2021-08-12 20:05 (UTC+0000), William Tu:
> Currently there are a couple of public header files include
Suggested subject: "eal: remove sys/queue.h from public headers".
1. The state before the patch should be described in the past tense.
2. Really ten times more than "a couple", suggesting "some" (nit).
2. "files _that_ include"?
> 'sys/queue.h', which is a POSIX functionality.
It's not POSIX, it's found on many Unix systems.
> When compiling DPDK with OVS on Windows, we encountered issues such as, found
> the missing
> header.
This sentence is a little hard to parse. Instead, suggesting:
This file is missing on Windows. During the build, DPDK uses a
bundled copy, but it cannot be installed because macros it exports
may conflict with the ones from application code or environment.
> In file included from ../lib/dpdk.c:27:
> C:\temp\dpdk\include\rte_log.h:24:10: fatal error: 'sys/queue.h' file
> not found
An explanation is missing why <sys/queue.h> embedded in DPDK shouldn't be
installed (see above, maybe you can come up with something better).
>
> The patch fixes it by removing the #include <sys/queue.h> from
> DPDK public headers, so programs including DPDK headers don't depend
> on POSIX sys/queue.h. For Linux/FreeBSD, DPDK public headers only need a
> handful of macros for list/tailq heads and links. Those macros should be
> provided by DPDK, with RTE_ prefix.
It is worth noting that RTE_ macros must be compatible with <sys/queue.h>
at the level of API (to use with <sys/queue.h> macros in C files) and ABI
(to avoid breaking it).
Nit: "Should" is not the right word for things done in the patch. Same below.
> For Linux and FreeBSD it will just be:
> #include <sys/queue.h>
> #define RTE_TAILQ_ENTRY(type) TAILQ_ENTRY(type)
> /* ... */
> For Windows, we copy these definitions from <sys/queue.h> to rte_os.h.
No need to describe what's inside the patch, diff already does it :)
> With this patch, all the public headers should not have
> "#include <sys/queue.h>" or "TAILQ_xxx" macros.
>
> Suggested-by: Nick Connolly <nick.conno...@mayadata.io>
> Suggested-by: Dmitry Kozliuk <dmitry.kozl...@gmail.com>
> Signed-off-by: William Tu <u9012...@gmail.com>
> ---
> v2->v3:
> * follow the suggestion by Dmitry
> * run checkpatches, there are some errors but I think either
> the original file has over 80-char line due to comments,
> or some false positive about macro.
> v1->v2:
> - follow the suggestion by Nick and Dmitry
> - http://mails.dpdk.org/archives/dev/2021-August/216304.html
>
> Signed-off-by: William Tu <u9012...@gmail.com>
> ---
[...]
> diff --git a/lib/eal/freebsd/include/rte_os.h
> b/lib/eal/freebsd/include/rte_os.h
> index 627f0483ab..dc889e5826 100644
> --- a/lib/eal/freebsd/include/rte_os.h
> +++ b/lib/eal/freebsd/include/rte_os.h
> @@ -11,6 +11,39 @@
> */
>
> #include <pthread_np.h>
> +#include <sys/queue.h>
> +
> +/* These macros are compatible with system's sys/queue.h. */
> +#define RTE_TAILQ_INIT(head) TAILQ_INIT(head)
> +#define RTE_TAILQ_HEAD(name, type) TAILQ_HEAD(name, type)
> +#define RTE_TAILQ_LAST(head, headname) TAILQ_LAST(head, headname)
> +#define RTE_TAILQ_ENTRY(type) TAILQ_ENTRY(type)
> +#define RTE_TAILQ_FIRST(head) TAILQ_FIRST(head)
> +#define RTE_TAILQ_EMPTY(head) TAILQ_EMPTY(head)
> +#define RTE_TAILQ_NEXT(elem, field) TAILQ_NEXT(elem, field)
> +#define RTE_TAILQ_HEAD_INITIALIZER(head) TAILQ_HEAD_INITIALIZER(head)
> +#define RTE_TAILQ_FOREACH(var, head, field) TAILQ_FOREACH(var, head, field)
> +#define RTE_TAILQ_INSERT_TAIL(head, elm, field) \
> + TAILQ_INSERT_TAIL(head, elm, field)
> +#define RTE_TAILQ_REMOVE(head, elm, field) TAILQ_REMOVE(head, elm, field)
> +#define RTE_TAILQ_INSERT_BEFORE(listelm, elm, field) \
> + TAILQ_INSERT_BEFORE(listelm, elm, field)
> +#define RTE_TAILQ_INSERT_AFTER(head, listelm, elm, field) \
> + TAILQ_INSERT_AFTER(head, listelm, elm, field)
> +#define RTE_TAILQ_INSERT_HEAD(head, elm, field) \
> + TAILQ_INSERT_HEAD(head, elm, field)
> +
> +#define RTE_STAILQ_HEAD(name, type) STAILQ_HEAD(name, type)
> +#define RTE_STAILQ_HEAD_INITIALIZER(head) STAILQ_HEAD_INITIALIZER(head)
> +#define RTE_STAILQ_ENTRY(type) STAILQ_ENTRY(type)
Most of these macros are not used in public headers and are not needed.
