//fork子进程，内核线程不可直接调用
pid_t sys_fork(void){
	struct task_struct* parent_thread = running_thread();
	struct task_struct* child_thread = get_kernel_pages(1);	//为子进程创建pcb(task_struct结构)
	if(child_thread == NULL){
		return -1;
	}
	ASSERT(INTR_OFF == intr_get_status() && parent_thread->pgdir != NULL);

	if(copy_process(child_thread,parent_thread) == -1){
		return -1;
	}

	//添加到就绪线程队列和所有线程队列，子进程由调度器安排运行
	ASSERT(!elem_find(&thread_ready_list,&child_thread->general_tag));
	list_append(&thread_ready_list,&child_thread->general_tag);
	ASSERT(!elem_find(&thread_all_list,&child_thread->all_list_tag));
	list_append(&thread_all_list,&child_thread->all_list_tag);

	return child_thread->pid;
}

/*
 * fork系统调用。NOTE! 其参数须与copy_process()同步。fork只创建
 * 一个新进程，子进程与父进程暂时共享页表。直到父进程或子进程
 * 写页面时，子进程再分配自己的页表以及页面。
 */
int sys_fork(long none, long ebx, long ecx, long edx,
			 long gs, long fs, long es, long ds,
			 long ebp, long esi, long edi,
			 long eip, long cs, long eflags, long esp, long ss)
{
	int nr = 0;

	if(!(nr = find_empty_process())) {
		k_printf("fork: have no empty-process!");
		return -1;
	}
	if(0 == (proc[nr]=(struct proc_struct *)get_free_page())) {
		k_printf("fork: have no free-page!");
		return -1;
	}

	d_printf("pid-%d-proc-struct ADDR: %x.\n", last_pid, proc[nr]);
	
	copy_process(nr, gs, fs, es, ds, 
		edi, esi, ebp, edx, ecx, ebx,
		eip, cs, eflags, esp, ss);
	proc[nr]->state = RUNNING;
	return last_pid;
}

/*
 *  Ok, this is the main fork-routine.
 *
 * It copies the process, and if successful kick-starts
 * it and waits for it to finish using the VM if required.
 */
long do_fork(unsigned long clone_flags,
             unsigned long stack_start,
             struct pt_regs *regs,
             unsigned long stack_size,
             int __user *parent_tidptr,
             int __user *child_tidptr)
{
    struct task_struct *p;
    int trace = 0;
    long nr;

    /*
     * Do some preliminary argument and permissions checking before we
     * actually start allocating stuff
     */
    if (clone_flags & CLONE_NEWUSER) {
        if (clone_flags & CLONE_THREAD)
            return -EINVAL;
        /* hopefully this check will go away when userns support is
         * complete
         */
        if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SETUID) ||
                !capable(CAP_SETGID))
            return -EPERM;
    }

    /*
     * When called from kernel_thread, don't do user tracing stuff.
     */
    if (likely(user_mode(regs)))
        trace = tracehook_prepare_clone(clone_flags);

    p = copy_process(clone_flags, stack_start, regs, stack_size,
                     child_tidptr, NULL, trace);
    /*
     * Do this prior waking up the new thread - the thread pointer
     * might get invalid after that point, if the thread exits quickly.
     */
    if (!IS_ERR(p)) {
        struct completion vfork;

        trace_sched_process_fork(current, p);

        nr = task_pid_vnr(p);

        if (clone_flags & CLONE_PARENT_SETTID)
            put_user(nr, parent_tidptr);

        if (clone_flags & CLONE_VFORK) {
            p->vfork_done = &vfork;
            init_completion(&vfork);
        }

        audit_finish_fork(p);
        tracehook_report_clone(regs, clone_flags, nr, p);

        /*
         * We set PF_STARTING at creation in case tracing wants to
         * use this to distinguish a fully live task from one that
         * hasn't gotten to tracehook_report_clone() yet.  Now we
         * clear it and set the child going.
         */
        p->flags &= ~PF_STARTING;

        wake_up_new_task(p);

        tracehook_report_clone_complete(trace, regs,
                                        clone_flags, nr, p);

        if (clone_flags & CLONE_VFORK) {
            freezer_do_not_count();
            wait_for_completion(&vfork);
            freezer_count();
            tracehook_report_vfork_done(p, nr);
        }
    } else {
        nr = PTR_ERR(p);
    }
    return nr;
}

