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Read and write p->killed using atomics

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This commit is contained in:
Frans Kaashoek 2022-08-10 20:35:42 -04:00
parent b1fd09335a
commit 4087a6e7fc
5 changed files with 9 additions and 9 deletions
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2
kernel/console.c
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@ -89,7 +89,7 @@ consoleread(int user_dst, uint64 dst, int n)
// wait until interrupt handler has put some
// input into cons.buffer.
while(cons.r == cons.w){
if(myproc()->killed){
if(__sync_add_and_fetch(&(myproc()->killed), 0)){
release(&cons.lock);
return -1;
}

4
kernel/pipe.c
View file

@ -81,7 +81,7 @@ pipewrite(struct pipe *pi, uint64 addr, int n)
acquire(&pi->lock);
while(i < n){
if(pi->readopen == 0 || pr->killed){
if(pi->readopen == 0 || __sync_add_and_fetch(&pr->killed,0)){
release(&pi->lock);
return -1;
}
@ -111,7 +111,7 @@ piperead(struct pipe *pi, uint64 addr, int n)
acquire(&pi->lock);
while(pi->nread == pi->nwrite && pi->writeopen){ //DOC: pipe-empty
if(pr->killed){
if(__sync_add_and_fetch(&pr->killed,0)){
release(&pi->lock);
return -1;
}

4
kernel/proc.c
View file

@ -422,7 +422,7 @@ wait(uint64 addr)
}
// No point waiting if we don't have any children.
if(!havekids || p->killed){
if(!havekids || __sync_add_and_fetch(&p->killed, 0)){
release(&wait_lock);
return -1;
}
@ -588,7 +588,7 @@ kill(int pid)
for(p = proc; p < &proc[NPROC]; p++){
acquire(&p->lock);
if(p->pid == pid){
p->killed = 1;
__sync_bool_compare_and_swap(&p->killed, 0, 1);
if(p->state == SLEEPING){
// Wake process from sleep().
p->state = RUNNABLE;

2
kernel/sysproc.c
View file

@ -63,7 +63,7 @@ sys_sleep(void)
acquire(&tickslock);
ticks0 = ticks;
while(ticks - ticks0 < n){
if(myproc()->killed){
if(__sync_add_and_fetch(&(myproc()->killed), 0)){
release(&tickslock);
return -1;
}

6
kernel/trap.c
View file

@ -53,7 +53,7 @@ usertrap(void)
if(r_scause() == 8){
// system call
if(p->killed)
if(__sync_add_and_fetch(&p->killed, 0))
exit(-1);
// sepc points to the ecall instruction,
@ -70,10 +70,10 @@ usertrap(void)
} else {
printf("usertrap(): unexpected scause %p pid=%d\n", r_scause(), p->pid);
printf(" sepc=%p stval=%p\n", r_sepc(), r_stval());
p->killed = 1;
__sync_bool_compare_and_swap(&p->killed, 0, 1);
}
if(p->killed)
if(__sync_add_and_fetch(&p->killed, 0))
exit(-1);
// give up the CPU if this is a timer interrupt.