2.3 Binary Layout and Compiler Dependencies When a call to a virtual function is made through a base class pointer (i.e. a late binding call), the compiler quietly inserts code to fetch the VTABLE pointer (VPTR) and look up the requested method address in the VTABLE, thus calling it and causing late binding to take place. All of this VTABLE setting up for each class, initializing the VPTR and inserting the code for the virtual function call, happens automatically. Figure 5 shows the binary layout of a tlm fw transport if object and how a b transport virtual method invocation using two different object pointers, is resolved from the point of view of Microsoft VC++ and GCC 4.1 compilers. This situation is more complex since two key object- oriented features, such as polymorphic calls and multiple inheritance, are used at the same time. For TLM2 interfaces the arrangement of both compilers is as follows: • Microsoft Visual C++ 2008 (VC) distributes the information on each inherited class by placing them one next to another. If an inherited class has virtual methods, a pointer to its particular VTABLE is included. Since each interface has only one virtual method, there are four VTABLEs with only one entry pointing to the particular implementation of each method. When a call is made through a base class pointer, tlm fw transport if *p fw in Figure 5, the pointer is adjusted to point to its specific VPTR and class data. This pointer modification is known as pointer fix-up. Finally, since each interface has only one method, the first entry of the current VTABLE (i.e. entry 0) is used to call the right method. • The GCC 4.1 compiler places information on all classes at the beginning of the object. Depending on the kind of pointer used to ... ... middle of paper ... ... up of the following methods: • b transport wrapper: The start address of this method is inserted into the corresponding VTABLE entry of the intercepted target socket. It just redirects the call to b transport processing. • b transport processing (virtual): This method implements the desired behaviour of the wrapper. The default implementation in the base class just calls b transport original path resulting in a pass-through mode. As it is declared virtual, this method is intended to be redefined in the derived class for specialized behaviour. • b transport original path: This method is used to call the original entry of the modified VTABLE in order to maintain the overall transaction path. The WIL class has four methods: • wil get fw interface: For internal use. This method gets the TLM2 forward interface pointer given the hierarchical SystemC name of the socket.
When controlling communications of multiple devices are outlined on defined procedures. Arbitration structures are essential in the control of the bus communications in the presence of multiple devices.
Skeleton: which is a server side stub. It is responsible for unmarshalling arguments, invokes methods, marshals results and sends the results to sending proxy
This occurs when special carrier proteins carry solutes dissolved in the water across the membrane by using active transport. When the concentration gradient can not allow travel from one side of the membrane to the other fast enough for the cell’s nutritional needs, then facilitated diffusion is used. The transport protein is specialized for the solute it is carrying, just as enzymes are specialized for their substrate. The transport protein can be
The first end system requires to transmit the packet to the second link = L/R2
Leading pointer: This strategy ties the normal part needs to an alternate foreseen movement, for example, machine introduces or machine evacuations.
Active transport is the mediated transport of biochemical, and other atomic molecular substances across membrane. This process requires the expenditure of cellular energy to move molecules uphill against a gradient. It is also involves the use of a protein carrier to transfer a specifics substance across the membrane, but against its concentration
Fr om the articles in the modules that I have read in class these authors explain the
...plying with this communication, the path of the connection is now going back towards the user, opposite of the original intent.
At the outset, before the advent of user friendly operating systems, computers were run using the operating system CP/M (Control Program for Microcomputers). The program itself looked simple, but the complexity of its use meant that not many fully understood how to use it. As the program was also limited in use, since it was designed for 8-bit systems, a new operating system was needed when 16-bit IBM systems came out.
Virtualization technologies provide isolation of operating systems from hardware. This separation enables hardware resource sharing. With virtualization, a system pretends to be two or more of the same system [23]. Most modern operating systems contain a simplified system of virtualization. Each running process is able to act as if it is the only thing running. The CPUs and memory are virtualized. If a process tries to consume all of the CPU, a modern operating system will pre-empt it and allow others their fair share. Similarly, a running process typically has its own virtual address space that the operating system maps to physical memory to give the process the illusion that it is the only user of RAM.
Implementation of the virtual machine is difficult. A lot of work is required to provide an exact duplicate of the underlying machine, which has both the user mode and kernel mode. The virtual machine software can run in kernel mode since it is the operating system, where the virtual machine itself can only execute in user mode. In a virtual machine implementation, there must be a virtual user mode and a virtual kernel mode, both of which run in a physical user...
Von Neumann architecture, or the Von Neumann model, stems from a 1945 computer architecture description by the physicist, mathematician, and polymath John von Neumann and others. This describes a design architecture for an electronic digital computer with a control unit containing an instruction register and program counter , external mass storage, subdivisions of a processing unit consisting of arithmetic logic unit and processor registers, a memory to store both data and commands, also an input and output mechanisms. The meaning of the term has grown to mean a stored-program computer in which a command fetch and a data operation cannot occur at the same time because they share a common bus. This is commonly referred to as the Von Neumann bottleneck and often limits the performance of a system.
Explain in around 600 words, citing any literature you have consulted, what is meant by these terms in relation of object-oriented software design, and explain how they relate to the design you developed in your group.
Consecutive Voyage Charter or commonly known as CVC is a special type of a voyage charter where the vessel is contracted for several voyages which follow consecutively upon each other. It is similar to a voyage charter and shares its fundamental features such as freight, laytime, demurrage provisions and risk of delay on the owners. The main idea behind a CVC is that trading