[PATCH 2/2] eal: notify secondary on primary exit

[Stephen Hemminger]

When primary process exits, it should notify the secondary
processes. This allows for clean shutdown and eliminates need
for MP handling in applications (such as test-pmd).

Bugzilla ID: 1942
Fixes: 85d6815fa6d0 ("eal: close multi-process socket during cleanup")
Cc: sta...@dpdk.org

Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
---
 lib/eal/common/eal_common_proc.c | 51 ++++++++++++++++++++++++++++++--
 1 file changed, 49 insertions(+), 2 deletions(-)

diff --git a/lib/eal/common/eal_common_proc.c b/lib/eal/common/eal_common_proc.c
index 06f151818c..4369892e44 100644
--- a/lib/eal/common/eal_common_proc.c
+++ b/lib/eal/common/eal_common_proc.c
@@ -60,6 +60,15 @@ enum mp_type {
        MP_IGN, /* Response telling requester to ignore this response */
 };
 
+/* Message sent from primary EAL to secondary EAL */
+#define EAL_MP "mp_eal"
+struct eal_mp_req {
+       enum {
+               MP_REQ_NOP = 0,
+               MP_REQ_QUIT,
+       } type;
+};
+
 struct mp_msg_internal {
        int type;
        struct rte_mp_msg msg;
@@ -614,6 +623,25 @@ close_socket_fd(int fd)
                unlink(path);
 }
 
+/* callback in secondary when primary has exited */
+static int
+mp_primary_exited(const struct rte_mp_msg *msg, const void *peer __rte_unused)
+{
+       const struct eal_mp_req *req;
+
+       if (msg->len_param != sizeof(*req)) {
+               EAL_LOG(ERR, "invalid request from primary");
+               return -EINVAL;
+       }
+
+       req = (const struct eal_mp_req *)msg->param;
+       if (req->type == MP_REQ_QUIT)
+               rte_mp_channel_cleanup();
+
+       /* no reply needed */
+       return 0;
+}
+
 int
 rte_mp_channel_init(void)
 {
@@ -661,6 +689,10 @@ rte_mp_channel_init(void)
                return -1;
        }
 
+       /* listen for quit message from primary */
+       if (rte_eal_process_type() == RTE_PROC_SECONDARY)
+               rte_mp_action_register(EAL_MP, mp_primary_exited);
+
        if (rte_thread_create_internal_control(&mp_handle_tid, "mp-msg",
                        mp_handle, NULL) < 0) {
                EAL_LOG(ERR, "failed to create mp thread: %s",
@@ -682,12 +714,27 @@ rte_mp_channel_cleanup(void)
 {
        int fd;
 
+       /* Primary exiting, tell all secondary processes */
+       if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+               struct rte_mp_msg msg = { .name = EAL_MP };
+               struct eal_mp_req req = { .type = MP_REQ_QUIT };
+
+               memcpy(&msg.param, &req, sizeof(req));
+               msg.len_param = sizeof(req);
+
+               rte_mp_sendmsg(&msg);
+       } else {
+               rte_mp_action_unregister(EAL_MP);
+       }
+
        fd = rte_atomic_exchange_explicit(&mp_fd, -1, rte_memory_order_relaxed);
        if (fd < 0)
                return;
 
-       pthread_cancel((pthread_t)mp_handle_tid.opaque_id);
-       rte_thread_join(mp_handle_tid, NULL);
+       if (pthread_self() != (pthread_t)mp_handle_tid.opaque_id) {
+               pthread_cancel((pthread_t)mp_handle_tid.opaque_id);
+               rte_thread_join(mp_handle_tid, NULL);
+       }
        close_socket_fd(fd);
 }
 
-- 
2.53.0