Search Results

Search found 140 results on 6 pages for 'decrement'.

Page 5/6 | < Previous Page | 1 2 3 4 5 6  | Next Page >

  • Extended slice that goes to beginning of sequence with negative stride

    - by recursive
    Bear with me while I explain my question. Skip down to the bold heading if you already understand extended slice list indexing. In python, you can index lists using slice notation. Here's an example: >>> A = list(range(10)) >>> A[0:5] [0, 1, 2, 3, 4] You can also include a stride, which acts like a "step": >>> A[0:5:2] [0, 2, 4] The stride is also allowed to be negative, meaning the elements are retrieved in reverse order: >>> A[5:0:-1] [5, 4, 3, 2, 1] But wait! I wanted to see [4, 3, 2, 1, 0]. Oh, I see, I need to decrement the start and end indices: >>> A[4:-1:-1] [] What happened? It's interpreting -1 as being at the end of the array, not the beginning. I know you can achieve this as follows: >>> A[4::-1] [4, 3, 2, 1, 0] But you can't use this in all cases. For example, in a method that's been passed indices. My question is: Is there any good pythonic way of using extended slices with negative strides and explicit start and end indices that include the first element of a sequence? This is what I've come up with so far, but it seems unsatisfying. >>> A[0:5][::-1] [4, 3, 2, 1, 0]

    Read the article

  • How can I merge two Linq IEnumerable<T> queries without running them?

    - by makerofthings7
    How do I merge a List<T> of TPL-based tasks for later execution? public async IEnumerable<Task<string>> CreateTasks(){ /* stuff*/ } My assumption is .Concat() but that doesn't seem to work: void MainTestApp() // Full sample available upon request. { List<string> nothingList = new List<string>(); nothingList.Add("whatever"); cts = new CancellationTokenSource(); delayedExecution = from str in nothingList select AccessTheWebAsync("", cts.Token); delayedExecution2 = from str in nothingList select AccessTheWebAsync("1", cts.Token); delayedExecution = delayedExecution.Concat(delayedExecution2); } /// SNIP async Task AccessTheWebAsync(string nothing, CancellationToken ct) { // return a Task } I want to make sure that this won't spawn any task or evaluate anything. In fact, I suppose I'm asking "what logically executes an IQueryable to something that returns data"? Background Since I'm doing recursion and I don't want to execute this until the correct time, what is the correct way to merge the results if called multiple times? If it matters I'm thinking of running this command to launch all the tasks var AllRunningDataTasks = results.ToList(); followed by this code: while (AllRunningDataTasks.Count > 0) { // Identify the first task that completes. Task<TableResult> firstFinishedTask = await Task.WhenAny(AllRunningDataTasks); // ***Remove the selected task from the list so that you don't // process it more than once. AllRunningDataTasks.Remove(firstFinishedTask); // TODO: Await the completed task. var taskOfTableResult = await firstFinishedTask; // Todo: (doen't work) TrustState thisState = (TrustState)firstFinishedTask.AsyncState; // TODO: Update the concurrent dictionary with data // thisState.QueryStartPoint + thisState.ThingToSearchFor Interlocked.Decrement(ref thisState.RunningDirectQueries); Interlocked.Increment(ref thisState.CompletedDirectQueries); if (thisState.RunningDirectQueries == 0) { thisState.TimeCompleted = DateTime.UtcNow; } }

    Read the article

  • Java Days & Bookings

    - by sys_debug
    Ok this is an extension of a question I asked about earlier yet this is the next step that is unclear to me. Everything else will be ready and this part is driving me mad! some members provided great help and I already made progress with that info, but this is just another obstacle. I am creating a booking object (as was suggested) that will have a start date and end date. each booking will also have a number of seats associated with it (that I require to reserve). The total available number of seats any given day 46 (as the total capacity of the hall is 46 seats). so in assumption that I have a booking to be made in the system, and start date is 1st jan and end date is 10th jan. The question is how can I check the remaining seats in all those days between the range to see if requested number could be hosted or not? and then when the second booking is made, it will have to see that the days in this range already have less than 46 and decrement further if possible to host the reservation. one of the members, and I appreciate his effort, gladly contributed a method to compare if this booking is after or before the existing bookings. The code provided is here: public boolean overlapsWithExisting(Booking booking) { final Date early = booking.getStart(); final Date late = booking.getEnd(); for(Booking existing : existingBookings) { if(!(early.isAfter(existing.getEnd() || late.isBefore(existing.getStart())) return true; } return false; } I just want to know how to associate 46 with each day and keep record of days that are decremented by bookings. Thanks and reallllllly appreciated :D

    Read the article

  • Asynchronous Controller is blocking requests in ASP.NET MVC through jQuery

    - by Jason
    I have just started using the AsyncController in my project to take care of some long-running reports. Seemed ideal at the time since I could kick off the report and then perform a few other actions while waiting for it to come back and populate elements on the screen. My controller looks a bit like this. I tried to use a thread to perform the long task which I'd hoped would free up the controller to take more requests: public class ReportsController : AsyncController { public void LongRunningActionAsync() { AsyncManager.OutstandingOperations.Increment(); var newThread = new Thread(LongTask); newThread.Start(); } private void LongTask() { // Do something that takes a really long time //....... AsyncManager.OutstandingOperations.Decrement(); } public ActionResult LongRunningActionCompleted(string message) { // Set some data up on the view or something... return View(); } public JsonResult AnotherControllerAction() { // Do a quick task... return Json("..."); } } But what I am finding is that when I call LongRunningAction using the jQuery ajax request, any further requests I make after that back up behind it and are not processed until LongRunningAction completes. For example, call LongRunningAction which takes 10 seconds and then call AnotherControllerAction which is less than a second. AnotherControllerAction simply waits until LongRunningAction completes before returning a result. I've also checked the jQuery code, but this still happens if I specifically set "async: true": $.ajax({ async: true, type: "POST", url: "/Reports.aspx/LongRunningAction", dataType: "html", success: function(data, textStatus, XMLHttpRequest) { // ... }, error: function(XMLHttpRequest, textStatus, errorThrown) { // ... } }); At the moment I just have to assume that I'm using it incorrectly, but I'm hoping one of you guys can clear my mental block!

    Read the article

  • Using sortable_element in Rails on a list generated by a find()

    - by Eli B.
    Hey all, I'm trying to use the scriptaculous helper method sortable_element to implement a drag-and-drop sortable list in my Rails application. While the code for the view looks pretty simple, I'm really not quite sure what to write in the controller to update the "position" column. Here's what I've got in my view, "_show_related_pgs.erb": <ul id = "interest_<%=@related_interest.id.to_s%>_siblings_list"> <%= render :partial => "/interests/peer_group_map", :collection => @maps, :as => :related_pg %> </ul> <%= sortable_element("interest_"+@related_interest.id.to_s+"_siblings_list", :url => {:action => :resort_related_pgs}, :handle => "drag" ) %> <br/> And here's the relevant line from the partial, "interests/peer_group_map.erb" <li class = "interest_<%=@related_interest.id.to_s%>_siblings_list" id = "interest_<%=related_pg.interest_id.to_s%>_siblings_list_<%=related_pg.id.to_s%>"> The Scriptaculous UI magic works fine with these, but I am unsure as to how to change the "position" column in the db to reflect this. Should I be passing the collection @maps back to the controller and tell it to iterate through that and increment/decrement the attribute "position" in each? If so, how can I tell which item was moved up, and which down? I couldn't find anything specific using Chrome dev-tools in the generated html. After each reordering, I also need to re-render the collection @maps since the position is being printed out next to the name of each interest (I'm using it as the "handle" specified in my call to sortable_element() above) - though this should be trivial. Any thoughts? Thanks, -e

    Read the article

  • LLVM/Clang bug found in convenience method and NSClassFromString(...) alloc/release

    - by pirags
    I am analyzing Objective-C iPhone project with LLVM/Clang static analyzer. I keep getting two reported bugs, but I am pretty sure that the code is correct. 1) Convenience method. + (UILabel *)simpleLabel { UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(100, 10, 200, 25)]; label.adjustsFontSizeToFitWidth = YES; [label autorelease]; // Object with +0 retain counts returned to caller where a +1 (owning) retain count is expected. return label; } 2) The [NSClassFromString(...) alloc] returns retainCount + 1. Am I right? Class detailsViewControllerClass = NSClassFromString(self.detailsViewControllerName); UIViewController *detailsViewController = [[detailsViewControllerClass alloc] performSelector:@selector(initWithAdditive:) withObject:additive]; [self.parentController.navigationController pushViewController:detailsViewController animated:YES]; [detailsViewController release]; // Incorrect decrement of the reference count of an object is not owned... Are these some Clang issues or I am totally mistaken in these both cases?

