Re: [PATCH v5 1/3] eal: add basic thread ID and current thread identifier API

[Konstantin Ananyev <konstantin.v.ananyev@yandex.ru>]

04/05/2022 16:46, Tyler Retzlaff пишет:
> Provide a portable type-safe thread identifier.
> Provide rte_thread_self for obtaining current thread identifier.
> 
> Signed-off-by: Narcisa Vasile <navasile@microsoft.com>
> Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
> Acked-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
> ---
>   lib/eal/include/rte_thread.h | 22 ++++++++++++++++++++++
>   lib/eal/unix/rte_thread.c    | 11 +++++++++++
>   lib/eal/version.map          |  3 +++
>   lib/eal/windows/rte_thread.c | 10 ++++++++++
>   4 files changed, 46 insertions(+)
> 
> diff --git a/lib/eal/include/rte_thread.h b/lib/eal/include/rte_thread.h
> index 8be8ed8..14478ba 100644
> --- a/lib/eal/include/rte_thread.h
> +++ b/lib/eal/include/rte_thread.h
> @@ -1,7 +1,10 @@
>   /* SPDX-License-Identifier: BSD-3-Clause
>    * Copyright(c) 2021 Mellanox Technologies, Ltd
> + * Copyright (C) 2022 Microsoft Corporation
>    */
>   
> +#include <stdint.h>
> +
>   #include <rte_os.h>
>   #include <rte_compat.h>
>   
> @@ -21,10 +24,29 @@
>   #endif
>   
>   /**
> + * Thread id descriptor.
> + */
> +typedef struct {
> +	uintptr_t opaque_id; /**< thread identifier */


I know that currently on linux typeof(pthread_id) == unsigned long int.
Though wouldn't it be safer and cleaner to use pthread_t explicitly on 
posix-like systems?
Something like:
typedef struct {
#ifdef WINDOWS
	uintptr_t opaque_id;
#else
	pthread_t opaque_id;
#endif
};
AFAIK POSIX itself doesn't require pthread_t to be an 'arithmetic type'.


> +} rte_thread_t;
> +
> +/**
>    * TLS key type, an opaque pointer.
>    */
>   typedef struct eal_tls_key *rte_thread_key;
>   
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice.
> + *
> + * Get the id of the calling thread.
> + *
> + * @return
> + *   Return the thread id of the calling thread.
> + */
> +__rte_experimental
> +rte_thread_t rte_thread_self(void);
> +
>   #ifdef RTE_HAS_CPUSET
>   
>   /**
> diff --git a/lib/eal/unix/rte_thread.c b/lib/eal/unix/rte_thread.c
> index c34ede9..82e008f 100644
> --- a/lib/eal/unix/rte_thread.c
> +++ b/lib/eal/unix/rte_thread.c
> @@ -1,5 +1,6 @@
>   /* SPDX-License-Identifier: BSD-3-Clause
>    * Copyright 2021 Mellanox Technologies, Ltd
> + * Copyright (C) 2022 Microsoft Corporation
>    */
>   
>   #include <errno.h>
> @@ -15,6 +16,16 @@ struct eal_tls_key {
>   	pthread_key_t thread_index;
>   };
>   
> +rte_thread_t
> +rte_thread_self(void)
> +{
> +	rte_thread_t thread_id;
> +
> +	thread_id.opaque_id = (uintptr_t)pthread_self();
> +
> +	return thread_id;
> +}
> +
>   int
>   rte_thread_key_create(rte_thread_key *key, void (*destructor)(void *))
>   {
> diff --git a/lib/eal/version.map b/lib/eal/version.map
> index b53eeb3..05ce8f9 100644
> --- a/lib/eal/version.map
> +++ b/lib/eal/version.map
> @@ -420,6 +420,9 @@ EXPERIMENTAL {
>   	rte_intr_instance_free;
>   	rte_intr_type_get;
>   	rte_intr_type_set;
> +
> +	# added in 22.07
> +	rte_thread_self;
>   };
>   
>   INTERNAL {
> diff --git a/lib/eal/windows/rte_thread.c b/lib/eal/windows/rte_thread.c
> index 667287c..59fed3c 100644
> --- a/lib/eal/windows/rte_thread.c
> +++ b/lib/eal/windows/rte_thread.c
> @@ -11,6 +11,16 @@ struct eal_tls_key {
>   	DWORD thread_index;
>   };
>   
> +rte_thread_t
> +rte_thread_self(void)
> +{
> +	rte_thread_t thread_id;
> +
> +	thread_id.opaque_id = GetCurrentThreadId();
> +
> +	return thread_id;
> +}
> +
>   int
>   rte_thread_key_create(rte_thread_key *key,
>   		__rte_unused void (*destructor)(void *))