Search Results

Search found 756 results on 31 pages for 'malloc'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 8/31 | < Previous Page | 4 5 6 7 8 9 10 11 12 13 14 15  | Next Page >

  • EXC_BAD_ACCESS NSUrlConnection

    - by Lars
    Hi all, i got an EXC_BAD_ACCESS when i perform the last line of the function (webData). -(void)requestSoap{ NSString *requestUrl = @"http://www.website.com/webservice.php"; NSString *soapMessage = @"the soap message"; //website and soapmessage are valid in original code. NSError **error; NSURLResponse *response; //Convert parameter string to url NSURL *url = [NSURL URLWithString:requestUrl]; NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:10]; NSString *msgLength = [NSString stringWithFormat:@"%d", [soapMessage length]]; //Create an XML message for webservice [theRequest addValue: @"text/xml; charset=utf-8" forHTTPHeaderField:@"Content-Type"]; [theRequest addValue: msgLength forHTTPHeaderField:@"Content-Length"]; [theRequest setHTTPMethod:@"POST"]; [theRequest setHTTPBody: [soapMessage dataUsingEncoding:NSUTF8StringEncoding]]; NSData *webData = [NSURLConnection sendSynchronousRequest:theRequest returningResponse:&response error:error]; } I tried not to release a thing, because what i read on the net is it's almost always a memory thing. When i debug the code (NSZombieEnabled = YES) this is what i get: [Session started at 2010-05-31 15:56:13 +0200.] GNU gdb 6.3.50-20050815 (Apple version gdb-1461.2) (Fri Mar 5 04:43:10 UTC 2010) Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "x86_64-apple-darwin".sharedlibrary apply-load-rules all Attaching to process 19856. test(19856) malloc: recording malloc stacks to disk using standard recorder test(19856) malloc: enabling scribbling to detect mods to free blocks test(19856) malloc: process 19832 no longer exists, stack logs deleted from /tmp/stack-logs.19832.test.w9Ek4L.index test(19856) malloc: stack logs being written into /tmp/stack-logs.19856.test.URRpQF.index Program received signal: “EXC_BAD_ACCESS”. Does anybody have a clue?? Thanks a lot! Lars

    Read the article

  • Sending 2 dim array using scatter

    - by MPI_Beginner
    I am a beginner in MPI, and i am using C Language, and Simulator for Processors (MPICH2), i wrote the following code to send a 2D array to make 2 processors take a line from it but it produces error when running MPICH2, the code is: int main ( int argc , char *argv[] ) { int rank; int commsize; MPI_Init(&argc, &argv); MPI_Comm_size(MPI_COMM_WORLD,&commsize); MPI_Comm_rank(MPI_COMM_WORLD,&rank); char** name=malloc(2*sizeof(char*)); int i; for(i=0;i<2;i++){ name[i]=malloc(15*sizeof(char)); } name[0]="name"; name[1]="age"; if(rank==0){ char** mArray=malloc(2*sizeof(char*)); MPI_Scatter(&name,1,MPI_CHAR,&mArray,1,MPI_CHAR,0,MPI_COMM_WORLD);//send } else{ char** mArray=malloc(2*sizeof(char*)); int k; for(k=0;k<2;k++){ mArray[k]=malloc(15*sizeof(char)); } MPI_Scatter(&mArray,1,MPI_CHAR,&mArray,1,MPI_CHAR,0,MPI_COMM_WORLD);//receive printf("line is %s \n",mArray[rank-1]); } MPI_Finalize(); }

    Read the article

  • Is it safe to catch an access violation in this scenario?

    - by Eloff
    I've read a lot, including here on SO that suggests this is a very bad idea in general and that the only thing you can do safely is exit the program. I'm not sure that this is true. This is for a pooling memory allocator that hands off large allocations to malloc. During pool_free() a pointer needs to be checked it it belongs to a pool or was allocated with malloc. By rounding the address down to the nearest 1MB boundary, I get a pointer to the beginning of a block of memory in the pool, or undefined if malloc was used. In the first case I can easily verify that the block of memory belongs to the pool, but, if it does not I will either fail this verification, or I will get an access violation (note that this is a read-only process). Could I not catch this with SEH (Windows) or handle the signal (POSIX) and simply treat it as a failed verification? (i.e. this is only possible if malloc was used, so pass the ptr to free())

    Read the article

  • Pthread - setting scheduler parameters

    - by Andna
    I wanted to use read-writer locks from pthread library in a way, that writers have priority over readers. I read in my man pages that If the Thread Execution Scheduling option is supported, and the threads involved in the lock are executing with the scheduling policies SCHED_FIFO or SCHED_RR, the calling thread shall not acquire the lock if a writer holds the lock or if writers of higher or equal priority are blocked on the lock; otherwise, the calling thread shall acquire the lock. so I wrote small function that sets up thread scheduling options. void thread_set_up(int _thread) { struct sched_param *_param=malloc(sizeof (struct sched_param)); int *c=malloc(sizeof(int)); *c=sched_get_priority_min(SCHED_FIFO)+1; _param->__sched_priority=*c; long *a=malloc(sizeof(long)); *a=syscall(SYS_gettid); int *b=malloc(sizeof(int)); *b=SCHED_FIFO; if (pthread_setschedparam(*a,*b,_param) == -1) { //depending on which thread calls this functions, few thing can happen if (_thread == MAIN_THREAD) client_cleanup(); else if (_thread==ACCEPT_THREAD) { pthread_kill(params.main_thread_id,SIGINT); pthread_exit(NULL); } } } sorry for those a,b,c but I tried to malloc everything, still I get SIGSEGV on the call to pthread_setschedparam, I am wondering why?

    Read the article

  • iis7 compress dynamic content from custom handler

    - by Malloc
    I am having trouble getting dynamic content coming from a custom handler to be compressed by IIS 7. Our handler spits out json data (Content-Type: application/json; charset=utf-8) and responds to url that looks like: domain.com/example.mal/OperationName?Param1=Val1&Param2=Val2 In IIS 6, all we had to do was put the edit the MetaBase.xml and in the IIsCompressionScheme element make sure that the HcScriptFileExtensions attribute had the custom extension 'mal' included in it. Static and Dynamic compression is turned out at the server and website level. I can confirm that normal .aspx pages are compressed correctly. The only content I cannot have compressed is the content coming from the custom handler. I have tried the following configs with no success: <handlers> <add name="MyJsonService" verb="GET,POST" path="*.mal" type="Library.Web.HttpHandlers.MyJsonServiceHandlerFactory, Library.Web" /> </handlers> <httpCompression> <dynamicTypes> <add mimeType="application/json" enabled="true" /> </dynamicTypes> </httpCompression> _ <httpCompression> <dynamicTypes> <add mimeType="application/*" enabled="true" /> </dynamicTypes> </httpCompression> _ <staticContent> <mimeMap fileExtension=".mal" mimeType="application/json" /> </staticContent> <httpCompression> <dynamicTypes> <add mimeType="application/*" enabled="true" /> </dynamicTypes> </httpCompression> Thanks in advance for the help.

