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Object-Oriented Programming in LabVIEW
Published in Rick Bitter, Taqi Mohiuddin, Matt Nawrocki, LabVIEW™ Advanced Programming Techniques, 2017
Rick Bitter, Taqi Mohiuddin, Matt Nawrocki
The significance of destructors is important for objects that communicate with the outside world. For internally used objects, such as our point and circle, or for objects simulating things like signals, no destructor is necessary. Unlike constructors, there is only one destructor for an object. In our implementation it is possible to construct multiple destructors, but this should be avoided. It will be obvious in the object design what items need to be closed out; this should all be done in one point. The act of destroying an object will require the use of only one destructor. Having multiple destructors will serve to confuse programmers more than it will help clarify the code.
Introduction
Published in Randall L. Eubank, Ana Kupresanin, Statistical Computing in C++ and R, 2011
Randall L. Eubank, Ana Kupresanin
The next new function is the destructor Matrix () and we need to discuss this concept a bit before proceeding further. All classes have destructors that are called every time a class object goes out of scope. Thus, for example, our Power class had a default destructor implicitly supplied by the compiler even though one was never explicitly defined. The compiler’s destructor simply releases the memory for each of the class members (i.e., for the integer power K in the Power class) whenever a Power object goes out of scope. While this works fine for Power objects, for objects from classes with dynamically allocated memory acquired with the new operator this behavior is problematic. As a case in point, for an object of class Matrix a compiler supplied destructor would release the memory that has been allocated to the pointer pA. At the instance when this happens pA points to memory locations that hold the values of pointers which, in turn, hold the addresses for blocks of memory that have been allocated to hold the row elements of a two-dimensional array. Deleting pA releases none of this latter memory and has the side effect of making it impossible to access any of the memory that was previously accessible by dereferencing pA. To avoid this type of memory leak it is necessary to provide an explicit destructor for the Matrix class that releases memory correctly as described in Section 3.5. This will be done in Listing 3.14 that provides the method definitions for the Matrix class. The general rule concerning destructors is that an explicit destructor should be supplied for any class that uses dynamic memory allocation.
C++ and Objective C
Published in Paul W. Ross, The Handbook of Software for Engineers and Scientists, 2018
If a constructor is concerned about the birth of an object, then a destructor is concerned about its death. A destructor function of a class is invoked whenever a dynamically allocated object is being deleted, or when a statically allocated object is going out of scope. The name of the constructor function is the name of the class preceded by a tilde.
Blockchain-based Light-weight Authentication Approach for a Multiple Wireless Sensor Network
Published in IETE Journal of Research, 2022
The study of cryptography examines methods for private communication while outside observers are present. A cryptographic protocol establishes a set of guidelines for inter-entity communication while offering certain security assurances. Initial, reaction, and completion needs are some of these. Security protocol design often abstracts the execution of cryptographic operations and makes a fantastic cryptography assumption. Either symmetric or asymmetric encryption may be used to protect the confidentiality of information submitted over an unsecured model. However, asymmetric encryption is far cheaper and more reliable in practice than the encryption process. However, creating a shared secret key is an issue that must be avoided [31]. Exponential key transfer, as defined by Diffie-Hellman, may be utilised if a passive attacker can be considered. Key generation, however, typically necessitates the implementation of a protocol that utilises asymmetric encryption and a public-key management infrastructure because this is not the norm (such as one that uses certificate authorities). The validation of authentication and secret key methods is the main topic of this thesis. As a result, the verification procedure must provide proof that authentication cannot be concealed and that an enemy could see or change the secret keys. We have decided to employ the Proverif symbolic model checker. One of Proverif's intriguing capabilities is that it enables verification of protocol operations over an essentially unlimited number of sessions. Another appealing aspect of this modelling tool is the applied pi calculus on which it is built. We employ function Object () [native code] and destructor functions defined by the user in Proverif for activities like encryption and decryption. We can define functions as equivalence relations in Proverif. The Diffie-Hellman exponentiation and other features can be represented in this way. There is no need to model the attacker because it is implicit in ProVerif.