#include "types.h"
#include "defs.h"
#include "param.h"
#include "memlayout.h"
#include "mmu.h"
#include "x86.h"
#include "proc.h"
#include "spinlock.h"
struct {
struct spinlock lock;
struct proc proc[NPROC];
} ptable;
static struct proc *initproc;
int nextpid = 1;
extern void forkret(void);
extern void trapret(void);
static void wakeup1(void *chan);
void
pinit(void)
{
initlock(&ptable.lock, "ptable");
}
static struct proc*
allocproc(void)
{
struct proc *p;
char *sp;
acquire(&ptable.lock);
for(p = ptable.proc; p < &ptable.proc[NPROC]; p++)
if(p->state == UNUSED)
goto found;
release(&ptable.lock);
return 0;
found:
p->state = EMBRYO;
p->pid = nextpid++;
release(&ptable.lock);
if((p->kstack = kalloc()) == 0){
p->state = UNUSED;
return 0;
}
sp = p->kstack + KSTACKSIZE;
sp -= sizeof *p->tf;
p->tf = (struct trapframe*)sp;
sp -= 4;
*(uint*)sp = (uint)trapret;
sp -= sizeof *p->context;
p->context = (struct context*)sp;
memset(p->context, 0, sizeof *p->context);
p->context->eip = (uint)forkret;
return p;
}
void
userinit(void)
{
struct proc *p;
extern char _binary_initcode_start[], _binary_initcode_size[];
p = allocproc();
initproc = p;
if((p->pgdir = setupkvm()) == 0)
panic("userinit: out of memory?");
inituvm(p->pgdir, _binary_initcode_start, (int)_binary_initcode_size);
p->sz = PGSIZE;
memset(p->tf, 0, sizeof(*p->tf));
p->tf->cs = (SEG_UCODE << 3) | DPL_USER;
p->tf->ds = (SEG_UDATA << 3) | DPL_USER;
p->tf->es = p->tf->ds;
p->tf->ss = p->tf->ds;
p->tf->eflags = FL_IF;
p->tf->esp = PGSIZE;
p->tf->eip = 0;
safestrcpy(p->name, "initcode", sizeof(p->name));
p->cwd = namei("/");
acquire(&ptable.lock);
p->state = RUNNABLE;
release(&ptable.lock);
}
int
growproc(int n)
{
uint sz;
sz = proc->sz;
if(n > 0){
if((sz = allocuvm(proc->pgdir, sz, sz + n)) == 0)
return -1;
} else if(n < 0){
if((sz = deallocuvm(proc->pgdir, sz, sz + n)) == 0)
return -1;
}
proc->sz = sz;
switchuvm(proc);
return 0;
}
int
fork(void)
{
int i, pid;
struct proc *np;
if((np = allocproc()) == 0){
return -1;
}
if((np->pgdir = copyuvm(proc->pgdir, proc->sz)) == 0){
kfree(np->kstack);
np->kstack = 0;
np->state = UNUSED;
return -1;
}
np->sz = proc->sz;
np->parent = proc;
*np->tf = *proc->tf;
np->tf->eax = 0;
for(i = 0; i < NOFILE; i++)
if(proc->ofile[i])
np->ofile[i] = filedup(proc->ofile[i]);
np->cwd = idup(proc->cwd);
safestrcpy(np->name, proc->name, sizeof(proc->name));
pid = np->pid;
acquire(&ptable.lock);
np->state = RUNNABLE;
release(&ptable.lock);
return pid;
}
void
exit(void)
{
struct proc *p;
int fd;
if(proc == initproc)
panic("init exiting");
for(fd = 0; fd < NOFILE; fd++){
if(proc->ofile[fd]){
fileclose(proc->ofile[fd]);
proc->ofile[fd] = 0;
}
}
begin_op();
iput(proc->cwd);
end_op();
proc->cwd = 0;
acquire(&ptable.lock);
wakeup1(proc->parent);
for(p = ptable.proc; p < &ptable.proc[NPROC]; p++){
if(p->parent == proc){
p->parent = initproc;
if(p->state == ZOMBIE)
