what is diffrence between jav and dalvik machine?
A:
The jvm architecture is stack-based whereas the dvm architecture is register-based. Stack-based machines require more instructions(i.e. larger instruction set) than register-based machines for the same task. On the other side, each instruction in the register-based machines are larger.
off-hook
2010-08-10 06:31:47
A:
Conceptually, there is little difference from an application level between a DVM and a JVM. Architecturally, there is a major difference between the registerbased DVM and the stack-based JVM.
Both use a VM code model. However, the DVM uses registerbased opcodes that are comparable to the register-based bytecode instructions that most of the target platforms already execute. This includes architectures such as those available from ARM and MIPS and the x86-compatible architectures from Intel, AMD, and VIA Technologies.
Google developed Android and chose DVM for several reasons. First, there were licensing issues with most JVMs. Next, the DVM should be more efficient in terms of memory usage and performance on a register-based machine. DVM is also supposed to be more efficient when running multiple instances of the DVM. Applications are given their own instance. Hence, multiple active applications require multiple DVM instances. Like most Java implementations, the DVM has an automatic garbage collector.
DixonD
2010-08-10 06:33:42