Search Results

Search found 21759 results on 871 pages for 'int 0'.

Page 456/871 | < Previous Page | 452 453 454 455 456 457 458 459 460 461 462 463 | Next Page >

including tk.h and tcl.h in c program

- by user362075

hi, i am working on an ubuntu system. My aim is to basically make an IDE in C language using GUI tools from TCL/TK. I installed tcl 8.4, tk8.4, tcl8.4-dev, tk8.4-dev and have the tk.h and tcl.h headers file in my system. But, when I am running a basic hello world program it's showing a hell lot of errors. include "tk.h" include "stdio.h" void hello() { puts("Hello C++/Tk!"); } int main(int, char *argv[]) { init(argv[0]); button(".b") -text("Say Hello") -command(hello); pack(".b") -padx(20) -pady(6); } Some of the errors are tkDecls.h:644: error: expected declaration specifiers before ‘EXTERN’ /usr/include/libio.h:488: error: expected ‘)’ before ‘*’ token In file included from tk.h:1559, from new1.c:1: tkDecls.h:1196: error: storage class specified for parameter ‘TkStubs’ tkDecls.h:1201: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘attribute’ before ‘*’ token /usr/include/stdio.h:145: error: storage class specified for parameter ‘stdin’ tk.h:1273: error: declaration for parameter ‘Tk_PhotoHandle’ but no such parameter Can anyone please tell me how can I rectify these errors? Please help...

Read the article
including tk.h and tcl.h in c program

- by user362075

hi, i am working on an ubuntu system. My aim is to basically make an IDE in C language using GUI tools from TCL/TK. I installed tcl 8.4, tk8.4, tcl8.4-dev, tk8.4-dev and have the tk.h and tcl.h headers file in my system. But, when I am running a basic hello world program it's showing a hell lot of errors. include "tk.h" include "stdio.h" void hello() { puts("Hello C++/Tk!"); } int main(int, char *argv[]) { init(argv[0]); button(".b") -text("Say Hello") -command(hello); pack(".b") -padx(20) -pady(6); } Some of the errors are tkDecls.h:644: error: expected declaration specifiers before ‘EXTERN’ /usr/include/libio.h:488: error: expected ‘)’ before ‘*’ token In file included from tk.h:1559, from new1.c:1: tkDecls.h:1196: error: storage class specified for parameter ‘TkStubs’ tkDecls.h:1201: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘attribute’ before ‘*’ token /usr/include/stdio.h:145: error: storage class specified for parameter ‘stdin’ tk.h:1273: error: declaration for parameter ‘Tk_PhotoHandle’ but no such parameter Can anyone please tell me how can I rectify these errors? Please help...

Read the article
using .NET web service (Dataset) from progress OpenEdge 4GL

- by jasperdmx

I created web service in C# .net with input parameter : DataSet in other side, i need to use this web service from progress OpenEdge 4GL 10.1 (not 10.2) the problem is Dataset in OpenEdge cant match with DataSet in .net. always return 0 in the result I'm C# programmer, so dont have deep knowledge in porgress. I did research in progress forum, but not a good result. any help ? thanks in advance. *codes***** //web service : C# .net [webmethod] public int getResult(DataSet ds) { DataTable tbl = ds.Tables["datas"]; int result=0; foreach (DataRow dr in tbl.Rows){ //only 1 record = 1 row result = Convert.toInt32(dr["field1"]); } return result; } //progress OpenEdge 10.1 --- create and fill temp-table : field1 = 30 and only 1 record --- create dataset and bind to temp-table --- connect to web service --- call webmethod : define variable result as integer no-undo. RUN getResult IN hPortType(INPUT dataset,OUTPUT result). message result view-as alert-box info button ok. --- RESULT ALWAYS 0 /****/ anyone know how to "bridge" dataset in progress openedge to .net dataset ? note: this web service works well if called from .net

Read the article
C++ Newbie: Passing an fstream to a function to read data

- by vgm64

I have a text file named num.txt who's only contents is the line 123. Then I have the following: void alt_reader(ifstream &file, char* line){ file.read(line, 3); cout << "First Time: " << line << endl; } int main() { ifstream inFile; int num; inFile.open("num.txt"); alt_reader(inFile, (char*)&num); cout << "Second Time: " << num << endl; } The output is: First Time: 123 Second Time: 3355185 Can you help me figure out how to get an fstream that is read in a function still assign the variable in main? I'm doing this because alt_reader really has a lot more to it, but this is the part I'm stuck on. Thanks a lot for the help.