    Read the article

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

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

    Read the article

  • concurrency::index<N> from amp.h

    - by Daniel Moth
    Overview C++ AMP introduces a new template class index<N>, where N can be any value greater than zero, that represents a unique point in N-dimensional space, e.g. if N=2 then an index<2> object represents a point in 2-dimensional space. This class is essentially a coordinate vector of N integers representing a position in space relative to the origin of that space. It is ordered from most-significant to least-significant (so, if the 2-dimensional space is rows and columns, the first component represents the rows). The underlying type is a signed 32-bit integer, and component values can be negative. The rank field returns N. Creating an index The default parameterless constructor returns an index with each dimension set to zero, e.g. index<3> idx; //represents point (0,0,0) An index can also be created from another index through the copy constructor or assignment, e.g. index<3> idx2(idx); //or index<3> idx2 = idx; To create an index representing something other than 0, you call its constructor as per the following 4-dimensional example: int temp[4] = {2,4,-2,0}; index<4> idx(temp); Note that there are convenience constructors (that don’t require an array argument) for creating index objects of rank 1, 2, and 3, since those are the most common dimensions used, e.g. index<1> idx(3); index<2> idx(3, 6); index<3> idx(3, 6, 12); Accessing the component values You can access each component using the familiar subscript operator, e.g. One-dimensional example: index<1> idx(4); int i = idx[0]; // i=4 Two-dimensional example: index<2> idx(4,5); int i = idx[0]; // i=4 int j = idx[1]; // j=5 Three-dimensional example: index<3> idx(4,5,6); int i = idx[0]; // i=4 int j = idx[1]; // j=5 int k = idx[2]; // k=6 Basic operations Once you have your multi-dimensional point represented in the index, you can now treat it as a single entity, including performing common operations between it and an integer (through operator overloading): -- (pre- and post- decrement), ++ (pre- and post- increment), %=, *=, /=, +=, -=,%, *, /, +, -. There are also operator overloads for operations between index objects, i.e. ==, !=, +=, -=, +, –. Here is an example (where no assertions are broken): index<2> idx_a; index<2> idx_b(0, 0); index<2> idx_c(6, 9); _ASSERT(idx_a.rank == 2); _ASSERT(idx_a == idx_b); _ASSERT(idx_a != idx_c); idx_a += 5; idx_a[1] += 3; idx_a++; _ASSERT(idx_a != idx_b); _ASSERT(idx_a == idx_c); idx_b = idx_b + 10; idx_b -= index<2>(4, 1); _ASSERT(idx_a == idx_b); Usage You'll most commonly use index<N> objects to index into data types that we'll cover in future posts (namely array and array_view). Also when we look at the new parallel_for_each function we'll see that an index<N> object is the single parameter to the lambda, representing the (multi-dimensional) thread index… In the next post we'll go beyond being able to represent an N-dimensional point in space, and we'll see how to define the N-dimensional space itself through the extent<N> class. Comments about this post by Daniel Moth welcome at the original blog.

    Read the article

  • iPhone SDK: Audio Queue control

    - by codemercenary
    Hi all, I am new to the audio queue services so I have taken an example from a book called iPhone Cool Projects where it describes how to stream audio. I want to extend this to being able to play a continuous playlist of links to mp3 files like an internet radio. The problem with the example code it that it does not detect when a stream ends and does not call AudioQueueStop at any point, so I added a counter to number of buffers added to the queue, and then decrement this counter each time audioQueueOutputCallback is called by the queue. This works fine except if when the buffer count goes to 0, and then I add a call AudioQueueFlush(audioQueue) and then AudioQueueStop(audioQueue, false) I get an error. If I only call AudioQueueReset, it continues to load the buffers again, but plays them out faster then it loads them... getting stuck in a loop and then crashing. 2010-04-14 13:56:29.745 AudioPlayer[2269:207] init player with URL 2010-04-14 13:56:29.941 AudioPlayer[2269:207] did recieve data 2010-04-14 13:56:29.942 AudioPlayer[2269:207] audio request didReceiveData 2010-04-14 13:56:29.944 AudioPlayer[2269:207] >>> start audio queue 2010-04-14 13:56:29.960 AudioPlayer[2269:207] packetCallback count 2 2010-04-14 13:56:29.961 AudioPlayer[2269:207] add buffer: 1 2010-04-14 13:56:29.962 AudioPlayer[2269:207] did recieve data 2010-04-14 13:56:29.963 AudioPlayer[2269:207] audio request didReceiveData 2010-04-14 13:56:29.963 AudioPlayer[2269:207] packetCallback count 1 2010-04-14 13:56:29.964 AudioPlayer[2269:207] add buffer: 2 2010-04-14 13:56:29.965 AudioPlayer[2269:207] packetCallback count 13 2010-04-14 13:56:29.967 AudioPlayer[2269:207] add buffer: 3 2010-04-14 13:56:29.968 AudioPlayer[2269:207] done with buffer: 3 2010-04-14 13:56:29.969 AudioPlayer[2269:207] done with buffer: 2 2010-04-14 13:56:29.974 AudioPlayer[2269:207] done with buffer: 1 So this loop continues some 20 - 30 times and then it crashes. The first time it plays an audio file it queues up the buffers and then plays sound, but doesn't callback to delete them until some 100 or more have been played. Can anyone explain this behavior? I read that there was a limit of 1 audio queue for MP3 playback for the iPhone. Is that still true? If not then I suppose I should use another audio queue for the next mp3 stream. I've had a look through the apple docs but it doesn't explain this in any particular detail. A better insight into this would be great. TIA.

    Read the article

  • abstract data type list. . .

    - by aldrin
    A LIST is an ordered collection of items where items may be inserted anywhere in the list. Implement a LIST using an array as follows: struct list { int *items; // pointer to the array int size; // actual size of the array int count; // number of items in the array }; typedef struct list *List; // pointer to the structure Implement the following functions: a) List newList(int size); - will create a new List and return its pointer. Allocate space for the structure, allocate space for the array, then initialize size and count, return the pointer. b) void isEmpty(List list); c) void display(List list); d) int contains(List list, int item); e) void remove(List list, int i) ; f) void insertAfter(List list,int item, int i); g) void addEnd(List list,int item) - add item at the end of the list – simply store the data at position count, then increment count. If the array is full, allocate an array twice as big as the original. count = 5 size = 10 0 1 2 3 4 5 6 7 8 9 5 10 15 20 30 addEnd(list,40) will result to count = 6 size = 10 0 1 2 3 4 5 6 7 8 9 5 10 15 20 30 40 h) void addFront(List list,int item) - shift all elements to the right so that the item can be placed at position 0, then increment count. Bonus: if the array is full, allocate an array twice as big as the original. count = 5 size = 10 0 1 2 3 4 5 6 7 8 9 5 10 15 20 30 addFront(list,40) will result to count = 6 size = 10 0 1 2 3 4 5 6 7 8 9 40 5 10 15 20 30 i) void removeFront(List list) - shift all elements to the left and decrement count; count = 6 size = 10 0 1 2 3 4 5 6 7 8 9 40 5 10 15 20 30 removeFront(list) will result to count = 5 size = 10 0 1 2 3 4 5 6 7 8 9 5 10 15 20 30 j) void remove(List list,int item) - get the index of the item in the list and then shift all elements to the count = 6 size = 10 0 1 2 3 4 5 6 7 8 9 40 5 10 15 20 30 remove(list,10) will result to count = 5 size = 10 0 1 2 3 4 5 6 7 8 9 40 5 15 20 30

    Read the article

  • Most efficient method to query a Young Tableau

    - by Matthieu M.
    A Young Tableau is a 2D matrix A of dimensions M*N such that: i,j in [0,M)x[0,N): for each p in (i,M), A[i,j] <= A[p,j] for each q in (j,N), A[i,j] <= A[i,q] That is, it's sorted row-wise and column-wise. Since it may contain less than M*N numbers, the bottom-right values might be represented either as missing or using (in algorithm theory) infinity to denote their absence. Now the (elementary) question: how to check if a given number is contained in the Young Tableau ? Well, it's trivial to produce an algorithm in O(M*N) time of course, but what's interesting is that it is very easy to provide an algorithm in O(M+N) time: Bottom-Left search: Let x be the number we look for, initialize i,j as M-1, 0 (bottom left corner) If x == A[i,j], return true If x < A[i,j], then if i is 0, return false else decrement i and go to 2. Else, if j is N-1, return false else increment j This algorithm does not make more than M+N moves. The correctness is left as an exercise. It is possible though to obtain a better asymptotic runtime. Pivot Search: Let x be the number we look for, initialize i,j as floor(M/2), floor(N/2) If x == A[i,j], return true If x < A[i,j], search (recursively) in A[0:i-1, 0:j-1], A[i:M-1, 0:j-1] and A[0:i-1, j:N-1] Else search (recursively) in A[i+1:M-1, 0:j], A[i+1:M-1, j+1:N-1] and A[0:i, j+1:N-1] This algorithm proceed by discarding one of the 4 quadrants at each iteration and running recursively on the 3 left (divide and conquer), the master theorem yields a complexity of O((N+M)**(log 3 / log 4)) which is better asymptotically. However, this is only a big-O estimation... So, here are the questions: Do you know (or can think of) an algorithm with a better asymptotical runtime ? Like introsort prove, sometimes it's worth switching algorithms depending on the input size or input topology... do you think it would be possible here ? For 2., I am notably thinking that for small size inputs, the bottom-left search should be faster because of its O(1) space requirement / lower constant term.

    Read the article

  • Reading Source Code Aloud

    - by Jon Purdy
    After seeing this question, I got to thinking about the various challenges that blind programmers face, and how some of them are applicable even to sighted programmers. Particularly, the problem of reading source code aloud gives me pause. I have been programming for most of my life, and I frequently tutor fellow students in programming, most often in C++ or Java. It is uniquely aggravating to try to verbally convey the essential syntax of a C++ expression. The speaker must give either an idiomatic translation into English, or a full specification of the code in verbal longhand, using explicit yet slow terms such as "opening parenthesis", "bitwise and", et cetera. Neither of these solutions is optimal. On the one hand, an idiomatic translation is only useful to a programmer who can de-translate back into the relevant programming code—which is not usually the case when tutoring a student. In turn, education (or simply getting someone up to speed on a project) is the most common situation in which source is read aloud, and there is a very small margin for error. On the other hand, a literal specification is aggravatingly slow. It takes far far longer to say "pound, include, left angle bracket, iostream, right angle bracket, newline" than it does to simply type #include <iostream>. Indeed, most experienced C++ programmers would read this merely as "include iostream", but again, inexperienced programmers abound and literal specifications are sometimes necessary. So I've had an idea for a potential solution to this problem. In C++, there is a finite set of keywords—63—and operators—54, discounting named operators and treating compound assignment operators and prefix versus postfix auto-increment and decrement as distinct. There are just a few types of literal, a similar number of grouping symbols, and the semicolon. Unless I'm utterly mistaken, that's about it. So would it not then be feasible to simply ascribe a concise, unique pronunciation to each of these distinct concepts (including one for whitespace, where it is required) and go from there? Programming languages are far more regular than natural languages, so the pronunciation could be standardised. Speakers of any language would be able to verbally convey C++ code, and due to the regularity and fixity of the language, speech-to-text software could be optimised to accept C++ speech with a high degree of accuracy. So my question is twofold: first, is my solution feasible; and second, does anyone else have other potential solutions? I intend to take suggestions from here and use them to produce a formal paper with an example implementation of my solution.

