Re: [PATCH v7 1/5] eal: add thread set name API operating on rte thread

[Thomas Monjalon <thomas@monjalon.net>]

23/01/2023 20:39, Tyler Retzlaff:
> Add a rte_thread_set_name that sets the name of an rte_thread_t thread.
> This is a replacement for the rte_thread_setname(pthread_t, ...) which
> exposes platform-specific details.
> 
> Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
> 
> Acked-by: Morten Brørup <mb@smartsharesystems.com>
> 
> ---
>  lib/eal/common/eal_common_thread.c |  8 ++-----
>  lib/eal/freebsd/eal.c              |  3 +--
>  lib/eal/freebsd/eal_thread.c       | 11 ++++++++++
>  lib/eal/include/rte_thread.h       | 17 +++++++++++++++
>  lib/eal/linux/eal.c                |  6 +-----
>  lib/eal/linux/eal_thread.c         | 22 +++++++++++++++++++
>  lib/eal/version.map                |  3 +++
>  lib/eal/windows/rte_thread.c       | 43 ++++++++++++++++++++++++++++++++++++++
>  8 files changed, 100 insertions(+), 13 deletions(-)
> 
> diff --git a/lib/eal/common/eal_common_thread.c b/lib/eal/common/eal_common_thread.c
> index 38d83a6..3181515 100644
> --- a/lib/eal/common/eal_common_thread.c
> +++ b/lib/eal/common/eal_common_thread.c
> @@ -288,12 +288,8 @@ static void *ctrl_thread_init(void *arg)
>  		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((rte_thread_t){(uintptr_t)*thread}, name);
>  
>  	/* Wait for the control thread to initialize successfully */
>  	while ((ctrl_thread_status =
> diff --git a/lib/eal/freebsd/eal.c b/lib/eal/freebsd/eal.c
> index 8db5007..9303401 100644
> --- a/lib/eal/freebsd/eal.c
> +++ b/lib/eal/freebsd/eal.c
> @@ -817,8 +817,7 @@ 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((pthread_t)lcore_config[i].thread_id.opaque_id,
> -			thread_name);
> +		rte_thread_set_name(lcore_config[i].thread_id, thread_name);
>  
>  		ret = rte_thread_set_affinity_by_id(lcore_config[i].thread_id,
>  			&lcore_config[i].cpuset);
> diff --git a/lib/eal/freebsd/eal_thread.c b/lib/eal/freebsd/eal_thread.c
> index ab81b52..b69f5d3 100644
> --- a/lib/eal/freebsd/eal_thread.c
> +++ b/lib/eal/freebsd/eal_thread.c
> @@ -32,6 +32,17 @@ int rte_sys_gettid(void)
>  	return (int)lwpid;
>  }
>  
> +void rte_thread_set_name(rte_thread_t thread_id, const char *thread_name)
> +{
> +	char truncated[RTE_MAX_THREAD_NAME_LEN];
> +	const size_t truncatedsz = sizeof(truncated);
> +
> +	if (strlcpy(truncated, thread_name, truncatedsz) >= truncatedsz)
> +		RTE_LOG(DEBUG, EAL, "Truncated thread name\n");
> +
> +	pthread_set_name_np((pthread_t)thread_id.opaque_id, truncated);
> +}
> +
>  int rte_thread_setname(pthread_t id, const char *name)
>  {
>  	/* this BSD function returns no error */
> diff --git a/lib/eal/include/rte_thread.h b/lib/eal/include/rte_thread.h
> index b9edf70..8a63a52 100644
> --- a/lib/eal/include/rte_thread.h
> +++ b/lib/eal/include/rte_thread.h
> @@ -146,6 +146,23 @@ int rte_thread_create(rte_thread_t *thread_id,
>   * @warning
>   * @b EXPERIMENTAL: this API may change without prior notice.
>   *
> + * Set the name of the thread.

We need to explain that it can fail.

> + *
> + * @param thread_id
> + *    The id of the thread to set name.
> + *
> + * @param thread_name
> + *    The name to set. Truncated to RTE_MAX_THREAD_NAME_LEN,
> + *    including terminating NUL if necessary.
> + */
> +__rte_experimental
> +void
> +rte_thread_set_name(rte_thread_t thread_id, const char *thread_name);

[...]
> --- a/lib/eal/linux/eal_thread.c
> +++ b/lib/eal/linux/eal_thread.c
> +void rte_thread_set_name(rte_thread_t thread_id, const char *thread_name)
> +{
> +	int ret = ENOSYS;
> +#if defined(__GLIBC__) && defined(__GLIBC_PREREQ)
> +#if __GLIBC_PREREQ(2, 12)
> +	char truncated[RTE_MAX_THREAD_NAME_LEN];
> +	const size_t truncatedsz = sizeof(truncated);
> +
> +	if (strlcpy(truncated, thread_name, truncatedsz) >= truncatedsz)
> +		RTE_LOG(DEBUG, EAL, "Truncated thread name\n");
> +
> +	ret = pthread_setname_np((pthread_t)thread_id.opaque_id, truncated);
> +#endif
> +#endif
> +	RTE_SET_USED(thread_id);
> +	RTE_SET_USED(thread_name);
> +
> +	if (ret != 0)
> +		RTE_LOG(DEBUG, EAL, "Failed to set thread name\n");
> +}

It is very close to rte_thread_setname with few differences. OK


> --- a/lib/eal/windows/rte_thread.c
> +++ b/lib/eal/windows/rte_thread.c
> +void
> +rte_thread_set_name(rte_thread_t thread_id, const char *thread_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,
> +		thread_id.opaque_id);
> +	if (thread_handle == NULL) {
> +		ret = thread_log_last_error("OpenThread()");
> +		goto cleanup;
> +	}
> +
> +	memset(wname, 0, sizeof(wname));
> +	rv = mbsrtowcs(wname, &thread_name, RTE_DIM(wname) - 1, &state);
> +	if (rv == (size_t)-1) {
> +		ret = EILSEQ;
> +		goto cleanup;
> +	}
> +
> +#ifndef RTE_TOOLCHAIN_GCC
> +	if (FAILED(SetThreadDescription(thread_handle, wname))) {
> +		ret = EINVAL;
> +		goto cleanup;
> +	}
> +#else
> +	ret = ENOTSUP;
> +	goto cleanup;
> +#endif
> +
> +cleanup:
> +	if (thread_handle != NULL)
> +		CloseHandle(thread_handle);
> +
> +	if (ret != 0)
> +		RTE_LOG(DEBUG, EAL, "Failed to set thread name\n");
> +}

This is a new function for Windows, right?
It should be noted in the commit log.