moss.kernel
Class MProcess

java.lang.Object
  java.lang.Thread
      moss.kernel.MProcess

All Implemented Interfaces:

java.lang.Runnable

public class MProcess
extends java.lang.Thread

The MProcess class is effectively the process control block, it extends Thread so it can exist on its own.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

java.lang.Thread.State, java.lang.Thread.UncaughtExceptionHandler

Field Summary

java.lang.String[]	cmdline command-line arguments
MEnv	environ process environment
MFile[]	files array of open files (indexed by descriptor)
static int	INHERIT_OPEN_FILES
MKernelProcess	kernel_if handle on a system-process
boolean	ktask if true, a kernel-only process
MProcess	next previous and next processes on the run-queue
MProcess	next_task prev_task and next_task are a linked list of all processes
MProcess	parent link to parent process
MSignal	pending_signals queue of pending signals
moss.kernel.MProcess.PFS_mprocess	pfslink link to the proc-filesystem info handler
int	pid process id
int	ppid parent process id -- this is not used for active processes
MProcess	prev previous and next processes on the run-queue
MProcess	prev_task prev_task and next_task are a linked list of all processes
MProcess	q_next next process on a wait queue
int[]	sig_handling signal-handling states
boolean	signalled true if the process has been signalled (allows drivers/etc.
Semaphore	start_sem a semaphore used to synchronize process startup
int	state state holds the process's state (STOPPED, RUNNING, etc.)
java.lang.String	syscall string indicating what system-call the process is doing
static int	TASK_FINISHED
static int	TASK_INVALID
static int	TASK_RUNNABLE
static int	TASK_RUNNING
static int	TASK_SLEEPING
static int	TASK_STOPPED
static int	TASK_ZOMBIE
int	umask the process's file creation mask
MUserProcess	user_if handle on a user-process

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

MProcess()
MProcess constructor.

MProcess(MProcess parent)
MProcess constructor

Method Summary

static int	create_kernel_process(java.lang.String name, java.lang.String[] args) creates a new kernel process and adds it to the run-queue
static int	create_user_process(java.lang.String name, MProcess parent, java.lang.String[] args, int flags) creates a new user process and adds it to the run-queue
void	run() thread "run" method for an MProcess
static void	shutdown_process(MProcess p) this is used to tidy-up a process that's shutting down.
static boolean	sync_process_signals(MProcess p) this method is used by MPosixIf to deliver signals to a process.
void	terminate_process(int exitcode) this is called by MPosixIf's exit() to force a process to terminate

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Field Detail

prev

public MProcess prev

previous and next processes on the run-queue

next

public MProcess next

previous and next processes on the run-queue

q_next

public MProcess q_next

next process on a wait queue

prev_task

public MProcess prev_task

prev_task and next_task are a linked list of all processes

next_task

public MProcess next_task

prev_task and next_task are a linked list of all processes

state

public int state

state holds the process's state (STOPPED, RUNNING, etc.)

sig_handling

public int[] sig_handling

signal-handling states

pending_signals

public MSignal pending_signals

queue of pending signals

signalled

public boolean signalled

true if the process has been signalled (allows drivers/etc. to return EINTR)

pid

public int pid

process id

ppid

public int ppid

parent process id -- this is not used for active processes

parent

public MProcess parent

link to parent process

ktask

public boolean ktask

if true, a kernel-only process

files

public MFile[] files

array of open files (indexed by descriptor)

user_if

public MUserProcess user_if

handle on a user-process

kernel_if

public MKernelProcess kernel_if

handle on a system-process

cmdline

public java.lang.String[] cmdline

command-line arguments

start_sem

public Semaphore start_sem

a semaphore used to synchronize process startup

syscall

public java.lang.String syscall

string indicating what system-call the process is doing

umask

public int umask

the process's file creation mask

environ

public MEnv environ

process environment

pfslink

public moss.kernel.MProcess.PFS_mprocess pfslink

link to the proc-filesystem info handler

TASK_INVALID

public static final int TASK_INVALID

See Also:

Constant Field Values

TASK_STOPPED

public static final int TASK_STOPPED

See Also:

Constant Field Values

TASK_RUNNABLE

public static final int TASK_RUNNABLE

See Also:

Constant Field Values

TASK_RUNNING

public static final int TASK_RUNNING

See Also:

Constant Field Values

TASK_SLEEPING

public static final int TASK_SLEEPING

See Also:

Constant Field Values

TASK_FINISHED

public static final int TASK_FINISHED

See Also:

Constant Field Values

TASK_ZOMBIE

public static final int TASK_ZOMBIE

See Also:

Constant Field Values

INHERIT_OPEN_FILES

public static final int INHERIT_OPEN_FILES

See Also:

Constant Field Values

Constructor Detail

MProcess

public MProcess()

MProcess constructor. Should not be used for constructing things which will become processes; use the other constructor for that.

MProcess

public MProcess(MProcess parent)

MProcess constructor

Parameters:

parent - parent process

Method Detail

create_user_process

public static int create_user_process(java.lang.String name,
                                      MProcess parent,
                                      java.lang.String[] args,
                                      int flags)

creates a new user process and adds it to the run-queue

Parameters:

name - name of the class that provides the process

parent - parent process

args - arguments to be passed to the new process

flags - process creation flags (INHERIT_...)

Returns:

pid of new process on success, -1 on failure

create_kernel_process

public static int create_kernel_process(java.lang.String name,
                                        java.lang.String[] args)

creates a new kernel process and adds it to the run-queue

Parameters:

name - name of the class that provides the process

args - arguments to be passed to the new process

Returns:

pid of new process on success, -1 on failure

shutdown_process

public static void shutdown_process(MProcess p)

this is used to tidy-up a process that's shutting down.

Parameters:

p - process shutting down

terminate_process

public void terminate_process(int exitcode)

this is called by MPosixIf's exit() to force a process to terminate

Parameters:

exitcode - exit-code of the process

run

public void run()

thread "run" method for an MProcess

Specified by:

run in interface java.lang.Runnable

Overrides:

run in class java.lang.Thread

sync_process_signals

public static boolean sync_process_signals(MProcess p)

this method is used by MPosixIf to deliver signals to a process. The body is synchronized (on the process) to prevent races with other processes (on different virtual CPUs) delivering signals

Parameters:

p - process to handle signals for

Returns:

true if signals were processed, false otherwise