[dpdk-dev] [PATCH v2 2/4] eal: add and del secondary processes in the primary

[Jianfeng Tan <jianfeng.tan@intel.com>]

By the multi-process channel, we add an mp action named "proc".

As a secondary process starts, it sends a "proc add" message to
the primary.

As the primary finds a failure in sending message to a specific
secondary process, that secondary process is treated as exited;
and we remove it from the secondary array by sending a "proc del"
message to the primary itself.

Test:
  1. Start the primary and the secondary process
    $ (testpmd) -c 0x3 -n 4 -- -i
    $ (helloworld) -c 0xc -n 4 --proc-type=auto --

  2. Check the log of testpmd:
    ...
    EAL: bind to /var/run/.rte_unix
    ...
    EAL: add secondary: /var/run/.testpmd_unix_(xxx)
    ...

  3. Check the log of helloworld:
    ...
    EAL: bind to /var/run/.testpmd_unix_xxx
    EAL: bind to /var/run/.testpmd_unix_c_xxx
    ...

Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
---
 lib/librte_eal/common/eal_common_proc.c | 88 ++++++++++++++++++++++++++++++++-
 1 file changed, 86 insertions(+), 2 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_proc.c b/lib/librte_eal/common/eal_common_proc.c
index d700e9e..70519cc 100644
--- a/lib/librte_eal/common/eal_common_proc.c
+++ b/lib/librte_eal/common/eal_common_proc.c
@@ -54,6 +54,13 @@ struct mp_msghdr {
 	char params[0];
 } __rte_packed;
 
+struct proc_request {
+#define MP_PROC_ADD	0
+#define MP_PROC_DEL	1
+	int type;
+	char path[MAX_UNIX_PATH_LEN];
+};
+
 int
 rte_eal_primary_proc_alive(const char *config_file_path)
 {
@@ -214,6 +221,58 @@ mp_handle(void *arg __rte_unused)
 	return NULL;
 }
 
+static int
+add_sec_proc(const char *path)
+{
+	int i;
+
+	for (i = 0; i < MAX_SECONDARY_PROCS; ++i)
+		if (mp_sec_sockets[i] == NULL)
+			break;
+	if (i < MAX_SECONDARY_PROCS)
+		mp_sec_sockets[i] = strdup(path);
+
+	return i < MAX_SECONDARY_PROCS;
+}
+
+static int
+del_sec_proc(const char *path)
+{
+	int i;
+
+	for (i = 0; i < MAX_SECONDARY_PROCS; ++i) {
+		if (!strcmp(mp_sec_sockets[i], path)) {
+			free(mp_sec_sockets[i]);
+			mp_sec_sockets[i] = NULL;
+			break;
+		}
+	}
+
+	return i < MAX_SECONDARY_PROCS;
+}
+
+static int
+mp_primary_proc(const void *params,
+		int len __rte_unused,
+		int fds[] __rte_unused,
+		int fds_num __rte_unused)
+{
+	const struct proc_request *r = (const struct proc_request *)params;
+
+	switch (r->type) {
+	case MP_PROC_ADD:
+		RTE_LOG(INFO, EAL, "add secondary: %s\n", r->path);
+		return add_sec_proc(r->path);
+	case MP_PROC_DEL:
+		RTE_LOG(INFO, EAL, "del secondary: %s\n", r->path);
+		return del_sec_proc(r->path);
+	default:
+		RTE_LOG(ERR, EAL, "invalid type: %d\n", r->type);
+	}
+
+	return -1;
+}
+
 static inline const char *
 get_unix_path(int is_server)
 {
@@ -267,6 +326,22 @@ rte_eal_mp_channel_init(void)
 	if (mp_fd < 0)
 		return -1;
 
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+		if (rte_eal_mp_action_register("proc", mp_primary_proc) < 0) {
+			RTE_LOG(ERR, EAL, "failed to register handler\n");
+			goto error;
+		}
+	} else {
+		struct proc_request r;
+
+		r.type = MP_PROC_ADD;
+		snprintf(r.path, MAX_UNIX_PATH_LEN, "%s", get_unix_path(1));
+		if (rte_eal_mp_sendmsg("proc", &r, sizeof(r), NULL, 0) < 0) {
+			RTE_LOG(ERR, EAL, "failed to add into primary\n");
+			goto error;
+		}
+	}
+
 	if (pthread_create(&tid, NULL, mp_handle, NULL) < 0) {
 		RTE_LOG(ERR, EAL, "failed to create mp handle thead: %s\n",
 			strerror(errno));
@@ -354,10 +429,19 @@ send_msg(int fd, const char *dst_path, struct mp_msghdr *msg, int fds[])
 	if (ret < 0) {
 		RTE_LOG(ERR, EAL, "failed to send msg: %s\n", strerror(errno));
 
-		if (rte_eal_process_type() == RTE_PROC_PRIMARY)
+		if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+			struct proc_request r;
+
 			RTE_LOG(ERR, EAL, "secondary process (%s) exited\n",
 				dst_path);
-		else if (!rte_eal_primary_proc_alive(NULL))
+			r.type = MP_PROC_DEL;
+			snprintf(r.path, MAX_UNIX_PATH_LEN, "%s", dst_path);
+			if (rte_eal_mp_sendmsg("proc", &r,
+						sizeof(r), NULL, 0) < 0)
+				RTE_LOG(ERR, EAL,
+					"failed to del secondary %s\n",
+					dst_path);
+		} else if (!rte_eal_primary_proc_alive(NULL))
 			RTE_LOG(ERR, EAL, "primary process exited\n");
 
 		return 0;
-- 
2.7.4