Daryl Wilding-McBride - Java¿ Development on PDAs: Building Applications for Pocket PC and Palm Devices

This appendix describes the properties you can set to alter JeodeRuntime jeode.evm.memory settings.

[1] Reproduced with permission from Insignia Solutions.

jeode.evm.memory.compaction

[2] Denotes a property group.

jeode.evm.memory.size

jeode.evm.memory.overallSize

jeode.evm.memory.sysLimit

jeode.evm.memory.sysStart

jeode.evm.memory.sysExtend

jeode.evm.memory.javaLimit

jeode.evm.memory.javaStart

jeode.evm.memory.javaExtend

jeode.evm.memory.stackSize

jeode.evm.memory.stackOverflowZone

The overall amount of memory in the target machine, in bytes

Type : String

Default Value : 16 m

This property value is not used directly by the EVM, but is used to define appropriate default values for the following other types of memory properties:

• jeode.evm.memory.overallSize

• jeode.evm.memory.sysLimit

• jeode.evm.memory.javaLimit

• jeode.evm.memory.stackSize

• jeode.evm.compiler.ehSize

• jeode.evm.compiler.dataSize

• jeode.evm.compiler.codeBuffTotal

These default values represent Insignia's estimate of optimal generic settings for performance, based on this overall memory size. You can then alter these default values as required for your specific application and device.

Size of the stack overflow zone

Type : Integer

Default Value : 16 k

Must be positive

When a thread enters this zone, a stack overflow exception will be thrown.This needs to be less than the stack size setting. A value of zero indicates that stack overflow checks should not be performed.

The maximum amount of dynamic Java/System memory allowed

Type : Integer

Default Value : 15 m

Must be positive

This is the maximum amount of dynamic memory (in bytes) allowed at run-time for Java objects and EVM dataalso see notes for stack size. Dynamic memory use is that determined by JeodeRuntime at run-time, satisfied by dynamic memory allocation requests upon the target OS.

The dynamic memory acquired by JeodeRuntime is shared between:

• Java memory : relocatable, garbage collectable Java heap objects

• System memory : immovable Jeode "system" objects

Normally, either of these could (theoretically) occupy the whole of the dynamically allocated memory if run-time conditions required. You can also use the jeode.evm.memory.javaLimit and jeode.evm.memory.sysLimit properties to define ceiling values for Java or system memory usage if needed.

Note : To find static memory use (including the space occupied by the Jeode EVM executable and its predefined data structures), run a target-specific executable analyzer tool on your host (for example, objdump ).