[PATCH 1/5] eal: add lcore set name and get name API

[Tyler Retzlaff]

Add two new APIs that allow set and get of a name for an lcore that do
not explose platform thread details via the public interface.

If the underlying platform thread API does allow set of a name for the
lcore thread id it is called as a side-effect of set but lack of support
or failure from the platform-specific API does will not cause the call
to fail allowing for "debugging" on platforms that happen to support the
feature without exposing it as a part of the EAL.

Signed-off-by: Tyler Retzlaff <roretzla at linux.microsoft.com>
---
 lib/eal/common/eal_common_lcore.c  | 32 +++++++++++++++++++++++++++
 lib/eal/common/eal_common_thread.c | 15 ++++++-------
 lib/eal/common/eal_common_trace.c  |  2 +-
 lib/eal/freebsd/eal.c              |  5 ++++-
 lib/eal/freebsd/eal_thread.c       |  6 ++++++
 lib/eal/include/rte_lcore.h        | 44 ++++++++++++++++++++++++++++++++++++++
 lib/eal/include/rte_thread.h       |  8 +++++++
 lib/eal/linux/eal.c                |  5 ++---
 lib/eal/linux/eal_thread.c         | 19 ++++++++++++++++
 lib/eal/version.map                |  5 +++++
 lib/eal/windows/rte_thread.c       | 41 +++++++++++++++++++++++++++++++++++
 11 files changed, 169 insertions(+), 13 deletions(-)

diff --git a/lib/eal/common/eal_common_lcore.c b/lib/eal/common/eal_common_lcore.c
index 06c594b..700362a 100644
--- a/lib/eal/common/eal_common_lcore.c
+++ b/lib/eal/common/eal_common_lcore.c
@@ -14,6 +14,38 @@
 #include "eal_private.h"
 #include "eal_thread.h"
 
+static char lcore_names[RTE_MAX_LCORE][RTE_LCORE_NAME_MAX_LEN];
+
+int
+rte_lcore_set_name(unsigned int lcore_id, const char *name)
+{
+	if (unlikely(lcore_id >= RTE_MAX_LCORE))
+		return -EINVAL;
+
+	if (strlen(name) >= RTE_LCORE_NAME_MAX_LEN)
+		return -ERANGE;
+
+	(void)strcpy(&lcore_names[lcore_id][0], name);
+
+	rte_thread_set_name((rte_thread_t){lcore_config[lcore_id].thread_id}, name);
+
+	return 0;
+}
+
+int
+rte_lcore_get_name(unsigned int lcore_id, char *name, size_t len)
+{
+	if (unlikely(lcore_id >= RTE_MAX_LCORE))
+		return -EINVAL;
+
+	if (len < RTE_LCORE_NAME_MAX_LEN)
+		return -EINVAL;
+
+	(void)strcpy(name, &lcore_names[lcore_id][0]);
+
+	return 0;
+}
+
 unsigned int rte_get_main_lcore(void)
 {
 	return rte_eal_get_configuration()->main_lcore;
diff --git a/lib/eal/common/eal_common_thread.c b/lib/eal/common/eal_common_thread.c
index c5d8b43..91066e6 100644
--- a/lib/eal/common/eal_common_thread.c
+++ b/lib/eal/common/eal_common_thread.c
@@ -272,6 +272,7 @@ static void *ctrl_thread_init(void *arg)
 		const pthread_attr_t *attr,
 		void *(*start_routine)(void *), void *arg)
 {
+	rte_thread_t id;
 	struct rte_thread_ctrl_params *params;
 	enum __rte_ctrl_thread_status ctrl_thread_status;
 	int ret;
@@ -285,18 +286,16 @@ static void *ctrl_thread_init(void *arg)
 	params->ret = 0;
 	params->ctrl_thread_status = CTRL_THREAD_LAUNCHING;
 
-	ret = pthread_create(thread, attr, ctrl_thread_init, (void *)params);
+	ret = pthread_create((pthread_t *)&id.opaque_id, attr, ctrl_thread_init, params);
 	if (ret != 0) {
 		free(params);
 		return -ret;
 	}
 
-	if (name != NULL) {
-		ret = rte_thread_setname(*thread, name);
-		if (ret < 0)
-			RTE_LOG(DEBUG, EAL,
-				"Cannot set name for ctrl thread\n");
-	}
+	if (name != NULL)
+		rte_thread_set_name(id, name);
+
+	*thread = (pthread_t)id.opaque_id;
 