//.........这里部分代码省略.........
                }

                //Set the device id for the recently created i/o burst
                sub_out = strstr(line, "i/o device id:");
                if (sub_out != NULL) {
                    int id = get_num(sub_out);
                    Burst* burst_end = get_last_burst(end);
                    if (burst_end != NULL) {
                        burst_end->device_num = id;
                    } else {
                        end->bursts->device_num = id;
                    }
                }
            }
        }
        fclose(master_file);

        //Handle if no processes are read in
        if (processCount == 0) {
            fclose(out_file);
            fprintf(stderr, "Zero processes were read in.\nThis could be correct or an error in the format of the input file.\nPlease verify that the input file is formatted correctly. \n");
            exit(1);
        }

        //Run the simulation of the cpu until all processes have been completed
        while (processCompleted < processCount) {

            //Go through the list of processes that havent arrived yet
            Process* tempProc = futureProcesses->processes;
            Process* lastTemp = NULL;
            while (tempProc != NULL) {
                if (tempProc->arrival_time == cpu->time) {
                    //Create a copy of the process to move to the cpu
                    Process* moved = copy_process(tempProc);
                    fprintf(out_file, "Time: %-5d\tProcess#%d Arrived\n", cpu->time, moved->id);

                    if (moved->bursts->type == 1) { //Initial burst is cpu
                        printf("NEW PROCESS CPU FIRST\n");
                        fprintf(out_file, "Time: %-5d\tInitial burst of Process#%d is a CPU burst\n", cpu->time, moved->id);
                        if (cpu->idle == 1) { //If nothing is running on the cpu
                            fprintf(out_file, "Time: %-5d\tCPU was found to be idle, running process on CPU\n", cpu->time);
                            moved->state = 1;
                            cpu->current_process = moved;
                            cpu->idle = 0;
                            cpu->queue = 1;
                            printQueues(out_file, cpu);
                        } else { //If cpu is occupied put new process in Q1
                            fprintf(out_file, "Time: %-5d\tCPU was found to be busy, putting process in Q1\n", cpu->time);
                            Process* end = get_end(cpu->Q1);
                            moved->state = 2;
                            if (end != NULL) { //If Stuff is already in Q1
                                end->next = moved;
                            } else { //If nothing is in Q1
                                cpu->Q1->processes = moved;
                                cpu->Q1->isEmpty = 0;
                            }
                            printQueues(out_file, cpu);
                        }
                    } else { //Initial burst is I/O
                        printf("NEW PROCESS I/O FIRST\n");
                        Burst* i_burst = moved->bursts;
                        int device = i_burst->device_num;
                        IODevice* devQ;
                        switch (device) {
                            case 1: //Next burst is on D1
                                devQ = cpu->D1;

long do_fork(unsigned long clone_flags,
	      unsigned long stack_start,
	      unsigned long stack_size,
	      int __user *parent_tidptr,
	      int __user *child_tidptr)
{
	struct task_struct *p;
	int trace = 0;
	long nr;

	/*
	 * Do some preliminary argument and permissions checking before we
	 * actually start allocating stuff
	 */
	if (clone_flags & (CLONE_NEWUSER | CLONE_NEWPID)) {
		if (clone_flags & (CLONE_THREAD|CLONE_PARENT)) {
			printk("[%d:%s] fork fail at clone_thread, flags:0x%x\n", current->pid, current->comm, (unsigned int)clone_flags);
			return -EINVAL;
		}
	}