Read the article
Debugging MinGW program with gdb on Windows, not terminating at assert failure

- by devil

How do I set up gdb on window so that it does not allow a program with assertion failure to terminate? I intend to check the stack trace and variables in the program. For example, running this test.cpp program compiled with MinGW 'g++ -g test.cpp -o test' in gdb: #include <cassert> int main(int argc, char ** argv) { assert(1==2); return 0; } Gives: $ gdb test.exe GNU gdb 6.8 Copyright (C) 2008 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "i686-pc-mingw32"... (gdb) r Starting program: f:\code/test.exe [New thread 4616.0x1200] Error: dll starting at 0x77030000 not found. Error: dll starting at 0x75f80000 not found. Error: dll starting at 0x77030000 not found. Error: dll starting at 0x76f30000 not found. Assertion failed: 1==2, file test.cpp, line 2 This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. Program exited with code 03. (gdb) I would like to be able to stop the program from terminating immediately, like how Visual Studio's debugger and gdb on Linux does it. I have done a search and found some stuff on trapping signals but I can't seem to find a good post on how to set up gdb to do this.

Read the article
C# - Alternative to System.Time.Timer, to call a function at a specific time.

- by Fábio Antunes

Hello everybody. I want to call a specific function on my C# application at a specific time. At first i thought about using a Timer (System.Time.Timer), but that soon became impossible to use. Why? Simple. The Timer Class requires a Interval in milliseconds, but considering that i might want the function to be executed, lets says in a week that would mean: 7 Days = 168 hours; 168 Hours = 10,080 minutes; 10,080 Minutes = 6,048,000 seconds; 6,048,000 Seconds = 6,048,000,000 milliseconds; So the Interval would be 6,048,000,000; Now lets remember that the Interval accepted data type is int, and as we know int range goes from -2,147,483,648 to 2,147,483,647. That makes Timer useless in this case once we cannot set a Interval bigger that 2,147,483,647 milliseconds. So i need a solution where i could specify when the function should be called. Something like this: solution.ExecuteAt = "30-04-2010 15:10:00"; solution.Function = "functionName"; solution.Start(); So when the System Time would reach "30-04-2010 15:10:00" the function would be executed in the application. How can this problem be solved? Thanks just by taking the time to read my question. But if you could provide me with some help i would be most grateful. Additional Info: What these functions will do? Getting climate information and based on that info: Starting / Shutting down other Applications (most of them Console Based); Sending custom Commands to those Console Applications; Power down, Rebooting, Sleep, Hibernate the computer; And if possible schedule the BIOS to Power Up the Computer;

Read the article
Webdev.Webserver has stopped working

- by Alexander

When I execute the code saveXML below it generates the error above, why?? using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Xml.Serialization; using System.IO; /// <summary> /// Summary description for Post /// </summary> public class Post { private int postIDCounter = 0; private String DateCreated; public Post() { Author = "unknown"; Title = "unkown"; Content = ""; DateCreated = DateTime.Now.ToString(); ID = postIDCounter++; } public int ID { get { return ID; } set { if (ID != value) ID = value; } } public string Author { get { return Author; } set { if (Author != value) Author = value; } } public string Title { get { return Title; } set { if (Title != value) Title = value; } } public string Content { get { return Content; } set { if (Content != value) Content = value; } } public void saveXML() { XmlSerializer serializer = new XmlSerializer(typeof(Post)); Stream writer = new FileStream("..'\'App_Data'\'posts'\'" + new Guid(ID.ToString()).ToString() + ".xml", FileMode.Create); serializer.Serialize(writer, this); writer.Close(); } }