 	/* Wait for the control thread to initialize successfully */
 	while ((ctrl_thread_status =
@@ -312,7 +311,7 @@ static void *ctrl_thread_init(void *arg)
 	/* Check if the control thread encountered an error */
 	if (ctrl_thread_status == CTRL_THREAD_ERROR) {
 		/* ctrl thread is exiting */
-		pthread_join(*thread, NULL);
+		(void)rte_thread_join(id, NULL);
 	}
 
 	ret = params->ret;
diff --git a/lib/eal/common/eal_common_trace.c b/lib/eal/common/eal_common_trace.c
index 5caaac8..03c1055 100644
--- a/lib/eal/common/eal_common_trace.c
+++ b/lib/eal/common/eal_common_trace.c
@@ -356,7 +356,7 @@ rte_trace_mode rte_trace_mode_get(void)
 	/* Store the thread name */
 	char *name = header->stream_header.thread_name;
 	memset(name, 0, __RTE_TRACE_EMIT_STRING_LEN_MAX);
-	rte_thread_getname(pthread_self(), name,
+	(void)rte_lcore_get_name(rte_lcore_id(), name,
 		__RTE_TRACE_EMIT_STRING_LEN_MAX);
 
 	trace->lcore_meta[count].mem = header;
diff --git a/lib/eal/freebsd/eal.c b/lib/eal/freebsd/eal.c
index 607684c..e6a76de 100644
--- a/lib/eal/freebsd/eal.c
+++ b/lib/eal/freebsd/eal.c
@@ -817,7 +817,10 @@ static void rte_eal_init_alert(const char *msg)
 		/* Set thread_name for aid in debugging. */
 		snprintf(thread_name, sizeof(thread_name),
 				"rte-worker-%d", i);
-		rte_thread_setname(lcore_config[i].thread_id, thread_name);
+		ret = rte_lcore_set_name(i, thread_name);
+		if (ret != 0)
+			RTE_LOG(DEBUG, EAL,
+				"Cannot set name for lcore\n");
 
 		ret = pthread_setaffinity_np(lcore_config[i].thread_id,
 			sizeof(rte_cpuset_t), &lcore_config[i].cpuset);
diff --git a/lib/eal/freebsd/eal_thread.c b/lib/eal/freebsd/eal_thread.c
index ab81b52..af85c48 100644
--- a/lib/eal/freebsd/eal_thread.c
+++ b/lib/eal/freebsd/eal_thread.c
@@ -32,6 +32,12 @@ int rte_sys_gettid(void)
 	return (int)lwpid;
 }
 
+void rte_thread_set_name(rte_thread_t id, const char *name)
+{
+	/* this BSD function returns no error */
+	pthread_set_name_np(id.opaque_id, name);
+}
+
 int rte_thread_setname(pthread_t id, const char *name)
 {
 	/* this BSD function returns no error */
diff --git a/lib/eal/include/rte_lcore.h b/lib/eal/include/rte_lcore.h
index 6938c3f..251208f 100644
--- a/lib/eal/include/rte_lcore.h
+++ b/lib/eal/include/rte_lcore.h
@@ -13,6 +13,7 @@
  */
 #include <stdio.h>
 
+#include <rte_common.h>
 #include <rte_compat.h>
 #include <rte_config.h>
 #include <rte_per_lcore.h>
@@ -25,6 +26,7 @@
 #endif
 
 #define LCORE_ID_ANY     UINT32_MAX       /**< Any lcore. */
+#define RTE_LCORE_NAME_MAX_LEN RTE_MAX_THREAD_NAME_LEN
 
 RTE_DECLARE_PER_LCORE(unsigned, _lcore_id);  /**< Per thread "lcore id". */
 
@@ -90,6 +92,48 @@ enum rte_lcore_role_t {
 unsigned int rte_get_main_lcore(void);
 
 /**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Sets the name of an lcore and (if supported) implicitly sets the
+ * debugging name of the lcores thread.
+ *
+ * @param lcore_id
+ *   The targeted lcore.
+ *
+ * @param name
+ *   The name to set for the specified lcore_id. strlen(name) shall be
+ *   no more than RTE_LCORE_NAME_MAX_LEN - 1 long.
+ *
+ * @return
+ *   0 on success or, -errno on failure.
+ */
+__rte_experimental
+int rte_lcore_set_name(unsigned int lcore_id, const char *name);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Gets the name of an lcore thread.
+ *
+ * @param lcore_id
+ *   The targeted lcore.
+ *
+ * @param name
+ *   The buffer used to receive the lcore name.
+ *
+ * @param len
+ *   The length of the buffer name. The buffer len shall be at
+ *   least RTE_LCORE_NAME_MAX_LEN.
+ *
+ * @return
+ *   0 on success or, -errno on failure.
+ */
+__rte_experimental
+int rte_lcore_get_name(unsigned int lcore_id, char *name, size_t len);
+
+/**
  * Return the number of execution units (lcores) on the system.
  *
  * @return
diff --git a/lib/eal/include/rte_thread.h b/lib/eal/include/rte_thread.h
index b9edf70..713330c 100644
--- a/lib/eal/include/rte_thread.h
+++ b/lib/eal/include/rte_thread.h
@@ -143,6 +143,14 @@ int rte_thread_create(rte_thread_t *thread_id,
 rte_thread_t rte_thread_self(void);
 
