Found a better solution for implementing ieee80211_node_dectestref().

Now the reference count get accessed only once, leading to true atomarity.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34823 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Colin Günther 2009-12-30 01:00:51 +00:00
parent 210124c810
commit 485da29cbc

View File

@ -397,8 +397,6 @@ ieee80211_getmgtframe(uint8_t** frm, int headroom, int pktlen)
/*
* Decrements the reference-counter and
* tests whether it became zero.
* NB: The negation of atomic_add is not atomar. Must work until sth. better is
* found.
*
* @return 1 reference-counter became zero
* @return 0 reference-counter didn't became zero
@ -406,9 +404,8 @@ ieee80211_getmgtframe(uint8_t** frm, int headroom, int pktlen)
int
ieee80211_node_dectestref(struct ieee80211_node* ni)
{
// XXX need equivalent of atomic_dec_and_test
atomic_add((vint32*)&ni->ni_refcnt, -1);
return !atomic_add((vint32*)&ni->ni_refcnt, 0);
// atomic_add returns old value
return 1 == atomic_add((vint32*)&ni->ni_refcnt, -1);
}