	/*
	 * Determine whether and which event to report to ptracer.  When
	 * called from kernel_thread or CLONE_UNTRACED is explicitly
	 * requested, no event is reported; otherwise, report if the event
	 * for the type of forking is enabled.
	 */
	if (!(clone_flags & CLONE_UNTRACED)) {
		if (clone_flags & CLONE_VFORK)
			trace = PTRACE_EVENT_VFORK;
		else if ((clone_flags & CSIGNAL) != SIGCHLD)
			trace = PTRACE_EVENT_CLONE;
		else
			trace = PTRACE_EVENT_FORK;

		if (likely(!ptrace_event_enabled(current, trace)))
			trace = 0;
	}

	p = copy_process(clone_flags, stack_start, stack_size,
			 child_tidptr, NULL, trace);
	/*
	 * Do this prior waking up the new thread - the thread pointer
	 * might get invalid after that point, if the thread exits quickly.
	 */
	if (!IS_ERR(p)) {
		struct completion vfork;
		struct pid *pid;

		trace_sched_process_fork(current, p);

		pid = get_task_pid(p, PIDTYPE_PID);
		nr = pid_vnr(pid);

		if (clone_flags & CLONE_PARENT_SETTID)
			put_user(nr, parent_tidptr);

		if (clone_flags & CLONE_VFORK) {
			p->vfork_done = &vfork;
			init_completion(&vfork);
			get_task_struct(p);
		}

#ifdef CONFIG_SCHEDSTATS
        /* mt shceduler profiling*/
        save_mtproc_info(p, sched_clock());	
        printk(KERN_DEBUG "[%d:%s] fork [%d:%s]\n", current->pid, current->comm, p->pid, p->comm);
#endif
		wake_up_new_task(p);

		/* forking complete and child started to run, tell ptracer */
		if (unlikely(trace))
			ptrace_event_pid(trace, pid);

		if (clone_flags & CLONE_VFORK) {
			if (!wait_for_vfork_done(p, &vfork))
				ptrace_event_pid(PTRACE_EVENT_VFORK_DONE, pid);
		}

		put_pid(pid);
#ifdef CONFIG_MT_PRIO_TRACER
		create_prio_tracer(task_pid_nr(p));
		update_prio_tracer(task_pid_nr(p), p->prio, p->policy, PTS_KRNL);
#endif
	} else {
		nr = PTR_ERR(p);
		printk("[%d:%s] fork fail:[0x%x, %d]\n", current->pid, current->comm, (unsigned int)p,(int) nr);
	}
	return nr;
}

/*
 *  Ok, this is the main fork-routine.
 *
 * It copies the process, and if successful kick-starts
 * it and waits for it to finish using the VM if required.
 */
long do_fork(unsigned long clone_flags,
	      unsigned long stack_start,
	      struct pt_regs *regs,
	      unsigned long stack_size,
	      int __user *parent_tidptr,
	      int __user *child_tidptr)
{
	struct task_struct *p;
	int trace = 0;
	long nr;

	/*
	 * Do some preliminary argument and permissions checking before we
	 * actually start allocating stuff
	 */
	if (clone_flags & CLONE_NEWUSER) {
		if (clone_flags & CLONE_THREAD)
			return -EINVAL;
		/* hopefully this check will go away when userns support is
		 * complete
		 */
		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SETUID) ||
				!capable(CAP_SETGID))
			return -EPERM;
	}

	/*
	 * We hope to recycle these flags after 2.6.26
	 */
	if (unlikely(clone_flags & CLONE_STOPPED)) {
		static int __read_mostly count = 100;

		if (count > 0 && printk_ratelimit()) {
			char comm[TASK_COMM_LEN];

			count--;
			printk(KERN_INFO "fork(): process `%s' used deprecated "
					"clone flags 0x%lx\n",
				get_task_comm(comm, current),
				clone_flags & CLONE_STOPPED);
		}
	}

	/*
	 * When called from kernel_thread, don't do user tracing stuff.
	 */
	if (likely(user_mode(regs)))
		trace = tracehook_prepare_clone(clone_flags);

	p = copy_process(clone_flags, stack_start, regs, stack_size,
			 child_tidptr, NULL, trace);
	/*
	 * Do this prior waking up the new thread - the thread pointer
	 * might get invalid after that point, if the thread exits quickly.
	 */
	if (!IS_ERR(p)) {
		struct completion vfork;

		trace_sched_process_fork(current, p);

		nr = task_pid_vnr(p);

		if (clone_flags & CLONE_PARENT_SETTID)
			put_user(nr, parent_tidptr);

		if (clone_flags & CLONE_VFORK) {
			p->vfork_done = &vfork;
			init_completion(&vfork);
		}

		audit_finish_fork(p);
		tracehook_report_clone(regs, clone_flags, nr, p);