    Read the article

  • Memory read/write access efficiency

    - by wolfPack88
    I've heard conflicting information from different sources, and I'm not really sure which one to believe. As such, I'll post what I understand and ask for corrections. Let's say I want to use a 2D matrix. There are three ways that I can do this (at least that I know of). 1: int i; char **matrix; matrix = malloc(50 * sizeof(char *)); for(i = 0; i < 50; i++) matrix[i] = malloc(50); 2: int i; int rowSize = 50; int pointerSize = 50 * sizeof(char *); int dataSize = 50 * 50; char **matrix; matrix = malloc(dataSize + pointerSize); char *pData = matrix + pointerSize - rowSize; for(i = 0; i < 50; i++) { pData += rowSize; matrix[i] = pData; } 3: //instead of accessing matrix[i][j] here, we would access matrix[i * 50 + j] char *matrix = malloc(50 * 50); In terms of memory usage, my understanding is that 3 is the most efficient, 2 is next, and 1 is least efficient, for the reasons below: 3: There is only one pointer and one allocation, and therefore, minimal overhead. 2: Once again, there is only one allocation, but there are now 51 pointers. This means there is 50 * sizeof(char *) more overhead. 1: There are 51 allocations and 51 pointers, causing the most overhead of all options. In terms of performance, once again my understanding is that 3 is the most efficient, 2 is next, and 1 is least efficient. Reasons being: 3: Only one memory access is needed. We will have to do a multiplication and an addition as opposed to two additions (as in the case of a pointer to a pointer), but memory access is slow enough that this doesn't matter. 2: We need two memory accesses; once to get a char *, and then to the appropriate char. Only two additions are performed here (once to get to the correct char * pointer from the original memory location, and once to get to the correct char variable from wherever the char * points to), so multiplication (which is slower than addition) is not required. However, on modern CPUs, multiplication is faster than memory access, so this point is moot. 1: Same issues as 2, but now the memory isn't contiguous. This causes cache misses and extra page table lookups, making it the least efficient of the lot. First and foremost: Is this correct? Second: Is there an option 4 that I am missing that would be even more efficient?

