use the operating system

... 0); // Close the files close(infd); close(outfd); Figure 6-36. A program fragment for copying a file using the UNIX system calls. This fragment is in C because Java hides the low-level system calls ... hardware) Context Valid Physical page Virtual page tag Flags (b) (c) Format is entirely defined by the operating system Translation table (Operating system) TSB (MMU + sofware) Context Entry 0 is shared by all virtual pages ending ... main class p = new producer( ); // create the producer c = new consumer( ); // create the consumer p.start( ); // start the producer c.start( ); // start the consumer } // This is a utility function...

Ngày tải lên: 12/12/2013, 09:15

Ngày tải lên: 19/03/2014, 13:35

... tasks. Many other operating systems have met with this problem. Often these systems solve the problem by using inside knowledge of the algorithms used to manage secondary storage. Unfortunately, the Mach ... architectures. Today, the concept of an extensible operating system is once again gaining acceptance this time as the solution to the unconstrained growth of UNIX. During the last 20 years operating systems and their ... message with the server to get access to the array and, if other clients had already referenced the data of the array, the physical memory cache of the array would be directly accessible to the client...

Ngày tải lên: 12/09/2012, 15:05

... with system messages—messages generated and dispatched by the system. The Message Protocols appendix of the Be Book defines all the system messages. In short, system messages fall into the following categories: Application ... 1) The name and data parameters serve the same purposes as their counterparts in the other Add routines—name serves as an identifier that’s used when later access- ing the data through the use ... 30.0 Regardless of whether the user launches AlertMessage from the desktop or from the shell, one window is always opened. The AlertMessage version of ArgvReceived() looks at the value the user typed in...

Ngày tải lên: 17/10/2013, 19:15

... For the Save file panel, the display of the panel comes when the user chooses the Save As item from the File menu. In response to the message issued by the system to the appropriate MessageReceived() ... control is in the hands of the user. Once the user confirms a choice (whether it’s a file selection in the Open file panel, a click on the Save button in the Save file panel, or a click on the Can- cel ... create the panel at any time, then display it only in response to the user’s request. For an Open file panel, that’s typically when the user chooses the Open item from the File menu. For the Save...

Ngày tải lên: 20/10/2013, 10:15

Ngày tải lên: 25/11/2013, 11:07

... an overview of the object-oriented nature of the BeOS. The remainder of the book fills in the details of the names, purposes, and uses of the important and commonly used classes. The BControl class ... organizing the files used in a project takes full advantage of the Be graphical user interface. Figure 1-7 shows the window that appears when you use the BeIDE to open the project file for the HelloWorld ... during the execution of a program. An object can be added or deleted from the heap without regard for its placement in the heap, or for the other contents of the heap. The stack, on the other hand,...

Ngày tải lên: 26/01/2014, 07:20

... file with the same name as the project (and thus the same name as the application that will be built from the project). The header file holds the definition of the class derived from the BApplication ... the current state of these characteristics. The font used to draw text in the view and the width of lines that are to be drawn in the view are two examples of these characteristics. The information ... parameter to the BWindow constructor, which comes from the HelloWindow constructor, sets the size of the window. The second parameter is a string that is used as the window’s title. The SimpleWindow...

Ngày tải lên: 26/01/2014, 07:20

... to another window. Class Descriptions and the Be Book The definitive source of information for the many classes that make up the BeOS software kits is the Be class reference by the programmers of the ... to them, some of their classes appear throughout the book. See the description of the Support Kit below for a specific example concerning the BLocker class. Application Kit The classes of the ... variables are declared—there’s no need to use the new operator. There’s also no need to use the delete operator to destroy such objects. The Constructor section reveals that there are four BRect...

Ngày tải lên: 26/01/2014, 07:20

... the time the mouse button was clicked. The values of the point are in the view’s coor- dinate system. For example, if the cursor was over the very top left corner of the view at the time of the mouse ... time of the mouse button click. The window that receives the message calls the BView hook function MouseDown() of the view the cursor was over at the time of the mouse button click. B_MOUSE_UP Reaches ... the user moves the cursor over the window. As the user drags the mouse, repeated B_MOUSE_MOVED messages are issued by the Application Server. As the cursor moves over one window to another, the...

Ngày tải lên: 26/01/2014, 07:20

... the user clicks the mouse in the MyDrawView view, MouseDown() makes the system aware of the fact that the view needs updating, and the system invokes Draw(): void MyDrawView::MouseDown(BPoint ... make use of it. That’s done in the Draw() function, where a call to MovePenTo() ensures that the drawing will start in the top left corner of the view (and, because the view is the same size as the ... defines one of the four edges of a rectangle. The values of the left and right members are relative to the left edge of the view that is to hold the rectangle, while the values of the top and bottom...

Ngày tải lên: 26/01/2014, 07:20

... bringing it back to the forefront doesn’t cause the border to disappear the update message that the Application Server sends to the MyHelloWindow window results in the calling of the Draw() function ... radio buttons? Answer: because I use the radio button view only as a means to group the radio buttons together—I don’t draw to the view. The simple approach of creating a BView on the fly works for that ... values to the variables to be used in the control’s con- structor • Create the control using new and the control’s constructor • Attach the control to the window by adding it to one of the window’s...

Ngày tải lên: 26/01/2014, 07:20

... as the item’s label when the user pulls down the menu in which the item appears. The message parameter assigns a message of a particular type to the menu item. When the user chooses the item, the ... given the variable used to represent the sub- menu the name subMenu, it really is nothing more than a BMenu object. The items in the Dogs submenu were added the same way as the items in the Animal menu—by ... are the interface between the user and the program, and are the primary means by which a user carries out tasks. A Be program that makes use of menus usually places a menubar along the top of the...

Ngày tải lên: 26/01/2014, 07:20

... When the contents of the view a scrollbar is attached to exceed the size of the view, the scrollbar’s knob appears and the scrollbar becomes enabled. As the content of the view increases, the ... fonts. Contradictory as it sounds, the user can change the font that’s used for any of the global system fonts. Figure 8-2 shows that the FontPanel preferences program lets the user pick a different plain, ... allows for the display of text in any font on the user’s computer. Querying the user’s machine for available fonts is a topic covered in the BFont section of the Interface Kit chapter of the Be Book. Figure...

Ngày tải lên: 26/01/2014, 07:20

... the process of how the router determines which path to use when forwarding a packet. l To determine the best path, the router searches its routing table for a network address that matches the ... will not be used in this curriculum. 18 Verify the router boot-up process l show version command is used to view information about the router during the bootup process (later). Inside the Router l ... is on the same network as one of its interfaces and it can sent the packet directly to the destination and not another router. l Since the exit interface is on an directly connected Ethernet...

Ngày tải lên: 09/03/2014, 13:20

Ngày tải lên: 18/03/2014, 00:20

Ngày tải lên: 07/04/2014, 15:52

Ngày tải lên: 28/06/2014, 02:20

Ngày tải lên: 01/07/2014, 17:30