struct cds_list_head *pdeq_pop_l(struct pdeq *d)
{
struct cds_list_head *e;
spin_lock(&d->llock);
e = deq_pop_l(&d->ldeq);
if (e == NULL) {
spin_lock(&d->rlock);
e = deq_pop_l(&d->rdeq);
cds_list_splice(&d->rdeq.chain, &d->ldeq.chain);
CDS_INIT_LIST_HEAD(&d->rdeq.chain);
spin_unlock(&d->rlock);
}
spin_unlock(&d->llock);
return e;
}
//\begin{snippet}[labelbase=ln:SMPdesign:locktdeq:pop_push,commandchars=\\\@\$]
struct cds_list_head *pdeq_pop_l(struct pdeq *d) //\lnlbl{popl:b}
{
struct cds_list_head *e;
spin_lock(&d->llock); //\lnlbl{popl:acq:l}
e = deq_pop_l(&d->ldeq); //\lnlbl{popl:deq:ll}
if (e == NULL) {
spin_lock(&d->rlock); //\lnlbl{popl:acq:r}
e = deq_pop_l(&d->rdeq); //\lnlbl{popl:deq:lr}
cds_list_splice(&d->rdeq.chain, &d->ldeq.chain);//\lnlbl{popl:move}
CDS_INIT_LIST_HEAD(&d->rdeq.chain); //\lnlbl{popl:init:r}
spin_unlock(&d->rlock); //\lnlbl{popl:rel:r}
} //\lnlbl{popl:skip}
spin_unlock(&d->llock); //\lnlbl{popl:rel:l}
return e;
} //\lnlbl{popl:e}
struct cds_list_head *pdeq_pop_r(struct pdeq *d) //\lnlbl{popr:b}
{
struct cds_list_head *e;
spin_lock(&d->rlock); //\lnlbl{popr:acq:r1}
e = deq_pop_r(&d->rdeq); //\lnlbl{popr:deq:rr1}
if (e == NULL) { //\lnlbl{popr:check1}
spin_unlock(&d->rlock); //\lnlbl{popr:rel:r1}
spin_lock(&d->llock); //\lnlbl{popr:acq:l}
spin_lock(&d->rlock); //\lnlbl{popr:acq:r2}
e = deq_pop_r(&d->rdeq); //\lnlbl{popr:deq:rr2}
if (e == NULL) { //\lnlbl{popr:check2}
e = deq_pop_r(&d->ldeq); //\lnlbl{popr:deq:rl}
cds_list_splice(&d->ldeq.chain, &d->rdeq.chain);//\lnlbl{popr:move}
CDS_INIT_LIST_HEAD(&d->ldeq.chain); //\lnlbl{popr:init:l}
}
spin_unlock(&d->llock); //\lnlbl{popr:rel:l}
} //\lnlbl{popr:skip2}
spin_unlock(&d->rlock); //\lnlbl{popr:rel:r2}
return e;
} //\lnlbl{popr:e}