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add locking

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This commit is contained in:
rsc 2006-02-17 19:30:59 +00:00
parent 19256e0dd9
commit b65f95f6d8
1 changed files with 9 additions and 2 deletions
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11
src/cmd/ndb/dnudpserver.c
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@ -21,6 +21,7 @@ struct Inprogress
int id;
};
Inprogress inprog[Maxactive+2];
QLock inproglk;
/*
* record client id and ignore retransmissions.
@ -32,6 +33,7 @@ clientrxmit(DNSmsg *req, uchar *buf)
Inprogress *p, *empty;
Udphdr *uh;
qlock(&inproglk);
uh = (Udphdr *)buf;
empty = 0;
for(p = inprog; p < &inprog[Maxactive]; p++){
@ -43,17 +45,22 @@ clientrxmit(DNSmsg *req, uchar *buf)
if(req->id == p->id)
if(req->qd->owner == p->owner)
if(req->qd->type == p->type)
if(memcmp(uh, &p->uh, Udphdrsize) == 0)
if(memcmp(uh, &p->uh, Udphdrsize) == 0){
qunlock(&inproglk);
return 0;
}
if(empty == 0)
}
if(empty == 0){
qunlock(&inproglk);
return 0; /* shouldn't happen - see slave() and definition of Maxactive */
}
empty->id = req->id;
empty->owner = req->qd->owner;
empty->type = req->qd->type;
memmove(&empty->uh, uh, Udphdrsize);
empty->inuse = 1;
qunlock(&inproglk);
return empty;
}