[dpdk-dev] [PATCH v6 03/10] windows/eal: translate Windows errors to errno-style errors

[Dmitry Kozlyuk]

2021-04-02 18:39 (UTC-0700), Narcisa Ana Maria Vasile:
> From: Narcisa Vasile <navasile at microsoft.com>
> 
> Add function to translate Windows error codes to
> errno-style error codes.
> 
> Signed-off-by: Narcisa Vasile <navasile at microsoft.com>

Commit topic should be "eal/windows", not "windows/eal".

> ---
>  lib/librte_eal/include/rte_thread.h |  5 +-
>  lib/librte_eal/windows/rte_thread.c | 75 ++++++++++++++++++++++-------
>  2 files changed, 60 insertions(+), 20 deletions(-)
> 
> diff --git a/lib/librte_eal/include/rte_thread.h b/lib/librte_eal/include/rte_thread.h
> index bfdd8e1b1..2d7b3bc05 100644
> --- a/lib/librte_eal/include/rte_thread.h
> +++ b/lib/librte_eal/include/rte_thread.h
> @@ -221,9 +221,8 @@ int rte_thread_value_set(rte_thread_key key, const void *value);
>   *
>   * @return
>   *   On success, value data pointer (can also be NULL).
> - *   On failure, NULL and an error number is set in rte_errno.
> - *   rte_errno can be: EINVAL  - Invalid parameter passed.
> - *                     ENOEXEC - Specific OS error.
> + *   On failure, NULL and a positive error number is set in rte_errno.
> + *
>   */
>  __rte_experimental
>  void *rte_thread_value_get(rte_thread_key key);
> diff --git a/lib/librte_eal/windows/rte_thread.c b/lib/librte_eal/windows/rte_thread.c
> index b29336cbd..ecd2f810f 100644
> --- a/lib/librte_eal/windows/rte_thread.c
> +++ b/lib/librte_eal/windows/rte_thread.c
> @@ -12,6 +12,51 @@ struct eal_tls_key {
>  	DWORD thread_index;
>  };
>  
> +/* Translates the most common error codes related to threads */
> +static int rte_thread_translate_win32_error(void)

Return type should be on a separate line.

> +{
> +	DWORD error = 0;
> +
> +	error = GetLastError();

You could declare "error" and assign it in one statement.

Don't initialize variables if there's no good initial value:
it prevents compiler to issue a warning if the variable is not assigned a
meaningful value afterwards.

> +
> +	switch (error) {
> +	case ERROR_SUCCESS:
> +		return 0;
> +
> +	case ERROR_INVALID_PARAMETER:
> +		return EINVAL;
> +
> +	case ERROR_INVALID_HANDLE:
> +		return EFAULT;
> +
> +	case ERROR_NOT_ENOUGH_MEMORY:
> +	/* FALLTHROUGH */
> +	case ERROR_NO_SYSTEM_RESOURCES:
> +		return ENOMEM;
> +
> +	case ERROR_PRIVILEGE_NOT_HELD:
> +	/* FALLTHROUGH */
> +	case ERROR_ACCESS_DENIED:
> +		return EACCES;
> +
> +	case ERROR_ALREADY_EXISTS:
> +		return EEXIST;
> +
> +	case ERROR_POSSIBLE_DEADLOCK:
> +		return EDEADLK;
> +
> +	case ERROR_INVALID_FUNCTION:
> +	/* FALLTHROUGH */
> +	case ERROR_CALL_NOT_IMPLEMENTED:
> +		return ENOSYS;
> +
> +	default:
> +		return EINVAL;
> +	}

Default branch is redundant at the end of function.

> +
> +	return EINVAL;
> +}
> +
>  rte_thread_t
>  rte_thread_self(void)
>  {
> @@ -87,15 +132,13 @@ rte_thread_key_create(rte_thread_key *key,
>  	*key = malloc(sizeof(**key));
>  	if ((*key) == NULL) {
>  		RTE_LOG(DEBUG, EAL, "Cannot allocate TLS key.\n");
> -		rte_errno = ENOMEM;
> -		return -1;
> +		return ENOMEM;
>  	}
>  	(*key)->thread_index = TlsAlloc();
>  	if ((*key)->thread_index == TLS_OUT_OF_INDEXES) {
>  		RTE_LOG_WIN32_ERR("TlsAlloc()");
>  		free(*key);
> -		rte_errno = ENOEXEC;
> -		return -1;
> +		return rte_thread_translate_win32_error();

Logging above can overwrite GetLastError() value.
I suggest splitting rte_thread_translate_win32_error() into translation part
for cases when you have error number already, and a wrapper that calls
GetLastError() to shorten calling code.

Same applies below in this file.

[...]