documentation says: it must change the color on mouse click. Maybe, someone have same symptoms and can help me ! I googled over that problem many pages but they don't help me. Maybe it's some Visual Studio settings or compiler options ? I use VS 2005.

  Read the article

• Hibernate: order multiple one-to-many relations

  - by Markos Fragkakis

  I have a search screen, using JSF, JBoss Seam and Hibernate underneath. There are columns for A, B and C, where the relations are as follows: A (1< -- ) B (1< -- ) C A has a List< B and B has a List< C (both relations are one-to-many). The UI table supports ordering by any column (ASC or DESC), so I want the results of the query to be ordered. This is the reason I used Lists in the model. However, I got an exception that Hibernate cannot eagerly fetch multiple bags (it considers both lists to be bags). There is an interesting blog post here, and they identify the following solutions: Use @IndexColumn annotation (there is none in my DB, and what's more, I want the position of results to be determined by the ordering, not by an index column) Fetch lazily (for performance reasons, I need eager fetching) Change List to Set So, I changed the List to Set, which by the way is more correct, model-wise. First, if don't use @OrderBy, the PersistentSet returned by Hibernate wraps a HashSet, which has no ordering. Second, If I do use @OrderBy, the PersistentSet wraps a LinkedHashSet, which is what I would like, but the OrderBy property is hardcoded, so all other ordering I perform through the UI comes after it. I tried again with Sets, and used SortedSet (and its implementation, TreeSet), but I have some issues: I want ordering to take place in the DB, and not in-memory, which is what TreeSet does (either through a Comparator, or through the Comparable interface of the elements). Second, I found that there is the Hibernate annotation @Sort, which has a SortOrder.UNSORTED and you can also set a Comparator. I still haven't managed to make it compile, but I am still not convinced it is what I need. Any advice?

  Read the article

• Haskell Linear Algebra Matrix Library for Arbitrary Element Types

  - by Johannes Weiß

  I'm looking for a Haskell linear algebra library that has the following features: Matrix multiplication Matrix addition Matrix transposition Rank calculation Matrix inversion is a plus and has the following properties: arbitrary element (scalar) types (in particular element types that are not Storable instances). My elements are an instance of Num, additionally the multiplicative inverse can be calculated. The elements mathematically form a finite field (??2256). That should be enough to implement the features mentioned above. arbitrary matrix sizes (I'll probably need something like 100x100, but the matrix sizes will depend on the user's input so it should not be limited by anything else but the memory or the computational power available) as fast as possible, but I'm aware that a library for arbitrary elements will probably not perform like a C/Fortran library that does the work (interfaced via FFI) because of the indirection of arbitrary (non Int, Double or similar) types. At least one pointer gets dereferenced when an element is touched (written in Haskell, this is not a real requirement for me, but since my elements are no Storable instances the library has to be written in Haskell) I already tried very hard and evaluated everything that looked promising (most of the libraries on Hackage directly state that they wont work for me). In particular I wrote test code using: hmatrix, assumes Storable elements Vec, but the documentation states: Low Dimension : Although the dimensionality is limited only by what GHC will handle, the library is meant for 2,3 and 4 dimensions. For general linear algebra, check out the excellent hmatrix library and blas bindings I looked into the code and the documentation of many more libraries but nothing seems to suit my needs :-(. Update Since there seems to be nothing, I started a project on GitHub which aims to develop such a library. The current state is very minimalistic, not optimized for speed at all and only the most basic functions have tests and therefore should work. But should you be interested in using or helping out developing it: Contact me (you'll find my mail address on my web site) or send pull requests.

  Read the article

• Why calling Process.killProcess(Process.myPid()) is a bad idea?

  - by Tal Kanel

  I've read some posts saying using this method is "not good", shouldn't been use, it's not the right way to "close" the application and it's not how android works... I understand and accept the fact that Android OS knows better then me when it's the right time to terminate the process, but I didn't heard yet a good explanation why it's wrong using the killProcess() method?. after all - it's part of the android API... what I do know is that calling this method while other threads doing in potential an important work (operations on files, writing to DB, HTTP requests, running services..) can be terminated in the middle, and it's clearly not good. also I know I can benefit from the fact that "re-open" the application will be faster, cause the system maybe still "holds" in memory state from last time been used, and killProcess() prevents that. beside this reason, in assumption I don't have such operations, and I don't care my application will load from scratch each run, there are other reasons why not using the killProcess() method? I know about finish() method to close an Activity, so don't write me about that please.. finish() is only for Activity. not to all application, and I think I know exactly why and when to use it... and another thing - I'm developing also games with the Unity3D framework, and exporting the project to android. when I decompiled the generated apk, I was very suprised to find out that the java source code created from unity - implementing Unity's - Application.quit() method, with Process.killProcess(Process.myPid()). Application.quit() is suppose to be the right way to close game according to Unity3d guides (is it really?? maybe I'm wrong, and missed something), so how it happens that the Unity's framework developers which doing a very good work as it seems implemented this in native android to killProcess()? anyway - I wish to have a "list of reasons" why not using the killProcess() method, so please write down your answer - if you have something interesting to say about that. TIA

