cirno/plan9front
1
0
Fork 0
mirror of git://git.9front.org/plan9front/plan9front synced 2025-01-12 11:10:06 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

kernel: handle errors in semacquire

Browse source 
Move waserror()/poperror() out of the loop,
so we can also catch errors from canacquire().

This is theoretically possible if memory has
been paged out and we get I/O errors when
trying to page it back in.
This commit is contained in:
cinap_lenrek 2024-01-04 04:49:33 +00:00
parent 16c1cc99ec
commit e38d42b4a7
2 changed files with 27 additions and 33 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
sys/src/9/port/segment.c
View file

@ -109,6 +109,9 @@ putseg(Segment *s)
} else if(decref(s) != 0)
return;
assert(s->sema.prev == &s->sema);
assert(s->sema.next = &s->sema);
if(s->mapsize > 0){
emap = &s->map[s->mapsize];
for(pte = s->map; pte < emap; pte++)

29
sys/src/9/port/sysproc.c
View file

@ -236,7 +236,6 @@ sysrfork(va_list list)
wm = up->wired;
if(wm != nil)
procwired(p, wm->machno);
p->psstate = nil;
ready(p);
sched();
return pid;
@ -1141,19 +1140,15 @@ semacquire(Segment *s, long *addr, int block)
return 1;
if(!block)
return 0;
acquired = 0;
semqueue(s, addr, &phore);
if(acquired = !waserror()){
for(;;){
phore.waiting = 1;
coherence();
if(canacquire(addr)){
acquired = 1;
break;
}
if(waserror())
if(canacquire(addr))
break;
sleep(&phore, semawoke, &phore);
}
poperror();
}
semdequeue(s, &phore);
@ -1169,7 +1164,7 @@ semacquire(Segment *s, long *addr, int block)
static int
tsemacquire(Segment *s, long *addr, ulong ms)
{
int acquired, timedout;
int timedout, acquired;
ulong t;
Sema phore;
@ -1177,36 +1172,32 @@ tsemacquire(Segment *s, long *addr, ulong ms)
return 1;
if(ms == 0)
return 0;
acquired = timedout = 0;
timedout = 0;
semqueue(s, addr, &phore);
if(acquired = !waserror()){
for(;;){
phore.waiting = 1;
coherence();
if(canacquire(addr)){
acquired = 1;
break;
}
if(waserror())
if(canacquire(addr))
break;
t = MACHP(0)->ticks;
tsleep(&phore, semawoke, &phore, ms);
t = TK2MS(MACHP(0)->ticks - t);
poperror();
if(t >= ms){
timedout = 1;
break;
}
ms -= t;
}
poperror();
}
semdequeue(s, &phore);
coherence(); /* not strictly necessary due to lock in semdequeue */
if(!phore.waiting)
semwakeup(s, addr, 1);
if(timedout)
return 0;
if(!acquired)
nexterror();
return 1;
return !timedout;
}
uintptr