test: fork handling

[urcu.git] / urcu-call-rcu-impl.h

diff --git a/urcu-call-rcu-impl.h b/urcu-call-rcu-impl.h
index 4e5879f381eadc8ebacd2efd079bfa588ac41c4b..6580397b1ee42b04a8e48b5c29a76220ea39b6d0 100644 (file)
--- a/urcu-call-rcu-impl.h
+++ b/urcu-call-rcu-impl.h
@@ -69,7 +69,7 @@ struct call_rcu_data {
  * Protected by call_rcu_mutex.
  */
 
-CDS_LIST_HEAD(call_rcu_data_list);
+static CDS_LIST_HEAD(call_rcu_data_list);
 
 /* Link a thread using call_rcu() to its call_rcu thread. */
 
@@ -252,11 +252,14 @@ static void *call_rcu_thread(void *arg)
                struct cds_wfcq_head cbs_tmp_head;
                struct cds_wfcq_tail cbs_tmp_tail;
                struct cds_wfcq_node *cbs, *cbs_tmp_n;
+               enum cds_wfcq_ret splice_ret;
 
                cds_wfcq_init(&cbs_tmp_head, &cbs_tmp_tail);
-               __cds_wfcq_splice_blocking(&cbs_tmp_head, &cbs_tmp_tail,
-                       &crdp->cbs_head, &crdp->cbs_tail);
-               if (!cds_wfcq_empty(&cbs_tmp_head, &cbs_tmp_tail)) {
+               splice_ret = __cds_wfcq_splice_blocking(&cbs_tmp_head,
+                       &cbs_tmp_tail, &crdp->cbs_head, &crdp->cbs_tail);
+               assert(splice_ret != CDS_WFCQ_RET_WOULDBLOCK);
+               assert(splice_ret != CDS_WFCQ_RET_DEST_NON_EMPTY);
+               if (splice_ret != CDS_WFCQ_RET_SRC_EMPTY) {
                        synchronize_rcu();
                        cbcount = 0;
                        __cds_wfcq_for_each_blocking_safe(&cbs_tmp_head,
@@ -626,6 +629,10 @@ void call_rcu(struct rcu_head *head,
  * The caller must wait for a grace-period to pass between return from
  * set_cpu_call_rcu_data() and call to call_rcu_data_free() passing the
  * previous call rcu data as argument.
+ *
+ * Note: introducing __cds_wfcq_splice_blocking() in this function fixed
+ * a list corruption bug in the 0.7.x series. The equivalent fix
+ * appeared in 0.6.8 for the stable-0.6 branch.
  */
 void call_rcu_data_free(struct call_rcu_data *crdp)
 {