    Read the article

  • Core Data error when assigning variable with one-to-one relationship

    - by Hoang Pham
    I tried to assign a managed object (C) with its property another managed object (B) (a one-to-one relationship) in which this other managed object (B) has a to-many relationship with one other managed object (A). There is an error from this assignment in which I copied as follows: #0 0x020e53a7 in ___forwarding___ #1 0x020c16c2 in __forwarding_prep_0___ #2 0x02078988 in CFRetain #3 0x0207a728 in CFSetAddValue #4 0x020c2fb2 in CFSetCreate #5 0x01e51ce8 in -[_NSFaultingMutableSet copyWithZone:] #6 0x020afcca in -[NSObject copy] #7 0x01e50d22 in -[NSManagedObject(_NSInternalMethods) _newPropertiesForRetainedTypes:andCopiedTypes:preserveFaults:] #8 0x01e51aa0 in -[NSManagedObject(_NSInternalMethods) _newAllPropertiesWithRelationshipFaultsIntact__] #9 0x01e519b4 in -[NSManagedObjectContext(_NSInternalChangeProcessing) _establishEventSnapshotsForObject:] #10 0x01e51866 in _PFFastMOCObjectWillChange #11 0x01e516c5 in _PF_ManagedObject_WillChangeValueForKeyIndex #12 0x01e51525 in _sharedIMPL_setvfk_core #13 0x01e51483 in _PF_Handler_Public_SetProperty #14 0x01e546d1 in -[NSManagedObject(_NSInternalMethods) _didChangeValue:forRelationship:named:withInverse:] #15 0x0030ec1e in NSKVONotify #16 0x002aae2a in -[NSObject(NSKeyValueObserverNotification) didChangeValueForKey:] #17 0x01e5212f in _PF_ManagedObject_DidChangeValueForKeyIndex #18 0x01e515b1 in _sharedIMPL_setvfk_core #19 0x01e55827 in _svfk_5 I don't understand very well what the exact description of this error is. Can someone explain to me what it is and how to solve this one. Note that all other assignments in which the managed object B does not have any A items do not raise this error. ObjectC *objectC = [NSEntityDescription insertNewObjectForEntityForName:@"ObjectC" inManagedObjectContext:managedObjectContext]; objectC.objectB = objectB; Thank you in advance. I added some more NSZombieEnabled/MallocStackLogging generated log: 2010-05-18 17:28:05.327 Foo[2069:207] *** -[CFSet retain]: message sent to deallocated instance 0x800c880 (gdb) shell malloc_history 207 0x800c880 malloc_history cannot examine process 207 because the process does not exist. (gdb) shell malloc_history 2069 0x800c880 ALLOC 0x800c880-0x800c884 [size=5]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlIOParseDTD | _endElementNs | -[Parser parser:didEndElement:namespaceURI:qualifiedName:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asl_set_query | strdup | malloc | malloc_zone_malloc ---- FREE 0x800c880-0x800c884 [size=5]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlIOParseDTD | _endElementNs | -[Parser parser:didEndElement:namespaceURI:qualifiedName:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asl_free | free ALLOC 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asl_set_query | asprintf | malloc | malloc_zone_malloc ---- FREE 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asl_set_query | free ALLOC 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asprintf | malloc | malloc_zone_malloc ---- FREE 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | free ALLOC 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asprintf | malloc | malloc_zone_malloc ---- FREE 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | free ALLOC 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asprintf | malloc | malloc_zone_malloc ---- FREE 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | free ALLOC 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asprintf | malloc | malloc_zone_malloc ---- FREE 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | free ALLOC 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | asprintf | malloc | malloc_zone_malloc ---- FREE 0x800c860-0x800c8df [size=128]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlParseCharData | _characters | -[Parser parser:foundCharacters:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | asl_send | _asl_send_level_message | free ALLOC 0x800c700-0x800c893 [size=404]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlIOParseDTD | _startElementNs | -[Parser parser:didStartElement:namespaceURI:qualifiedName:attributes:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | CFCalendarDecomposeAbsoluteTime | _CFCalendarDecomposeAbsoluteTimeV | __CFCalendarSetupCal | __CFCalendarCreateUCalendar | ucal_open | icu::Calendar::createInstance(icu::TimeZone*, icu::Locale const&, UErrorCode&) | malloc | malloc_zone_malloc ---- FREE 0x800c700-0x800c893 [size=404]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlIOParseDTD | _startElementNs | -[Parser parser:didStartElement:namespaceURI:qualifiedName:attributes:] | NSLog | NSLogv | _CFLogvEx | __CFLogCString | _CFRelease | free ALLOC 0x800c880-0x800c8c7 [size=72]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __NSFireDelayedPerform | -[Step2ViewController downloadData] | -[Parser downloadVariantsWithPin:forTerminal:] | -[Parser parseByNSXMLParser:] | -[NSXMLParser parse] | xmlParseChunk | xmlIOParseDTD | _startElementNs | -[Parser parser:didStartElement:namespaceURI:qualifiedName:attributes:] | +[NSEntityDescription insertNewObjectForEntityForName:inManagedObjectContext:] | +[NSManagedObject(_PFDynamicAccessorsAndPropertySupport) allocWithEntity:] | _PFAllocateObject | malloc_zone_calloc ---- FREE 0x800c880-0x800c8c7 [size=72]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __CFRunLoopDoObservers | _performRunLoopAction | -[_PFManagedObjectReferenceQueue _processReferenceQueue:] | _PFDeallocateObject | malloc_zone_free ALLOC 0x800c880-0x800c8a7 [size=40]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __CFRunLoopDoObservers | CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) | CA::Transaction::commit() | CA::Context::commit_transaction(CA::Transaction*) | CALayerDisplayIfNeeded | -[TileLayer display] | -[CALayer _display] | CABackingStoreUpdate | backing_callback(CGContext*, void*) | WebCore::TiledSurface::drawLayer(CALayer*, CGContext*) | WKWindowDrawRect | WKViewDisplayRect | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | -[WebHTMLView drawSingleRect:] | -[WebFrame(WebInternal) _drawRect:contentsOnly:] | WebCore::FrameView::paintContents(WebCore::GraphicsContext*, WebCore::IntRect const&) | WebCore::RenderLayer::paint(WebCore::GraphicsContext*, WebCore::IntRect const&, WebCore::PaintRestriction, WebCore::RenderObject*) | WebCore::RenderLayer::paintLayer(WebCore::RenderLayer*, WebCore::GraphicsContext*, WebCore::IntRect const&, bool, WebCore::PaintRestriction, WebCore::RenderObject*, bool, bool) | WebCore::RenderLayer::paintLayer(WebCore::RenderLayer*, WebCore::GraphicsContext*, WebCore::IntRect const&, bool, WebCore::PaintRestriction, WebCore::RenderObject*, bool, bool) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintChildren(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintChildren(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintChildren(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderFlow::paintLines(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RootInlineBox::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::InlineFlowBox::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::InlineTextBox::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::paintTextWithShadows(WebCore::GraphicsContext*, WebCore::Font const&, WebCore::TextRun const&, int, int, WebCore::IntPoint const&, int, int, int, int, WebCore::ShadowData*, bool) | WebCore::GraphicsContext::drawText(WebCore::Font const&, WebCore::TextRun const&, WebCore::IntPoint const&, int, int) | WebCore::Font::drawSimpleText(WebCore::GraphicsContext*, WebCore::TextRun const&, WebCore::FloatPoint const&, int, int) const | WebCore::Font::drawGlyphBuffer(WebCore::GraphicsContext*, WebCore::GlyphBuffer const&, WebCore::TextRun const&, WebCore::FloatPoint&) const | WebCore::Font::drawGlyphs(WebCore::GraphicsContext*, WebCore::SimpleFontData const*, WebCore::GlyphBuffer const&, int, int, WebCore::FloatPoint const&, bool) const | CGGStateSetFont | maybeCopyTextState | calloc | malloc_zone_calloc ---- FREE 0x800c880-0x800c8a7 [size=40]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | __CFRunLoopDoObservers | CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) | CA::Transaction::commit() | CA::Context::commit_transaction(CA::Transaction*) | CALayerDisplayIfNeeded | -[TileLayer display] | -[CALayer _display] | CABackingStoreUpdate | backing_callback(CGContext*, void*) | WebCore::TiledSurface::drawLayer(CALayer*, CGContext*) | WKWindowDrawRect | WKViewDisplayRect | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | _WKViewDraw(CGContext*, WKView*, CGRect) | -[WebHTMLView drawSingleRect:] | -[WebFrame(WebInternal) _drawRect:contentsOnly:] | WebCore::FrameView::paintContents(WebCore::GraphicsContext*, WebCore::IntRect const&) | WebCore::RenderLayer::paint(WebCore::GraphicsContext*, WebCore::IntRect const&, WebCore::PaintRestriction, WebCore::RenderObject*) | WebCore::RenderLayer::paintLayer(WebCore::RenderLayer*, WebCore::GraphicsContext*, WebCore::IntRect const&, bool, WebCore::PaintRestriction, WebCore::RenderObject*, bool, bool) | WebCore::RenderLayer::paintLayer(WebCore::RenderLayer*, WebCore::GraphicsContext*, WebCore::IntRect const&, bool, WebCore::PaintRestriction, WebCore::RenderObject*, bool, bool) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintChildren(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintChildren(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintChildren(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderBlock::paintObject(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RenderFlow::paintLines(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::RootInlineBox::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::InlineFlowBox::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::InlineTextBox::paint(WebCore::RenderObject::PaintInfo&, int, int) | WebCore::paintTextWithShadows(WebCore::GraphicsContext*, WebCore::Font const&, WebCore::TextRun const&, int, int, WebCore::IntPoint const&, int, int, int, int, WebCore::ShadowData*, bool) | WebCore::GraphicsContext::restorePlatformState() | CGContextRestoreGState | CGGStackRestore | CGGStateRelease | textStateRelease | free ALLOC 0x800c880-0x800c8bf [size=64]: thread_a0a8c4e0 |start | main | UIApplicationMain | GSEventRun | GSEventRunModal | CFRunLoopRunInMode | CFRunLoopRunSpecific | CA::timer_callback(__CFRunLoopTimer*, void*) | run_animation_callbacks(double, void*) | -[UIViewAnimationState animationDidStop:finished:] | -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] | -[UINavigationTransitionView _navigationTransitionDidStop] | -[UIView(Hierarchy) removeFromSuperview] | -[UITextField resignFirstResponder] | -[UIFieldEditor resignFirstResponder] | -[UIKeyboardImpl setDelegate:] | -[UIKeyboardImpl setDelegate:force:] | -[UITextInteractionAssistant setGestureRecognizers] | -[UITextInteractionAssistant addTwoFingerRangedSelectRecognizer] | -[UILongPressGestureRecognizer initWithTarget:action:] | -[__NSPlaceholderSet init] | -[__NSPlaceholderSet initWithCapacity:] | __CFSetInit | _CFRuntimeCreateInstance | malloc_zone_malloc

