Merge commit 'origin/master' into page

1 files changed, 131 insertions, 126 deletions

diff --git a/proc.c b/proc.c
index 5ac2780..eb334d0 100644
--- a/proc.c
+++ b/proc.c
@@ -17,53 +17,18 @@ int nextpid = 1;
 extern void forkret(void);
 extern void trapret(void);
 
+static void wakeup1(void *chan);
+
 void
 pinit(void)
 {
   initlock(&ptable.lock, "ptable");
 }
 
-//PAGEBREAK: 36
-// Print a process listing to console.  For debugging.
-// Runs when user types ^P on console.
-// No lock to avoid wedging a stuck machine further.
-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");
-  }
-}
-
-
 //PAGEBREAK: 32
 // Look in the process table for an UNUSED proc.
-// If found, change state to EMBRYO and return it.
+// If found, change state to EMBRYO and initialize
+// state required to run in the kernel.
 // Otherwise return 0.
 static struct proc*
 allocproc(void)
@@ -95,7 +60,7 @@ found:
   p->tf = (struct trapframe*)sp;
   
   // Set up new context to start executing at forkret,
-  // which returns to trapret (see below).
+  // which returns to trapret.
   sp -= 4;
   *(uint*)sp = (uint)trapret;
 
@@ -103,6 +68,7 @@ found:
   p->context = (struct context*)sp;
   memset(p->context, 0, sizeof *p->context);
   p->context->eip = (uint)forkret;
+
   return p;
 }
 
@@ -116,12 +82,10 @@ userinit(void)
   
   p = allocproc();
   initproc = p;
-  if (!(p->pgdir = setupkvm()))
+  if((p->pgdir = setupkvm()) == 0)
     panic("userinit: out of memory?");
-  if (!allocuvm(p->pgdir, 0x0, (int)_binary_initcode_size))
-    panic("userinit: out of memory?");
-  inituvm(p->pgdir, 0x0, _binary_initcode_start, (int)_binary_initcode_size);
-  p->sz = PGROUNDUP((int)_binary_initcode_size);
+  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;
@@ -142,14 +106,17 @@ userinit(void)
 int
 growproc(int n)
 {
+  uint sz;
+  
+  sz = proc->sz;
   if(n > 0){
-    if (!allocuvm(proc->pgdir, (char *)proc->sz, n))
+    if((sz = allocuvm(proc->pgdir, sz, sz + n)) == 0)
       return -1;
   } else if(n < 0){
-    if (!deallocuvm(proc->pgdir, (char *)(proc->sz + n), 0 - n))
+    if((sz = deallocuvm(proc->pgdir, sz, sz + n)) == 0)
       return -1;
   }
-  proc->sz += n;
+  proc->sz = sz;
   switchuvm(proc);
   return 0;
 }
@@ -168,7 +135,7 @@ fork(void)
     return -1;
 
   // Copy process state from p.
-  if (!(np->pgdir = copyuvm(proc->pgdir, proc->sz))) {
+  if((np->pgdir = copyuvm(proc->pgdir, proc->sz)) == 0){
     kfree(np->kstack);
     np->kstack = 0;
     np->state = UNUSED;
@@ -192,6 +159,92 @@ fork(void)
   return pid;
 }
 