The idea is that TAILQ_* macros from sys/queue.h can be used in C files
with variables declared with RTE_TAILQ_HEAD/ENTRY in public headers.
Needed macros:
RTE_TAILQ_HEAD
RTE_TAILQ_ENTRY
RTE_TAILQ_FOREACH
RTE_TAILQ_FIRST (for RTE_TAILQ_FOREACH_SAFE only)
RTE_TAILQ_NEXT (ditto)
RTE_STAILQ_HEAD
RTE_STAILQ_ENTRY
> +
> +/* This is not defined in sys/queue.h */
> +#ifndef TAILQ_FOREACH_SAFE
> +#define TAILQ_FOREACH_SAFE(var, head, field, tvar) \
> + for ((var) = RTE_TAILQ_FIRST((head)); \
> + (var) && ((tvar) = RTE_TAILQ_NEXT((var), field), 1); \
> + (var) = (tvar))
> +#endif
Please simply change the three usages of TAILQ_FOREACH_SAFE to
RTE_TAILQ_FOREACH_SAFE and remove this one. It cannot be placed in rte_os.h,
because rte_os.h is public and it must not export non-RTE symbols.
All comments to this file obviously apply to Linux version as well.
>
> typedef cpuset_t rte_cpuset_t;
> #define RTE_HAS_CPUSET
[...]
> diff --git a/lib/eal/windows/include/rte_os.h
> b/lib/eal/windows/include/rte_os.h
> index 66c711d458..d0935c5003 100644
> --- a/lib/eal/windows/include/rte_os.h
> +++ b/lib/eal/windows/include/rte_os.h
> @@ -18,6 +18,144 @@
> extern "C" {
> #endif
>
> +#ifdef QUEUE_MACRO_DEBUG_TRACE
IMO we all these debugging macros should be removed from this header,
including their use in user-facing macros.
They are implementation detail for <sys/queue.h> developers.
> +/* Store the last 2 places the queue element or head was altered */
> +struct qm_trace {
> + unsigned long lastline;
> + unsigned long prevline;
> + const char *lastfile;
> + const char *prevfile;
> +};
> +
> +/**
> + * These macros are compatible with the sys/queue.h provided
> + * at DPDK source code.
> + */
[...]
> +
> +#define QMD_TAILQ_CHECK_HEAD(head, field)
> +#define QMD_TAILQ_CHECK_TAIL(head, headname)
> +#define QMD_TAILQ_CHECK_NEXT(elm, field)
> +#define QMD_TAILQ_CHECK_PREV(elm, field)
Redundant empty lines below.
> +
> +
> +#define RTE_TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
> +
> +#define RTE_TAILQ_FIRST(head) ((head)->tqh_first)
> +
> +#define RTE_TAILQ_INIT(head) do {
> \
I suggest removing all spaces but one before the backslash
so that you don't need to manually align.
At least please keep the lines within 80 characters.
> + RTE_TAILQ_FIRST((head)) = NULL; \
> + (head)->tqh_last = &RTE_TAILQ_FIRST((head)); \
> + QMD_TRACE_HEAD(head); \
> +} while (0)
[...]