    Read the article

  • Basic C question, concerning memory allocation and value assignment

    - by VHristov
    Hi there, I have recently started working on my master thesis in C that I haven't used in quite a long time. Being used to Java, I'm now facing all kinds of problems all the time. I hope someone can help me with the following one, since I've been struggling with it for the past two days. So I have a really basic model of a database: tables, tuples, attributes and I'm trying to load some data into this structure. Following are the definitions: typedef struct attribute { int type; char * name; void * value; } attribute; typedef struct tuple { int tuple_id; int attribute_count; attribute * attributes; } tuple; typedef struct table { char * name; int row_count; tuple * tuples; } table; Data is coming from a file with inserts (generated for the Wisconsin benchmark), which I'm parsing. I have only integer or string values. A sample row would look like: insert into table values (9205, 541, 1, 1, 5, 5, 5, 5, 0, 1, 9205, 10, 11, 'HHHHHHH', 'HHHHHHH', 'HHHHHHH'); I've "managed" to load and parse the data and also to assign it. However, the assignment bit is buggy, since all values point to the same memory location, i.e. all rows look identical after I've loaded the data. Here is what I do: char value[10]; // assuming no value is longer than 10 chars int i, j, k; table * data = (table*) malloc(sizeof(data)); data->name = "table"; data->row_count = number_of_lines; data->tuples = (tuple*) malloc(number_of_lines*sizeof(tuple)); tuple* current_tuple; for(i=0; i<number_of_lines; i++) { current_tuple = &data->tuples[i]; current_tuple->tuple_id = i; current_tuple->attribute_count = 16; // static in our system current_tuple->attributes = (attribute*) malloc(16*sizeof(attribute)); for(k = 0; k < 16; k++) { current_tuple->attributes[k].name = attribute_names[k]; // for int values: current_tuple->attributes[k].type = DB_ATT_TYPE_INT; // write data into value-field int v = atoi(value); current_tuple->attributes[k].value = &v; // for string values: current_tuple->attributes[k].type = DB_ATT_TYPE_STRING; current_tuple->attributes[k].value = value; } // ... } While I am perfectly aware, why this is not working, I can't figure out how to get it working. I've tried following things, none of which worked: memcpy(current_tuple->attributes[k].value, &v, sizeof(int)); This results in a bad access error. Same for the following code (since I'm not quite sure which one would be the correct usage): memcpy(current_tuple->attributes[k].value, &v, 1); Not even sure if memcpy is what I need here... Also I've tried allocating memory, by doing something like: current_tuple->attributes[k].value = (int *) malloc(sizeof(int)); only to get "malloc: * error for object 0x100108e98: incorrect checksum for freed object - object was probably modified after being freed." As far as I understand this error, memory has already been allocated for this object, but I don't see where this happened. Doesn't the malloc(sizeof(attribute)) only allocate the memory needed to store an integer and two pointers (i.e. not the memory those pointers point to)? Any help would be greatly appreciated! Regards, Vassil

    Read the article

  • Landscape orientation for UITabBarController?

    - by gingersnap
    The UITabBarController does not allow landscape orientation. So I used a subclass of UITabBarContoller (called RotatingTabBarController). Its sole purpose it to allow rotation by returning YES to shouldAutorotateToInterfaceOrientation call. The problem is that when you rotate the iPhone in simulator it gives the following malloc error. malloc: *** error for object 0x3888000: pointer being freed was not allocated *** set a breakpoint in malloc_error_break to debug I am using 3.0 SDK with Xcode 3.2 on Snow Leopard. I set a breakpoint in malloc_error_break but I can not trace it back to my code. Is there something I can do to make this error go away? Here is the RotatingTabBarController class: #import <UIKit/UIKit.h> @interface RotatingTabBarController : UITabBarController { } @end @implementation RotatingTabBarController -(BOOL)shouldAutorotateToInterfaceOrientation:UIInterfaceOrientation)interfaceOrientation { return YES; } @end Update: I tried the same with a category. But it gives the same malloc error. // UITabBarController+Rotation.h @interface UITabBarController (rotation) - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation; @end // UITabBarController+Rotation.m #import "UITabBarController+Rotation.h" @implementation UITabBarController (rotation) - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { return YES; } @end Backtrace [Session started at 2009-09-05 12:13:19 -0400.] Untitled(992,0xa06d9500) malloc: *** error for object 0x2024000: pointer being freed was not allocated *** set a breakpoint in malloc_error_break to debug Untitled(992,0xa06d9500) malloc: *** error for object 0x2014000: pointer being freed was not allocated *** set a breakpoint in malloc_error_break to debug [Session started at 2009-09-05 12:13:27 -0400.] GNU gdb 6.3.50-20050815 (Apple version gdb-1344) (Fri Jul 3 01:19:56 UTC 2009) Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "x86_64-apple-darwin".Attaching to process 992. sharedlibrary apply-load-rules all (gdb) bt #0 0x951908fa in mach_msg_trap () #1 0x95191067 in mach_msg () #2 0x30244d62 in CFRunLoopRunSpecific () #3 0x30244628 in CFRunLoopRunInMode () #4 0x32044c31 in GSEventRunModal () #5 0x32044cf6 in GSEventRun () #6 0x309021ee in UIApplicationMain () #7 0x00002608 in main (argc=1, argv=0xbfffef94) at /Users/vishwas/Desktop/Untitled/main.m:13 (gdb)

    Read the article

  • who free's setvbuf buffer?

    - by Evan Teran
    So I've been digging into how the stdio portion of libc is implemented and I've come across another question. Looking at man setvbuf I see the following: When the first I/O operation occurs on a file, malloc(3) is called, and a buffer is obtained. This makes sense, your program should have a malloc in it for I/O unless you actually use it. My gut reaction to this is that libc will clean up its own mess here. Which I can only assume it does because valgrind reports no memory leaks (they could of course do something dirty and not allocate it via malloc directly... but we'll assume that it literally uses malloc for now). But, you can specify your own buffer too... int main() { char *p = malloc(100); setvbuf(stdio, p, _IOFBF, 100); puts("hello world"); } Oh no, memory leak! valgrind confirms it. So it seems that whenever stdio allocates a buffer on its own, it will get deleted automatically (at the latest on program exit, but perhaps on stream close). But if you specify the buffer explicitly, then you must clean it up yourself. There is a catch though. The man page also says this: You must make sure that the space that buf points to still exists by the time stream is closed, which also happens at program termination. For example, the following is invalid: Now this is getting interesting for the standard streams. How would one properly clean up a manually allocated buffer for them, since they are closed in program termination? I could imagine a "clean this up when I close flag" inside the file struct, but it get hairy because if I read this right doing something like this: setvbuf(stdio, 0, _IOFBF, 100); printf("hello "); setvbuf(stdio, 0, _IOLBF, 100); printf("world\n"); would cause 2 allocations by the standard library because of this sentence: If the argument buf is NULL, only the mode is affected; a new buffer will be allocated on the next read or write operation.