Read the article
Problem counting item frequency on T-SQL

- by Raúl Roa

I'm trying to count the frequency of numbers from 1 to 100 on different fields of a table. Let's say I have the table "Results" with the following data: LottoId Winner Second Third --------- --------- --------- --------- 1 1 2 3 2 1 2 3 I'd like to be able to get the frequency per numbers. For that I'm using the following code: --Creating numbers temp table CREATE TABLE #Numbers( Number int) --Inserting the numbers into the temp table declare @counter int set @counter = 0 while @counter < 100 begin set @counter = @counter + 1 INSERT INTO #Numbers(Number) VALUES(@counter) end -- SELECT #Numbers.Number, Count(Results.Winner) as Winner,Count(Results.Second) as Second, Count(Results.Third) as Third FROM #Numbers LEFT JOIN Results ON #Numbers.Number = Results.Winner OR #Numbers.Number = Results.Second OR #Numbers.Number = Results.Third GROUP BY #Numbers.Number The problem is that the counts are repeating the same values for each number. In this particular case I'm getting the following result: Number Winner Second Third --------- --------- --------- --------- 1 2 2 2 2 2 2 2 3 2 2 2 ... When I should get this: Number Winner Second Third --------- --------- --------- --------- 1 2 0 0 2 0 2 0 3 0 0 2 ... What am I missing?

Read the article
AudioFileWriteBytes fails with error code -40

- by alexbw

I'm trying to write raw audio bytes to a file using AudioFileWriteBytes(). Here's what I'm doing: void writeSingleChannelRingBufferDataToFileAsSInt16(AudioFileID audioFileID, AudioConverterRef audioConverter, ringBuffer *rb, SInt16 *holdingBuffer) { // First, figure out which bits of audio we'll be // writing to file from the ring buffer UInt32 lastFreshSample = rb->lastWrittenIndex; OSStatus status; int numSamplesToWrite; UInt32 numBytesToWrite; if (lastFreshSample < rb->lastReadIndex) { numSamplesToWrite = kNumPointsInWave + lastFreshSample - rb->lastReadIndex - 1; } else { numSamplesToWrite = lastFreshSample - rb->lastReadIndex; } numBytesToWrite = numSamplesToWrite*sizeof(SInt16); Then we copy the audio data (stored as floats) to a holding buffer (SInt16) that will be written directly to the file. The copying looks funky because it's from a ring buffer. UInt32 buffLen = rb->sizeOfBuffer - 1; for (int i=0; i < numSamplesToWrite; ++i) { holdingBuffer[i] = rb->data[(i + rb->lastReadIndex) & buffLen]; } Okay, now we actually try to write the audio from the SInt16 buffer "holdingBuffer" to the audio file. The NSLog will spit out an error -40, but also claims that it's writing bytes. No data is written to file. status = AudioFileWriteBytes(audioFileID, NO, 0, &numBytesToWrite, &holdingBuffer); rb->lastReadIndex = lastFreshSample; NSLog(@"Error = %d, wrote %d bytes", status, numBytesToWrite); return;

