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