		/*
		 * We set PF_STARTING at creation in case tracing wants to
		 * use this to distinguish a fully live task from one that
		 * hasn't gotten to tracehook_report_clone() yet.  Now we
		 * clear it and set the child going.
		 */
		p->flags &= ~PF_STARTING;

		if (unlikely(clone_flags & CLONE_STOPPED)) {
			/*
			 * We'll start up with an immediate SIGSTOP.
			 */
			sigaddset(&p->pending.signal, SIGSTOP);
			set_tsk_thread_flag(p, TIF_SIGPENDING);
			__set_task_state(p, TASK_STOPPED);
		} else {
			wake_up_new_task(p, clone_flags);
		}

		tracehook_report_clone_complete(trace, regs,
						clone_flags, nr, p);
//.........这里部分代码省略.........

long do_fork(unsigned long clone_flags,
	      unsigned long stack_start,
	      struct pt_regs *regs,
	      unsigned long stack_size,
	      int __user *parent_tidptr,
	      int __user *child_tidptr)
{
	struct task_struct *p;
	int trace = 0;
	long nr;

	if (clone_flags & CLONE_NEWUSER) {
		if (clone_flags & CLONE_THREAD)
			return -EINVAL;
		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SETUID) ||
				!capable(CAP_SETGID))
			return -EPERM;
	}

	if (likely(user_mode(regs)) && !(clone_flags & CLONE_UNTRACED)) {
		if (clone_flags & CLONE_VFORK)
			trace = PTRACE_EVENT_VFORK;
		else if ((clone_flags & CSIGNAL) != SIGCHLD)
			trace = PTRACE_EVENT_CLONE;
		else
			trace = PTRACE_EVENT_FORK;

		if (likely(!ptrace_event_enabled(current, trace)))
			trace = 0;
	}

	p = copy_process(clone_flags, stack_start, regs, stack_size,
			 child_tidptr, NULL, trace);
	if (!IS_ERR(p)) {
		struct completion vfork;

		trace_sched_process_fork(current, p);

		nr = task_pid_vnr(p);

		if (clone_flags & CLONE_PARENT_SETTID)
			put_user(nr, parent_tidptr);

		if (clone_flags & CLONE_VFORK) {
			p->vfork_done = &vfork;
			init_completion(&vfork);
			get_task_struct(p);
		}

		wake_up_new_task(p);

		
		if (unlikely(trace))
			ptrace_event(trace, nr);

		if (clone_flags & CLONE_VFORK) {
			if (!wait_for_vfork_done(p, &vfork))
				ptrace_event(PTRACE_EVENT_VFORK_DONE, nr);
		}
	} else {
		nr = PTR_ERR(p);
	}
	return nr;
}

/*
 *  Ok, this is the main fork-routine.
 *
 * It copies the process, and if successful kick-starts
 * it and waits for it to finish using the VM if required.
 */
long do_fork(unsigned long clone_flags,
	      unsigned long stack_start,
	      struct pt_regs *regs,
	      unsigned long stack_size,
	      int __user *parent_tidptr,
	      int __user *child_tidptr)
{
	struct task_struct *p;
	int trace = 0;
	long nr;

	if (unlikely(current->ptrace)) {
		trace = fork_traceflag (clone_flags);
		if (trace)
			clone_flags |= CLONE_PTRACE;
	}

	p = copy_process(clone_flags, stack_start, regs, stack_size,
			child_tidptr, NULL);
	/*
	 * Do this prior waking up the new thread - the thread pointer
	 * might get invalid after that point, if the thread exits quickly.
	 */
	if (!IS_ERR(p)) {
		struct completion vfork;