wakeup1(initproc);
}
}
proc->state = ZOMBIE;
sched();
panic("zombie exit");
}
int
wait(void)
{
struct proc *p;
int havekids, pid;
acquire(&ptable.lock);
for(;;){
havekids = 0;
for(p = ptable.proc; p < &ptable.proc[NPROC]; p++){
if(p->parent != proc)
continue;
havekids = 1;
if(p->state == ZOMBIE){
pid = p->pid;
kfree(p->kstack);
p->kstack = 0;
freevm(p->pgdir);
p->pid = 0;
p->parent = 0;
p->name[0] = 0;
p->killed = 0;
p->state = UNUSED;
release(&ptable.lock);
return pid;
}
}
if(!havekids || proc->killed){
release(&ptable.lock);
return -1;
}
sleep(proc, &ptable.lock);
}
}
void
scheduler(void)
{
struct proc *p;
for(;;){
sti();
acquire(&ptable.lock);
for(p = ptable.proc; p < &ptable.proc[NPROC]; p++){
if(p->state != RUNNABLE)
continue;
proc = p;
switchuvm(p);
p->state = RUNNING;
swtch(&cpu->scheduler, p->context);
switchkvm();
proc = 0;
}
release(&ptable.lock);
}
}
void
sched(void)
{
int intena;
if(!holding(&ptable.lock))
panic("sched ptable.lock");
if(cpu->ncli != 1)
panic("sched locks");
if(proc->state == RUNNING)
panic("sched running");
if(readeflags()&FL_IF)
panic("sched interruptible");
intena = cpu->intena;
swtch(&proc->context, cpu->scheduler);
cpu->intena = intena;
}
void
yield(void)
{
acquire(&ptable.lock);
proc->state = RUNNABLE;
sched();
release(&ptable.lock);
}
void
forkret(void)
{
static int first = 1;
release(&ptable.lock);
if (first) {
first = 0;
iinit(ROOTDEV);
initlog(ROOTDEV);
}
}
void
sleep(void *chan, struct spinlock *lk)
{
if(proc == 0)
panic("sleep");
if(lk == 0)
panic("sleep without lk");
if(lk != &ptable.lock){
acquire(&ptable.lock);
release(lk);
}
proc->chan = chan;
proc->state = SLEEPING;
sched();
proc->chan = 0;
if(lk != &ptable.lock){
release(&ptable.lock);
acquire(lk);
}
}
static void
wakeup1(void *chan)
{
struct proc *p;
for(p = ptable.proc; p < &ptable.proc[NPROC]; p++)
if(p->state == SLEEPING && p->chan == chan)
p->state = RUNNABLE;
}
void
wakeup(void *chan)
{
acquire(&ptable.lock);
wakeup1(chan);
release(&ptable.lock);
}
int
kill(int pid)
{
struct proc *p;
acquire(&ptable.lock);
for(p = ptable.proc; p < &ptable.proc[NPROC]; p++){
if(p->pid == pid){
p->killed = 1;
if(p->state == SLEEPING)
p->state = RUNNABLE;
release(&ptable.lock);
return 0;
}
}
release(&ptable.lock);
return -1;
}
void
procdump(void)
{
static char *states[] = {
[UNUSED] "unused",
[EMBRYO] "embryo",
[SLEEPING] "sleep ",
[RUNNABLE] "runble",
[RUNNING] "run ",
[ZOMBIE] "zombie"
};
int i;
struct proc *p;
char *state;
uint pc[10];
for(p = ptable.proc; p < &ptable.proc[NPROC]; p++){
if(p->state == UNUSED)
continue;
if(p->state >= 0 && p->state < NELEM(states) && states[p->state])
state = states[p->state];
else
state = "???";
cprintf("%d %s %s", p->pid, state, p->name);
if(p->state == SLEEPING){
getcallerpcs((uint*)p->context->ebp+2, pc);
for(i=0; i<10 && pc[i] != 0; i++)
cprintf(" %p", pc[i]);
}
cprintf("\n");
}
}