    Read the article

  • Abstract Data Type: Any1 can help me this? thanks..

    - by Aga Hibaya
    Objectives: Implement the Abstract Data Type (ADT) List using dynamically allocated arrays and structures. Description A LIST is an ordered collection of items where items may be inserted anywhere in the list. Implement a LIST using an array as follows: struct list { int *items; // pointer to the array int size; // actual size of the array int count; // number of items in the array }; typedef struct list *List; // pointer to the structure Implement the following functions: a) List newList(int size); - will create a new List and return its pointer. Allocate space for the structure, allocate space for the array, then initialize size and count, return the pointer. b) void isEmpty(List list); c) void display(List list); d) int contains(List list, int item); e) void remove(List list, int i) ; f) void insertAfter(List list,int item, int i); g) void addEnd(List list,int item) - add item at the end of the list – simply store the data at position count, then increment count. If the array is full, allocate an array twice as big as the original. count = 5 size = 10 0 1 2 3 4 5 6 7 8 9 5 10 15 20 30 addEnd(list,40) will result to count = 6 size = 10 0 1 2 3 4 5 6 7 8 9 5 10 15 20 30 40 h) void addFront(List list,int item) - shift all elements to the right so that the item can be placed at position 0, then increment count. Bonus: if the array is full, allocate an array twice as big as the original. count = 5 size = 10 0 1 2 3 4 5 6 7 8 9 5 10 15 20 30 addFront(list,40) will result to count = 6 size = 10 0 1 2 3 4 5 6 7 8 9 40 5 10 15 20 30 i) void removeFront(List list) - shift all elements to the left and decrement count; count = 6 size = 10 0 1 2 3 4 5 6 7 8 9 40 5 10 15 20 30 removeFront(list) will result to count = 5 size = 10 0 1 2 3 4 5 6 7 8 9 5 10 15 20 30 j) void remove(List list,int item) - get the index of the item in the list and then shift all elements to the count = 6 size = 10 0 1 2 3 4 5 6 7 8 9 40 5 10 15 20 30 remove(list,10) will result to count = 5 size = 10 0 1 2 3 4 5 6 7 8 9 40 5 15 20 30 Remarks

    Read the article

  • Why is my variable uninitialized in a separate if test?

    - by user2932733
    For the first run, I need to use dates that are six months prior to the last MySQL date $row_recent[0]. For all of the runs after 1, I am using a previous variable to store the previous date and then decrease the date by 6 months. I have confirmed that the first if test produces the expected result. (MySQL date - 6 Months). However, the second if test outputs $startdate6m as the PHP default due to $previous_6m being uninitialized. Any idea why it won't recognize $previous_6m = $initial6m? <?php while ($run_number < 15) { $run_number++; if($run_number == 1){ if ($month <= 06){ $year6m = date("Y", strtotime($row_recent[0]))-1; $month6m = str_pad((12-(6-date("m", strtotime($row_recent[0])))), 2, "0", STR_PAD_LEFT); $startdate6m = "'".$year6m."-".$month6m."-01'"; $end_date = $startdate6m; $initial6m = $startdate6m; } else{ $year6m = date("Y", strtotime($row_recent[0])); $month6m = str_pad(date("m", strtotime($row_recent[0]))-6, 2, "0", STR_PAD_LEFT); $startdate6m = "'".$year6m."-".$month6m."-01'"; $end_date = $startdate6m; $initial6m = $startdate6m; } } $previous_6m = $initial6m; if($run_number > 1){ # 6 Month # Decrement date by 6 months $month6m = date("m", strtotime($previous_6m)); if ($month6m <= 06){ $year6m = date("Y", strtotime($previous_6m))-1; $month6m = str_pad((12-(6-date("m", strtotime($previous_6m)))), 2, "0", STR_PAD_LEFT); $startdate6m = "'".$year6m."-".$month6m."-01'"; $end_date = $startdate6m; } else{ $year6m = date("Y", strtotime($previous_6m)); $month6m = str_pad(date("m", strtotime($previous_6m))-6, 2, "0", STR_PAD_LEFT); $startdate6m = "'".$year6m."-".$month6m."-01'"; $end_date = $startdate6m; } } $previous_6m = $startdate6m; } ?>

    Read the article

  • Error in Print Function in Bubble Sort MIPS?

    - by m00nbeam360
    Sorry that this is such a long block of code, but do you see any obvious syntax errors in this? I feel like the problem is that the code isn't printing correctly since the sort and swap methods were from my textbook. Please help if you can! .data save: .word 1,2,4,2,5,6 size: .word 6 .text swap: sll $t1, $a1, 2 #shift bits by 2 add $t1, $a1, $t1 #set $t1 address to v[k] lw $t0, 0($t1) #load v[k] into t1 lw $t2, 4($t1) #load v[k+1] into t1 sw $t2, 0($t1) #swap addresses sw $t0, 4($t1) #swap addresses jr $ra #return sort: addi $sp, $sp, -20 #make enough room on the stack for five registers sw $ra, 16($sp) #save the return address on the stack sw $s3, 12($sp) #save $s3 on the stack sw $s2, 8($sp) #save Ss2 on the stack sw $s1, 4($sp) #save $s1 on the stack sw $s0, 0($sp) #save $s0 on the stack move $s2, $a0 #copy the parameter $a0 into $s2 (save $a0) move $s3, $a1 #copy the parameter $a1 into $s3 (save $a1) move $s0, $zero #start of for loop, i = 0 for1tst: slt $t0, $s0, $s3 #$t0 = 0 if $s0 S $s3 (i S n) beq $t0, $zero, exit1 #go to exit1 if $s0 S $s3 (i S n) addi $s1, $s0, -1 #j - i - 1 for2tst: slti $t0, $s1, 0 #$t0 = 1 if $s1 < 0 (j < 0) bne $t0, $zero, exit2 #$t0 = 1 if $s1 < 0 (j < 0) sll $t1, $s1, 2 #$t1 = j * 4 (shift by 2 bits) add $t2, $s2, $t1 #$t2 = v + (j*4) lw $t3, 0($t2) #$t3 = v[j] lw $t4, 4($t2) #$t4 = v[j+1] slt $t0, $t4, $t3 #$t0 = 0 if $t4 S $t3 beq $t0, $zero, exit2 #go to exit2 if $t4 S $t3 move $a0, $s2 #1st parameter of swap is v(old $a0) move $a1, $s1 #2nd parameter of swap is j jal swap #swap addi $s1, $s1, -1 j for2tst #jump to test of inner loop j print exit2: addi $s0, $s0, 1 #i = i + 1 j for1tst #jump to test of outer loop exit1: lw $s0, 0($sp) #restore $s0 from stack lw $s1, 4($sp) #resture $s1 from stack lw $s2, 8($sp) #restore $s2 from stack lw $s3, 12($sp) #restore $s3 from stack lw $ra, 16($sp) #restore $ra from stack addi $sp, $sp, 20 #restore stack pointer jr $ra #return to calling routine .data space:.asciiz " " # space to insert between numbers head: .asciiz "The sorted numbers are:\n" .text print:add $t0, $zero, $a0 # starting address of array add $t1, $zero, $a1 # initialize loop counter to array size la $a0, head # load address of print heading li $v0, 4 # specify Print String service syscall # print heading out: lw $a0, 0($t0) # load fibonacci number for syscall li $v0, 1 # specify Print Integer service syscall # print fibonacci number la $a0, space # load address of spacer for syscall li $v0, 4 # specify Print String service syscall # output string addi $t0, $t0, 4 # increment address addi $t1, $t1, -1 # decrement loop counter bgtz $t1, out # repeat if not finished jr $ra # return

    Read the article

  • The Math of a Jump in a 2D game.

