memory usage in java

[Bala]

Java doesn't access memory from the local libraries, where as C and
C++ do that. why is that?

 

[Joseph Millar]

Java doesn't access memory from the local libraries, where as C and
C++ do that. why is that?

Not sure what you mean by memory from local libraries. If
you mean malloc() and such, in fact it does, but most of
the large memory allocations of the JVM are done using
some form of OS memory allocation routine, which is all
malloc() and its brethren use. The exact routines called
depend on OS and JVM implementation.

The JVM usually makes an initial large memory allocation,
called the Java heap. Code in Java that allocates objects
will have these objects created in the heap and managed by
the JVM. The heap is grown at need up to set limits (see
the -Xms and -Xmx startup parameters for more info on
controlling the size of the Java heap).

--Joe

 

[Roedy Green]

Java doesn't access memory from the local libraries, where as C and
C++ do that. why is that?

Java has its own memory allocation system that scavenges unused
objects. C/C++ requires the programmer to carefully free unused
objects. In practice he never gets all of them. They are two many
exception paths. See http://mindprod.com/jgloss/reference.html