oshi.hardware

Interface VirtualMemory

All Known Implementing Classes:

AbstractVirtualMemory, FreeBsdVirtualMemory, LinuxVirtualMemory, MacVirtualMemory, SolarisVirtualMemory, WindowsVirtualMemory

public interface VirtualMemory

The VirtuallMemory class tracks information about the use of a computer's virtual memory (swap file) which temporarily moves rarely accessed information to a disk or other storage device.

Method Summary

Modifier and Type	Method and Description
long	getSwapPagesIn() Number of pages read from paging/swap file(s) to resolve hard page faults.
long	getSwapPagesOut() Number of pages written to paging/swap file(s) to free up space in physical memory.
long	getSwapTotal() The current size of the paging/swap file(s), in bytes.
long	getSwapUsed() The current memory committed to the paging/swap file(s), in bytes

Method Detail

getSwapTotal

long getSwapTotal()

The current size of the paging/swap file(s), in bytes. If the paging/swap file can be extended, this is a soft limit.

Returns:

Total swap in bytes.

getSwapUsed

long getSwapUsed()

The current memory committed to the paging/swap file(s), in bytes

Returns:

Swap used in bytes

getSwapPagesIn

long getSwapPagesIn()

Number of pages read from paging/swap file(s) to resolve hard page faults. (Hard page faults occur when a process requires code or data that is not in its working set or elsewhere in physical memory, and must be retrieved from disk.) This property was designed as a primary indicator of the kinds of faults that cause system-wide delays. It includes pages retrieved to satisfy faults in the file system cache (usually requested by applications) and in non-cached mapped memory files.

Returns:

Pages swapped in

getSwapPagesOut

long getSwapPagesOut()

Number of pages written to paging/swap file(s) to free up space in physical memory. Pages are written back to disk only if they are changed in physical memory, so they are likely to hold data, not code. A high rate of pages output might indicate a memory shortage. The operating system writes more pages back to disk to free up space when physical memory is in short supply.

Returns:

Pages swapped out