    - by ONi
    I have been all around with this question and I can't find the correct answer! So, behold, the description of my question: I'm working in J2ME, I have my gameloop that do the following: public void run() { Graphics g = this.getGraphics(); while (running) { long diff = System.currentTimeMillis() - lastLoop; lastLoop = System.currentTimeMillis(); input(); this.level.doLogic(); render(g, diff); try { Thread.sleep(10); } catch (InterruptedException e) { stop(e); } } } so it's just a basic gameloop, the doLogic() function calls for all the logic functions of the characters in the scene and render(g, diff) calls the animateChar function of every character on scene, following this, the animChar function in the Character class sets up everything in the screen as this: protected void animChar(long diff) { this.checkGravity(); this.move((int) ((diff * this.dx) / 1000), (int) ((diff * this.dy) / 1000)); if (this.acumFrame > this.framerate) { this.nextFrame(); this.acumFrame = 0; } else { this.acumFrame += diff; } } This ensures me that everything must to move according to the time that the machine takes to go from cycle to cycle (remember it's a phone, not a gaming rig). I'm sure it's not the most efficient way to achieve this behavior so I'm totally open for criticism of my programming skills in the comments, but here my problem: When I make I character jump, what I do is that I put his dy to a negative value, say -200 and I set the boolean jumping to true, that makes the character go up, and then I have this function called checkGravity() that ensure that everything that goes up has to go down, checkGravity also checks for the character being over platforms so I will strip it down a little for the sake of your time: public void checkGravity() { if (this.jumping) { this.jumpSpeed += 10; if (this.jumpSpeed > 0) { this.jumping = false; this.falling = true; } this.dy = this.jumpSpeed; } if (this.falling) { this.jumpSpeed += 10; if (this.jumpSpeed > 200) this.jumpSpeed = 200; this.dy = this.jumpSpeed; if (this.collidesWithPlatform()) { this.falling = false; this.standing = true; this.jumping = false; this.jumpSpeed = 0; this.dy = this.jumpSpeed; } } } So, the problem is, that this function updates the dy regardless of the diff, making the characters fly like Superman in slow machines, and I have no idea how to implement the diff factor so that when a character is jumping, his speed decrement in a proportional way to the game speed. Can anyone help me fix this issue? or give me pointers on how to make a 2D Jump in J2ME the right way. Thank you very much for your time.

    Read the article

  • Different data for different dates

    - by nsw1475
    I am making a web page which will allow users to input and view data for different dates, and to change the date, there are two buttons, one of which will display the previous day, and one which will show the next day. I know that I can do this by submitting forms and reloading the page every time they press one of these buttons, but I would rather use javascript and not have to submit a form, but I am having troubles getting it to work. Currently, I have the two buttons, and the date stored in a PHP variable, as shown in my code below: <script> function init() { <? $nutrDate = $this->parseDate(date('m/d/Y')); ?> } function nutrPrevDay() { <? $nutrDate = mktime(0, 0, 0, date('m',$nutrDate), date('d',$nutrDate)-1, date('Y',$nutrDate)); ?> alert("<? echo(date("m/d/y", $nutrDate)) ?>"); } function nutrNextDay() { <? $nutrDate = mktime(0, 0, 0, date('m',$nutrDate), date('d',$nutrDate)+1, date('Y',$nutrDate)); ?> } window.onload = init; </script> <p style="text-align:center; font-size:14px; color:#03F"> <button onclick="nutrPrevDay()" style="width:200px" >< Show Previous Day</button> <? echo(date('m/d/Y', $nutrDate)) ?> <button onclick="nutrNextDay()" style="width:200px">Show Next Day ></button> </p> I have the alert in the nutrPrevDay() only as debugging. What happens is when I click on the button, the alert shows that the day is correctly decreased (for example from May 17 to May 16), but only decreases one day, and not one day for every click. Also, I do not know how to make the text on the page (created by the line ) change to display the new date after a button is clicked. So here are my questions: 1) Is it possible to dynamically change data (such as text, and in the future, SQL queries) on a page using javascript without having to reload a page when clicking on a button? 2) If possible, how can I make those changes? 3) How can I fix this so that it will increment and decrement through dates every time a button is clicked?

    Read the article

  • WSUS 3.0 SP2 installation fails at "configuring database" step.

    - by flashkube
    Attempting to install WSUS 3.0 SP2 on a Windows Server 2003 Enterprise system. I'm asking the setup to create a new database on one of our existing SQL Server 2005 systems. When the setup gets to the "configuring database" step it stops and throws "There is a problem with this Windows Installer package. A program run as part of the setup did not finish as expected. Contact your support personnel or package vendor." The two logs it suggests I look at are below. I'm not seeing any errors that mean anything to me. Any direction you can give will be greatly appreciated. WSUSSetup.log: 2009-12-04 15:26:21 Success MWUSSetup Validating pre-requisites... 2009-12-04 15:26:22 Error MWUSSetup Failed to determine if an higher version of WSUS is installed. Assuming it is not... (Error 0x80070002: The system cannot find the file specified.) 2009-12-04 15:26:28 Success MWUSSetup No SQL instances found 2009-12-04 15:26:42 Success MWUSSetup Initializing installation details 2009-12-04 15:26:42 Success MWUSSetup Installing ASP.Net 2009-12-04 15:27:24 Success MWUSSetup ASP.Net is installed successfully 2009-12-04 15:27:24 Success MWUSSetup Installing WSUS... 2009-12-04 15:27:28 Success CustomActions.Dll Unable to get INSTALL_LANGUAGE property, calculating it... 2009-12-04 15:27:28 Success CustomActions.Dll Successfully set propery of WSUS admin groups' full names 2009-12-04 15:27:29 Success CustomActions.Dll .Net framework path: C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727 2009-12-04 15:27:33 Success CustomActions.Dll Creating user group: WSUS Reporters with Description: WSUS Administrators who can only run reports on the Windows Server Update Services server. 2009-12-04 15:27:33 Success CustomActions.Dll Creating WSUS Reporters user group 2009-12-04 15:27:33 Success CustomActions.Dll WSUS Reporters user group already exists 2009-12-04 15:27:33 Success CustomActions.Dll Successfully created WSUS Reporters user group 2009-12-04 15:27:33 Success CustomActions.Dll Creating user group: WSUS Administrators with Description: WSUS Administrators can administer the Windows Server Update Services server. 2009-12-04 15:27:33 Success CustomActions.Dll Creating WSUS Administrators user group 2009-12-04 15:27:33 Success CustomActions.Dll WSUS Administrators user group already exists 2009-12-04 15:27:33 Success CustomActions.Dll Successfully created WSUS Administrators user group 2009-12-04 15:27:33 Success CustomActions.Dll Successfully created WSUS user groups 2009-12-04 15:27:33 Success CustomActions.Dll Succesfully set binary SID property 2009-12-04 15:27:33 Success CustomActions.Dll Succesfully set binary SID property 2009-12-04 15:27:33 Success CustomActions.Dll Successfully set binary SID properties 2009-12-04 15:28:50 Error MWUSSetup InstallWsus: MWUS Installation Failed (Error 0x80070643: Fatal error during installation.) 2009-12-04 15:28:50 Error MWUSSetup CInstallDriver::PerformSetup: WSUS installation failed (Error 0x80070643: Fatal error during installation.) 2009-12-04 15:28:50 Error MWUSSetup CSetupDriver::LaunchSetup: Setup failed (Error 0x80070643: Fatal error during installation.) From the end of WSUSSetupmsi_091204_1527.log MSI (s) (58:7C) [15:28:49:860]: Note: 1: 1708 MSI (s) (58:7C) [15:28:49:860]: Product: Windows Server Update Services 3.0 SP2 -- Installation failed. MSI (s) (58:7C) [15:28:49:875]: Cleaning up uninstalled install packages, if any exist MSI (s) (58:7C) [15:28:49:875]: MainEngineThread is returning 1603 MSI (s) (58:78) [15:28:49:985]: Destroying RemoteAPI object. MSI (s) (58:90) [15:28:49:985]: Custom Action Manager thread ending. === Logging stopped: 12/4/2009 15:28:49 === MSI (c) (30:54) [15:28:50:016]: Decrementing counter to disable shutdown. If counter = 0, shutdown will be denied. Counter after decrement: -1 MSI (c) (30:54) [15:28:50:016]: MainEngineThread is returning 1603 === Verbose logging stopped: 12/4/2009 15:28:50 ===

    Read the article

  • SQL2008R2 install issues on windows 7 - unable to install setup support files?

    - by Liam
    I am trying to install the above but am getting the following errors when its attempting to install the setup support files, This is the first error that occurs during installation of the setup support files TITLE: Microsoft SQL Server 2008 R2 Setup ------------------------------ The following error has occurred: The installer has encountered an unexpected error. The error code is 2337. Could not close file: Microsoft.SqlServer.GridControl.dll GetLastError: 0. Click 'Retry' to retry the failed action, or click 'Cancel' to cancel this action and continue setup. For help, click: http://go.microsoft.com/fwlink?LinkID=20476&ProdName=Microsoft+SQL+Server&EvtSrc=setup.rll&EvtID=50000&ProdVer=10.50.1600.1&EvtType=0xDF039760%25401201%25401 This is the second error that occurs after clicking continue in the installer after the first error is generated TITLE: Microsoft SQL Server 2008 R2 Setup ------------------------------ The following error has occurred: SQL Server Setup has encountered an error when running a Windows Installer file. Windows Installer error message: The Windows Installer Service could not be accessed. This can occur if the Windows Installer is not correctly installed. Contact your support personnel for assistance. Windows Installer file: C:\Users\watto_uk\Desktop\In-Digital\Software\Microsoft\SQL Server 2008 R2\1033_ENU_LP\x64\setup\sqlsupport_msi\SqlSupport.msi Windows Installer log file: C:\Program Files\Microsoft SQL Server\100\Setup Bootstrap\Log\20110713_205508\SqlSupport_Cpu64_1_ComponentUpdate.log Click 'Retry' to retry the failed action, or click 'Cancel' to cancel this action and continue setup. For help, click: http://go.microsoft.com/fwlink?LinkID=20476&ProdName=Microsoft+SQL+Server&EvtSrc=setup.rll&EvtID=50000&ProdVer=10.50.1600.1&EvtType=0xDC80C325 These errors are generated from an ISO package downloaded from Microsoft. I have also tried using the web platform installer to install the express version instead but the SQL Server Installation fails with that also. The management studio installs fine but not the server. I have checked to make sure that the Windows Installer is started and it is. Cant seem to find an answer for this anywhere as all previous reported issues appear to be related to XP. I did have the express edition installed on the machine previously but uninstalled it to upgrade to the full version, I wish I hadn't now. Can anyone kindly offer any advice or point me in the right direction to stop me going insane with this? Any advice will be appreciated. Update======================= After digging a bit deeper ive located details of the error from the setup log file, i can also upload the log file if required. MSI (s) (E8:28) [23:35:18:705]: Assembly Error:The module '%1' was expected to contain an assembly manifest. MSI (s) (E8:28) [23:35:18:705]: Note: 1: 1935 2: 3: 0x80131018 4: IStream 5: Commit 6: MSI (s) (E8:28) [23:35:18:705]: Note: 1: 2337 2: 0 3: Microsoft.SqlServer.GridControl.dll MSI (s) (E8:28) [23:35:22:869]: Product: Microsoft SQL Server 2008 R2 Setup (English) -- Error 2337. The installer has encountered an unexpected error. The error code is 2337. Could not close file: Microsoft.SqlServer.GridControl.dll GetLastError: 0. MSI (s) (E8:28) [23:35:22:916]: Internal Exception during install operation: 0xc0000005 at 0x000007FEE908A23E. MSI (s) (E8:28) [23:35:22:916]: WER report disabled for silent install. MSI (s) (E8:28) [23:35:22:932]: Internal MSI error. Installer terminated prematurely. Error 2337. The installer has encountered an unexpected error. The error code is 2337. Could not close file: Microsoft.SqlServer.GridControl.dll GetLastError: 0. MSI (s) (E8:28) [23:35:22:932]: MainEngineThread is returning 1603 MSI (s) (E8:58) [23:35:22:932]: RESTART MANAGER: Session closed. Installer stopped prematurely. MSI (c) (0C:14) [23:35:22:947]: Decrementing counter to disable shutdown. If counter >= 0, shutdown will be denied. Counter after decrement: -1 MSI (c) (0C:14) [23:35:22:947]: MainEngineThread is returning 1601 === Verbose logging stopped: 13/07/2011 23:35:22 ===

