[dpdk-dev] [RFC 3/4] eal: set name when creating a control thread

[Olivier Matz]

To avoid code duplication, add a parameter to rte_ctrl_thread_create()
to specify the name of the thread.

This requires to add a wrapper for the thread start routine in
rte_thread_init(), which will first wait that the thread is configured.

Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
---
 lib/librte_eal/common/eal_common_thread.c      | 53 +++++++++++++++++++++++++-
 lib/librte_eal/common/include/rte_lcore.h      |  7 +++-
 lib/librte_eal/linuxapp/eal/eal_interrupts.c   | 13 ++-----
 lib/librte_eal/linuxapp/eal/eal_timer.c        | 12 +-----
 lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c | 10 +----
 lib/librte_pdump/rte_pdump.c                   | 10 +----
 lib/librte_vhost/socket.c                      |  7 ++--
 7 files changed, 69 insertions(+), 43 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_thread.c b/lib/librte_eal/common/eal_common_thread.c
index f1a88f85e..b4335e04e 100644
--- a/lib/librte_eal/common/eal_common_thread.c
+++ b/lib/librte_eal/common/eal_common_thread.c
@@ -36,6 +36,7 @@
 #include <stdint.h>
 #include <unistd.h>
 #include <pthread.h>
+#include <signal.h>
 #include <sched.h>
 #include <assert.h>
 #include <string.h>
@@ -170,9 +171,57 @@ eal_thread_dump_affinity(char *str, unsigned size)
 	return ret;
 }
 
-int rte_ctrl_thread_create(pthread_t *thread,
+
+struct rte_thread_ctrl_params {
+	void *(*start_routine)(void *);
+	void *arg;
+	pthread_barrier_t launched;
+	pthread_barrier_t configured;
+};
+
+static void *rte_thread_init(void *arg)
+{
+	struct rte_thread_ctrl_params *params = arg;
+	void *(*start_routine)(void *) = params->start_routine;
+	void *routine_arg = params->arg;
+
+	pthread_barrier_wait(&params->launched);
+	pthread_barrier_wait(&params->configured);
+
+	return start_routine(routine_arg);
+}
+
+int rte_ctrl_thread_create(pthread_t *thread, const char *name,
 			const pthread_attr_t *attr,
 			void *(*start_routine)(void *), void *arg)
 {
-	return pthread_create(thread, attr, start_routine, arg);
+	struct rte_thread_ctrl_params params = {
+		.start_routine = start_routine,
+		.arg = arg,
+	};
+	int ret;
+
+	pthread_barrier_init(&params.launched, NULL, 2);
+	pthread_barrier_init(&params.configured, NULL, 2);
+
+	ret = pthread_create(thread, attr, rte_thread_init, (void *)&params);
+	if (ret != 0)
+		return ret;
+
+	pthread_barrier_wait(&params.launched);
+
+	if (name != NULL) {
+		ret = rte_thread_setname(*thread, name);
+		if (ret < 0)
+			goto fail;
+	}
+
+	pthread_barrier_wait(&params.configured);
+
+	return 0;
+
+fail:
+	pthread_kill(*thread, SIGTERM);
+	pthread_join(*thread, NULL);
+	return ret;
 }
diff --git a/lib/librte_eal/common/include/rte_lcore.h b/lib/librte_eal/common/include/rte_lcore.h
index 11f481c52..f7f67868c 100644
--- a/lib/librte_eal/common/include/rte_lcore.h
+++ b/lib/librte_eal/common/include/rte_lcore.h
@@ -265,10 +265,12 @@ int rte_thread_setname(pthread_t id, const char *name);
 /**
  * Create a control thread.
  *
- * Wrapper to pthread_create().
+ * Wrapper to pthread_create() and pthread_setname_np().
  *
  * @param thread
  *   Filled with the thread id of the new created thread.
+ * @param name
+ *   The name of the control thread (max 16 characters including '\0').
  * @param attr
  *   Attributes for the new thread.
  * @param start_routine
@@ -279,7 +281,8 @@ int rte_thread_setname(pthread_t id, const char *name);
  *   On success, returns 0; on error, it returns a negative value
  *   corresponding to the error number.
  */
-int rte_ctrl_thread_create(pthread_t *thread, const pthread_attr_t *attr,
+int rte_ctrl_thread_create(pthread_t *thread, const char *name,
+			const pthread_attr_t *attr,
 			void *(*start_routine)(void *), void *arg);
 
 /**
diff --git a/lib/librte_eal/linuxapp/eal/eal_interrupts.c b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
index 8fee317e5..4b5e6da31 100644
--- a/lib/librte_eal/linuxapp/eal/eal_interrupts.c
+++ b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
@@ -873,7 +873,7 @@ eal_intr_thread_main(__rte_unused void *arg)
 int
 rte_eal_intr_init(void)
 {
-	int ret = 0, ret_1 = 0;
+	int ret = 0;
 	char thread_name[RTE_MAX_THREAD_NAME_LEN];
 
 	/* init the global interrupt source head */
@@ -889,20 +889,13 @@ rte_eal_intr_init(void)
 	}
 
