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wait_lock and initproc

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This commit is contained in:
Garen Tyler 2023-11-12 14:30:51 -07:00
parent 7c79dbddf5
commit 931884f6df
Signed by: garentyler
GPG Key ID: D7A048C454CB7054
2 changed files with 15 additions and 25 deletions
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7
kernel/proc.c
View File

@ -7,10 +7,3 @@
#include "defs.h"
struct proc proc[NPROC];
struct proc *initproc;
// helps ensure that wakeups of wait()ing
// parents are not lost. helps obey the
// memory model when using p->parent.
// must be acquired before any p->lock.
struct spinlock wait_lock;

33
kernel/rustkernel/src/proc/process.rs
View File

@ -36,23 +36,20 @@ use core::{
extern "C" {
pub static mut proc: [Process; crate::NPROC];
pub static mut initproc: *mut Process;
/// Helps ensure that wakeups of wait()ing
/// parents are not lost. Helps obey the
/// memory model when using p->parent.
/// Must be acquired before any p->lock.
pub static mut wait_lock: Spinlock;
// trampoline.S
pub static mut trampoline: *mut c_char;
// pub fn userinit();
}
pub static NEXT_PID: AtomicI32 = AtomicI32::new(1);
/// Helps ensure that wakeups of wait()ing
/// parents are not lost. Helps obey the
/// memory model when using p->parent.
/// Must be acquired before any p->lock.
pub static mut WAIT_LOCK: Spinlock = Spinlock::new();
pub static mut INITPROC: usize = 0;
/// Initialize the proc table.
pub unsafe fn procinit() {
wait_lock = Spinlock::new();
for (i, p) in proc.iter_mut().enumerate() {
*p = Process::new();
p.state = ProcessState::Unused;
@ -62,7 +59,7 @@ pub unsafe fn procinit() {
/// Set up the first user process.
pub unsafe fn userinit() {
let p = Process::alloc().unwrap();
initproc = addr_of_mut!(*p);
INITPROC = addr_of_mut!(*p) as usize;
let initcode: &[u8] = &[
0x17, 0x05, 0x00, 0x00, 0x13, 0x05, 0x45, 0x02,
@ -129,7 +126,7 @@ pub struct Process {
/// Process ID
pub pid: i32,
// wait_lock msut be held when using this:
// WAIT_LOCK must be held when using this:
/// Parent process
pub parent: *mut Process,
@ -181,7 +178,7 @@ impl Process {
addr_of!(*self).cast_mut() == Cpu::current().proc
}
pub fn is_initproc(&self) -> bool {
addr_of!(*self).cast_mut() == unsafe { initproc }
addr_of!(*self) as usize == unsafe { INITPROC }
}
pub fn alloc_pid() -> i32 {
@ -362,7 +359,7 @@ impl Process {
child.lock.unlock();
{
let _guard = wait_lock.lock();
let _guard = WAIT_LOCK.lock();
child.parent = addr_of!(*parent).cast_mut();
}
{
@ -391,12 +388,12 @@ impl Process {
}
/// Pass p's abandoned children to init.
/// Caller must hold wait_lock.
/// Caller must hold WAIT_LOCK.
pub unsafe fn reparent(&self) {
for p in proc.iter_mut() {
if p.parent == addr_of!(*self).cast_mut() {
p.parent = initproc;
wakeup(initproc.cast());
p.parent = INITPROC as *mut Process;
wakeup((INITPROC as *mut Process).cast());
}
}
}
@ -424,7 +421,7 @@ impl Process {
self.current_dir = null_mut();
{
let _guard = wait_lock.lock();
let _guard = WAIT_LOCK.lock();
// Give any children to init.
self.reparent();
@ -444,7 +441,7 @@ impl Process {
/// Wait for a child process to exit, and return its pid.
pub unsafe fn wait_for_child(&mut self, addr: u64) -> Result<i32, ProcessError> {
let guard = wait_lock.lock();
let guard = WAIT_LOCK.lock();
loop {
// Scan through the table looking for exited children.