Read the article
Cannot Cache NHibernate Future Criteria Results

- by Emilian

I have the following code: public void FuturesQuery() { using (var session = SessionFactory.OpenSession()) { var blogs = session.CreateCriteria<Blog>() .SetMaxResults(5) .SetCacheable(true) .SetCacheMode(CacheMode.Normal) .SetCacheRegion("BlogQuery") .Future<Blog>(); var countOfBlogs = session.CreateCriteria<Blog>() .SetProjection(Projections.Count(Projections.Id())) .SetCacheable(true) .SetCacheMode(CacheMode.Normal) .SetCacheRegion("BlogQuery") .FutureValue<int>(); Console.WriteLine("Number of blogs: {0}", countOfBlogs.Value); foreach (var blog in blogs) { Console.WriteLine(blog.Title); } } using (var session = SessionFactory.OpenSession()) { var blogs = session.CreateCriteria<Blog>() .SetMaxResults(5) .SetCacheable(true) .SetCacheMode(CacheMode.Normal) .SetCacheRegion("BlogQuery") .Future<Blog>(); var countOfBlogs = session.CreateCriteria<Blog>() .SetProjection(Projections.Count(Projections.Id())) .SetCacheable(true) .SetCacheMode(CacheMode.Normal) .SetCacheRegion("BlogQuery") .FutureValue<int>(); Console.WriteLine("Number of blogs: {0}", countOfBlogs.Value); foreach (var blog in blogs) { Console.WriteLine(blog.Title); } } } I was expecting that the second time I query for blogs and count of blogs I will get values from cache but instead the queries hit the database. If I don't use Futures I get the expected results. Does this means that results from Criteria using futures cannot be cached?

Read the article
How to pass a value from a method to property procedure in c#?

- by sameer

Here is my code: The jewellery class is my main class in which i am inheriting a connection string class. class Jewellery : Connectionstr { string lmcode; public string LM_code/**/Here i want to access the value of the method ReadData i.e displaystring and i want to store this value in the insert query below.** { get { return lmcode; } set { lmcode = value; } } string mname; public string M_Name { get { return mname; } set { mname = value; } } string desc; public string Desc { get { return desc; } set { desc = value; } } public string ReadData() { OleDbDataReader dr; string jid = string.Empty; string displayString = string.Empty; String query = "select max(LM_code)from Master_Accounts"; Datamanager.RunExecuteReader(Constr, query); if (dr.Read()) { jid = dr[0].ToString(); if (string.IsNullOrEmpty(jid)) { jid = "AM0000"; } int len = jid.Length; string split = jid.Substring(2, len - 2); int num = Convert.ToInt32(split); num++; displayString = jid.Substring(0, 2) + num.ToString("0000"); dr.Close(); } **return displayString;** I want to pass this value to the above property procedure above i.e LM_code. } public void add() { String query ="insert into Master_Accounts values ('" + LM_code + "','" + M_Name + "'," + "'" + Desc + "')"; Datamanager.RunExecuteNonQuery(Constr , query);// } If possible can u edit this code! Anticipated thanks by sameer

Read the article
java regex: capture multiline sequence between tokens

- by Guillaume

I'm struggling with regex for splitting logs files into log sequence in order to match pattern inside these sequences. log format is: timestamp fieldA fieldB fieldn log message1 timestamp fieldA fieldB fieldn log message2 log message2bis timestamp fieldA fieldB fieldn log message3 The timestamp regex is known. I want to extract every log sequence (potentialy multiline) between timestamps. And I want to keep the timestamp. I want in the same time to keep the exact count of lines. What I need is how to decorate timestamp pattern to make it split my log file in log sequence. I can not split the whole file as a String, since the file content is provided in a CharBuffer Here is sample method that will be using this log sequence matcher: private void matches(File f, CharBuffer cb) { Matcher sequenceBreak = sequencePattern.matcher(cb); // sequence matcher int lines = 1; int sequences = 0; while (sequenceBreak.find()) { sequences++; String sequence = sequenceBreak.group(); if (filter.accept(sequence)) { System.out.println(f + ":" + lines + ":" + sequence); } //count lines Matcher lineBreak = LINE_PATTERN.matcher(sequence); while (lineBreak.find()) { lines++; } if (sequenceBreak.end() == cb.limit()) { break; } } }

Read the article
Ajax Autocompleteextender not showing the autocompletelist to choose