 /**
+ * @internal
+ * Set the name of the thread.
+ */
+__rte_internal
+void
+rte_thread_set_name(rte_thread_t id, const char *name);
+
+/**
  * @warning
  * @b EXPERIMENTAL: this API may change without prior notice.
  *
diff --git a/lib/eal/linux/eal.c b/lib/eal/linux/eal.c
index 8c118d0..97e2fec 100644
--- a/lib/eal/linux/eal.c
+++ b/lib/eal/linux/eal.c
@@ -1255,11 +1255,10 @@ static void rte_eal_init_alert(const char *msg)
 		/* Set thread_name for aid in debugging. */
 		snprintf(thread_name, sizeof(thread_name),
 			"rte-worker-%d", i);
-		ret = rte_thread_setname(lcore_config[i].thread_id,
-						thread_name);
+		ret = rte_lcore_set_name(i, thread_name);
 		if (ret != 0)
 			RTE_LOG(DEBUG, EAL,
-				"Cannot set name for lcore thread\n");
+				"Cannot set name for lcore\n");
 
 		ret = pthread_setaffinity_np(lcore_config[i].thread_id,
 			sizeof(rte_cpuset_t), &lcore_config[i].cpuset);
diff --git a/lib/eal/linux/eal_thread.c b/lib/eal/linux/eal_thread.c
index 625bde6..2413bc6 100644
--- a/lib/eal/linux/eal_thread.c
+++ b/lib/eal/linux/eal_thread.c
@@ -10,6 +10,7 @@
 
 #include <rte_eal.h>
 #include <rte_lcore.h>
+#include <rte_log.h>
 #include <rte_string_fns.h>
 
 /* require calling thread tid by gettid() */
@@ -18,6 +19,24 @@ int rte_sys_gettid(void)
 	return (int)syscall(SYS_gettid);
 }
 
+void rte_thread_set_name(rte_thread_t id, const char *name)
+{
+	int ret = ENOSYS;
+#if defined(__GLIBC__) && defined(__GLIBC_PREREQ)
+#if __GLIBC_PREREQ(2, 12)
+	char truncated[16];
+
+	strlcpy(truncated, name, sizeof(truncated));
+	ret = pthread_setname_np(id.opaque_id, truncated);
+#endif
+#endif
+	RTE_SET_USED(id);
+	RTE_SET_USED(name);
+
+	if (ret != 0)
+		RTE_LOG(DEBUG, EAL, "Cannot set thread name\n");
+}
+
 int rte_thread_setname(pthread_t id, const char *name)
 {
 	int ret = ENOSYS;
diff --git a/lib/eal/version.map b/lib/eal/version.map
index 7ad12a7..4110f75 100644
--- a/lib/eal/version.map
+++ b/lib/eal/version.map
@@ -440,6 +440,10 @@ EXPERIMENTAL {
 	rte_thread_detach;
 	rte_thread_equal;
 	rte_thread_join;
+
+	# added in 23.03
+	rte_lcore_get_name;
+	rte_lcore_set_name;
 };
 
 INTERNAL {
@@ -483,4 +487,5 @@ INTERNAL {
 	rte_mem_map;
 	rte_mem_page_size;
 	rte_mem_unmap;
+	rte_thread_set_name;
 };
diff --git a/lib/eal/windows/rte_thread.c b/lib/eal/windows/rte_thread.c
index 1c1e9d0..51028ef 100644
--- a/lib/eal/windows/rte_thread.c
+++ b/lib/eal/windows/rte_thread.c
@@ -4,7 +4,9 @@
  */
 
 #include <errno.h>
+#include <wchar.h>
 
+#include <rte_eal.h>
 #include <rte_common.h>
 #include <rte_errno.h>
 #include <rte_thread.h>
@@ -305,6 +307,45 @@ struct thread_routine_ctx {
 	return thread_id;
 }
 
+void
+rte_thread_set_name(rte_thread_t id, const char *name)
+{
+	int ret = 0;
+	wchar_t wname[RTE_MAX_THREAD_NAME_LEN];
+	mbstate_t state = {0};
+	size_t rv;
+	HANDLE thread_handle;
+
+	thread_handle = OpenThread(THREAD_ALL_ACCESS, FALSE, id.opaque_id);
+	if (thread_handle == NULL) {
+		ret = thread_log_last_error("OpenThread()");
+		goto cleanup;
+	}
+
+	rv = mbsrtowcs(wname, &name, sizeof(wname) / sizeof(wname[0]), &state);
+	if (rv == (size_t)-1) {
+		ret = EILSEQ;
+		goto cleanup;
+	}
+
+	if (name != NULL) {
+		ret = ERANGE;
+		goto cleanup;
+	}
+
+	if (FAILED(SetThreadDescription(thread_handle, wname))) {
+		ret = EINVAL;
+		goto cleanup;
+	}
+
+cleanup:
+	if (thread_handle != NULL)
+		CloseHandle(thread_handle);
+
+	if (ret != 0)
+		RTE_LOG(DEBUG, EAL, "Cannot set name for lcore\n");
+}
+
 int
 rte_thread_get_priority(rte_thread_t thread_id,
 	enum rte_thread_priority *priority)
-- 
1.8.3.1