 	/* create the host thread to wait/handle the interrupt */
-	ret = rte_ctrl_thread_create(&intr_thread, NULL,
+	snprintf(thread_name, sizeof(thread_name), "eal-intr-thread");
+	ret = rte_ctrl_thread_create(&intr_thread, thread_name, NULL,
 			eal_intr_thread_main, NULL);
 	if (ret != 0) {
 		rte_errno = -ret;
 		RTE_LOG(ERR, EAL,
 			"Failed to create thread for interrupt handling\n");
-	} else {
-		/* Set thread_name for aid in debugging. */
-		snprintf(thread_name, RTE_MAX_THREAD_NAME_LEN,
-			"eal-intr-thread");
-		ret_1 = rte_thread_setname(intr_thread, thread_name);
-		if (ret_1 != 0)
-			RTE_LOG(DEBUG, EAL,
-			"Failed to set thread name for interrupt handling\n");
 	}
 
 	return ret;
diff --git a/lib/librte_eal/linuxapp/eal/eal_timer.c b/lib/librte_eal/linuxapp/eal/eal_timer.c
index 1766f9353..669dc9ceb 100644
--- a/lib/librte_eal/linuxapp/eal/eal_timer.c
+++ b/lib/librte_eal/linuxapp/eal/eal_timer.c
@@ -207,7 +207,8 @@ rte_eal_hpet_init(int make_default)
 
 	/* create a thread that will increment a global variable for
 	 * msb (hpet is 32 bits by default under linux) */
-	ret = rte_ctrl_thread_create(&msb_inc_thread_id, NULL,
+	snprintf(thread_name, sizeof(thread_name), "hpet-msb-inc");
+	ret = rte_ctrl_thread_create(&msb_inc_thread_id, thread_name, NULL,
 			(void *(*)(void *))hpet_msb_inc, NULL);
 	if (ret != 0) {
 		RTE_LOG(ERR, EAL, "ERROR: Cannot create HPET timer thread!\n");
@@ -215,15 +216,6 @@ rte_eal_hpet_init(int make_default)
 		return -1;
 	}
 
-	/*
-	 * Set thread_name for aid in debugging.
-	 */
-	snprintf(thread_name, RTE_MAX_THREAD_NAME_LEN, "hpet-msb-inc");
-	ret = rte_thread_setname(msb_inc_thread_id, thread_name);
-	if (ret != 0)
-		RTE_LOG(DEBUG, EAL,
-			"Cannot set HPET timer thread name!\n");
-
 	if (make_default)
 		eal_timer_source = EAL_TIMER_HPET;
 	return 0;
diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c b/lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c
index d104f8920..a20fb8691 100644
--- a/lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c
+++ b/lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c
@@ -403,7 +403,8 @@ vfio_mp_sync_setup(void)
 		return -1;
 	}
 
-	ret = rte_ctrl_thread_create(&socket_thread, NULL,
+	snprintf(thread_name, sizeof(thread_name), "vfio-sync");
+	ret = rte_ctrl_thread_create(&socket_thread, thread_name, NULL,
 			vfio_mp_sync_thread, NULL);
 	if (ret) {
 		RTE_LOG(ERR, EAL,
@@ -412,13 +413,6 @@ vfio_mp_sync_setup(void)
 		return -1;
 	}
 
-	/* Set thread_name for aid in debugging. */
-	snprintf(thread_name, RTE_MAX_THREAD_NAME_LEN, "vfio-sync");
-	ret = rte_thread_setname(socket_thread, thread_name);
-	if (ret)
-		RTE_LOG(DEBUG, EAL,
-			"Failed to set thread name for secondary processes!\n");
-
 	return 0;
 }
 
diff --git a/lib/librte_pdump/rte_pdump.c b/lib/librte_pdump/rte_pdump.c
index 70de0c48b..061263236 100644
--- a/lib/librte_pdump/rte_pdump.c
+++ b/lib/librte_pdump/rte_pdump.c
@@ -577,7 +577,8 @@ rte_pdump_init(const char *path)
 	}
 
 	/* create the host thread to wait/handle pdump requests */
-	ret = rte_ctrl_thread_create(&pdump_thread, NULL,
+	snprintf(thread_name, sizeof(thread_name), "pdump-thread");
+	ret = rte_ctrl_thread_create(&pdump_thread, thread_name, NULL,
 				pdump_thread_main, NULL);
 	if (ret != 0) {
 		RTE_LOG(ERR, PDUMP,
@@ -585,13 +586,6 @@ rte_pdump_init(const char *path)
 			strerror(-ret), __func__, __LINE__);
 		return -1;
 	}
-	/* Set thread_name for aid in debugging. */
-	snprintf(thread_name, RTE_MAX_THREAD_NAME_LEN, "pdump-thread");
-	ret = rte_thread_setname(pdump_thread, thread_name);
-	if (ret != 0) {
-		RTE_LOG(DEBUG, PDUMP,
-			"Failed to set thread name for pdump handling\n");
-	}
 
 	return 0;
 }
diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
index 905d040a4..43d699ef7 100644
--- a/lib/librte_vhost/socket.c
+++ b/lib/librte_vhost/socket.c
@@ -470,7 +470,7 @@ vhost_user_reconnect_init(void)
 	}
 	TAILQ_INIT(&reconn_list.head);
 
-	ret = rte_ctrl_thread_create(&reconn_tid, NULL,
+	ret = rte_ctrl_thread_create(&reconn_tid, "vhost_reconnect", NULL,
 			     vhost_user_client_reconnect, NULL);
 	if (ret != 0) {
 		RTE_LOG(ERR, VHOST_CONFIG, "failed to create reconnect thread");
@@ -834,8 +834,9 @@ rte_vhost_driver_start(const char *path)
 		return -1;
 
 	if (fdset_tid == 0) {
-		int ret = rte_ctrl_thread_create(&fdset_tid, NULL,
-			fdset_event_dispatch, &vhost_user.fdset);
+		int ret = rte_ctrl_thread_create(&fdset_tid,
+			"vhost_dispatch", NULL, fdset_event_dispatch,
+			&vhost_user.fdset);
 		if (ret != 0)
 			RTE_LOG(ERR, VHOST_CONFIG,
 				"failed to create fdset handling thread");
-- 
2.11.0