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提交 3bf5e592 创建 作者: Frans Kaashoek's avatar Frans Kaashoek
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Made a mess of sequence coordination

Maybe have sleep/wakeup races too
上级 a0c1c2fd
显示空白字符变更
内嵌 并排
正在显示 包含 48 行增加 和 27 行删除
proc.c
浏览文件 @ 3bf5e592
...@@ -13,7 +13,7 @@ int nextpid = 1; ...@@ -13,7 +13,7 @@ int nextpid = 1;
extern void forkret(void); extern void forkret(void);
extern void trapret(void); extern void trapret(void);
static void wakeup1(void *chan); static void wakeup1(struct ptable *pt, void *chan);
void void
pinit(void) pinit(void)
...@@ -74,11 +74,11 @@ found: ...@@ -74,11 +74,11 @@ found:
} }
static void static void
addrun1(struct proc *p) addrun1(struct ptable *pt, struct proc *p)
{ {
struct proc *q; struct proc *q;
cprintf("%d: add to run %d\n", cpu->id, p->pid); cprintf("%d: add to run %d\n", cpu->id, p->pid);
for (q = ptable->runq; q != 0; q = q->next) { for (q = pt->runq; q != 0; q = q->next) {
if (q == p) { if (q == p) {
cprintf("allready on q\n"); cprintf("allready on q\n");
p->state = RUNNABLE; p->state = RUNNABLE;
...@@ -86,15 +86,15 @@ addrun1(struct proc *p) ...@@ -86,15 +86,15 @@ addrun1(struct proc *p)
} }
} }
p->state = RUNNABLE; // race? p->state = RUNNABLE; // race?
p->next = ptable->runq; p->next = pt->runq;
ptable->runq = p; pt->runq = p;
} }
static void static void
addrun(struct proc *p) addrun(struct proc *p)
{ {
acquire(&ptable->lock); acquire(&ptable->lock);
addrun1(p); addrun1(ptable, p);
release(&ptable->lock); release(&ptable->lock);
} }
...@@ -225,6 +225,7 @@ exit(void) ...@@ -225,6 +225,7 @@ exit(void)
{ {
struct proc *p; struct proc *p;
int fd; int fd;
int c;
if(proc == initproc) if(proc == initproc)
panic("init exiting"); panic("init exiting");
...@@ -242,22 +243,30 @@ exit(void) ...@@ -242,22 +243,30 @@ exit(void)
cprintf("%d: exit %s\n", cpunum(), proc->name); cprintf("%d: exit %s\n", cpunum(), proc->name);
acquire(&ptable->lock); acquire(&ptable->lock); // XXX sleep/wakeup race? lock on all ptables?
delrun1(ptable, proc); delrun1(ptable, proc);
release(&ptable->lock); // XXX sleep/wakeup race? lock on all ptables?
// Parent might be sleeping in wait(). // Parent might be sleeping in wait().
wakeup1(proc->parent); wakeup(proc->parent);
// Pass abandoned children to init. // Pass abandoned children to init.
for(p = ptable->proc; p < &ptable->proc[NPROC]; p++){ for (c = 0; c < NCPU; c++) {
acquire(&ptable[c].lock); // XXX sleep/wakeup race? lock on all ptables?
for(p = ptables[c].proc; p < &ptables[c].proc[NPROC]; p++){
if(p->parent == proc){ if(p->parent == proc){
p->parent = initproc; p->parent = initproc;
if(p->state == ZOMBIE) if(p->state == ZOMBIE)
wakeup1(initproc); wakeup1(&ptables[c], initproc); // XXX race
}
} }
release(&ptable[c].lock); // XXX sleep/wakeup race? lock on all ptables?
} }
acquire(&ptable->lock); // XXX sleep/wakeup race? lock on all ptables?