- by subash

i was working ajax auto completeextender witha text box in asp.net and c#.net. i am not able to get list to choose ,i have the appropriate web service method called..can anyone guide me to get the automo complete done. <form id="form1" runat="server"> <asp:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server"> </asp:ToolkitScriptManager> <div> <asp:AutoCompleteExtender runat="server" ID="autoComplete1" TargetControlID="TextBox1" ServiceMethod="GetCompletionList" ServicePath="AutoComplete.asmx" MinimumPrefixLength="0" CompletionInterval="50" EnableCaching="true" CompletionSetCount="1" DelimiterCharacters=";, :" ShowOnlyCurrentWordInCompletionListItem="true"> </asp:AutoCompleteExtender> <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox> </div> </form> and the web service method contains the following code [WebService(Namespace = "http://tempuri.org/")] [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)] [System.ComponentModel.ToolboxItem(false)] [ScriptService] // To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. // [System.Web.Script.Services.ScriptService] public class AutoComplete : System.Web.Services.WebService { [WebMethod] public string HelloWorld() { return "Hello World"; } [WebMethod] public string[] GetCompletionList(string prefixText, int count) { List<string> responses = new List<string>(); for (int i = 0; i < count; i++) responses.Add(prefixText + (char)(i + 65)); return responses.ToArray(); } }

Read the article
GZIP Java vs .NET

- by Jim Jones

Using the following Java code to compress/decompress bytes[] to/from GZIP. First text bytes to gzip bytes: public static byte[] fromByteToGByte(byte[] bytes) { ByteArrayOutputStream baos = null; try { ByteArrayInputStream bais = new ByteArrayInputStream(bytes); baos = new ByteArrayOutputStream(); GZIPOutputStream gzos = new GZIPOutputStream(baos); byte[] buffer = new byte[1024]; int len; while((len = bais.read(buffer)) >= 0) { gzos.write(buffer, 0, len); } gzos.close(); baos.close(); } catch (IOException e) { e.printStackTrace(); } return(baos.toByteArray()); } Then the method that goes the other way compressed bytes to uncompressed bytes: public static byte[] fromGByteToByte(byte[] gbytes) { ByteArrayOutputStream baos = null; ByteArrayInputStream bais = new ByteArrayInputStream(gbytes); try { baos = new ByteArrayOutputStream(); GZIPInputStream gzis = new GZIPInputStream(bais); byte[] bytes = new byte[1024]; int len; while((len = gzis.read(bytes)) > 0) { baos.write(bytes, 0, len); } } catch (IOException e) { e.printStackTrace(); } return(baos.toByteArray()); } Think there is any effect since I'm not writing out to a gzip file? Also I noticed that in the standard C# function that BitConverter reads the first four bytes and then the MemoryStream Write function is called with a start point of 4 and a length of input buffer length - 4. So is that effect the validity of the header? Jim

Read the article
Android: how to tell if a view is scrolling

- by Dave

in iPhone, this would be simple---each view has a scrollViewDidScroll method. I am trying to find the equivalent in Android. My code works, but it isn't giving me what I want. I need to execute code the entire duration that a view is scrolling. So, even though I use OnGestureListener's onScroll method, it only fires when the finger is on the screen (it's not really named correctly---it should be called "onSlide" or "onSwipe", focusing on the gesture rather than the UI animation). It does not continue to fire if the user flicks the view and it is still scrolling for a few moments after the user lifts his finger. is there a method that is called at every step of the scroll? public class Scroll extends Activity implements OnGestureListener { public WebView webview; public GestureDetector gestureScanner; public int currentYPosition; public int lastYPosition; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); webview = new WebView(this); setContentView(webview); webview.loadUrl("file:///android_asset/Scroll.html"); gestureScanner = new GestureDetector(this); currentYPosition = 0; lastYPosition = 0; } public boolean onTouchEvent(final MotionEvent me) { return gestureScanner.onTouchEvent(me); } public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { // I do stuff here. return true; }