    Read the article

  • C#/.NET Little Wonders: Interlocked Read() and Exchange()

    - by James Michael Hare
    Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. Last time we discussed the Interlocked class and its Add(), Increment(), and Decrement() methods which are all useful for updating a value atomically by adding (or subtracting).  However, this begs the question of how do we set and read those values atomically as well? Read() – Read a value atomically Let’s begin by examining the following code: 1: public class Incrementor 2: { 3: private long _value = 0; 4:  5: public long Value { get { return _value; } } 6:  7: public void Increment() 8: { 9: Interlocked.Increment(ref _value); 10: } 11: } 12:  It uses an interlocked increment, as we discuss in my previous post (here), so we know that the increment will be thread-safe.  But, to realize what’s potentially wrong we have to know a bit about how atomic reads are in 32 bit and 64 bit .NET environments. When you are dealing with an item smaller or equal to the system word size (such as an int on a 32 bit system or a long on a 64 bit system) then the read is generally atomic, because it can grab all of the bits needed at once.  However, when dealing with something larger than the system word size (reading a long on a 32 bit system for example), it cannot grab the whole value at once, which can lead to some problems since this read isn’t atomic. For example, this means that on a 32 bit system we may read one half of the long before another thread increments the value, and the other half of it after the increment.  To protect us from reading an invalid value in this manner, we can do an Interlocked.Read() to force the read to be atomic (of course, you’d want to make sure any writes or increments are atomic also): 1: public class Incrementor 2: { 3: private long _value = 0; 4:  5: public long Value 6: { 7: get { return Interlocked.Read(ref _value); } 8: } 9:  10: public void Increment() 11: { 12: Interlocked.Increment(ref _value); 13: } 14: } Now we are guaranteed that we will read the 64 bit value atomically on a 32 bit system, thus ensuring our thread safety (assuming all other reads, writes, increments, etc. are likewise protected).  Note that as stated before, and according to the MSDN (here), it isn’t strictly necessary to use Interlocked.Read() for reading 64 bit values on 64 bit systems, but for those still working in 32 bit environments, it comes in handy when dealing with long atomically. Exchange() – Exchanges two values atomically Exchange() lets us store a new value in the given location (the ref parameter) and return the old value as a result. So just as Read() allows us to read atomically, one use of Exchange() is to write values atomically.  For example, if we wanted to add a Reset() method to our Incrementor, we could do something like this: 1: public void Reset() 2: { 3: _value = 0; 4: } But the assignment wouldn’t be atomic on 32 bit systems, since the word size is 32 bits and the variable is a long (64 bits).  Thus our assignment could have only set half the value when a threaded read or increment happens, which would put us in a bad state. So instead, we could write Reset() like this: 1: public void Reset() 2: { 3: Interlocked.Exchange(ref _value, 0); 4: } And we’d be safe again on a 32 bit system. But this isn’t the only reason Exchange() is valuable.  The key comes in realizing that Exchange() doesn’t just set a new value, it returns the old as well in an atomic step.  Hence the name “exchange”: you are swapping the value to set with the stored value. So why would we want to do this?  Well, anytime you want to set a value and take action based on the previous value.  An example of this might be a scheme where you have several tasks, and during every so often, each of the tasks may nominate themselves to do some administrative chore.  Perhaps you don’t want to make this thread dedicated for whatever reason, but want to be robust enough to let any of the threads that isn’t currently occupied nominate itself for the job.  An easy and lightweight way to do this would be to have a long representing whether someone has acquired the “election” or not.  So a 0 would indicate no one has been elected and 1 would indicate someone has been elected. We could then base our nomination strategy as follows: every so often, a thread will attempt an Interlocked.Exchange() on the long and with a value of 1.  The first thread to do so will set it to a 1 and return back the old value of 0.  We can use this to show that they were the first to nominate and be chosen are thus “in charge”.  Anyone who nominates after that will attempt the same Exchange() but will get back a value of 1, which indicates that someone already had set it to a 1 before them, thus they are not elected. Then, the only other step we need take is to remember to release the election flag once the elected thread accomplishes its task, which we’d do by setting the value back to 0.  In this way, the next thread to nominate with Exchange() will get back the 0 letting them know they are the new elected nominee. Such code might look like this: 1: public class Nominator 2: { 3: private long _nomination = 0; 4: public bool Elect() 5: { 6: return Interlocked.Exchange(ref _nomination, 1) == 0; 7: } 8: public bool Release() 9: { 10: return Interlocked.Exchange(ref _nomination, 0) == 1; 11: } 12: } There’s many ways to do this, of course, but you get the idea.  Running 5 threads doing some “sleep” work might look like this: 1: var nominator = new Nominator(); 2: var random = new Random(); 3: Parallel.For(0, 5, i => 4: { 5:  6: for (int j = 0; j < _iterations; ++j) 7: { 8: if (nominator.Elect()) 9: { 10: // elected 11: Console.WriteLine("Elected nominee " + i); 12: Thread.Sleep(random.Next(100, 5000)); 13: nominator.Release(); 14: } 15: else 16: { 17: // not elected 18: Console.WriteLine("Did not elect nominee " + i); 19: } 20: // sleep before check again 21: Thread.Sleep(1000); 22: } 23: }); And would spit out results like: 1: Elected nominee 0 2: Did not elect nominee 2 3: Did not elect nominee 1 4: Did not elect nominee 4 5: Did not elect nominee 3 6: Did not elect nominee 3 7: Did not elect nominee 1 8: Did not elect nominee 2 9: Did not elect nominee 4 10: Elected nominee 3 11: Did not elect nominee 2 12: Did not elect nominee 1 13: Did not elect nominee 4 14: Elected nominee 0 15: Did not elect nominee 2 16: Did not elect nominee 4 17: ... Another nice thing about the Interlocked.Exchange() is it can be used to thread-safely set pretty much anything 64 bits or less in size including references, pointers (in unsafe mode), floats, doubles, etc.  Summary So, now we’ve seen two more things we can do with Interlocked: reading and exchanging a value atomically.  Read() and Exchange() are especially valuable for reading/writing 64 bit values atomically in a 32 bit system.  Exchange() has value even beyond simply atomic writes by using the Exchange() to your advantage, since it reads and set the value atomically, which allows you to do lightweight nomination systems. There’s still a few more goodies in the Interlocked class which we’ll explore next time! Technorati Tags: C#,CSharp,.NET,Little Wonders,Interlocked

