20191317王鹏宇第五章学习笔记

#-----------ts. s file-----------+		 
.global tswitch, scheduler, running 
tswitch:
SAVE:   pushal
        pushfl
        movl running, %ebx
        movl %esp , 4(%ebp)
FIND:   call scheduler
RESUME: movl running, %ebx
        movl 4(%ebx), %esp
        popfl
        popal
        ret

t.c file:

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <sys/time.h>

#define NPROC	9
#define SSIZE	1024
// PROC status	
#define FREE	0
#define READY	1
#define SLEEP	2
#define BLOCK	3
#define PAUSE	4
#define ZOMBIE  5

typedef struct	proc {  
    struct proc	*next;
    int ksp;	//
    int pid;	//
    int priority;	//
    int status;	//
    int event;	//
    int ppid;
    int exitStatus;
    int joinPid;	
    int time;	//
    int pause;	//
    int stack[SSIZE];	//
}PROC;	

PROC proc[NPROC];
PROC *freeList, *readyQueue, *running;
PROC *sleepList;
PROC *pauseList;
#include "queue.c"
//#include "wait.c" 

int menu()
{
    printf("**********menu**********\n");
    printf("* creat switch exit ps *\n");
    printf("************************\n");
}

int init()
{
    int i, j;
    PROC *p;
    for (i=0; i<NPROC; i++)
    {
        p = &proc[i];
        p->pid = i;
        p->priority = 1;
        p->status = FREE; 
        p->event = 0; 
        p->next = p+1;
    }
    proc[NPROC-1].next = 0;
    freeList = &proc[0];	// all PROCs in freeList
    readyQueue = 0;
    sleepList = 0;
    pauseList = 0;
    // create P0 as initial running task 
    running = dequeue(&freeList);
    running->status = READY;
    running->priority = 0; // P0 has lowest priority 0 
    printList("freeList", freeList);
    printf("init complete: P0 running\n");
}

int do_exit()
{
    printf("task %d exit: ", running->pid); 
    running->status = FREE; 
    running->priority = 0;
    enqueue(&freeList, running);
    printList("freeList", freeList); 
    tswitch();
}

int do_ps()
{
    printf("---------ps---------\n");
    printList("readyQueue", readyQueue);
    printList("sleepList ", sleepList);
    printf ("-------------------\n"); 
}

int create(void (f)(), void *parm) // create a new task
{
    int i;
    PROC *p = dequeue(&freeList);
    if (!p)
    {
        printf("create failed\n");
        return -1;
    }
    p->ppid = running->pid;
    p->status = READY;
    p->priority = 1;
    for (i=1; i<12; i++)
        p->stack[SSIZE-i] = 0;

    p->stack[SSIZE-1] = (int)parm;
    p->stack[SSIZE-2] = (int)do_exit;
    p->stack[SSIZE-3] = (int)f;
    p->ksp = &p->stack[SSIZE-12];
    enqueue(&readyQueue, p);
    printf("%d created a new task %d\n", running->pid, p->pid); 
    return p->pid;
}

int func(void *parm)
{
    char line[64], cmd[16];
    printf("task %d start: parm = %d\n", running->pid, parm); 
    while(1)
    {
        printf("task %d running\n", running->pid);
        menu();
        printf("enter a command line:");
        fgets(line, 64, stdin);
        line[strlen(line)-1] = 0; // kill \n at end of line 
        sscanf(line, "%s", cmd);
        if (strcmp(cmd, "create")==0)
            create((void *)func, 0);
        else if (strcmp(cmd, "switch")==0)
            tswitch();
        else if (strcmp(cmd, "exit")==0)
            do_exit();
        else if (strcmp(cmd, "ps")==0)
            do_ps();
    }
}

int main()
{
    int i;
    printf("Welcome to the MT multitasking system\n"); 
    init();
    for (i=1; i<5; i++)	// create tasks
        create((void *)func, 0);
    printf("P0 switch to Pl\n");
    while(1)
    {
        if (readyQueue) 
            tswitch();
    }
}
int scheduler()
{
    if (running->status == READY)
    enqueue(&readyQueue, running);
    running = dequeue(&readyQueue);
    printf("next running = %d\n", running->pid);

}

项目运行截图：