Software Complexity

Software is more complex, for the effort and the expense required to construct it, than most artifacts produced by human endeavor. Assuming it costs $ 50 (USD) per line of code to construct a one - million line program (specify, design, implement, verify, validate, and deliver it), the resulting cost will be $ 50,000,000. While this is a large sum of money, it is a small fraction of the cost of constructing a complex spacecraft, a skyscraper, or a naval aircraft carrier.

Brooks says, “ Software entities are more complex for their size [emphasis added] than perhaps any other human construct, because no two parts are alike (at least
above the statement level). ” It is diffi cult to visualize the size of a software program because software has no physical attributes; however, if one were to print a one - million line program the stack of paper would be about 10 feet (roughly 3 meters) high if the program were printed 50 lines per page. The printout would occupy a volume of about 6.5 cubic feet. Biological entities such as human beings are of similar volume and they are far more complex than computer software, but there are few, if any, human - made artifacts of comparable size that are as complex as software.

How is the java memory pool divided?

Heap memory

The heap memory is the runtime data area from which the Java VM allocates memory for all class instances and arrays. The heap may be of a fixed or variable size. The garbage collector is an automatic memory management system that reclaims heap memory for objects.

• Eden Space: The pool from which memory is initially allocated for most objects.
• Survivor Space: The pool containing objects that have survived the garbage collection of the Eden space.
• Tenured Generation: The pool containing objects that have existed for some time in the survivor space.

Non-heap memory

Non-heap memory includes a method area shared among all threads and memory required for the internal processing or optimization for the Java VM. It stores per-class structures such as a runtime constant pool, field and method data, and the code for methods and constructors. The method area is logically part of the heap but, depending on the implementation, a Java VM may not garbage collect or compact it. Like the heap memory, the method area may be of a fixed or variable size. The memory for the method area does not need to be contiguous.

• Permanent Generation: The pool containing all the reflective data of the virtual machine itself, such as class and method objects. With Java VMs that use class data sharing, this generation is divided into read-only and read-write areas.
• Code Cache: The HotSpot Java VM also includes a code cache, containing memory that is used for compilation and storage of native code.

Here's some documentation on how to use Jconsole.

Sheep

Harmlessly passing your time in the grassland away
Only dimly aware of a certain unease in the air
You better watch out,
There may be dogs about
I've looked over Jordan, and I have seen.
Things are not what they seem

Alice In Chains - Man In The Box

Elaboração de um PDTI (Plano Diretor de Tecnologia da Informação)

  Elaboração de PDTI

Prisoner Dilemma

Fail, Leis, Negócios, Princípios

Lex Animata - Uma Constituição não Promulgada from Paulo Vasconcellos