  Read the article

• Accessing frame info in gdb

  - by Maelstrom

  In gdb, is there a way to access the contents of info frame in a script? I'm debugging a problem somewhere between Apache, PHP, APC and my own code, and I have about a hundred cores to choose from. Following the instructions here http://bugs.php.net/bugs-generating-backtrace.php I end up with a stacktrace like: #0 0x0121a31a in do_bind_function (opline=0xa94dd750, function_table=0x9b9cf98, compile_time=0 '\0') at /usr/src/debug/php-5.2.7/Zend/zend_compile.c:2407 #1 0x0124bb2e in ZEND_DECLARE_FUNCTION_SPEC_HANDLER (execute_data=0xbfef7990) at /usr/src/debug/php-5.2.7/Zend/zend_vm_execute.h:498 #2 0x01249dfa in execute (op_array=0xb79d5d3c) at /usr/src/debug/php-5.2.7/Zend/zend_vm_execute.h:92 #3 0x01261e31 in ZEND_INCLUDE_OR_EVAL_SPEC_VAR_HANDLER (execute_data=0xbfef80d0) at /usr/src/debug/php-5.2.7/Zend/zend_vm_execute.h:7809 #4 0x01249dfa in execute (op_array=0xb79d55ec) at /usr/src/debug/php-5.2.7/Zend/zend_vm_execute.h:92 ... #26 0x09caa894 in ?? () #27 0x00000000 in ?? () The stack will always look similar, with function execute and ZEND_something interleaved several times. I need to go up to the last instance of execute (up 2 in this case) and print myVar. Obviously gdb knows the function names, but does it surface them in any user variables I could access? Typing frame 2 shows a one-line version, and info frame shows a single stackframe in detail. I want to do something like while ($current_frame.function_name != "execute") {up;} print myVar but I don't see how to do it strictly within gdb. Is there a variable / structure / special memory location / something that allows access to gdb's information on either the whole stack (like bt) or to the current stack frame (like info frame)?

  Read the article

• Ways std::stringstream can set fail/bad bit?

  - by Evan Teran

  A common piece of code I use for simple string splitting looks like this: inline std::vector<std::string> split(const std::string &s, char delim) { std::vector<std::string> elems; std::stringstream ss(s); std::string item; while(std::getline(ss, item, delim)) { elems.push_back(item); } return elems; } Someone mentioned that this will silently "swallow" errors occurring in std::getline. And of course I agree that's the case. But it occurred to me, what could possibly go wrong here in practice that I would need to worry about. basically it all boils down to this: inline std::vector<std::string> split(const std::string &s, char delim) { std::vector<std::string> elems; std::stringstream ss(s); std::string item; while(std::getline(ss, item, delim)) { elems.push_back(item); } if(ss.fail()) { // *** How did we get here!? *** } return elems; } A stringstream is backed by a string, so we don't have to worry about any of the issues associated with reading from a file. There is no type conversion going on here since getline simply reads until it sees a newline or EOF. So we can't get any of the errors that something like boost::lexical_cast has to worry about. I simply can't think of something besides failing to allocate enough memory that could go wrong, but that'll just throw a std::bad_alloc well before the std::getline even takes place. What am I missing?

  Read the article

• Looking for a smarter way to convert a Python list to a GList?

  - by Kingdom of Fish

  I'm really new to C - Python interaction and am currently writing a small app in C which will read a file (using Python to parse it) and then using the parsed information to execute small Python snippets. At the moment I'm feeling very much like I'm reinventing wheels, for example this function: typedef gpointer (list_func)(PyObject *obj); GList *pylist_to_glist(list_func func, PyObject *pylist) { GList *result = NULL; if (func == NULL) { fprintf(stderr, "No function definied for coverting PyObject.\n"); } else if (PyList_Check(pylist)) { PyObject *pIter = PyObject_GetIter(pylist); PyObject *pItem; while ((pItem = PyIter_Next(pIter))) { gpointer obj = func(pItem); if (obj != NULL) result = g_list_append(result, obj); else fprintf(stderr, "Could not convert PyObject to C object.\n"); Py_DECREF(pItem); } Py_DECREF(pIter); } return result; } I would really like to do this in a easier/smarter way less prone to memory leaks and errors. All comments and suggestions are appreciated.