    Read the article

  • RTS style fog of war woes

    - by Fricken Hamster
    So I'm trying to make a rts style line of sight fog of war style engine for my grid based game. Currently I am getting a set of vertices by raycasting in 360 degree. Then I use that list of vertices to do a graphics style polygon scanline fill to get a list of all points within the polygon. The I compare the new list of seen tiles and compare that with the old one and increment or decrement the world vision array as needed. The polygon scanline function is giving me trouble. I'm mostly following this http://www.cs.uic.edu/~jbell/CourseNotes/ComputerGraphics/PolygonFilling.html So far this is my code without cleaning anything up var edgeMinX:Vector.<int> = new Vector.<int>; var edgeMinY:Vector.<int> = new Vector.<int>; var edgeMaxY:Vector.<int> = new Vector.<int>; var edgeInvSlope:Vector.<Number> = new Vector.<Number>; var ilen:int = outvert.length; var miny:int = -1; var maxy:int = -1; for (i = 0; i < ilen; i++) { var curpoint:Point = outvert[i]; if (i == ilen -1) { var nextpoint:Point = outvert[0]; } else { nextpoint = outvert[i + 1]; } if (nextpoint.y == curpoint.y) { continue; } if (curpoint.y < nextpoint.y) { var curslope:Number = ((nextpoint.y - curpoint.y) / (nextpoint.x - curpoint.x)); edgeMinY.push(curpoint.y); edgeMinX.push(curpoint.x); edgeMaxY.push(nextpoint.y); edgeInvSlope.push(1 / curslope); if (curpoint.y < miny || miny == -1) { miny = curpoint.y; } if (nextpoint.y > maxy) { maxy = nextpoint.y; } } else { curslope = ((curpoint.y - nextpoint.y) / (curpoint.x - nextpoint.x)); edgeMinY.push(nextpoint.y); edgeMinX.push(nextpoint.x); edgeMaxY.push(curpoint.y); edgeInvSlope.push(1 / curslope); if (nextpoint.y < miny || miny == -1) { miny = curpoint.y; } if (curpoint.y > maxy) { maxy = nextpoint.y; } } } var activeMaxY:Vector.<int> = new Vector.<int>; var activeCurX:Vector.<Number> = new Vector.<Number>; var activeInvSlope:Vector.<Number> = new Vector.<Number>; for (var scanline:int = miny; scanline < maxy + 1; scanline++) { ilen = edgeMinY.length; for (i = 0; i < ilen; i++) { if (edgeMinY[i] == scanline) { activeMaxY.push(edgeMaxY[i]); activeCurX.push(edgeMinX[i]); activeInvSlope.push(edgeInvSlope[i]); //trace("added(" + edgeMinX[i]); edgeMaxY.splice(i, 1); edgeMinX.splice(i, 1); edgeMinY.splice(i, 1); edgeInvSlope.splice(i, 1); i--; ilen--; } } ilen = activeCurX.length; for (i = 0; i < ilen - 1; i++) { for (var j:int = i; j < ilen - 1; j++) { if (activeCurX[j] > activeCurX[j + 1]) { var tempint:int = activeMaxY[j]; activeMaxY[j] = activeMaxY[j + 1]; activeMaxY[j + 1] = tempint; var tempnum:Number = activeCurX[j]; activeCurX[j] = activeCurX[j + 1]; activeCurX[j + 1] = tempnum; tempnum = activeInvSlope[j]; activeInvSlope[j] = activeInvSlope[j + 1]; activeInvSlope[j + 1] = tempnum; } } } var prevx:int = -1; var jlen:int = activeCurX.length; for (j = 0; j < jlen; j++) { if (prevx == -1) { prevx = activeCurX[j]; } else { for (var k:int = prevx; k < activeCurX[j]; k++) { graphics.lineStyle(2, 0x124132); graphics.drawCircle(k * 20 + 10, scanline * 20 + 10, 5); if (k == prevx || k > activeCurX[j] - 1) { graphics.lineStyle(3, 0x004132); graphics.drawCircle(k * 20 + 10, scanline * 20 + 10, 2); } prevx = -1; //tileLightList.push(k, scanline); } } } ilen = activeCurX.length; for (i = 0; i < ilen; i++) { if (activeMaxY[i] == scanline + 1) { activeCurX.splice(i, 1); activeMaxY.splice(i, 1); activeInvSlope.splice(i, 1); i--; ilen--; } else { activeCurX[i] += activeInvSlope[i]; } } } It works in some cases but some of the x intersections are skipped, primarily when there are more than 2 x intersections in one scanline I think. Is there a way to fix this, or a better way to do what I described? Thanks

    Read the article

  • Cannot install .NET Framework 4.0 on Windows XP SP3

    - by Bob
    I'm using Windows XP SP3 logged in as the administrator. I had RAID Mirroring running. The motherboard broke earlier in the year. When I got a new battery I did not resync. I just use the disks as two separate disks. I searched Google for the errors but I didn't find anything detailed enough. The following Microsoft components are in Add/Remove programs: .NET Framework 1.1 .NET Framework 2.0 Service Pack 2 .NET Framework 3.0 Service Pack 2 .NET Framework 3.5 SP1 Microsoft Compression Client Pack 1.0 for Windows XP Microsoft Office Enterprise 2007 Microsoft Silverlight Microsoft USB Flash Driver Manager Micrsoft User-mode Driver Framework Feature Pack 1.0 Microsoft Visual C++ 2005 ATL Update KB 973923 x86 8.050727.4053 Microsoft Visual C++ 2005 Redistributable This is the installation log: Exists: evaluating... [10/21/2011, 22:17:14]MsiGetProductInfo with product code {3C3901C5-3455-3E0A-A214-0B093A5070A6} found no matches [10/21/2011, 22:17:14] Exists evaluated to false [10/21/2011, 22:15:50]calling PerformAction on an installing performer [10/21/2011, 22:15:50] Action: Performing actions on all Items... [10/21/2011, 22:15:50]Wait for Item (clr_optimization_v2.0.50727_32) to be available [10/21/2011, 22:15:50]clr_optimization_v2.0.50727_32 is now available to install [10/21/2011, 22:15:50]Creating new Performer for ServiceControl item [10/21/2011, 22:15:50] Action: ServiceControl - Stop clr_optimization_v2.0.50727_32... [10/21/2011, 22:15:50]ServiceControl operation succeeded! [10/21/2011, 22:15:50] Action complete [10/21/2011, 22:15:50]Error 0 is mapped to Custom Error: [10/21/2011, 22:15:50]Wait for Item (Windows6.0-KB956250-v6001-x86.msu) to be available [10/21/2011, 22:15:51]Windows6.0-KB956250-v6001-x86.msu is now available to install [10/21/2011, 22:15:51]Created new DoNothingPerformer for File item [10/21/2011, 22:15:51]No CustomError defined for this item. [10/21/2011, 22:15:51]Wait for Item (Windows6.1-KB958488-v6001-x86.msu) to be available [10/21/2011, 22:15:51]Windows6.1-KB958488-v6001-x86.msu is now available to install [10/21/2011, 22:15:51]Created new DoNothingPerformer for File item [10/21/2011, 22:15:51]No CustomError defined for this item. [10/21/2011, 22:15:51]Wait for Item (netfx_Core.mzz) to be available [10/21/2011, 22:15:52]netfx_Core.mzz is now available to install [10/21/2011, 22:15:52]Created new DoNothingPerformer for File item [10/21/2011, 22:15:52]No CustomError defined for this item. [10/21/2011, 22:15:52]Wait for Item (netfx_Core_x86.msi) to be available [10/21/2011, 22:15:52]netfx_Core_x86.msi is now available to install [10/21/2011, 22:15:52]Creating new Performer for MSI item [10/21/2011, 22:15:52] Action: Performing Action on MSI at F:\DOCUME~1\Owner\LOCALS~1\Temp\Microsoft .NET Framework 4 Client Profile Setup_4.0.30319\netfx_Core_x86.msi... [10/21/2011, 22:15:52]Log File F:\DOCUME~1\Owner\LOCALS~1\Temp\Microsoft .NET Framework 4 Client Profile Setup_20111021_221545515-MSI_netfx_Core_x86.msi.txt does not yet exist but may do at Watson upload time [10/21/2011, 22:15:52]Calling MsiInstallProduct(F:\DOCUME~1\Owner\LOCALS~1\Temp\Microsoft .NET Framework 4 Client Profile Setup_4.0.30319\netfx_Core_x86.msi, EXTUI=1 [10/21/2011, 22:17:14]MSI (F:\DOCUME~1\Owner\LOCALS~1\Temp\Microsoft .NET Framework 4 Client Profile Setup_4.0.30319\netfx_Core_x86.msi) Installation failed. Msi Log: Microsoft .NET Framework 4 Client Profile Setup_20111021_221545515-MSI_netfx_Core_x86.msi.txt [10/21/2011, 22:17:14]PerformOperation returned 1603 (translates to HRESULT = 0x80070643) [10/21/2011, 22:17:14] Action complete [10/21/2011, 22:17:14]OnFailureBehavior for this item is to Rollback. [10/21/2011, 22:17:14] Action: Performing actions on all Items... [10/21/2011, 22:17:14] Action complete [10/21/2011, 22:17:14] Action complete [10/21/2011, 22:17:14]Final Result: Installation failed with error code: (0x80070643), "Fatal error during installation. " (Elapsed time: 0 00:01:29). [10/21/2011, 22:17:41]WM_ACTIVATEAPP: Focus stealer's windows WAS visible, NOT taking back focus SECOND LOG REQUESTED BELOW: MSI (s) (6C:EC) [22:17:13:828]: Invoking remote custom action. DLL: F:\WINDOWS\Installer\MSIBB4.tmp, Entrypoint: NgenUpdateHighestVersionRollback MSI (s) (6C:64) [22:17:13:984]: Executing op: ActionStart(Name=CA_NgenRemoveNicPFROs_I_DEF_x86.3643236F_FC70_11D3_A536_0090278A1BB8,,) MSI (s) (6C:64) [22:17:13:984]: Executing op: ActionStart(Name=CA_NgenRemoveNicPFROs_I_RB_x86.3643236F_FC70_11D3_A536_0090278A1BB8,,) MSI (s) (6C:64) [22:17:13:984]: Executing op: CustomActionRollback(Action=CA_NgenRemoveNicPFROs_I_RB_x86.3643236F_FC70_11D3_A536_0090278A1BB8,ActionType=17729,Source=BinaryData,Target=NgenRemoveNicPFROs,) MSI (s) (6C:AC) [22:17:13:984]: Invoking remote custom action. DLL: F:\WINDOWS\Installer\MSIBB5.tmp, Entrypoint: NgenRemoveNicPFROs MSI (s) (6C:64) [22:17:14:000]: Executing op: End(Checksum=0,ProgressTotalHDWord=0,ProgressTotalLDWord=0) MSI (s) (6C:64) [22:17:14:000]: Error in rollback skipped. Return: 5 MSI (s) (6C:64) [22:17:14:015]: No System Restore sequence number for this installation. MSI (s) (6C:64) [22:17:14:015]: Unlocking Server MSI (s) (6C:64) [22:17:14:015]: PROPERTY CHANGE: Deleting UpdateStarted property. Its current value is '1'. MSI (s) (6C:64) [22:17:14:031]: Note: 1: 1708 MSI (s) (6C:64) [22:17:14:031]: Product: Microsoft .NET Framework 4 Client Profile -- Installation failed. MSI (s) (6C:64) [22:17:14:078]: Cleaning up uninstalled install packages, if any exist MSI (s) (6C:64) [22:17:14:078]: MainEngineThread is returning 1603 MSI (s) (6C:EC) [22:17:14:171]: Destroying RemoteAPI object. MSI (s) (6C:9C) [22:17:14:171]: Custom Action Manager thread ending. MSI (c) (F4:C4) [22:17:14:203]: Decrementing counter to disable shutdown. If counter >= 0, shutdown will be denied. Counter after decrement: -1 MSI (c) (F4:C4) [22:17:14:203]: MainEngineThread is returning 1603 === Verbose logging stopped: 10/21/2011 22:17:14 ===