// Jump into the scheduler, never to return. // Jump into the scheduler, never to return.
proc->state = ZOMBIE; proc->state = ZOMBIE;
sched(); sched();
...@@ -271,12 +280,14 @@ wait(void) ...@@ -271,12 +280,14 @@ wait(void)
{ {
struct proc *p; struct proc *p;
int havekids, pid; int havekids, pid;
int c;
acquire(&ptable->lock);
for(;;){ for(;;){
// Scan through table looking for zombie children. // Scan through table looking for zombie children.
havekids = 0; havekids = 0;
for(p = ptable->proc; p < &ptable->proc[NPROC]; p++){ for (c = 0; c < NCPU; c++) {
acquire(&ptables[c].lock); // XXX race on sleep and wakeup?
for(p = ptables[c].proc; p < &ptables[c].proc[NPROC]; p++){
if(p->parent != proc) if(p->parent != proc)
continue; continue;
havekids = 1; havekids = 1;
...@@ -291,10 +302,14 @@ wait(void) ...@@ -291,10 +302,14 @@ wait(void)
p->parent = 0; p->parent = 0;
p->name[0] = 0; p->name[0] = 0;
p->killed = 0; p->killed = 0;
release(&ptable->lock); release(&ptables[c].lock);
return pid; return pid;
} }
} }
release(&ptables[c].lock); // XXX race on sleep and wakeup?
}
acquire(&ptable->lock); // XXX race on sleep and wakeup?
// No point waiting if we don't have any children. // No point waiting if we don't have any children.
if(!havekids || proc->killed){ if(!havekids || proc->killed){
...@@ -304,6 +319,8 @@ wait(void) ...@@ -304,6 +319,8 @@ wait(void)
// Wait for children to exit. (See wakeup1 call in proc_exit.) // Wait for children to exit. (See wakeup1 call in proc_exit.)
sleep(proc, &ptable->lock); //DOC: wait-sleep sleep(proc, &ptable->lock); //DOC: wait-sleep
release(&ptable->lock); // XXX race on sleep and wakeup?
} }
} }
...@@ -455,27 +472,28 @@ sleep(void *chan, struct spinlock *lk) ...@@ -455,27 +472,28 @@ sleep(void *chan, struct spinlock *lk)
} }
} }
//PAGEBREAK! // scan a proctable and wakeup any process sleeping on chan
// Wake up all processes sleeping on chan.
// The ptable lock must be held.
static void static void
wakeup1(void *chan) wakeup1(struct ptable *pt, void *chan)
{ {
struct proc *p; struct proc *p;
for(p = ptable->proc; p < &ptable->proc[NPROC]; p++) for(p = pt->proc; p < &pt->proc[NPROC]; p++)
if(p->state == SLEEPING && p->chan == chan) if(p->state == SLEEPING && p->chan == chan)
addrun1(p); addrun1(pt, p);
} }
// Wake up all processes sleeping on chan. // Wake up all processes sleeping on chan.
void void
wakeup(void *chan) wakeup(void *chan)
{ {
// XXX should go through all proctables int c;
acquire(&ptable->lock);
wakeup1(chan); for (c = 0; c < NCPU; c++) {
release(&ptable->lock); acquire(&ptables[c].lock);
wakeup1(ptable, chan);
release(&ptables[c].lock);
}
} }
// Kill the process with the given pid. // Kill the process with the given pid.
...@@ -485,19 +503,22 @@ int ...@@ -485,19 +503,22 @@ int
kill(int pid) kill(int pid)
{ {
struct proc *p; struct proc *p;
int c;
acquire(&ptable->lock); for (c = 0; c < NCPU; c++) {
acquire(&ptables[c].lock);
for(p = ptable->proc; p < &ptable->proc[NPROC]; p++){ for(p = ptable->proc; p < &ptable->proc[NPROC]; p++){
if(p->pid == pid){ if(p->pid == pid){
p->killed = 1; p->killed = 1;
// Wake process from sleep if necessary. // Wake process from sleep if necessary.
if(p->state == SLEEPING) if(p->state == SLEEPING)
addrun1(p); addrun1(&ptables[c], p);
release(&ptable->lock); release(&ptables[c].lock);
return 0; return 0;
} }
} }
release(&ptable->lock); release(&ptables[c].lock);
}
return -1; return -1;
} }
......
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