  Read the article

• Implementing the ‘defer’ statement from Go in Objective-C?

  - by zoul

  Hello! Today I read about the defer statement in the Go language: A defer statement pushes a function call onto a list. The list of saved calls is executed after the surrounding function returns. Defer is commonly used to simplify functions that perform various clean-up actions. I thought it would be fun to implement something like this in Objective-C. Do you have some idea how to do it? I thought about dispatch finalizers, autoreleased objects and C++ destructors. Autoreleased objects: @interface Defer : NSObject {} + (id) withCode: (dispatch_block_t) block; @end @implementation Defer - (void) dealloc { block(); [super dealloc]; } @end #define defer(__x) [Defer withCode:^{__x}] - (void) function { defer(NSLog(@"Done")); … } Autoreleased objects seem like the only solution that would last at least to the end of the function, as the other solutions would trigger when the current scope ends. On the other hand they could stay in the memory much longer, which would be asking for trouble. Dispatch finalizers were my first thought, because blocks live on the stack and therefore I could easily make something execute when the stack unrolls. But after a peek in the documentation it doesn’t look like I can attach a simple “destructor” function to a block, can I? C++ destructors are about the same thing, I would create a stack-based object with a block to be executed when the destructor runs. This would have the ugly disadvantage of turning the plain .m files into Objective-C++? I don’t really think about using this stuff in production, I’m just interested in various solutions. Can you come up with something working, without obvious disadvantages? Both scope-based and function-based solutions would be interesting.

  Read the article

• Updating multiple related tables in SQLite with C#

  - by PerryJ

  Just some background, sorry so long winded. I'm using the System.Data.SQLite ADO.net adapter to create a local sqlite database and this will be the only process hitting the database, so I don't need to worry about concurrency. I'm building the database from various sources and don't want to build this all in memory using datasets or dataadapters or anything like that. I want to do this using SQL (DdCommands). I'm not very good with SQL and complete noob in sqlite. I'm basically using sqlite as a local database / save file structure. The database has a lot of related tables and the data has nothing to do with People or Regions or Districts, but to use a simple analogy, imagine: Region table with auto increment RegionID, RegionName column and various optional columns. District table with auto increment DistrictID, DistrictName, RegionId, and various optional columns Person table with auto increment PersonID, PersonName, DistrictID, and various optional columns So I get some data representing RegionName, DistrictName,PersonName, and other Person related data. The Region, District and/or Person may or may not be created at this point. Once again, not being the greatest with this, my thoughts would be something like: Check to see if Region exists and if so get the RegionID else create it and get RegionID Check to see if District exists and if so get the DistrictID else create it adding in RegionID from above and get DistrictID Check to see if Person exists and if so get the PersonID else create it adding in DistrictID from above and get PersonID Update Person with rest of data. In MS SQL Server I would create a stored procedure to handle all this. Only way I can see to do this with sqlite is a lot of commands. So I'm sure I'm not getting this. I've spent hours looking around on various sites but just don't feel like I'm going down the right road. Any suggestions would be greatly appreciated.

  Read the article

• Why does perl crash with "*** glibc detected *** perl: munmap_chunk(): invalid pointer"?

