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Commit ea6e3709 authored by rsc's avatar rsc
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i cannot prove that release before wakeup is wrong, but i cannot convince myself it is right either

parent 4bc5056c
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......@@ -64,7 +64,6 @@ void
pipe_close(struct pipe *p, int writable)
{
acquire(&p->lock);
if(writable){
p->writeopen = 0;
wakeup(&p->readp);
......@@ -72,7 +71,6 @@ pipe_close(struct pipe *p, int writable)
p->readopen = 0;
wakeup(&p->writep);
}
release(&p->lock);
if(p->readopen == 0 && p->writeopen == 0)
......@@ -86,7 +84,6 @@ pipe_write(struct pipe *p, char *addr, int n)
int i;
acquire(&p->lock);
for(i = 0; i < n; i++){
while(((p->writep + 1) % PIPESIZE) == p->readp){
if(p->readopen == 0 || cp->killed){
......@@ -99,9 +96,8 @@ pipe_write(struct pipe *p, char *addr, int n)
p->data[p->writep] = addr[i];
p->writep = (p->writep + 1) % PIPESIZE;
}
release(&p->lock);
wakeup(&p->readp);
release(&p->lock);
return i;
}
......@@ -111,7 +107,6 @@ pipe_read(struct pipe *p, char *addr, int n)
int i;
acquire(&p->lock);
while(p->readp == p->writep){
if(p->writeopen == 0 || cp->killed){
release(&p->lock);
......@@ -125,8 +120,7 @@ pipe_read(struct pipe *p, char *addr, int n)
addr[i] = p->data[p->readp];
p->readp = (p->readp + 1) % PIPESIZE;
}
release(&p->lock);
wakeup(&p->writep);
release(&p->lock);
return i;
}
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