scheduler

kernel/defs.h

@@ -79,18 +79,13 @@ void printstr(char *s);
 void printint(int n);
 
 // proc.c
-void exit(int);
 void proc_mapstacks(pagetable_t);
 pagetable_t proc_pagetable(struct proc *);
 void proc_freepagetable(pagetable_t, uint64);
-int kill(int);
 int killed(struct proc *);
-void setkilled(struct proc *);
 struct cpu *mycpu(void);
 struct proc *myproc();
 void procinit(void);
-void scheduler(void) __attribute__((noreturn));
-void sched(void);
 void sleep_lock(void *, struct spinlock *);
 void userinit(void);
 int wait(uint64);

kernel/proc.c

@@ -109,11 +109,6 @@ userinit(void)
 // Caller must hold wait_lock.
 void reparent(struct proc *p);
 
-// Exit the current process.  Does not return.
-// An exited process remains in the zombie state
-// until its parent calls wait().
-void exit(int status);
-
 // Wait for a child process to exit and return its pid.
 // Return -1 if this process has no children.
 int
@@ -163,52 +158,6 @@ wait(uint64 addr)
   }
 }
 
-// Per-CPU process scheduler.
-// Each CPU calls scheduler() after setting itself up.
-// Scheduler never returns.  It loops, doing:
-//  - choose a process to run.
-//  - swtch to start running that process.
-//  - eventually that process transfers control
-//    via swtch back to the scheduler.
-void
-scheduler(void)
-{
-  struct proc *p;
-  struct cpu *c = mycpu();
-  
-  c->proc = 0;
-  for(;;){
-    // Avoid deadlock by ensuring that devices can interrupt.
-    intr_on();
-
-    for(p = proc; p < &proc[NPROC]; p++) {
-      acquire(&p->lock);
-      if(p->state == RUNNABLE) {
-        // Switch to chosen process.  It is the process's job
-        // to release its lock and then reacquire it
-        // before jumping back to us.
-        p->state = RUNNING;
-        c->proc = p;
-        swtch(&c->context, &p->context);
-
-        // Process is done running for now.
-        // It should have changed its p->state before coming back.
-        c->proc = 0;
-      }
-      release(&p->lock);
-    }
-  }
-}
-
-// Switch to scheduler.  Must hold only p->lock
-// and have changed proc->state. Saves and restores
-// intena because intena is a property of this
-// kernel thread, not this CPU. It should
-// be proc->intena and proc->noff, but that would
-// break in the few places where a lock is held but
-// there's no process.
-void sched(void);
-
 // A fork child's very first scheduling by scheduler()
 // will swtch to forkret.
 void
@@ -251,11 +200,6 @@ void wakeup(void *chan)
   }
 }
 
-// Kill the process with the given pid.
-// The victim won't exit until it tries to return
-// to user space (see usertrap() in trap.c).
-int kill(int pid);
-void setkilled(struct proc *p);
 int killed(struct proc *p);
 
 // Copy to either a user address, or kernel address,

kernel/rustkernel/src/proc/scheduler.rs

@@ -1,20 +1,20 @@
 use super::{
     context::Context,
     cpu::Cpu,
-    process::{Process, ProcessState},
+    process::{proc, Process, ProcessState},
 };
 use crate::{
-    arch::riscv::intr_get,
+    arch::riscv::{intr_get, intr_on},
     sync::spinlock::{Spinlock, SpinlockGuard},
 };
 use core::{
     ffi::c_void,
-    ptr::{addr_of_mut, null_mut},
+    ptr::{addr_of, addr_of_mut, null_mut},
 };
 
 extern "C" {
     pub fn wakeup(chan: *const c_void);
-    pub fn scheduler() -> !;
+    // pub fn scheduler() -> !;
     pub fn swtch(a: *mut Context, b: *mut Context);
 }
 
@@ -26,6 +26,41 @@ pub unsafe fn r#yield() {
     sched();
 }
 
+// Per-CPU process scheduler.
+// Each CPU calls scheduler() after setting itself up.
+// Scheduler never returns.  It loops, doing:
+//  - choose a process to run.
+//  - swtch to start running that process.
+//  - eventually that process transfers control
+//    via swtch back to the scheduler.
+pub unsafe fn scheduler() -> ! {
+    let cpu = Cpu::current();
+    cpu.proc = null_mut();
+
+    loop {
+        // Avoid deadlock by ensuring that devices can interrupt.
+        intr_on();
+
+        for p in &mut proc {
+            let _guard = p.lock.lock();
+            if p.state == ProcessState::Runnable {
+                // Switch to the chosen process. It's the process's job
+                // to release its lock and then reacquire it before
+                // jumping back to us.
+                p.state = ProcessState::Running;
+                cpu.proc = addr_of!(*p).cast_mut();
+
+                // Run the process.
+                swtch(addr_of_mut!(cpu.context), addr_of_mut!(p.context));
+                
+                // Process is done running for now.
+                // It should have changed its state before coming back.
+                cpu.proc = null_mut();
+            }
+        }
+    }
+}
+
 /// Switch to scheduler.  Must hold only p->lock
 /// and have changed proc->state. Saves and restores
 /// previous_interrupts_enabled because previous_interrupts_enabled is a property of this
@@ -33,8 +68,7 @@ pub unsafe fn r#yield() {
 /// be proc->previous_interrupts_enabled and proc->interrupt_disable_layers, but that would
 /// break in the few places where a lock is held but
 /// there's no process.
-#[no_mangle]
-pub unsafe extern "C" fn sched() {
+pub unsafe fn sched() {
     let p = Process::current().unwrap();
     let cpu = Cpu::current();