    Read the article

  • Split string in C every white space

    - by redsolja
    I want to write a program in C that displays each word of a whole sentence (taken as input) at a seperate line. This is what i have done so far: void manipulate(char *buffer); int get_words(char *buffer); int main(){ char buff[100]; printf("sizeof %d\nstrlen %d\n", sizeof(buff), strlen(buff)); // Debugging reasons bzero(buff, sizeof(buff)); printf("Give me the text:\n"); fgets(buff, sizeof(buff), stdin); manipulate(buff); return 0; } int get_words(char *buffer){ // Function that gets the word count, by counting the spaces. int count; int wordcount = 0; char ch; for (count = 0; count < strlen(buffer); count ++){ ch = buffer[count]; if((isblank(ch)) || (buffer[count] == '\0')){ // if the character is blank, or null byte add 1 to the wordcounter wordcount += 1; } } printf("%d\n\n", wordcount); return wordcount; } void manipulate(char *buffer){ int words = get_words(buffer); char *newbuff[words]; char *ptr; int count = 0; int count2 = 0; char ch = '\n'; ptr = buffer; bzero(newbuff, sizeof(newbuff)); for (count = 0; count < 100; count ++){ ch = buffer[count]; if (isblank(ch) || buffer[count] == '\0'){ buffer[count] = '\0'; if((newbuff[count2] = (char *)malloc(strlen(buffer))) == NULL) { printf("MALLOC ERROR!\n"); exit(-1); } strcpy(newbuff[count2], ptr); printf("\n%s\n",newbuff[count2]); ptr = &buffer[count + 1]; count2 ++; } } } Although the output is what i want, i have really many black spaces after the final word displayed, and the malloc() returns NULL so the MALLOC ERROR! is displayed in the end. I can understand that there is a mistake at my malloc() implementation but i do not know what it is. Is there another more elegant - generally better way to do it? Thanks in advance.

    Read the article

  • Passing parameter to pthread

    - by Andrei Ciobanu
    Hello, i have the following code: #include <stdlib.h> #include <stdio.h> #include <pthread.h> #define NUM_THREADS 100 struct thread_param { char *f1; char *f2; int x; }; void *thread_function(void *arg){ printf("%d\n", ((struct thread_param*)arg)->x); } int main(int argc, char *argvs[]){ int i, thread_cr_res = 0; pthread_t *threads; threads = malloc(100 * sizeof(*threads)); if(threads == NULL){ fprintf(stderr,"MALLOC THREADS ERROR"); return (-1); } for(i = 0; i < NUM_THREADS; i++){ struct thread_param *tp; if((tp = malloc(sizeof(*tp))) == NULL){ fprintf(stderr,"MALLOC THREAD_PARAM ERROR"); return (-1); } tp->f1 = "f1"; tp->f2 = "f2"; tp->x = i; thread_cr_res = pthread_create(&threads[i], NULL, thread_function, (void*)tp); if(thread_cr_res != 0){ fprintf(stderr,"THREAD CREATE ERROR"); return (-1); } } return (0); } What i want to achieve, is to print all the numbers from 0 to 99, from threads. Also i am experimenting a way to pass a structure as a thread input parameter. What i am finding curios, is that not all the numbers are shown, eg: ./a.out | grep 9 9 19 29 39 49 And sometimes some numbers are shown twice: ... 75 74 89 77 78 79 91 91 Can you please explain me why is this happening ? No errors are shown.

    Read the article

  • How to store and remove dynamically and automatic variable of generic data type in custum list data

    - by Vineel Kumar Reddy
    Hi I have created a List data structure implementation for generic data type with each node declared as following. struct Node { void *data; .... .... } So each node in my list will have pointer to the actual data(generic could be anything) item that should be stored in the list. I have following signature for adding a node to the list AddNode(struct List *list, void* eledata); the problem is when i want to remove a node i want to free even the data block pointed by *data pointer inside the node structure that is going to be freed. at first freeing of datablock seems to be straight forward free(data) // forget about the syntax..... But if data is pointing to a block created by malloc then the above call is fine....and we can free that block using free function int *x = (int*) malloc(sizeof(int)); *x = 10; AddNode(list,(void*)x); // x can be freed as it was created using malloc what if a node is created as following int x = 10; AddNode(list,(void*)&x); // x cannot be freed as it was not created using malloc Here we cannot call free on variable x!!!! How do i know or implement the functionality for both dynamically allocated variables and static ones....that are passed to my list.... Thanks in advance...

    Read the article

  • struct to bidimensional struct pointer assigment in C

    - by argos.void
    i want to get work this code and i googled and asked in efnet and freenode but i didnt find the answer. what i want i to assign a struct woot to an another bidimensional struct woot *, and i need malloc to do that. then, how can i use malloc there and how to assign the struct? thanks. #include <stdio.h> struct omg { int foo; }; struct woot { struct omg *localfoo; int foo; }; int a = sizeof(struct woot); int main(void){ struct woot *what[10][10] = (struct woot *) malloc(100*a); struct omg hahaha[100]; hahaha[1].foo = 15; what[1][6].localfoo = &hahaha[1]; }

    Read the article

  • OpenAL causing leaks in my iPhone game. Help appreciated

    - by AptoTech
    Hi, I am integrating OpenAL in my iPhone game from code I found in this post, but the compiler gave me an error on this line of code: unsigned char *outData = malloc(fileSize);, so I changed it to this: unsigned char *outData = (unsigned char*) malloc(fileSize);. This got rid of the compiler errors, but seems to have thrown up two leaks: Malloc 32 Bytes 0x505cb40 AudioToolbox SimAggregateDevice::CreateAggregateDevice(__CFString const*, __CFString const*, unsigned long&) and NSCFDictionary 0x505be30 64 AudioToolbox SimAggregateDevice::CreateAggregateDevice(__CFString const*, __CFString const*, unsigned long&) Is this due to me changing the unsigned char line? I would be very grateful if someone could help me to remove these leaks.