Read the article
Use of for_each on map elements

- by Antonio

I have a map where I'd like to perform a call on every data type object member function. I yet know how to do this on any sequence but, is it possible to do it on an associative container? The closest answer I could find was this: Boost.Bind to access std::map elements in std::for_each. But I cannot use boost in my project so, is there an STL alternative that I'm missing to boost::bind? If not possible, I thought on creating a temporary sequence for pointers to the data objects and then, call for_each on it, something like this: class MyClass { public: void Method() const; } std::map<int, MyClass> Map; //... std::vector<MyClass*> Vector; std::transform(Map.begin(), Map.end(), std::back_inserter(Vector), std::mem_fun_ref(&std::map<int, MyClass>::value_type::second)); std::for_each(Vector.begin(), Vector.end(), std::mem_fun(&MyClass::Method)); It looks too obfuscated and I don't really like it. Any suggestions?

Read the article
Database warehoue design: fact tables and dimension tables

- by morpheous

I am building a poor man's data warehouse using a RDBMS. I have identified the key 'attributes' to be recorded as: sex (true/false) demographic classification (A, B, C etc) place of birth date of birth weight (recorded daily): The fact that is being recorded My requirements are to be able to run 'OLAP' queries that allow me to: 'slice and dice' 'drill up/down' the data and generally, be able to view the data from different perspectives After reading up on this topic area, the general consensus seems to be that this is best implemented using dimension tables rather than normalized tables. Assuming that this assertion is true (i.e. the solution is best implemented using fact and dimension tables), I would like to see some help in the design of these tables. 'Natural' (or obvious) dimensions are: Date dimension Geographical location Which have hierarchical attributes. However, I am struggling with how to model the following fields: sex (true/false) demographic classification (A, B, C etc) The reason I am struggling with these fields is that: They have no obvious hierarchical attributes which will aid aggregation (AFAIA) - which suggest they should be in a fact table They are mostly static or very rarely change - which suggests they should be in a dimension table. Maybe the heuristic I am using above is too crude? I will give some examples on the type of analysis I would like to carryout on the data warehouse - hopefully that will clarify things further. I would like to aggregate and analyze the data by sex and demographic classification - e.g. answer questions like: How does male and female weights compare across different demographic classifications? Which demographic classification (male AND female), show the most increase in weight this quarter. etc. Can anyone clarify whether sex and demographic classification are part of the fact table, or whether they are (as I suspect) dimension tables.? Also assuming they are dimension tables, could someone elaborate on the table structures (i.e. the fields)? The 'obvious' schema: CREATE TABLE sex_type (is_male int); CREATE TABLE demographic_category (id int, name varchar(4)); may not be the correct one.

Read the article
Suppress task switch keys (winkey, alt-tab, alt-esc, ctrl-esc) using low-level keyboard hook

- by matt

I'm trying to suppress task switch keys (such as winkey, alt-tab, alt-esc, ctrl-esc, etc.) by using a low-level keyboard hook. I'm using the following LowLevelKeyboardProc callback: IntPtr HookCallback(int nCode, IntPtr wParam, ref KBDLLHOOKSTRUCT lParam) { if (nCode >= 0) { bool suppress = false; // Suppress left and right windows keys. if (lParam.Key == VK_LWIN || lParam.Key == VK_RWIN) suppress = true; // Suppress alt-tab. if (lParam.Key == VK_TAB && HasAltModifier(lParam.Flags)) suppress = true; // Suppress alt-escape. if (lParam.Key == VK_ESCAPE && HasAltModifier(lParam.Flags)) suppress = true; // Suppress ctrl-escape. /* How do I hook CTRL-ESCAPE ? */ // Suppress keys by returning 1. if (suppress) return new IntPtr(1); } return CallNextHookEx(HookID, nCode, wParam, ref lParam); } bool HasAltModifier(int flags) { return (flags & 0x20) == 0x20; } However, I'm at a loss as to how to suppress the CTRL-ESC combination. Any suggestions? Thanks.

Read the article
What Qt container class to use for a sorted list?