    Read the article

  • CodePlex Daily Summary for Tuesday, February 23, 2010

    CodePlex Daily Summary for Tuesday, February 23, 2010New Projects.NET Beginners: This project is a summary of project for first time developer and .net beginners. the aim is to provide tools and libraries to get startet with dev...A simple ASP.NET Currency / Money TextBox User Control: A ASP.NET TextBox control used with AJAX maskeditextender makes it possible to enter numbers but it's not very intuitive to use. CurrencyTextBox co...Academiki: Academik The project aims to be a university social network with content sharing and intellectual property. Academik makes it easier for students t...Acessando Campos com XPath Expression: Esse é um exemplo de como usar Xpath Expression na orchestration do Biztalk 2006. O Artigo do exemplo esta em www.biztalkbrasil.blogspot.comAg.CommandManager: A command manager implementation for Silverlights. Supports commanding to more or less any event using the ICommand interfaceApunta Notas: Apunta notas is just a note taking program that I created to learn WPF. Now you can write everything you need to remember or tell somebody. Or you...AzureKit: AzureKit provides a more direct approach to Azure's Table Service, which takes more advantage of the NoSQL nature of the storage medium.CRM 4.0 Distribute Workflow Activity: This plugin allows to execute a workflow for each entity that has a 1:N or N:N relationship to a given entity. For example: execute a workflow for...Dbg Shell: Dbg Shell replaces WinDbg for debugging dumps. All standard Dbg commands are supported. You can also write scripts in .Net assemblies to automated ...Egg Timer: Egg Timer is a very simple Windows Form application for setting short time-frame alarms.Enterprise Library Extensions: Extensions for the Microsoft Enterprise Library applications blocks which makes programming applications even easier.Event Calendar 2.0 Data Extractor: Really simple app to recover event calendar 2.0 information from iGoogle settings files and turn them into CSV format info for importing to other c...iTwiit: Silverlight Twitter Clientlibtym: Have your complete movie collection at a glance to manage all your movie files very comfortably!Metabolite Enterprise Libraries for EPiServer CMS using Page Type Builder: The Metabolite Enterprise libraries are a set of C# Class Libraries developed for use with EPiServer 5 R2 SP2+ projects using PageTypeBuilder. They...Metro UX: Metro UXMTI: -Personal Expense Tracker: Personal Expense Tracker helps you track your expenses. I tried to find simple win forms expense tracker but found none interesting, so i made one...rarouš: repository for rarouš.weblog articlesSacDotNetUG: SacDotNetUG is an ASP.NET MVC 2 Web application intended for the Sacramento .NET user group. This project servers 2 main goals: to promote the adop...ShellLight: ShellLight is essentially a graphical shell for Silverlight applications that enables a quick auto-complete launcher for features in your solution.Sina Weibo(Microblog): sina weibo .NET libraries and applications.Terrain Independant Navigating Automaton v2.0: This is where members of the Robot Design Team from Stony Brook University come together and work on our unique TINA. This project is for a self-go...Url Rewrite.Net: Url Rewrite.Net is an open-source SEO project which contains Custom Http Module example and Custom Configrutaion Module.It is developed in C#.NET 2...WebPart and WebService Currency Converter: This is only a sample code how to get data from yahoo finance and how to implementing on Sharepoint WebPart or WebServices. This code it is freely...WPF AutoComplete TextBox Control: A AutoComplete TextBox Control written in WPF, Looks like the system built-in auto-completion(SHAutoComplete).ZWaveAPI: This project is aim to create an open class library on ZWave. It is based on article from digiWave.dk New Releases.NET Beginners: MathLab Visual Studio Project Template: First preview to a mathlab beginners library..NET Beginners: Turtle Visual Studio Project Template: The turtle engine is a very simlpe turtle which runs over a beach and leaves a track.A simple ASP.NET Currency / Money TextBox User Control: CurrencyTextBox Source v1.0: Source code with a test project.A simple ASP.NET Currency / Money TextBox User Control: CurrencyTextBox.dll: The User Control for use in projects.Acessando Campos com XPath Expression: Source Code SampleXPathExpression: O Source code contem o Projeto em Visual Studio 2005.Actipro WPF Controls Contrib: v2009.2 build 515: Minor tweaks and updated to target Actipro WPF Studio 2009.2 (build 515).Analysis Management System: 1.0.0.1 Update: Fix - Issue 4004 Nieuw - Beschikbare klanten kunnen nu bekeken worden via Extra/Aanvragers (Ctrl R)Apunta Notas: Apunta Notas 1.0 Release Candidate: There is the Release Candidate of Apunta Notas.ARSoft.Tools.Net - C# DNS and SPF Library: 1.2.0: Added asynchronous operations for DNS client.CRM 4.0 Distribute Workflow Activity: Beta: Initial release. Complete functionality, limited testing.Dbg Shell: First Public Release: First ReleaseDnDns and PocketDnDns - A .NET DNS Client Resolver Library: DnDns Library Release 2: A DNS protocol library written completely in managed code (C#). Supports common DNS records types like A, CNAME, MX, SRV, and more. Works on Window...Egg Timer: Egg Timer v1.0: Pretty simple application. Set the time directly or use the 5 minute and 1 hour increment/decrement buttons.EnhSim: EnhSim v1.9.7.2 BETA: 1.9.7.2 BETAImportant!: This beta version includes the changes to the Flame shock damage-over-time component which are currently on the PTR. Downlo...EnhSim: EnhSim v1.9.7.3 BETA: Important!: This beta version includes the changes to the Flame shock damage-over-time component which are currently on the PTR. Download 1.9.7.1 f...Esendex SMS SDK and Downloads for Microsoft.NET languages: Esendex .NET SDK v0.4.0: Features Messaging Service: Send a single SMS message and multiple SMS messages. Send a single Voice Message and multiple Voice Messages. Send...Event Calendar 2.0 Data Extractor: V1.0: First ever build of extractorExcelDna: ExcelDna Version 0.22: An important bugfix release that fixes a critical bug in the MultiThreaded marshaling support (under Excel 2007).InfoService: InfoService v1.5 Beta 8: InfoService Beta Release Please note this is a BETA. It should be stable, but i can't gurantee that! So use it on your own risk. Please read Plugi...Krypton Palette Selectors: Release 1.2: Adds the new KryptonPaletteContextMenu and refactors the KryptonPaletteDropButton to use it.kuuy static system: kss_v1.0beta: kuuy static sytem 1.0 beta editionlibtym: libtym: First public release version. Full functionality, tested. Please notify about bugs.mojoPortal: 2.3.3.9: see release notes on mojoPortal.com http://www.mojoportal.com/mojoportal-2339-released.aspx This release makes it easy to use Artisteer html templa...Net Tool: v1.01: User interface has been changedOpen NFSe: Open NFSe 0.1 (Salvador): Open NFSe 0.1 (Salvador)Paint.NET PSD Plugin: 1.0.7: Further substantial improvements in speed of both loading and saving. In particular, loading is about 5x as fast as in version 1.0.6. Saving is ...Project Starlight: 2.0: Release 2.0 final Changes: -Numerous stability fixes -Firefox 3.5 support -Safari 64 bit support (Snow Leopard) Mac and Windows Binaries are avai...RoTwee: RoTwee 5.0.0.1: This version fix for 16620Secure Data: Secure Data 2010.02.22.01: This version has been rewritten and contains many enhancements and I encourage anyone interested to download the source code and work through the Q...TreeSizeNet: TreeSizeNet 0.10.1: - Complete Redesign - Improved Stability - Improved Performance - PieChart for directory contentUrl Rewrite.Net: Beta V0.1 Release: Includes : -Custom Http Module -Custom Configuration Section Module ( in web.config) -Rewriting ModuleVCC: Latest build, v2.1.30222.0: Automatic drop of latest buildWebPart and WebService Currency Converter: CurrencyConverter.zip: CurrencyConverter.zip Have 3 Project on this files: 1. Library Project 2. Load Library Project Using Web Services 3. Load Library Project Using We...WSUS Smart Approve: 1.0.0.2: Fix: 25903ZuneConsole: ZuneConsole: Console GUI for the Zune Customs library, which should make everything work. This is what you should download.ZuneConsole: ZuneConsole How-To Manual: A quick (only 9 pages lol) tutorial on how to add custom artist info to your Zune.Most Popular ProjectsRawrWBFS ManagerAJAX Control ToolkitMicrosoft SQL Server Product Samples: DatabaseSilverlight ToolkitWindows Presentation Foundation (WPF)ASP.NETDotNetNuke® Community EditionImage Resizer Powertoy Clone for WindowsMicrosoft SQL Server Community & SamplesMost Active ProjectsDinnerNow.netRawrBlogEngine.NETNB_Store - Free DotNetNuke Ecommerce Catalog ModuleSharpyInfoServicejQuery Library for SharePoint Web ServicesPHPExcelpatterns & practices – Enterprise LibrarySharePoint Contrib