    Read the article

  • c99 goto past initialization

    - by R Samuel Klatchko
    While debugging a crash, I came across this issue in some code: int func() { char *p1 = malloc(...); if (p1 == NULL) goto err_exit; char *p2 = malloc(...); if (p2 == NULL) goto err_exit; ... err_exit: free(p2); free(p1); return -1; } The problem occurs when the first malloc fails. Because we jump across the initialization of p2, it contains random data and the call to free(p2) can crash. I would expect/hope that this would be treated the same way as in C++ where the compiler does not allow a goto to jump across an initialization. My question: is jumping across an initialization allowed by the standard or is this a bug in gcc's implementation of c99?

    Read the article

  • C : Memory layout of C program execution

    - by pavun_cool
    Hi All , I wanted know how the kernel is providing memory for simple C program . For example : #include<stdio.h> #include<malloc.h> int my_global = 10 ; main() { char *str ; static int val ; str = ( char *) malloc ( 100 ) ; scanf ( "%s" , str ) ; printf( " val:%s\n",str ) ; } See, In this program I have used static , global and malloc for allocating dynamic memory So , how the memory lay out will be ... ? Any one give me url , which will have have details information about this process..

    Read the article

  • between syntax, are there any equal function

    - by gcc
    /* char **mainp=malloc(sizeof(char *)*2); mainp[0]=malloc(sizeof(char)*300); mainp[1]=malloc(sizeof(char )*300); */ *I have some input about propositional calculus *After calculating some math funtion-removing paranthesis-changing"&" with ","-replacing "|" with"," I have >> (1) P,-Q,Q,-R is stored in mainp[0] R,A,P,B,F is stored in mainp[1] *My question is: Between comma , I have want to compare two pointer array. If there is any equal two or more functions(Q,-R is function representation) ,function which you will show me how to write must return int. According to example (1),function will return 1 (I expect like that) /*I have som thought://which function should I have use:*/ in for loop if( strspn(mainp[0][i])==1 ) increment d; continue; or in for loop srtcmp(mainp[0][i],mainp[1]);

    Read the article

  • Pointer initialization doubt

    - by Jestin Joy
    We could initialize a character pointer like this in C. char *c="test"; Where c points to the first character(t). But when I gave code like below. It gives segmentation fault. #include<stdio.h> #include<stdlib.h> main() { int *i; *i=0; printf("%d",*i); } But when I give #include<stdio.h> #include<stdlib.h> main() { int *i; i=(int *)malloc(2); *i=0; printf("%d",*i); } It works( gives output 0). Also when I give malloc(0), It also works( gives output 0). Please tell what is happening

    Read the article

  • Performance triage

    - by Dave
    Folks often ask me how to approach a suspected performance issue. My personal strategy is informed by the fact that I work on concurrency issues. (When you have a hammer everything looks like a nail, but I'll try to keep this general). A good starting point is to ask yourself if the observed performance matches your expectations. Expectations might be derived from known system performance limits, prototypes, and other software or environments that are comparable to your particular system-under-test. Some simple comparisons and microbenchmarks can be useful at this stage. It's also useful to write some very simple programs to validate some of the reported or expected system limits. Can that disk controller really tolerate and sustain 500 reads per second? To reduce the number of confounding factors it's better to try to answer that question with a very simple targeted program. And finally, nothing beats having familiarity with the technologies that underlying your particular layer. On the topic of confounding factors, as our technology stacks become deeper and less transparent, we often find our own technology working against us in some unexpected way to choke performance rather than simply running into some fundamental system limit. A good example is the warm-up time needed by just-in-time compilers in Java Virtual Machines. I won't delve too far into that particular hole except to say that it's rare to find good benchmarks and methodology for java code. Another example is power management on x86. Power management is great, but it can take a while for the CPUs to throttle up from low(er) frequencies to full throttle. And while I love "turbo" mode, it makes benchmarking applications with multiple threads a chore as you have to remember to turn it off and then back on otherwise short single-threaded runs may look abnormally fast compared to runs with higher thread counts. In general for performance characterization I disable turbo mode and fix the power governor at "performance" state. Another source of complexity is the scheduler, which I've discussed in prior blog entries. Lets say I have a running application and I want to better understand its behavior and performance. We'll presume it's warmed up, is under load, and is an execution mode representative of what we think the norm would be. It should be in steady-state, if a steady-state mode even exists. On Solaris the very first thing I'll do is take a set of "pstack" samples. Pstack briefly stops the process and walks each of the stacks, reporting symbolic information (if available) for each frame. For Java, pstack has been augmented to understand java frames, and even report inlining. A few pstack samples can provide powerful insight into what's actually going on inside the program. You'll be able to see calling patterns, which threads are blocked on what system calls or synchronization constructs, memory allocation, etc. If your code is CPU-bound then you'll get a good sense where the cycles are being spent. (I should caution that normal C/C++ inlining can diffuse an otherwise "hot" method into other methods. This is a rare instance where pstack sampling might not immediately point to the key problem). At this point you'll need to reconcile what you're seeing with pstack and your mental model of what you think the program should be doing. They're often rather different. And generally if there's a key performance issue, you'll spot it with a moderate number of samples. I'll also use OS-level observability tools to lock for the existence of bottlenecks where threads contend for locks; other situations where threads are blocked; and the distribution of threads over the system. On Solaris some good tools are mpstat and too a lesser degree, vmstat. Try running "mpstat -a 5" in one window while the application program runs concurrently. One key measure is the voluntary context switch rate "vctx" or "csw" which reflects threads descheduling themselves. It's also good to look at the user; system; and idle CPU percentages. This can give a broad but useful understanding if your threads are mostly parked or mostly running. For instance if your program makes heavy use of malloc/free, then it might be the case you're contending on the central malloc lock in the default allocator. In that case you'd see malloc calling lock in the stack traces, observe a high csw/vctx rate as threads block for the malloc lock, and your "usr" time would be less than expected. Solaris dtrace is a wonderful and invaluable performance tool as well, but in a sense you have to frame and articulate a meaningful and specific question to get a useful answer, so I tend not to use it for first-order screening of problems. It's also most effective for OS and software-level performance issues as opposed to HW-level issues. For that reason I recommend mpstat & pstack as my the 1st step in performance triage. If some other OS-level issue is evident then it's good to switch to dtrace to drill more deeply into the problem. Only after I've ruled out OS-level issues do I switch to using hardware performance counters to look for architectural impediments.