		/*
		 * this is enough to call pid_nr_ns here, but this if
		 * improves optimisation of regular fork()
		 */
		nr = (clone_flags & CLONE_NEWPID) ?
			task_pid_nr_ns(p, current->nsproxy->pid_ns) :
				task_pid_vnr(p);

		if (clone_flags & CLONE_PARENT_SETTID)
			put_user(nr, parent_tidptr);

		if (clone_flags & CLONE_VFORK) {
			p->vfork_done = &vfork;
			init_completion(&vfork);
		}

		if ((p->ptrace & PT_PTRACED) || (clone_flags & CLONE_STOPPED)) {
			/*
			 * We'll start up with an immediate SIGSTOP.
			 */
			sigaddset(&p->pending.signal, SIGSTOP);
			set_tsk_thread_flag(p, TIF_SIGPENDING);
		}

		if (!(clone_flags & CLONE_STOPPED))
			wake_up_new_task(p, clone_flags);
		else
			p->state = TASK_STOPPED;

		if (unlikely (trace)) {
			current->ptrace_message = nr;
			ptrace_notify ((trace << 8) | SIGTRAP);
		}

		if (clone_flags & CLONE_VFORK) {
			freezer_do_not_count();
			wait_for_completion(&vfork);
			freezer_count();
			if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE)) {
				current->ptrace_message = nr;
				ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
			}
		}
	} else {
		nr = PTR_ERR(p);
	}
	return nr;
}

int sys_fork(){
	return copy_process(0, 0, 0);
}

/*
 *  Ok, this is the main fork-routine.
 *
 * It copies the process, and if successful kick-starts
 * it and waits for it to finish using the VM if required.
 */
long do_fork(unsigned long clone_flags,
	      unsigned long stack_start,
	      unsigned long stack_size,
	      int __user *parent_tidptr,
	      int __user *child_tidptr)
{
	struct task_struct *p;
	int trace = 0;
	long nr;

	/*
	 * Determine whether and which event to report to ptracer.  When
	 * called from kernel_thread or CLONE_UNTRACED is explicitly
	 * requested, no event is reported; otherwise, report if the event
	 * for the type of forking is enabled.
	 */
	if (!(clone_flags & CLONE_UNTRACED)) {
		if (clone_flags & CLONE_VFORK)
			trace = PTRACE_EVENT_VFORK;
		else if ((clone_flags & CSIGNAL) != SIGCHLD)
			trace = PTRACE_EVENT_CLONE;
		else
			trace = PTRACE_EVENT_FORK;

		if (likely(!ptrace_event_enabled(current, trace)))
			trace = 0;
	}

	p = copy_process(clone_flags, stack_start, stack_size,
			 child_tidptr, NULL, trace);
	/*
	 * Do this prior waking up the new thread - the thread pointer
	 * might get invalid after that point, if the thread exits quickly.
	 */
	if (!IS_ERR(p)) {
		struct completion vfork;
		struct pid *pid;

		trace_sched_process_fork(current, p);

		pid = get_task_pid(p, PIDTYPE_PID);
		nr = pid_vnr(pid);

		if (clone_flags & CLONE_PARENT_SETTID)
			put_user(nr, parent_tidptr);

		if (clone_flags & CLONE_VFORK) {
			p->vfork_done = &vfork;
			init_completion(&vfork);
			get_task_struct(p);
		}

		wake_up_new_task(p);

		/* forking complete and child started to run, tell ptracer */
		if (unlikely(trace))
			ptrace_event_pid(trace, pid);

		if (clone_flags & CLONE_VFORK) {
			if (!wait_for_vfork_done(p, &vfork))
				ptrace_event_pid(PTRACE_EVENT_VFORK_DONE, pid);
		}

		put_pid(pid);
	} else {
		nr = PTR_ERR(p);
	}
	return nr;
}

/*
 *  Ok, this is the main fork-routine.
 *
 * It copies the process, and if successful kick-starts
 * it and waits for it to finish using the VM if required.
 */
long do_fork(unsigned long clone_flags,
	      unsigned long stack_start,
	      struct pt_regs *regs,
	      unsigned long stack_size,
	      int __user *parent_tidptr,
	      int __user *child_tidptr)
{
	struct task_struct *p;
	int trace = 0;
	long pid;

	if (unlikely(current->ptrace)) {
		trace = fork_traceflag (clone_flags);
		if (trace)
			clone_flags |= CLONE_PTRACE;
	}