- by Dave

Part of my application involves rendering audio waveforms. The user will be able to zoom in/out of the waveform. Starting at fully zoomed-out, I only want to sample the audio at the necessary internals to draw the waveform at the given resolution. Then, when they zoom in, asynchronously resample the "missing points" and provide a clearer waveform. (Think Google Maps.) I'm not sure the best data structure to use in Qt world. Ideally, I would like to store data samples sorted by time, but with the ability to fill-in points as needed. So, for example, the data points might initially look like: data[0 ms] = 10 data[10 ms] = 32 data[20 ms] = 21 ... But when they zoom in, I would get more points as necessary, perhaps: data[0 ms] = 10 data[2 ms] = 11 data[4 ms] = 18 data[6 ms] = 30 data[10 ms] = 32 data[20 ms] = 21 ... Note that the values in brackets are lookup values (milliseconds), not array indices. In .Net I might have used a SortedList<int, int>. What would be the best class to use in Qt? Or should I use a STL container?

Read the article
How to make Stack.Pop threadsafe

- by user260197

I am using the BlockingQueue code posted in this question, but realized I needed to use a Stack instead of a Queue given how my program runs. I converted it to use a Stack and renamed the class as needed. For performance I removed locking in Push, since my producer code is single threaded. My problem is how can thread working on the (now) thread safe Stack know when it is empty. Even if I add another thread safe wrapper around Count that locks on the underlying collection like Push and Pop do, I still run into the race condition that access Count and then Pop are not atomic. Possible solutions as I see them (which is preferred and am I missing any that would work better?): Consumer threads catch the InvalidOperationException thrown by Pop(). Pop() return a nullptr when _stack-Count == 0, however C++-CLI does not have the default() operator ala C#. Pop() returns a boolean and uses an output parameter to return the popped element. Here is the code I am using right now: generic <typename T> public ref class ThreadSafeStack { public: ThreadSafeStack() { _stack = gcnew Collections::Generic::Stack<T>(); } public: void Push(T element) { _stack->Push(element); } T Pop(void) { System::Threading::Monitor::Enter(_stack); try { return _stack->Pop(); } finally { System::Threading::Monitor::Exit(_stack); } } public: property int Count { int get(void) { System::Threading::Monitor::Enter(_stack); try { return _stack->Count; } finally { System::Threading::Monitor::Exit(_stack); } } } private: Collections::Generic::Stack<T> ^_stack; };

Read the article
Clearing canvas with Canvas.drawColor()

- by strangeInAStrangerLand

I'm attempting to change the background image of a custom View with some success. The image will change but the problem is that I still see traces of the old image. When I attempt to clear the canvas before drawing the new image, it doesn't appear to work. I create a bitmap to store the image. When changing the image, I call Canvas.drawColor() before drawing the new image but the old image persists. I've tried drawColor(0), drawColor(Color.BLACK), c.drawColor(0, PorterDuff.Mode.CLEAR), and none of the above works. As such, I had to post this for review from more experienced minds than mine. The actual code is as follows: private int bgnd; private boolean switching; public void setBgnd(int incoming){ switching = true; switch (incoming){ case R.drawable.image1: bgnd = incoming; this.invalidate(); break; case R.drawable.image2: bgnd = incoming; this.invalidate(); break; } } protected void onDraw(Canvas c){ if(switching == true){ Bitmap b = BitmapFactory.decodeResource(getResources(), bgnd); c.drawColor(0, PorterDuff.Mode.CLEAR); c.drawBitmap(b, 0, 0, null); switching = false; }else{ Bitmap b = BitmapFactory.decodeResource(getResources(), bgnd); c.drawBitmap(b, 0, 0, null); } }