    Read the article

  • Program using read() entering into an infinite loop

    - by Soham
    1oid ReadBinary(char *infile,HXmap* AssetMap) { int fd; size_t bytes_read, bytes_expected = 100000000*sizeof(char); char *data; if ((fd = open(infile,O_RDONLY)) < 0) err(EX_NOINPUT, "%s", infile); if ((data = malloc(bytes_expected)) == NULL) err(EX_OSERR, "data malloc"); bytes_read = read(fd, data, bytes_expected); if (bytes_read != bytes_expected) printf("Read only %d of %d bytes %d\n", \ bytes_read, bytes_expected,EX_DATAERR); /* ... operate on data ... */ printf("\n"); int i=0; int counter=0; char ch=data[0]; char message[512]; Message* newMessage; while(i!=bytes_read) { while(ch!='\n') { message[counter]=ch; i++; counter++; ch =data[i]; } message[counter]='\n'; message[counter+1]='\0'; //--------------------------------------------------- newMessage = (Message*)parser(message); MessageProcess(newMessage,AssetMap); //-------------------------------------------------- //printf("idNUM %e\n",newMessage->idNum); free(newMessage); i++; counter=0; ch =data[i]; } free(data); } Here, I have allocated 100MB of data with malloc, and passed a file big enough(not 500MB) size of 926KB about. When I pass small files, it reads and exits like a charm, but when I pass a big enough file, the program executes till some point after which it just hangs. I suspect it either entered an infinite loop, or there is memory leak. EDIT For better understanding I stripped away all unnecessary function calls, and checked what happens, when given a large file as input. I have attached the modified code void ReadBinary(char *infile,HXmap* AssetMap) { int fd; size_t bytes_read, bytes_expected = 500000000*sizeof(char); char *data; if ((fd = open(infile,O_RDONLY)) < 0) err(EX_NOINPUT, "%s", infile); if ((data = malloc(bytes_expected)) == NULL) err(EX_OSERR, "data malloc"); bytes_read = read(fd, data, bytes_expected); if (bytes_read != bytes_expected) printf("Read only %d of %d bytes %d\n", \ bytes_read, bytes_expected,EX_DATAERR); /* ... operate on data ... */ printf("\n"); int i=0; int counter=0; char ch=data[0]; char message[512]; while(i<=bytes_read) { while(ch!='\n') { message[counter]=ch; i++; counter++; ch =data[i]; } message[counter]='\n'; message[counter+1]='\0'; i++; printf("idNUM \n"); counter=0; ch =data[i]; } free(data); } What looks like is, it prints a whole lot of idNUM's and then poof segmentation fault I think this is an interesting behaviour, and to me it looks like there is some problem with memory FURTHER EDIT I changed back the i!=bytes_read it gives no segmentation fault. When I check for i<=bytes_read it blows past the limits in the innerloop.(courtesy gdb)

    Read the article

  • mysterical error

    - by Görkem Buzcu
    i get "customer_service_simulator.exe stopped" error, but i dont know why? this is my c programming project and i have limited time left before deadline. the code is: #include <stdio.h> #include <stdlib.h> #include<time.h> #define FALSE 0 #define TRUE 1 /*A Node declaration to store a value, pointer to the next node and a priority value*/ struct Node { int priority; //arrival time int val; //type int wait_time; int departure_time; struct Node *next; }; Queue Record that will store the following: size: total number of elements stored in the list front: it shows the front node of the queue (front of the queue) rear: it shows the rare node of the queue (rear of the queue) availability: availabity of the teller struct QueueRecord { struct Node *front; struct Node *rear; int size; int availability; }; typedef struct Node *niyazi; typedef struct QueueRecord *Queue; Queue CreateQueue(int); void MakeEmptyQueue(Queue); void enqueue(Queue, int, int); int QueueSize(Queue); int FrontOfQueue(Queue); int RearOfQueue(Queue); niyazi dequeue(Queue); int IsFullQueue(Queue); int IsEmptyQueue(Queue); void DisplayQueue(Queue); void sorteddequeue(Queue); void sortedenqueue(Queue, int, int); void tellerzfunctionz(Queue *, Queue, int, int); int main() { int system_clock=0; Queue waitqueue; int exit, val, priority, customers, tellers, avg_serv_time, sim_time,counter; char command; waitqueue = CreateQueue(0); srand(time(NULL)); fflush(stdin); printf("Enter number of customers, number of tellers, average service time, simulation time\n:"); scanf("%d%c %d%c %d%c %d",&customers, &command,&tellers,&command,&avg_serv_time,&command,&sim_time); fflush(stdin); Queue tellerarray[tellers]; for(counter=0;counter<tellers;counter++){ tellerarray[counter]=CreateQueue(0); //burada teller sayisi kadar queue yaratiyorum } for(counter=0;counter<customers;counter++){ priority=1+(int)rand()%sim_time; //this will generate the arrival time sortedenqueue(waitqueue,1,priority); //here i put the customers in the waiting queue } tellerzfunctionz(tellerarray,waitqueue,tellers,customers); DisplayQueue(waitqueue); DisplayQueue(tellerarray[0]); DisplayQueue(tellerarray[1]); // waitqueue-> printf("\n\n"); system("PAUSE"); return 0; } /*This function initialises the queue*/ Queue CreateQueue(int maxElements) { Queue q; q = (struct QueueRecord *) malloc(sizeof(struct QueueRecord)); if (q == NULL) printf("Out of memory space\n"); else MakeEmptyQueue(q); return q; } /*This function sets the queue size to 0, and creates a dummy element and sets the front and rear point to this dummy element*/ void MakeEmptyQueue(Queue q) { q->size = 0; q->availability=0; q->front = (struct Node *) malloc(sizeof(struct Node)); if (q->front == NULL) printf("Out of memory space\n"); else{ q->front->next = NULL; q->rear = q->front; } } /*Shows if the queue is empty*/ int IsEmptyQueue(Queue q) { return (q->size == 0); } /*Returns the queue size*/ int QueueSize(Queue q) { return (q->size); } /*Shows the queue is full or not*/ int IsFullQueue(Queue q) { return FALSE; } /*Returns the value stored in the front of the queue*/ int FrontOfQueue(Queue q) { if (!IsEmptyQueue(q)) return q->front->next->val; else { printf("The queue is empty\n"); return -1; } } /*Returns the value stored in the rear of the queue*/ int RearOfQueue(Queue q) { if (!IsEmptyQueue(q)) return q->rear->val; else { printf("The queue is empty\n"); return -1; } } /*Displays the content of the queue*/ void DisplayQueue(Queue q) { struct Node *pos; pos=q->front->next; printf("Queue content:\n"); printf("-->Priority Value\n"); while (pos != NULL) { printf("--> %d\t %d\n", pos->priority, pos->val); pos = pos->next; } } void enqueue(Queue q, int element, int priority){ if(IsFullQueue(q)){ printf("Error queue is full"); } else{ q->rear->next=(struct Node *)malloc(sizeof(struct Node)); q->rear=q->rear->next; q->rear->next=NULL; q->rear->val=element; q->rear->priority=priority; q->size++; } } void sortedenqueue(Queue q, int val, int priority) { struct Node *insert,*temp; insert=(struct Node *)malloc(sizeof(struct Node)); insert->val=val; insert->priority=priority; temp=q->front; if(q->size==0){ enqueue(q, val, priority); } else{ while(temp->next!=NULL && temp->next->priority<insert->priority){ temp=temp->next; } //printf("%d",temp->priority); insert->next=temp->next; temp->next=insert; q->size++; if(insert->next==NULL){ q->rear=insert; } } } niyazi dequeue(Queue q) { niyazi del; niyazi deli; del=(niyazi)malloc(sizeof(struct Node)); deli=(niyazi)malloc(sizeof(struct Node)); if(IsEmptyQueue(q)){ printf("Queue is empty!"); return NULL; } else { del=q->front->next; q->front->next=del->next; deli->val=del->val; deli->priority=del->priority; free(del); q->size--; return deli; } } void sorteddequeue(Queue q) { struct Node *temp; struct Node *min; temp=q->front->next; min=q->front; int i; for(i=1;i<q->size;i++) { if(temp->next->priority<min->next->priority) { min=temp; } temp=temp->next; } temp=min->next; min->next=min->next->next; free(temp); if(min->next==NULL){ q->rear=min; } q->size--; } void tellerzfunctionz(Queue *a, Queue b, int c, int d){ int i; int value=0; int priority; niyazi temp; temp=(niyazi)malloc(sizeof(struct Node)); if(c==1){ for(i=0;i<d;i++){ temp=dequeue(b); sortedenqueue((*(a)),temp->val,temp->priority); } } else{ for(i=0;i<d;i++){ while(b->front->next->val==1){ if((*(a+value))->availability==1){ temp=dequeue(b); sortedenqueue((*(a+value)),temp->val,temp->priority); (*(a+value))->rear->val=2; } else{ value++; } } } } } //end of the program

