org.jikesrvm.runtime

Class FileSystem

java.lang.Object

org.jikesrvm.runtime.FileSystem

public class FileSystem
extends Object

Interface to filesystem of underlying operating system. Historically this has provided a blocking IO abstraction on top of non-blocking IO, which was necessary for green threads. The current code contains only abstractions for dealing with things like file status.

Constructor Summary

Constructors

Constructor and Description
FileSystem()

Method Summary

Modifier and Type	Method and Description
static void	initializeStandardStreams() Called from VM.boot to set up java.lang.System.in, java.lang.System.out, and java.lang.System.err
static int	readByte(int fd) Read single byte from file.
static int	readBytes(int fd, byte[] buf, int off, int cnt) Reads multiple bytes.
static int	writeByte(int fd, int b) Write single byte to file
static int	writeBytes(int fd, byte[] buf, int off, int cnt) Writes multiple bytes.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FileSystem

public FileSystem()

Method Detail

readByte

public static int readByte(int fd)

Read single byte from file.

Parameters:

fd - file descriptor

Returns:

byte that was read (< -2: i/o error, -2: timeout, -1: eof, >= 0: data)

writeByte

public static int writeByte(int fd,
                            int b)

Write single byte to file

Parameters:

fd - file descriptor

b - byte to be written

Returns:

-2: i/o error, -1: timeout, 0: ok

readBytes

public static int readBytes(int fd,
                            byte[] buf,
                            int off,
                            int cnt)

Reads multiple bytes.

Parameters:

fd - the file descriptor for the file that should be read from

buf - a pinned byte array to read into

off - the offset in the buffer to read into

cnt - the number of bytes to read

Returns:

-2: i/o error, -1: timeout, >=0: number of bytes read

writeBytes

public static int writeBytes(int fd,
                             byte[] buf,
                             int off,
                             int cnt)

Writes multiple bytes.

Parameters:

fd - the file descriptor for the file that should be written to

buf - a pinned byte array to write from

off - the offset in the buffer to start writing from

cnt - the number of bytes to write

Returns:

-2: i/o error, -1: timeout, >=0: number of bytes written

initializeStandardStreams

public static void initializeStandardStreams()

Called from VM.boot to set up java.lang.System.in, java.lang.System.out, and java.lang.System.err