visual basic barcode generator Host s supervisor code 2 AppDomain Boundary 5 in .NET

Generation qr-codes in .NET Host s supervisor code 2 AppDomain Boundary 5

11111111 11111111 11111000 00000000

Platform fragmentation is a serious challenge for mobile software developers. Already, developers are often asked to support multiple platforms the market is the mobile market, not just users of a specific smartphone. Thus, many developers are tasked with writing an application not just for an iPhone, Android, or Nokia, but they also write for all three. Seemingly worse is that it appears Nokia isn t just one platform, but several. To address this challenge, Nokia products support a number of development platforms across product lines. Key platforms include: Qt with C++ Browser-based applications leveraging HTML5, JavaScript, and CSS Java ME Flash Table 1 1 shows Nokia s phone platforms and the development options available for each. To summarize, Nokia provides Qt as the definitive platform for smartphone development, spanning both Symbian and MeeGo. For developers with legacy web

Configure the client computers to obtain an address automatically and the critical servers to specify a default gateway of 192.168.0.1.

Figure 19 5 : The managed heap showing pointers that moved from the finalization list to the freachable queue In this figure, you see that the memory occupied by objects B, G, and H has been reclaimed because these objects didn t have a Finalize method that needed to be called. However, the memory occupied by objects E, I, and J couldn t be reclaimed because their Finalize methods haven t been called yet. A special high priority CLR thread is dedicated to calling Finalize methods. A dedicated thread is used to avoid potential thread synchronization situations that could arise if one of the application s threads was used instead. When the freachable queue is empty (the usual case), this thread sleeps. But when entries appear, this thread wakes, removes each entry from the queue, and calls each object s Finalize method. Because of the way this thread works, you shouldn t execute any code in a Finalize method that makes any assumptions about the thread that s executing the code. For example, avoid accessing thread local storage in the Finalize method. The interaction between the finalization list and the freachable queue is fascinating. First I ll tell you how the freachable queue got its name. Well, the f is obvious and stands for finalization : every entry in the freachable queue should have its Finalize method called. But the "reachable" part of the name means that the objects are reachable. To put it another way, the freachable queue is considered a root just as global and static variables are roots. So if an object is on the freachable queue, the object is reachable and is not garbage. In short, when an object isn t reachable, the garbage collector considers the object garbage. Then when the garbage collector moves an object s entry from the finalization list to the freachable queue, the object is no longer considered garbage and its memory can t be reclaimed. At this point, the garbage collector has finished identifying garbage. Some of the objects identified as garbage have been reclassified as not garbage: in a sense, the object has become resurrected. The garbage 364

public sealed class Program { public static void Main() { Rational r1 = 5; // Implicit cast from Int32 to Rational Rational r2 = 2.5F; // Implicit cast from Single to Rational Int32 x = (Int32) r1; Single s = (Single) r2; } } // Explicit cast from Rational to Int32 // Explicit cast from Rational to Single

IPHostEntry x_hostentry = Dns.GetHostByName("www.microsoft.com"); IPAddress x_addr = x_hostentry.AddressList[0]; IPEndPoint x_endpoint = new IPEndPoint(x_addr, 80);

Notice how the code first checks to see if logging is enabled. There is no point using valuable processor cycles and memory generating log entries if they aren t going anywhere. The Filters section of the Logging block configuration can contain a special filter named the Log Enabled Filter (we have configured one in our example application). This filter has the single property, Enabled, that allows administrators to enable and disable all logging for the block. When it is set to False, the IsLoggingEnabled property of the LogWriter will return false as well. The example produces the following result. All of the events are sent to the General category, which is configured to write events to the Windows Application Event Log (this is the default configuration for the block).

DECLARE @roomid AS VARCHAR(10), @seats AS INT, @eventid AS INT, @attendees AS INT; DECLARE @Result AS TABLE(roomid VARCHAR(10), eventid INT);

This is an ugly test to have to read through if you re not interested in the test itself. By putting it into a boolean function, you can isolate the test and allow the reader to forget about it unless it s important. Here s how you could put the if test into a function:

namespace parameter sets the namespace of your web service. This should be a domain name under your control and where your web service is hosted. Visual Studio uses the http://tempuri.org namespace as a placeholder until you define your actual namespace. As an example, suppose again that you are creating a web service centered on exposing author information from the pubs database. You would define your class inside the Authors.cs file as discussed previously. You could then add the WebService attribute to the class, as shown in the following code.

10, 10, 10, 10, 10, 10, 10, 10, 10,

9