Static memory allocation
Encyclopedia
Static memory allocation refers to the process of allocating memory at compile-time
before the associated program is executed, unlike dynamic memory allocation or automatic memory allocation
where memory is allocated as required at run-time.
An application of this technique involves a program module (e.g. function or subroutine
) declaring static data locally, such that these data are inaccessible in other modules unless references to it are passed as parameters or returned. A single copy of static data is retained and accessible through many calls to the function in which it is declared. Static memory allocation therefore has the advantage of modularising data within a program design in the situation where these data must be retained through the runtime of the program.
The use of static variable
s within a class in object oriented programming enables a single copy of such data to be shared between all the objects of that class.
Object constants known at compile-time, like string literal
s, are usually allocated statically. In object-oriented programming, the virtual method table
s of classes are usually allocated statically. A statically defined value can also be global
in its scope ensuring the same immutable
value is used throughout a run for consistency.
Static memory allocation may be used to create queues or stack.
Compile time
In computer science, compile time refers to either the operations performed by a compiler , programming language requirements that must be met by source code for it to be successfully compiled , or properties of the program that can be reasoned about at compile time.The operations performed at...
before the associated program is executed, unlike dynamic memory allocation or automatic memory allocation
Automatic memory allocation
In computer programming, an automatic variable is a lexically-scoped variable which is allocated and de-allocated automatically when program flow enters and leaves the variable's scope...
where memory is allocated as required at run-time.
An application of this technique involves a program module (e.g. function or subroutine
Subroutine
In computer science, a subroutine is a portion of code within a larger program that performs a specific task and is relatively independent of the remaining code....
) declaring static data locally, such that these data are inaccessible in other modules unless references to it are passed as parameters or returned. A single copy of static data is retained and accessible through many calls to the function in which it is declared. Static memory allocation therefore has the advantage of modularising data within a program design in the situation where these data must be retained through the runtime of the program.
The use of static variable
Static variable
In computer programming, a static variable is a variable that has been allocated statically — whose lifetime extends across the entire run of the program...
s within a class in object oriented programming enables a single copy of such data to be shared between all the objects of that class.
Object constants known at compile-time, like string literal
String literal
A string literal is the representation of a string value within the source code of a computer program. There are numerous alternate notations for specifying string literals, and the exact notation depends on the individual programming language in question...
s, are usually allocated statically. In object-oriented programming, the virtual method table
Virtual method table
A virtual method table, virtual function table, dispatch table, or vtable, is a mechanism used in a programming language to support dynamic dispatch ....
s of classes are usually allocated statically. A statically defined value can also be global
Global variable
In computer programming, a global variable is a variable that is accessible in every scope . Interaction mechanisms with global variables are called global environment mechanisms...
in its scope ensuring the same immutable
Immutable object
In object-oriented and functional programming, an immutable object is an object whose state cannot be modified after it is created. This is in contrast to a mutable object, which can be modified after it is created...
value is used throughout a run for consistency.
Static memory allocation may be used to create queues or stack.
See also
- ConstantConstant (programming)In computer programming, a constant is an identifier whose associated value cannot typically be altered by the program during its execution...
- Dynamic memory allocation
- Global variableGlobal variableIn computer programming, a global variable is a variable that is accessible in every scope . Interaction mechanisms with global variables are called global environment mechanisms...