+/*
+ * Find a lock request that can be scheduled
+ */
+struct lock_context *ctdb_find_lock_context(struct ctdb_context *ctdb)
+{
+ struct lock_context *lock_ctx, *next_ctx;
+ struct ctdb_db_context *ctdb_db;
+
+ /* First check if there are database lock requests */
+ lock_ctx = ctdb->lock_pending;
+ while (lock_ctx != NULL) {
+ next_ctx = lock_ctx->next;
+ if (! lock_ctx->request) {
+ DEBUG(DEBUG_INFO, ("Removing lock context without lock request\n"));
+ DLIST_REMOVE(ctdb->lock_pending, lock_ctx);
+ CTDB_DECREMENT_STAT(ctdb, locks.num_pending);
+ if (lock_ctx->ctdb_db) {
+ CTDB_DECREMENT_DB_STAT(lock_ctx->ctdb_db, locks.num_pending);
+ }
+ talloc_free(lock_ctx);
+ } else {
+ /* Found a lock context with lock requests */
+ break;
+ }
+ lock_ctx = next_ctx;
+ }
+
+ if (lock_ctx) {
+ return lock_ctx;
+ }
+
+ /* Next check database queues */
+ for (ctdb_db = ctdb->db_list; ctdb_db; ctdb_db = ctdb_db->next) {
+ if (ctdb_db->lock_num_current == ctdb->tunable.lock_processes_per_db) {
+ continue;
+ }
+ lock_ctx = ctdb_db->lock_pending;
+ while (lock_ctx != NULL) {
+ next_ctx = lock_ctx->next;
+ if (! lock_ctx->request) {
+ DEBUG(DEBUG_INFO, ("Removing lock context without lock request\n"));
+ DLIST_REMOVE(ctdb_db->lock_pending, lock_ctx);
+ CTDB_DECREMENT_STAT(ctdb, locks.num_pending);
+ CTDB_DECREMENT_DB_STAT(ctdb_db, locks.num_pending);
+ talloc_free(lock_ctx);
+ } else {
+ break;
+ }
+
+ lock_ctx = next_ctx;
+ }
+
+ if (lock_ctx) {
+ return lock_ctx;
+ }
+ }
+
+ return NULL;
+}