tasking.c File Reference

#include "cpu/halt.h"
#include "cpu/paging.h"
#include "cpu/serial.h"
#include "cpu/tasking_helpers.h"
#include "kmalloc.h"
#include "tasking.h"
#include <sys/types.h>

Macros
#define	MAX_PROCS   32768
	Maximum number of processes that can be running at a time.
#define	HAS_UNBLOCKED_THREADS(proc)   (proc->numThreads!=proc->numThreadsBlocked)
	Macro to check whethe a process has unblocked threads.
#define	NUM_UNBLOCKED_THREADS(proc)   (proc->numThreads-proc->numThreadsBlocked)
	Macro to get the number of unblocked threads for a process.
#define	SAME_PROC(thread1, thread2)   (thread1->process->pid==thread2->process->pid)
	Macro to check whether two threads have the same PID.
#define	SAME_THREAD(thread1, thread2)   (thread1->process->pid==thread2->process->pid&&thread1->tid==thread2->tid)
	Macro to check whether two threads have the same PID and TID.

Functions
static char	is_proc_scheduled (pid_t index)
static void	mark_proc_scheduled (pid_t index)
static void	unmark_proc_scheduled (pid_t index)
void	tasking_create_task (void *eip, void *cr3, char kmode, char param1_exists, void *param1_arg, char param2_exists, void *param2_arg, char isThread)
void	tasking_init ()
char	tasking_is_privleged ()
pid_t	tasking_get_PID ()
int *	tasking_get_errno_address ()
pid_t	tasking_new_thread (void *start, pid_t pid, char param_exists, void *param_arg)
void	switch_to_thread (Thread *thread)
void	tasking_yield ()
void	tasking_block (thread_state newstate)
void	tasking_unblock (pid_t pid, pid_t tid)
void	tasking_exit (int code)

Variables
pid_t	next_pid =0
	PID to use for the next created process.
size_t	num_procs =0
	Number of non-exited processes.
Process *	processes [MAX_PROCS]
	Array pf processes by PID.
char	proc_schedule_bmap [MAX_PROCS/8]
	Bitmap of what processes are scheduled.
Thread *	current_thread
	Currently running thread.
static Thread *	ready_to_run_head =NULL
	Head of the linked list of ready to run threads.
static Thread *	ready_to_run_tail =NULL
	Tail of the linked list of ready to run threads.

Function Documentation

is_proc_scheduled()

static char is_proc_scheduled ( pid_t  index )

static

Check whether a process is scheduled

Parameters

index

The PID to check

Returns

whether the process is scheduled

mark_proc_scheduled()

static void mark_proc_scheduled ( pid_t  index )

static

Mark a process as scheduled

Parameters

index

The PID to mark

switch_to_thread()

void switch_to_thread

(

Thread *

thread

)

Switch to a thread and schedule the next ready thread in the current process, if there is one.

Parameters

thread

The thread to switch to

tasking_block()

void tasking_block

(

thread_state

newstate

)

Block the current thread & yield

Parameters

newstate

The state to block it in

tasking_create_task()

void tasking_create_task	(	void *	eip,
		void *	cr3,
		char	kmode,
		char	param1_exists,
		void *	param1_arg,
		char	param2_exists,
		void *	param2_arg,
		char	isThread
	)

Create a task

Parameters

eip	The start address of the task
cr3	The address space of the task
kmode	Whether the task is a kernel mode task
param1_exists	Whether param1_arg is a valid value
param1_arg	The thread's start function first parameter
param2_exists	Whether param2_arg is a valid value
param2_arg	The thread's start function second parameter/
isThread	Whether we are creating a new process or a thread in a process. If we are creating a theead, param2_arg becomes the PID for the newly created thread, and param2_exists must be 0.

tasking_exit()

void tasking_exit

(

int

code

)

Terminate the current thread If the main thread terminates, the whole process terminates.

Note

Currently, calling tasking_exit from any thread terminates the whole process.

Parameters

code	The exit code of the thread

tasking_get_errno_address()

int* tasking_get_errno_address

(

)

Get the adddress of errno for the current thread

Returns

The address of errno

tasking_get_PID()

pid_t tasking_get_PID

(

)

Get the PID of the current thread.

Returns

The current thread's PID

tasking_init()

void tasking_init

(

)

Initialize tasking

tasking_is_privleged()

char tasking_is_privleged

(

)

Check whether the current process is privleged

Returns

whether the current process is privleged

tasking_new_thread()

pid_t tasking_new_thread	(	void *	start,
		pid_t	pid,
		char	param_exists,
		void *	param_arg
	)

Create a new thread

Parameters

start	The start address of the task
pid	The PID that gets the new thread
param_exists	Whether param_arg is a valid value
param_arg	The thread's start function parameter

Returns

the TID of the thread

tasking_unblock()

void tasking_unblock	(	pid_t	pid,
		pid_t	tid
	)

Unblock a thread

Parameters

pid	The PID that contains the thread to unblock
tid	The TID in the process to unblock.

tasking_yield()

void tasking_yield

(

)

Yield to the next ready thread in any process

unmark_proc_scheduled()

static void unmark_proc_scheduled ( pid_t  index )

static

Unmark a process as scheduled

Parameters

index

The PID to unmark