[dpdk-dev] [PATCH v3 1/2] telemetry: fix missing check for thread creation

[Power, Ciara]

Hi Connor, 

Thanks for looking at this. Left some comments inline.

Ciara

>-----Original Message-----
>From: Min Hu (Connor) <humin29 at huawei.com>
>Sent: Thursday 15 April 2021 12:50
>To: dev at dpdk.org
>Cc: Yigit, Ferruh <ferruh.yigit at intel.com>; Power, Ciara
><ciara.power at intel.com>; Pattan, Reshma <reshma.pattan at intel.com>;
>david.marchand at redhat.com
>Subject: [PATCH v3 1/2] telemetry: fix missing check for thread creation
>
>From: Chengwen Feng <fengchengwen at huawei.com>
>
>Add result check and message print out for thread creation after failure.
>
>Fixes: b80fe1805eee ("telemetry: introduce backward compatibility")
>Cc: stable at dpdk.org
>
>Signed-off-by: Chengwen Feng <fengchengwen at huawei.com>
>Signed-off-by: Min Hu (Connor) <humin29 at huawei.com>
>---
> lib/librte_telemetry/telemetry.c        | 30 +++++++++++++++++++++++++++-
>--
> lib/librte_telemetry/telemetry_legacy.c | 10 ++++++++--
> 2 files changed, 35 insertions(+), 5 deletions(-)
>
>diff --git a/lib/librte_telemetry/telemetry.c
>b/lib/librte_telemetry/telemetry.c
>index 7e08afd..e6a99f3 100644
>--- a/lib/librte_telemetry/telemetry.c
>+++ b/lib/librte_telemetry/telemetry.c
>@@ -350,6 +350,7 @@ socket_listener(void *socket)  {
> 	while (1) {
> 		pthread_t th;
>+		int rc;
> 		struct socket *s = (struct socket *)socket;
> 		int s_accepted = accept(s->sock, NULL, NULL);
> 		if (s_accepted < 0) {
>@@ -366,7 +367,12 @@ socket_listener(void *socket)
> 			__atomic_add_fetch(s->num_clients, 1,
> 					__ATOMIC_RELAXED);
> 		}
>-		pthread_create(&th, NULL, s->fn, (void
>*)(uintptr_t)s_accepted);
>+		rc = pthread_create(&th, NULL, s->fn, (void
>*)(uintptr_t)s_accepted);
>+		if (rc != 0) {
>+			TMTY_LOG(ERR, "Error with create client thread\n");
>+			close(s_accepted);
>+			return NULL;


I think this should be "continue" instead of "return NULL" - if one client connection thread fails,
we probably want to keep listening for more clients rather than stop completely.

The "s->num_clients" counter should be decremented here too,
it gets incremented above when the connection is accepted, but if we are closing the connection,
the counter should reflect that.


>+		}
> 		pthread_detach(th);
> 	}
> 	return NULL;
>@@ -425,6 +431,7 @@ static int
> telemetry_legacy_init(void)
> {
> 	pthread_t t_old;
>+	int rc;
>
> 	if (num_legacy_callbacks == 1) {
> 		TMTY_LOG(WARNING, "No legacy callbacks, legacy socket not
>created\n"); @@ -440,7 +447,15 @@ telemetry_legacy_init(void)
> 	v1_socket.sock = create_socket(v1_socket.path);
> 	if (v1_socket.sock < 0)
> 		return -1;
>-	pthread_create(&t_old, NULL, socket_listener, &v1_socket);
>+	rc = pthread_create(&t_old, NULL, socket_listener, &v1_socket);
>+	if (rc != 0) {
>+		TMTY_LOG(ERR, "Error with create thread for legacy
>socket\n");
>+		close(v1_socket.sock);
>+		v1_socket.sock = -1;
>+		unlink(v1_socket.path);
>+		v1_socket.path[0] = '\0';
>+		return -1;
>+	}
> 	pthread_setaffinity_np(t_old, sizeof(*thread_cpuset),
>thread_cpuset);
>
> 	TMTY_LOG(DEBUG, "Legacy telemetry socket initialized ok\n"); @@ -
>451,6 +466,7 @@ static int
> telemetry_v2_init(void)
> {
> 	pthread_t t_new;
>+	int rc;
>
> 	v2_socket.num_clients = &v2_clients;
> 	rte_telemetry_register_cmd("/", list_commands, @@ -469,7 +485,15
>@@ telemetry_v2_init(void)
> 	v2_socket.sock = create_socket(v2_socket.path);
> 	if (v2_socket.sock < 0)
> 		return -1;
>-	pthread_create(&t_new, NULL, socket_listener, &v2_socket);
>+	rc = pthread_create(&t_new, NULL, socket_listener, &v2_socket);
>+	if (rc != 0) {
>+		TMTY_LOG(ERR, "Error with create thread for socket");
>+		close(v2_socket.sock);
>+		v2_socket.sock = -1;
>+		unlink(v2_socket.path);
>+		v2_socket.path[0] = '\0';
>+		return -1;
>+	}
> 	pthread_setaffinity_np(t_new, sizeof(*thread_cpuset),
>thread_cpuset);
> 	atexit(unlink_sockets);
>
>diff --git a/lib/librte_telemetry/telemetry_legacy.c
>b/lib/librte_telemetry/telemetry_legacy.c
>index 5e9af37..fd242bf 100644
>--- a/lib/librte_telemetry/telemetry_legacy.c
>+++ b/lib/librte_telemetry/telemetry_legacy.c
>@@ -83,6 +83,7 @@ register_client(const char *cmd __rte_unused, const
>char *params,
> 	pthread_t th;
> 	char data[BUF_SIZE];
> 	int fd;
>+	int rc;
> 	struct sockaddr_un addrs;
> #endif /* !RTE_EXEC_ENV_WINDOWS */
>
>@@ -112,8 +113,13 @@ register_client(const char *cmd __rte_unused, const
>char *params,
> 		close(fd);
> 		return -1;
> 	}
>-	pthread_create(&th, NULL, &legacy_client_handler,
>-			(void *)(uintptr_t)fd);
>+	rc = pthread_create(&th, NULL, &legacy_client_handler,
>+				(void *)(uintptr_t)fd);
>+	if (rc != 0) {
>+		perror("Failed to create legacy client thread\n");
>+		close(fd);
>+		return -1;
>+	}
> #endif /* !RTE_EXEC_ENV_WINDOWS */
> 	return 0;
> }
>--
>2.7.4