MINOR: backend: replace the lbprm lock with an rwlock
It was previously a spinlock, and it happens that a number of LB algos
only lock it for lookups, without performing any modification. Let's
first turn it to an rwlock and w-lock it everywhere. This is strictly
identical.
It was carefully checked that every HA_SPIN_LOCK() was turned to
HA_RWLOCK_WRLOCK() and that HA_SPIN_UNLOCK() was turned to
HA_RWLOCK_WRUNLOCK() on this lock. _INIT and _DESTROY were updated too.
diff --git a/src/lb_fwrr.c b/src/lb_fwrr.c
index 05ae5f6..e2cdd9f 100644
--- a/src/lb_fwrr.c
+++ b/src/lb_fwrr.c
@@ -43,7 +43,7 @@
if (srv_willbe_usable(srv))
goto out_update_state;
- HA_SPIN_LOCK(LBPRM_LOCK, &p->lbprm.lock);
+ HA_RWLOCK_WRLOCK(LBPRM_LOCK, &p->lbprm.lock);
if (!srv_currently_usable(srv))
/* server was already down */
@@ -79,7 +79,7 @@
out_update_backend:
/* check/update tot_used, tot_weight */
update_backend_weight(p);
- HA_SPIN_UNLOCK(LBPRM_LOCK, &p->lbprm.lock);
+ HA_RWLOCK_WRUNLOCK(LBPRM_LOCK, &p->lbprm.lock);
out_update_state:
srv_lb_commit_status(srv);
@@ -105,7 +105,7 @@
if (!srv_willbe_usable(srv))
goto out_update_state;
- HA_SPIN_LOCK(LBPRM_LOCK, &p->lbprm.lock);
+ HA_RWLOCK_WRLOCK(LBPRM_LOCK, &p->lbprm.lock);
if (srv_currently_usable(srv))
/* server was already up */
@@ -147,7 +147,7 @@
out_update_backend:
/* check/update tot_used, tot_weight */
update_backend_weight(p);
- HA_SPIN_UNLOCK(LBPRM_LOCK, &p->lbprm.lock);
+ HA_RWLOCK_WRUNLOCK(LBPRM_LOCK, &p->lbprm.lock);
out_update_state:
srv_lb_commit_status(srv);
@@ -191,7 +191,7 @@
return;
}
- HA_SPIN_LOCK(LBPRM_LOCK, &p->lbprm.lock);
+ HA_RWLOCK_WRLOCK(LBPRM_LOCK, &p->lbprm.lock);
grp = (srv->flags & SRV_F_BACKUP) ? &p->lbprm.fwrr.bck : &p->lbprm.fwrr.act;
grp->next_weight = grp->next_weight - srv->cur_eweight + srv->next_eweight;
@@ -239,7 +239,7 @@
}
update_backend_weight(p);
- HA_SPIN_UNLOCK(LBPRM_LOCK, &p->lbprm.lock);
+ HA_RWLOCK_WRUNLOCK(LBPRM_LOCK, &p->lbprm.lock);
srv_lb_commit_status(srv);
}
@@ -514,7 +514,7 @@
struct fwrr_group *grp;
int switched;
- HA_SPIN_LOCK(LBPRM_LOCK, &p->lbprm.lock);
+ HA_RWLOCK_WRLOCK(LBPRM_LOCK, &p->lbprm.lock);
if (p->srv_act)
grp = &p->lbprm.fwrr.act;
else if (p->lbprm.fbck) {
@@ -611,7 +611,7 @@
}
}
out:
- HA_SPIN_UNLOCK(LBPRM_LOCK, &p->lbprm.lock);
+ HA_RWLOCK_WRUNLOCK(LBPRM_LOCK, &p->lbprm.lock);
return srv;
}