* Thread-safety
* =============
*
- * Only a single thread may use a given nl_sock or nl_dump at one time.
+ * Most of the netlink functions are not fully thread-safe: Only a single
+ * thread may use a given nl_sock or nl_dump at one time. The exceptions are:
+ *
+ * - nl_sock_recv() is conditionally thread-safe: it may be called from
+ * different threads with the same nl_sock, but each caller must provide
+ * an independent receive buffer.
+ *
+ * - nl_dump_next() is conditionally thread-safe: it may be called from
+ * different threads with the same nl_dump, but each caller must provide
+ * independent buffers.
*/
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include "ofpbuf.h"
+#include "ovs-atomic.h"
struct nl_sock;
struct nl_dump {
struct nl_sock *sock; /* Socket being dumped. */
uint32_t nl_seq; /* Expected nlmsg_seq for replies. */
- int status; /* 0=OK, EOF=done, or positive errno value. */
+ atomic_uint status; /* Low bit set if we read final message.
+ * Other bits hold an errno (0 for success). */
+ struct seq *status_seq; /* Tracks changes to the above 'status'. */
};
void nl_dump_start(struct nl_dump *, int protocol,