+// Exit the current process.  Does not return.
+// An exited process remains in the zombie state
+// until its parent calls wait() to find out it exited.
+void
+exit(void)
+{
+  struct proc *p;
+  int fd;
+
+  if(proc == initproc)
+    panic("init exiting");
+
+  // Close all open files.
+  for(fd = 0; fd < NOFILE; fd++){
+    if(proc->ofile[fd]){
+      fileclose(proc->ofile[fd]);
+      proc->ofile[fd] = 0;
+    }
+  }
+
+  iput(proc->cwd);
+  proc->cwd = 0;
+
+  acquire(&ptable.lock);
+
+  // Parent might be sleeping in wait().
+  wakeup1(proc->parent);
+
+  // Pass abandoned children to init.
+  for(p = ptable.proc; p < &ptable.proc[NPROC]; p++){
+    if(p->parent == proc){
+      p->parent = initproc;
+      if(p->state == ZOMBIE)
+        wakeup1(initproc);
+    }
+  }
+
+  // Jump into the scheduler, never to return.
+  proc->state = ZOMBIE;
+  sched();
+  panic("zombie exit");
+}
+
+// Wait for a child process to exit and return its pid.
+// Return -1 if this process has no children.
+int
+wait(void)
+{
+  struct proc *p;
+  int havekids, pid;
+
+  acquire(&ptable.lock);
+  for(;;){
+    // Scan through table looking for zombie children.
+    havekids = 0;
+    for(p = ptable.proc; p < &ptable.proc[NPROC]; p++){
+      if(p->parent != proc)
+        continue;
+      havekids = 1;
+      if(p->state == ZOMBIE){
+        // Found one.
+        pid = p->pid;
+        kfree(p->kstack);
+        p->kstack = 0;
+        freevm(p->pgdir);
+        p->state = UNUSED;
+        p->pid = 0;
+        p->parent = 0;
+        p->name[0] = 0;
+        p->killed = 0;
+        release(&ptable.lock);
+        return pid;
+      }
+    }
+
+    // No point waiting if we don't have any children.
+    if(!havekids || proc->killed){
+      release(&ptable.lock);
+      return -1;
+    }
+
+    // Wait for children to exit.  (See wakeup1 call in proc_exit.)
+    sleep(proc, &ptable.lock);  //DOC: wait-sleep
+  }
+}
+
 //PAGEBREAK: 42
 // Per-CPU process scheduler.
 // Each CPU calls scheduler() after setting itself up.
@@ -356,89 +409,41 @@ kill(int pid)
   return -1;
 }
 
-// Exit the current process.  Does not return.
-// An exited process remains in the zombie state
-// until its parent calls wait() to find out it exited.
+//PAGEBREAK: 36
+// Print a process listing to console.  For debugging.
+// Runs when user types ^P on console.
+// No lock to avoid wedging a stuck machine further.
 void
-exit(void)
+procdump(void)
 {
+  static char *states[] = {
+  [UNUSED]    "unused",
+  [EMBRYO]    "embryo",
+  [SLEEPING]  "sleep ",
+  [RUNNABLE]  "runble",
+  [RUNNING]   "run   ",
+  [ZOMBIE]    "zombie"
+  };
+  int i;
   struct proc *p;
-  int fd;
-
-  if(proc == initproc)
-    panic("init exiting");
-
-  // Close all open files.
-  for(fd = 0; fd < NOFILE; fd++){
-    if(proc->ofile[fd]){
-      fileclose(proc->ofile[fd]);
-      proc->ofile[fd] = 0;
-    }
-  }
-
-  iput(proc->cwd);
-  proc->cwd = 0;
-
-  acquire(&ptable.lock);
-
-  // Parent might be sleeping in wait().
-  wakeup1(proc->parent);
-
-  // Pass abandoned children to init.
+  char *state;
+  uint pc[10];
+  
   for(p = ptable.proc; p < &ptable.proc[NPROC]; p++){
-    if(p->parent == proc){
-      p->parent = initproc;
-      if(p->state == ZOMBIE)
-        wakeup1(initproc);
+    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");
   }
-
-  // Jump into the scheduler, never to return.
-  proc->state = ZOMBIE;
-  sched();
-  panic("zombie exit");
 }
 
-// Wait for a child process to exit and return its pid.
-// Return -1 if this process has no children.
-int
-wait(void)
-{
-  struct proc *p;
-  int havekids, pid;
-
-  acquire(&ptable.lock);
-  for(;;){
-    // Scan through table looking for zombie children.
-    havekids = 0;
-    for(p = ptable.proc; p < &ptable.proc[NPROC]; p++){
-      if(p->parent != proc)
-        continue;
-      havekids = 1;
-      if(p->state == ZOMBIE){
-        // Found one.
-        pid = p->pid;
-        kfree(p->kstack);
-        p->kstack = 0;
-        freevm(p->pgdir);
-        p->state = UNUSED;
-        p->pid = 0;
-        p->parent = 0;
-        p->name[0] = 0;
-        p->killed = 0;
-        release(&ptable.lock);
-        return pid;
-      }
-    }
-
-    // No point waiting if we don't have any children.
-    if(!havekids || proc->killed){
-      release(&ptable.lock);
-      return -1;
-    }
-
-    // Wait for children to exit.  (See wakeup1 call in proc_exit.)
-    sleep(proc, &ptable.lock);  //DOC: wait-sleep
-  }
-}