  - by sid_com

  #!/usr/bin/env perl use warnings; use strict; use 5.012; use XML::LibXML::Reader; my $reader = XML::LibXML::Reader->new( location => 'http://www.heise.de/' ) or die $!; while ( $reader->read ) { say $reader->name; } At the end of the output from this script I get this error-messages: * glibc detected * perl: munmap_chunk(): invalid pointer: 0x0000000000b362e0 * ======= Backtrace: ========= /lib64/libc.so.6[0x7fb84952fc76] ... ======= Memory map: ======== 00400000-0053d000 r-xp 00000000 08:01 182002 /usr/local/bin/perl ... Is this due a bug? perl -V: Summary of my perl5 (revision 5 version 12 subversion 0) configuration: Platform: osname=linux, osvers=2.6.31.12-0.2-desktop, archname=x86_64-linux uname='linux linux1 2.6.31.12-0.2-desktop #1 smp preempt 2010-03-16 21:25:39 +0100 x86_64 x86_64 x86_64 gnulinux ' config_args='-Dnoextensions=ODBM_File' hint=recommended, useposix=true, d_sigaction=define useithreads=undef, usemultiplicity=undef useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef use64bitint=define, use64bitall=define, uselongdouble=undef usemymalloc=n, bincompat5005=undef Compiler: cc='cc', ccflags ='-fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64', optimize='-O2', cppflags='-fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include' ccversion='', gccversion='4.4.1 [gcc-4_4-branch revision 150839]', gccosandvers='' intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678 d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16 ivtype='long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8 alignbytes=8, prototype=define Linker and Libraries: ld='cc', ldflags =' -fstack-protector -L/usr/local/lib' libpth=/usr/local/lib /lib /usr/lib /lib64 /usr/lib64 /usr/local/lib64 libs=-lnsl -ldl -lm -lcrypt -lutil -lc perllibs=-lnsl -ldl -lm -lcrypt -lutil -lc libc=/lib/libc-2.10.1.so, so=so, useshrplib=false, libperl=libperl.a gnulibc_version='2.10.1' Dynamic Linking: dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E' cccdlflags='-fPIC', lddlflags='-shared -O2 -L/usr/local/lib -fstack-protector' Characteristics of this binary (from libperl): Compile-time options: PERL_DONT_CREATE_GVSV PERL_MALLOC_WRAP USE_64_BIT_ALL USE_64_BIT_INT USE_LARGE_FILES USE_PERLIO USE_PERL_ATOF Built under linux Compiled at Apr 15 2010 13:25:46 @INC: /usr/local/lib/perl5/site_perl/5.12.0/x86_64-linux /usr/local/lib/perl5/site_perl/5.12.0 /usr/local/lib/perl5/5.12.0/x86_64-linux /usr/local/lib/perl5/5.12.0 .

  Read the article

• Array: mathematical sequence

  - by VaioIsBorn

  An array of integers A[i] (i 1) is defined in the following way: an element A[k] ( k 1) is the smallest number greater than A[k-1] such that the sum of its digits is equal to the sum of the digits of the number 4* A[k-1] . You need to write a program that calculates the N th number in this array based on the given first element A[1] . INPUT: In one line of standard input there are two numbers seperated with a single space: A[1] (1 <= A[1] <= 100) and N (1 <= N <= 10000). OUTPUT: The standard output should only contain a single integer A[N] , the Nth number of the defined sequence. Input: 7 4 Output: 79 Explanation: Elements of the array are as follows: 7, 19, 49, 79... and the 4th element is solution. I tried solving this by coding a separate function that for a given number A[k] calculates the sum of it's digits and finds the smallest number greater than A[k-1] as it says in the problem, but with no success. The first testing failed because of a memory limit, the second testing failed because of a time limit, and now i don't have any possible idea how to solve this. One friend suggested recursion, but i don't know how to set that. Anyone who can help me in any way please write, also suggest some ideas about using recursion/DP for solving this problem. Thanks.

  Read the article

• Storing URLs while Spidering

  - by itemio

  I created a little web spider in python which I'm using to collect URLs. I'm not interested in the content. Right now I'm keeping all the visited URLs in a set in memory, because I don't want my spider to visit URLs twice. Of course that's a very limited way of accomplishing this. So what's the best way to keep track of my visited URLs? Should I use a database? * which one? MySQL, sqlite, postgre? * how should I save the URLs? As a primary key trying to insert every URL before visiting it? Or should I write them to a file? * one file? * multiple files? how should I design the file-structure? I'm sure there are books and a lot of papers on this or similar topics. Can you give me some advice what I should read?

  Read the article

• when long polling, Why are my other requests taking so long?

  - by Pascal

  The client makes 2 concurrent requests. (1 which takes 60 seconds - long polling) and another which is NOT long polling - supposed to return right away. It does return right away when I'm not doing long polling. But as soon as I start doing long polling with the other thread, the other one takes forever to execute. Firebug shows that the request is waiting for 10-50 seconds. On the server, I profiled ALL requests from the moment the php script starts to the time it goes back to the client, and it shows that each one only took 300ms or less. This problem started about the same time I started doing long polling (with the other XHR requests). I'm using jquery for both requests. The server shows that it is under very light load. CPU and memory less then 2%. 8 processes running out of a pool of 15. (it doesn't seem to deviate much from that number 8, even when I run more ajax requests). I guess each process can run multiple ajax threads concurrently. I made sure to EXIT from all processes as soon as their done executing. I don't see how the process pool has run out, if there are still 7 unused processes listed under prstat -J. Also, the problem happens somewhat intermittently. Firefox should be able to handle 2 concurrent ajax requests. i dont get what the problem is.

  Read the article

< Previous Page | 607 608 609 610 611 612 613 614 615 616 617 618  | Next Page >