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#include "types.h"
#include "param.h"
#include "mmu.h"
#include "proc.h"
#include "defs.h"
#include "x86.h"
#include "traps.h"
#include "syscall.h"
/*
* User code makes a system call with INT T_SYSCALL.
* System call number in %eax.
* Arguments on the stack.
*
* Return value? Error indication? Errno?
*/
void
sys_fork()
{
newproc();
}
void
sys_exit()
{
struct proc *p;
curproc->state = ZOMBIE;
// wake up parent
for(p = proc; p < &proc[NPROC]; p++)
if(p->pid == curproc->ppid)
wakeup(p);
// abandon children
for(p = proc; p < &proc[NPROC]; p++)
if(p->ppid == curproc->pid)
p->pid = 1;
swtch();
}
void
sys_wait()
{
struct proc *p;
int any;
cprintf("waid pid %d ppid %d\n", curproc->pid, curproc->ppid);
while(1){
any = 0;
for(p = proc; p < &proc[NPROC]; p++){
if(p->state == ZOMBIE && p->ppid == curproc->pid){
kfree(p->mem, p->sz);
kfree(p->kstack, KSTACKSIZE);
p->state = UNUSED;
cprintf("%x collected %x\n", curproc, p);
return;
}
if(p->state != UNUSED && p->ppid == curproc->pid)
any = 1;
}
if(any == 0){
cprintf("%x nothing to wait for\n", curproc);
return;
}
sleep(curproc);
}
}
void
syscall()
{
int num = curproc->tf->tf_regs.reg_eax;
cprintf("%x sys %d\n", curproc, num);
switch(num){
case SYS_fork:
sys_fork();
break;
case SYS_exit:
sys_exit();
break;
case SYS_wait:
sys_wait();
break;
default:
cprintf("unknown sys call %d\n", num);
// XXX fault
break;
}
}
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