	p = copy_process(clone_flags, stack_start, regs, stack_size, parent_tidptr, child_tidptr);
	/*
	 * Do this prior waking up the new thread - the thread pointer
	 * might get invalid after that point, if the thread exits quickly.
	 */
	pid = IS_ERR(p) ? PTR_ERR(p) : p->pid;

	if (!IS_ERR(p)) {
		struct completion vfork;

		if (clone_flags & CLONE_VFORK) {
			p->vfork_done = &vfork;
			init_completion(&vfork);
		}

		if ((p->ptrace & PT_PTRACED) || (clone_flags & CLONE_STOPPED)) {
			/*
			 * We'll start up with an immediate SIGSTOP.
			 */
			sigaddset(&p->pending.signal, SIGSTOP);
			set_tsk_thread_flag(p, TIF_SIGPENDING);
		}

		if (!(clone_flags & CLONE_STOPPED)) {
			/*
			 * Do the wakeup last. On SMP we treat fork() and
			 * CLONE_VM separately, because fork() has already
			 * created cache footprint on this CPU (due to
			 * copying the pagetables), hence migration would
			 * probably be costy. Threads on the other hand
			 * have less traction to the current CPU, and if
			 * there's an imbalance then the scheduler can
			 * migrate this fresh thread now, before it
			 * accumulates a larger cache footprint:
			 */
			if (clone_flags & CLONE_VM)
				wake_up_forked_thread(p);
			else
				wake_up_forked_process(p);
		} else {
			int cpu = get_cpu();

			p->state = TASK_STOPPED;
			if (cpu_is_offline(task_cpu(p)))
				set_task_cpu(p, cpu);

			put_cpu();
		}
		++total_forks;

		if (unlikely (trace)) {
			current->ptrace_message = pid;
			ptrace_notify ((trace << 8) | SIGTRAP);
		}

		if (clone_flags & CLONE_VFORK) {
			wait_for_completion(&vfork);
			if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE))
				ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
		} else
			/*
			 * Let the child process run first, to avoid most of the
			 * COW overhead when the child exec()s afterwards.
			 */
			set_need_resched();
	}
	return pid;
}

/*
 *  Ok, this is the main fork-routine.
 *
 * It copies the process, and if successful kick-starts
 * it and waits for it to finish using the VM if required.
 */
long do_fork(unsigned long clone_flags,
	      unsigned long stack_start,
	      struct pt_regs *regs,
	      unsigned long stack_size,
	      int __user *parent_tidptr,
	      int __user *child_tidptr)
{
	struct task_struct *p;
	int trace = 0;
	long pid = alloc_pidmap();

	if (pid < 0)
		return -EAGAIN;
	if (unlikely(current->ptrace)) {
		trace = fork_traceflag (clone_flags);
		if (trace)
			clone_flags |= CLONE_PTRACE;
	}

	p = copy_process(clone_flags, stack_start, regs, stack_size, parent_tidptr, child_tidptr, pid);
	/*
	 * Do this prior waking up the new thread - the thread pointer
	 * might get invalid after that point, if the thread exits quickly.
	 */
	if (!IS_ERR(p)) {
		struct completion vfork;

		if (clone_flags & CLONE_VFORK) {
			p->vfork_done = &vfork;
			init_completion(&vfork);
		}

		if ((p->ptrace & PT_PTRACED) || (clone_flags & CLONE_STOPPED)) {
			/*
			 * We'll start up with an immediate SIGSTOP.
			 */
			sigaddset(&p->pending.signal, SIGSTOP);
			set_tsk_thread_flag(p, TIF_SIGPENDING);
		}

		if (!(clone_flags & CLONE_STOPPED))
			wake_up_new_task(p, clone_flags);
		else
			p->state = TASK_STOPPED;

		if (unlikely (trace)) {
			current->ptrace_message = pid;
			ptrace_notify ((trace << 8) | SIGTRAP);
		}

		if (clone_flags & CLONE_VFORK) {
			wait_for_completion(&vfork);
			if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE))
				ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
		}
	} else {
		free_pidmap(pid);
		pid = PTR_ERR(p);
	}
	return pid;
}