moss.kernel
Class MKernel

java.lang.Object
  moss.kernel.MKernel

public class MKernel
extends java.lang.Object

Field Summary

static MProcess[]	current array of active processes by CPU.
static MProcess	init_task the special "init task"
static MProcessor[]	processors virtual processor objects
static MProcess	task_list task list

Constructor Summary

MKernel()

Method Summary

static void	add_to_run_queue(MProcess p) adds a process to the run-queue.
static void	add_to_task_list(MProcess p) adds a process to the global task list.
static void	deliver_process_signals(MProcess p) this delivers any pending signals to process p.
static void	ending_process(MProcess p, int exitcode) this is invoked by a process as it finishes.
static void	finalinit() this is called by the init-task as the first thing it does; final kernel setup happens here, and we're in the context of the init-process.
static MProcess	find_process(int pid) finds a process from its PID
static void	first_process(MProcess p) this is called once to set the first process up.
static int	get_free_pid() returns a free PID (and stops it being allocated again until released)
static MProcess[]	get_process_list() extracts a process list.
static void	init_kernel(MProcessor[] cpus, java.io.PrintStream msgs) initialises the kernel
static void	log_msg(java.lang.String msg) generates a kernel `log' message
static void	module_fault(MProcess p, java.lang.RuntimeException e) called when a kernel module generates a run-time error
static void	panic(java.lang.String message) causes a kernel panic; that aborts the simulator
static void	process_fault(MProcess p, java.lang.RuntimeException e) called when a process generates a run-time error (typically caught RuntimeExceptions for main-code or signal-handling).
static void	queue_signal(MProcess p, MSignal signal) queues a signal to be delivered to the given process
static void	quiet_add_to_run_queue(MProcess p) adds a process to the run-queue.
static void	release_free_pid(int pid) returns a used PID to the system
static void	remove_from_task_list(MProcess p) removes a process from the global task queue.
static void	schedule() this deschedules the current process, picks a new process from the run-queue and runs it.
static void	start_process(MProcess p) this is called to start a new process.
static void	starting_process(MProcess p) this is invoked by a process as it starts up -- not "running" as far as MOSS is concerned.

Methods inherited from class java.lang.Object

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

Field Detail

current

public static MProcess[] current

array of active processes by CPU.

init_task

public static MProcess init_task

the special "init task"

task_list

public static MProcess task_list

task list

processors

public static MProcessor[] processors

virtual processor objects

Constructor Detail

MKernel

public MKernel()

Method Detail

init_kernel

public static void init_kernel(MProcessor[] cpus,
                               java.io.PrintStream msgs)

initialises the kernel

Parameters:

cpus - array of virtual processors to use

msgs - somewhere we can write boot-messages

panic

public static void panic(java.lang.String message)

causes a kernel panic; that aborts the simulator

Parameters:

message - informational message

log_msg

public static void log_msg(java.lang.String msg)

generates a kernel `log' message

Parameters:

msg - log string (without terminating newline)

schedule

public static void schedule()

this deschedules the current process, picks a new process from the run-queue and runs it.

first_process

public static void first_process(MProcess p)

this is called once to set the first process up. It gets PID 1.

Parameters:

p - an INVALID MProcess (not started as a Thread, yet)

finalinit

public static void finalinit()

this is called by the init-task as the first thing it does; final kernel setup happens here, and we're in the context of the init-process.

starting_process

public static void starting_process(MProcess p)

this is invoked by a process as it starts up -- not "running" as far as MOSS is concerned. When this returns, it is as a properly running MOSS process. The other half of this is performed by start_process

Parameters:

p - process that is starting

ending_process

public static void ending_process(MProcess p,
                                  int exitcode)

this is invoked by a process as it finishes.

start_process

public static void start_process(MProcess p)

this is called to start a new process. The process given should be a non-started MProcess (extending Java's Thread).

Parameters:

p - process to be started

get_free_pid

public static int get_free_pid()

returns a free PID (and stops it being allocated again until released)

release_free_pid

public static void release_free_pid(int pid)

returns a used PID to the system

Parameters:

pid - process-ID no longer in use

quiet_add_to_run_queue

public static void quiet_add_to_run_queue(MProcess p)

adds a process to the run-queue. Does not attempt to schedule process.

add_to_run_queue

public static void add_to_run_queue(MProcess p)

adds a process to the run-queue. If its not already running, and there is a free-processor, it is dispatched immediately.

Parameters:

p - process to add. Must not be on any other queue!

add_to_task_list

public static void add_to_task_list(MProcess p)

adds a process to the global task list. Should only be used when creating a new process.

Parameters:

p - process to add

remove_from_task_list

public static void remove_from_task_list(MProcess p)

removes a process from the global task queue. Should only be used when destroying a process.

Parameters:

p - process to remove

find_process

public static MProcess find_process(int pid)

finds a process from its PID

Parameters:

pid - PID of process to search for

Returns:

MProcess reference on success, or null if not found

deliver_process_signals

public static void deliver_process_signals(MProcess p)

this delivers any pending signals to process p. This (p) *must* be the/a current process..

Parameters:

p - a current process

queue_signal

public static void queue_signal(MProcess p,
                                MSignal signal)

queues a signal to be delivered to the given process

Parameters:

p - process to be signalled

signal - signal to be delivered

get_process_list

public static MProcess[] get_process_list()

extracts a process list. This returns an array of MProcess's, that are semi-populated copies of the real ones. There must be at least one..!

Returns:

array of process "control blocks"

process_fault

public static void process_fault(MProcess p,
                                 java.lang.RuntimeException e)

called when a process generates a run-time error (typically caught RuntimeExceptions for main-code or signal-handling).

Parameters:

p - process that faulted

e - Java RuntimeException generated

module_fault

public static void module_fault(MProcess p,
                                java.lang.RuntimeException e)

called when a kernel module generates a run-time error

Parameters:

p - process that faulted

e - Java RuntimeException generated