    Read the article

  • First toe in the water with Object Databases : DB4O

    - by REA_ANDREW
    I have been wanting to have a play with Object Databases for a while now, and today I have done just that.  One of the obvious choices I had to make was which one to use.  My criteria for choosing one today was simple, I wanted one which I could literally wack in and start using, which means I wanted one which either had a .NET API or was designed/ported to .NET.  My decision was between two being: db4o MongoDb I went for db4o for the single reason that it looked like I could get it running and integrated the quickest.  I am making a Blogging application and front end as a project with which I can test and learn with these object databases.  Another requirement which I thought I would mention is that I also want to be able to use the said database in a shared hosting environment where I cannot install, run and maintain a server instance of said object database.  I can do exactly this with db4o. I have not tried to do this with MongoDb at time of writing.  There are quite a few in the industry now and you read an interesting post about different ones and how they are used with some of the heavy weights in the industry here : http://blog.marcua.net/post/442594842/notes-from-nosql-live-boston-2010 In the example which I am building I am using StructureMap as my IOC.  To inject the object for db4o I went with a Singleton instance scope as I am using a single file and I need this to be available to any thread on in the process as opposed to using the server implementation where I could open and close client connections with the server handling each one respectively.  Again I want to point out that I have chosen to stick with the non server implementation of db4o as I wanted to use this in a shared hosting environment where I cannot have such servers installed and run.     public static class Bootstrapper    {        public static void ConfigureStructureMap()        {            ObjectFactory.Initialize(x => x.AddRegistry(new MyApplicationRegistry()));        }    }    public class MyApplicationRegistry : Registry    {        public const string DB4O_FILENAME = "blog123";        public string DbPath        {            get            {                return Path.Combine(Path.GetDirectoryName(Assembly.GetAssembly(typeof(IBlogRepository)).Location), DB4O_FILENAME);            }        }        public MyApplicationRegistry()        {            For<IObjectContainer>().Singleton().Use(                () => Db4oEmbedded.OpenFile(Db4oEmbedded.NewConfiguration(), DbPath));            Scan(assemblyScanner =>            {                assemblyScanner.TheCallingAssembly();                assemblyScanner.WithDefaultConventions();            });        }    } So my code above is the structure map plumbing which I use for the application.  I am doing this simply as a quick scratch pad to play around with different things so I am simply segregating logical layers with folder structure as opposed to different assemblies.  It will be easy if I want to do this with any segment but for the purposes of example I have literally just wacked everything in the one assembly.  You can see an example file structure I have on the right.  I am planning on testing out a few implementations of the object databases out there so I can program to an interface of IBlogRepository One of the things which I was unsure about was how it performed under a multi threaded environment which it will undoubtedly be used 9 times out of 10, and for the reason that I am using the db context as a singleton, I assumed that the library was of course thread safe but I did not know as I have not read any where in the documentation, again this is probably me not reading things correctly.  In short though I threw together a simple test where I simply iterate to a limit each time kicking a common task off with a thread from a thread pool.  This task simply created and added an random Post and added it to the storage. The execution of the threads I put inside the Setup of the Test and then simply ensure the number of posts committed to the database is equal to the number of iterations I made; here is the code I used to do the multi thread jobs: [TestInitialize] public void Setup() { var sw = new System.Diagnostics.Stopwatch(); sw.Start(); var resetEvent = new ManualResetEvent(false); ThreadPool.SetMaxThreads(20, 20); for (var i = 0; i < MAX_ITERATIONS; i++) { ThreadPool.QueueUserWorkItem(delegate(object state) { var eventToReset = (ManualResetEvent)state; var post = new Post { Author = MockUser, Content = "Mock Content", Title = "Title" }; Repository.Put(post); var counter = Interlocked.Decrement(ref _threadCounter); if (counter == 0) eventToReset.Set(); }, resetEvent); } WaitHandle.WaitAll(new[] { resetEvent }); sw.Stop(); Console.WriteLine("{0:00}.{1:00} seconds", sw.Elapsed.Seconds, sw.Elapsed.Milliseconds); }   I was not doing this to test out the speed performance of db4o but while I was doing this I could not help but put in a StopWatch and see out of sheer interest how fast it would take to insert a number of Posts.  I tested it out in this case with 10000 inserts of a small, simple POCO and it resulted in an average of:  899.36 object inserts / second.  Again this is just  simple crude test which came out of my curiosity at how it performed under many threads when using the non server implementation of db4o. The spec summary of the computer I used is as follows: With regards to the actual Repository implementation itself, it really is quite straight forward and I have to say I am very surprised at how easy it was to integrate and get up and running.  One thing I have noticed in the exposure I have had so far is that the Query returns IList<T> as opposed to IQueryable<T> but again I have not looked into this in depth and this could be there already and if not they have provided everything one needs to make there own repository.  An example of a couple of methods from by db4o implementation of the BlogRepository is below: public class BlogRepository : IBlogRepository { private readonly IObjectContainer _db; public BlogRepository(IObjectContainer db) { _db = db; } public void Put(DomainObject obj) { _db.Store(obj); } public void Delete(DomainObject obj) { _db.Delete(obj); } public Post GetByKey(object key) { return _db.Query<Post>(post => post.Key == key).FirstOrDefault(); } … Anyways I hope to get a few more implementations going of the object databases and literally just get familiarized with them and the concept of no sql databases. Cheers for now, Andrew

    Read the article

  • Need help with BOOST_FOREACH/compiler bug

    - by Jacek Lawrynowicz
    I know that boost or compiler should be last to blame, but I can't see another explanation here. I'm using msvc 2008 SP1 and boost 1.43. In the following code snippet execution never leaves third BOOST_FOREACH loop typedef Graph<unsigned, unsigned>::VertexIterator Iter; Graph<unsigned, unsigned> g; g.createVertex(0x66); // works fine Iter it = g.getVertices().first, end = g.getVertices().second; for(; it != end; ++it) ; // fine std::pair<Iter, Iter> p = g.getVertices(); BOOST_FOREACH(unsigned handle, p) ; // fine unsigned vertex_count = 0; BOOST_FOREACH(unsigned handle, g.getVertices()) vertex_count++; // oops, infinite loop vertex_count = 0; BOOST_FOREACH(unsigned handle, g.getVertices()) vertex_count++; vertex_count = 0; BOOST_FOREACH(unsigned handle, g.getVertices()) vertex_count++; // ... last block repeated 7 times Iterator code: class Iterator : public boost::iterator_facade<Iterator, unsigned const, boost::bidirectional_traversal_tag> { public: Iterator() : list(NULL), handle(INVALID_ELEMENT_HANDLE) {} explicit Iterator(const VectorElementsList &list, unsigned handle = INVALID_ELEMENT_HANDLE) : list(&list), handle(handle) {} friend std::ostream& operator<<(std::ostream &s, const Iterator &it) { s << "[list: " << it.list <<", handle: " << it.handle << "]"; return s; } private: friend class boost::iterator_core_access; void increment() { handle = list->getNext(handle); } void decrement() { handle = list->getPrev(handle); } unsigned const& dereference() const { return handle; } bool equal(Iterator const& other) const { return handle == other.handle && list == other.list; } const VectorElementsList<T> *list; unsigned handle; }; Some ASM fun: vertex_count = 0; BOOST_FOREACH(unsigned handle, g.getVertices()) // initialization 013E1369 mov edi,dword ptr [___defaultmatherr+8 (13E5034h)] // end iterator handle: 0xFFFFFFFF 013E136F mov ebp,dword ptr [esp+0ACh] // begin iterator handle: 0x0 013E1376 lea esi,[esp+0A8h] // begin iterator list pointer 013E137D mov ebx,esi 013E137F nop // forever loop begin 013E1380 cmp ebp,edi 013E1382 jne main+238h (13E1388h) 013E1384 cmp ebx,esi 013E1386 je main+244h (13E1394h) 013E1388 lea eax,[esp+18h] 013E138C push eax // here iterator is incremented in ram 013E138D call boost::iterator_facade<detail::VectorElementsList<Graph<unsigned int,unsigned int>::VertexWrapper>::Iterator,unsigned int const ,boost::bidirectional_traversal_tag,unsigned int const &,int>::operator++ (13E18E0h) 013E1392 jmp main+230h (13E1380h) vertex_count++; // forever loop end It's easy to see that iterator handle is cached in EBP and it never gets incremented despite of a call to iterator operator++() function. I've replaced Itarator implmentation with one deriving from std::iterator and the issue persisted, so this is not iterator_facade fault. This problem exists only on msvc 2008 SP1 x86 and amd64 release builds. Debug builds on msvc 2008 and debug/release builds on msvc 2010 and gcc 4.4 (linux) works fine. Furthermore the BOOST_FOREACH block must be repeaded exacly 10 times. If it's repeaded 9 times, it's all OK. I guess that due to BOOST_FOREACH use of template trickery (const auto_any), compiler assumes that iterator handle is constant and never reads its real value again. I would be very happy to hear that my code is wrong, correct it and move on with BOOST_FOREACH, which I'm very found of (as opposed to BOOST_FOREVER :). May be related to: http://stackoverflow.com/questions/1275852/why-does-boost-foreach-not-work-sometimes-with-c-strings

    Read the article

< Previous Page | 1 2 3 4 5 6  | Next Page >