Read the article
valgrind complains doing a very simple strtok in c

- by monkeyking

Hi I'm trying to tokenize a string by loading an entire file into a char[] using fread. For some strange reason it is not always working, and valgrind complains in this very small sample program. Given an input like test.txt first second And the following program #include <stdio.h> #include <string.h> #include <stdlib.h> #include <sys/stat.h> //returns the filesize in bytes size_t fsize(const char* fname){ struct stat st ; stat(fname,&st); return st.st_size; } int main(int argc, char *argv[]){ FILE *fp = NULL; if(NULL==(fp=fopen(argv[1],"r"))){ fprintf(stderr,"\t-> Error reading file:%s\n",argv[1]); return 0; } char buffer[fsize(argv[1])]; fread(buffer,sizeof(char),fsize(argv[1]),fp); char *str = strtok(buffer," \t\n"); while(NULL!=str){ fprintf(stderr,"token is:%s with strlen:%lu\n",str,strlen(str)); str = strtok(NULL," \t\n"); } return 0; } compiling like gcc test.c -std=c99 -ggdb running like ./a.out test.txt thanks

Read the article
PostgreSQL: Rolling back a transaction within a plpgsql function?

- by jamieb

Coming from the MS SQL world, I tend to make heavy use of stored procedures. I'm currently writing an application uses a lot of PostgreSQL plpgsql functions. What I'd like to do is rollback all INSERTS/UPDATES contained within a particular function if I get an exception at any point within it. I was originally under the impression that each function is wrapped in it's own transaction and that an exception would automatically rollback everything. However, that doesn't seem to be the case. I'm wondering if I ought to be using savepoints in combination with exception handling instead? But I don't really understand the difference between a transaction and a savepoint to know if this is the best approach. Any advice please? CREATE OR REPLACE FUNCTION do_something( _an_input_var int ) RETURNS bool AS $$ DECLARE _a_variable int; BEGIN INSERT INTO tableA (col1, col2, col3) VALUES (0, 1, 2); INSERT INTO tableB (col1, col2, col3); VALUES (0, 1, 'whoops! not an integer'); -- The exception will cause the function to bomb, but the values -- inserted into "tableA" are not rolled back. RETURN True; END; $$ LANGUAGE plpgsql;

Read the article
Parsing a string, Grammar file.

- by defn

How would I separate the below string into its parts. What I need to separate is each < Word including the angle brackets from the rest of the string. So in the below case I would end up with several strings 1. "I have to break up with you because " 2. "< reason " (without the spaces) 3. " . But Let's still " 4. "< disclaimer " 5. " ." I have to break up with you because <reason> . But let's still <disclaimer> . below is what I currently have (its ugly...) boolean complete = false; int begin = 0; int end = 0; while (complete == false) { if (s.charAt(end) == '<'){ stack.add(new Terminal(s.substring(begin, end))); begin = end; } else if (s.charAt(end) == '>') { stack.add(new NonTerminal(s.substring(begin, end))); begin = end; end++; } else if (end == s.length()){ if (isTerminal(getSubstring(s, begin, end))){ stack.add(new Terminal(s.substring(begin, end))); } else { stack.add(new NonTerminal(s.substring(begin, end))); } complete = true; } end++;

Read the article
Better why of looping to detect change.

- by Dremation

As of now I'm using a while(true) method to detect changes in memory. The problem with this is it's kill the applications performance. I have a list of 30 pointers that need checked as rapidly as possible for changes, without sacrificing a huge performance loss. Anyone have ideas on this? memScan = new Thread(ScanMem); public static void ScanMem() { int i = addy.Length; while (true) { Thread.Sleep(30000); //I do this to cut down on cpu usage for (int j = 0; j < i; j++) { string[] values = addy[j].Split(new char[] { Convert.ToChar(",") }); //MessageBox.Show(values[2]); try { if (Memory.Scanner.getIntFromMem(hwnd, (IntPtr)Convert.ToInt32(values[0], 16), 32).ToString() != values[1].ToString()) { //Ok, it changed lets do our work //work if (Globals.Working) return; SomeFunction("Results: " + values[2].ToString(), "Memory"); Globals.Working = true; }//end if }//end try catch { } }//end for }//end while }//end void

Read the article

< Previous Page | 452 453 454 455 456 457 458 459 460 461 462 463 | Next Page >