Search results
Results from the WOW.Com Content Network
Resource management therefore needs to be tied to the lifespan of suitable objects in order to gain automatic allocation and reclamation. Resources are acquired during initialization, when there is no chance of them being used before they are available, and released with the destruction of the same objects, which is guaranteed to take place ...
Object pooling requires resources – memory and possibly other resources, such as network sockets, and thus it is preferable that the number of instances in use at any one time is low, but this is not required. The pooled object is obtained in predictable time when creation of the new objects (especially over network) may take variable time.
This feature is often used to manage resource allocation and deallocation, like opening and then automatically closing files or freeing up memory, called Resource Acquisition Is Initialization (RAII). Since C++11, C++ allows variables to be declared with the auto type specifier, [3] but this means that the variable's type is inferred, and does ...
In manual memory allocation, this is also specified manually by the programmer; via functions such as free() in C, or the delete operator in C++ – this contrasts with automatic destruction of objects held in automatic variables, notably (non-static) local variables of functions, which are destroyed at the end of their scope in C and C++.
A singleton implementation may use lazy initialization in which the instance is created when the static method is first invoked. In multithreaded programs, this can cause race conditions that result in the creation of multiple instances. The following Java 5+ example [6] is a thread-safe implementation, using lazy initialization with double ...
In case of a more complicated object graph, such as multiple objects sharing a resource, or cycles between objects that hold resources, proper resource management can be quite complicated, and exactly the same issues arise as in object finalization (via destructors or finalizers); for example, the lapsed listener problem can occur and cause ...
In the language Rust, the type system has been extended to include also the variables lifetimes and resource acquisition is initialization. Unless one disables the features of the language, dangling pointers will be caught at compile time and reported as programming errors.
The C programming language manages memory statically, automatically, or dynamically.Static-duration variables are allocated in main memory, usually along with the executable code of the program, and persist for the lifetime of the program; automatic-duration variables are allocated on the stack and come and go as functions are called and return.