On Sun, 19 Jun 2022, adr wrote:
The solution is obvious, cancel the process' handlers before it
exits so we don't run out of space.
This was really silly...
Now, is there any reason to not do that in threadexits() when it
terminates the process?
Shouldn't threadnotify() cancel only the process' handlers? We are
sharing onnote[NFN] and the code as it is right now removes the
first handler that match the pointer, it can belong to another
process.
I ended up playing with this (do not register duplicated handlers,
cancel only the notes of the thread's process and cancel all notes
when the process exits):
/sys/src/libthread/sched.c:
[...]
if(t == nil){
_threaddebug(DBGSCHED, "all threads gone; exiting");
cancelnotes(p->pid);
_schedexit(p);
}
[...]
/sys/src/libthread/note.c
[...]
int
threadnotify(int (*f)(void*, char*), int in)
{
int i, frompid, topid;
int (*from)(void*, char*), (*to)(void*, char*);
if(in){
from = nil;
frompid = 0;
to = f;
topid = _threadgetproc()->pid;
lock(&onnotelock);
for(i=0; i<NFN; i++)
if(onnote[i]==to && onnotepid[i]==topid){
unlock(&onnotelock);
return i<NFN;
}
unlock(&onnotelock);
}else{
from = f;
frompid = _threadgetproc()->pid;
to = nil;
topid = 0;
}
lock(&onnotelock);
for(i=0; i<NFN; i++)
if(onnote[i]==from && onnotepid[i]==frompid){
onnote[i] = to;
onnotepid[i] = topid;
break;
}
unlock(&onnotelock);
return i<NFN;
}
void
cancelnotes(int pid)
{
int i;
lock(&onnotelock);
for(i=0; i<NFN; i++)
if(onnotepid[i] == pid){
onnote[i] = nil;
onnotepid[i] = 0;
}
unlock(&onnotelock);
return;
}
/sys/include/thread.h
[...]
void cancelnotes(int pid);
[...]
Anyway, I would like to know a real example when it is useful to
span a hundred processes using libthread without really exploiting
threads at all. I mean, we have been streching things a little
here!
adr.
------------------------------------------
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