    Read the article

  • Memory not being freed, causing giant memory leak

    - by Delan Azabani
    In my Unicode library for C++, the ustring class has operator= functions set for char* values and other ustring values. When doing the simple memory leak test: #include <cstdio> #include "ucpp" main() { ustring a; for(;;)a="MEMORY"; } the memory used by the program grows uncontrollably (characteristic of a program with a big memory leak) even though I've added free() calls to both of the functions. I am unsure why this is ineffective (am I missing free() calls in other places?) This is the current library code: #include <cstdlib> #include <cstring> class ustring { int * values; long len; public: long length() { return len; } ustring() { len = 0; values = (int *) malloc(0); } ustring(const ustring &input) { len = input.len; values = (int *) malloc(sizeof(int) * len); for (long i = 0; i < len; i++) values[i] = input.values[i]; } ustring operator=(ustring input) { ustring result(input); free(values); len = input.len; values = input.values; return * this; } ustring(const char * input) { values = (int *) malloc(0); long s = 0; // s = number of parsed chars int a, b, c, d, contNeed = 0, cont = 0; for (long i = 0; input[i]; i++) if (input[i] < 0x80) { // ASCII, direct copy (00-7f) values = (int *) realloc(values, sizeof(int) * ++s); values[s - 1] = input[i]; } else if (input[i] < 0xc0) { // this is a continuation (80-bf) if (cont == contNeed) { // no need for continuation, use U+fffd values = (int *) realloc(values, sizeof(int) * ++s); values[s - 1] = 0xfffd; } cont = cont + 1; values[s - 1] = values[s - 1] | ((input[i] & 0x3f) << ((contNeed - cont) * 6)); if (cont == contNeed) cont = contNeed = 0; } else if (input[i] < 0xc2) { // invalid byte, use U+fffd (c0-c1) values = (int *) realloc(values, sizeof(int) * ++s); values[s - 1] = 0xfffd; } else if (input[i] < 0xe0) { // start of 2-byte sequence (c2-df) contNeed = 1; values = (int *) realloc(values, sizeof(int) * ++s); values[s - 1] = (input[i] & 0x1f) << 6; } else if (input[i] < 0xf0) { // start of 3-byte sequence (e0-ef) contNeed = 2; values = (int *) realloc(values, sizeof(int) * ++s); values[s - 1] = (input[i] & 0x0f) << 12; } else if (input[i] < 0xf5) { // start of 4-byte sequence (f0-f4) contNeed = 3; values = (int *) realloc(values, sizeof(int) * ++s); values[s - 1] = (input[i] & 0x07) << 18; } else { // restricted or invalid (f5-ff) values = (int *) realloc(values, sizeof(int) * ++s); values[s - 1] = 0xfffd; } len = s; } ustring operator=(const char * input) { ustring result(input); free(values); len = result.len; values = result.values; return * this; } ustring operator+(ustring input) { ustring result; result.len = len + input.len; result.values = (int *) malloc(sizeof(int) * result.len); for (long i = 0; i < len; i++) result.values[i] = values[i]; for (long i = 0; i < input.len; i++) result.values[i + len] = input.values[i]; return result; } ustring operator[](long index) { ustring result; result.len = 1; result.values = (int *) malloc(sizeof(int)); result.values[0] = values[index]; return result; } operator char * () { return this -> encode(); } char * encode() { char * r = (char *) malloc(0); long s = 0; for (long i = 0; i < len; i++) { if (values[i] < 0x80) r = (char *) realloc(r, s + 1), r[s + 0] = char(values[i]), s += 1; else if (values[i] < 0x800) r = (char *) realloc(r, s + 2), r[s + 0] = char(values[i] >> 6 | 0x60), r[s + 1] = char(values[i] & 0x3f | 0x80), s += 2; else if (values[i] < 0x10000) r = (char *) realloc(r, s + 3), r[s + 0] = char(values[i] >> 12 | 0xe0), r[s + 1] = char(values[i] >> 6 & 0x3f | 0x80), r[s + 2] = char(values[i] & 0x3f | 0x80), s += 3; else r = (char *) realloc(r, s + 4), r[s + 0] = char(values[i] >> 18 | 0xf0), r[s + 1] = char(values[i] >> 12 & 0x3f | 0x80), r[s + 2] = char(values[i] >> 6 & 0x3f | 0x80), r[s + 3] = char(values[i] & 0x3f | 0x80), s += 4; } return r; } };

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 4 5 6 7 8 9 10 11 12 13 14 15  | Next Page >