From: Tyler Retzlaff <roretzla@linux.microsoft.com>
To: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
Cc: dev@dpdk.org, thomas@monjalon.net, anatoly.burakov@intel.com,
Narcisa Vasile <navasile@microsoft.com>
Subject: Re: [PATCH v2 2/6] eal: add thread lifetime management
Date: Tue, 21 Jun 2022 11:51:03 -0700 [thread overview]
Message-ID: <20220621185103.GC18214@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> (raw)
In-Reply-To: <20220618155908.70e822af@sovereign>
On Sat, Jun 18, 2022 at 03:59:08PM +0300, Dmitry Kozlyuk wrote:
> 2022-06-14 16:47 (UTC-0700), Tyler Retzlaff:
> > On Windows, the function executed by a thread when the thread starts is
> > represeneted by a function pointer of type DWORD (*func) (void*).
> > On other platforms, the function pointer is a void* (*func) (void*).
> >
> > Performing a cast between these two types of function pointers to
> > uniformize the API on all platforms may result in undefined behavior.
> > TO fix this issue, a wrapper that respects the signature required by
> > CreateThread() has been created on Windows.
>
> The interface issue is still there:
> `rte_thread_func` allows the thread routine to have a pointer-sized result.
> `rte_thread_join()` allows to obtain this value as `unsigned long`,
> which is pointer-sized on 32-bit platforms
> and less than that on 64-bit platforms.
> This can lead to issues when developers assume they can return a pointer
> and this works on 32 bits, but doesn't work on 64 bits.
> If you want to keep API as close to phtread as possible,
> the limitation must be at least clearly documented in Doxygen
> (`rte_thread_func` is undocumented BTW).
> I also suggest using `uint32_t` instead of `unsigned long`
> precisely to avoid "is it pointer-sized?" doubts.
> (I don't see much benefit in keeping pthread-like signature.
> When moving from pthread to rte_thread,
> it is as trivial to change the thread routine return type.)
i'll alter the rte api to use fixed width uint32_t for thread result. it
seems like an unnecessary feature to return a pointer and it can be
accomplished through void *arg if necessary.
>
> > +int
> > +rte_thread_join(rte_thread_t thread_id, unsigned long *value_ptr)
> > +{
> > + int ret = 0;
> > + void *res = NULL;
> > + void **pres = NULL;
> > +
> > + if (value_ptr != NULL)
> > + pres = &res;
> > +
> > + ret = pthread_join((pthread_t)thread_id.opaque_id, pres);
> > + if (ret != 0) {
> > + RTE_LOG(DEBUG, EAL, "pthread_join failed\n");
> > + return ret;
> > + }
> > +
> > + if (value_ptr != NULL && *pres != NULL)
> > + *value_ptr = *(unsigned long *)(*pres);
> > +
> > + return 0;
> > +}
>
> What makes *pres == NULL special?
it's not clear what you mean, can you explain? maybe there is some
context i am missing from the original patch series?
> > +int
> > +rte_thread_create(rte_thread_t *thread_id,
> > + const rte_thread_attr_t *thread_attr,
> > + rte_thread_func thread_func, void *args)
> > +{
> > + int ret = 0;
> > + DWORD tid;
> > + HANDLE thread_handle = NULL;
> > + GROUP_AFFINITY thread_affinity;
> > + struct thread_routine_ctx *ctx = NULL;
> > +
> > + ctx = calloc(1, sizeof(*ctx));
> > + if (ctx == NULL) {
> > + RTE_LOG(DEBUG, EAL, "Insufficient memory for thread context allocations\n");
> > + ret = ENOMEM;
> > + goto cleanup;
> > + }
> > + ctx->routine_args = args;
> > + ctx->thread_func = thread_func;
> > +
> > + thread_handle = CreateThread(NULL, 0, thread_func_wrapper, ctx,
> > + CREATE_SUSPENDED, &tid);
> > + if (thread_handle == NULL) {
> > + ret = thread_log_last_error("CreateThread()");
> > + free(ctx);
> > + goto cleanup;
>
> Missing `free(ctx)` from other error paths below.
beyond this point free(ctx) will happen in thread_func_wrapper. i will
add a comment to make it clear.
thanks.
next prev parent reply other threads:[~2022-06-21 18:51 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-09 13:58 [PATCH 0/6] add thread lifetime and attributes API Tyler Retzlaff
2022-06-09 13:58 ` [PATCH 1/6] eal: add thread attributes Tyler Retzlaff
2022-06-09 13:58 ` [PATCH 2/6] eal: add thread lifetime management Tyler Retzlaff
2022-06-09 13:58 ` [PATCH 3/6] eal: add basic rte thread ID equal API Tyler Retzlaff
2022-06-09 22:24 ` Konstantin Ananyev
2022-06-10 22:48 ` Tyler Retzlaff
2022-06-11 12:25 ` Konstantin Ananyev
2022-06-13 13:39 ` Tyler Retzlaff
2022-06-10 0:40 ` fengchengwen
2022-06-09 13:58 ` [PATCH 4/6] test/threads: add tests for thread lifetime API Tyler Retzlaff
2022-06-09 13:58 ` [PATCH 5/6] test/threads: add tests for thread attributes API Tyler Retzlaff
2022-06-09 13:58 ` [PATCH 6/6] test/threads: remove unit test use of pthread Tyler Retzlaff
2022-06-14 23:47 ` [PATCH v2 0/6] add thread lifetime and attributes API Tyler Retzlaff
2022-06-14 23:47 ` [PATCH v2 1/6] eal: add thread attributes Tyler Retzlaff
2022-06-14 23:47 ` [PATCH v2 2/6] eal: add thread lifetime management Tyler Retzlaff
2022-06-18 12:59 ` Dmitry Kozlyuk
2022-06-20 17:39 ` Tyler Retzlaff
2022-06-21 16:24 ` Tyler Retzlaff
2022-06-21 18:51 ` Tyler Retzlaff [this message]
2022-06-21 19:44 ` Dmitry Kozlyuk
2022-06-21 21:28 ` Tyler Retzlaff
2022-06-21 22:24 ` Dmitry Kozlyuk
2022-06-22 18:21 ` Tyler Retzlaff
2022-06-14 23:47 ` [PATCH v2 3/6] eal: add basic rte thread ID equal API Tyler Retzlaff
2022-06-20 8:34 ` Konstantin Ananyev
2022-06-14 23:47 ` [PATCH v2 4/6] test/threads: add tests for thread lifetime API Tyler Retzlaff
2022-06-14 23:47 ` [PATCH v2 5/6] test/threads: add tests for thread attributes API Tyler Retzlaff
2022-06-14 23:47 ` [PATCH v2 6/6] test/threads: remove unit test use of pthread Tyler Retzlaff
2022-06-22 20:26 ` [PATCH v3 0/6] add thread lifetime and attributes API Tyler Retzlaff
2022-06-22 20:26 ` [PATCH v3 1/6] eal: add thread attributes Tyler Retzlaff
2022-06-22 20:26 ` [PATCH v3 2/6] eal: add thread lifetime management Tyler Retzlaff
2022-06-22 20:26 ` [PATCH v3 3/6] eal: add basic rte thread ID equal API Tyler Retzlaff
2022-06-22 20:26 ` [PATCH v3 4/6] test/threads: add tests for thread lifetime API Tyler Retzlaff
2022-06-22 20:26 ` [PATCH v3 5/6] test/threads: add tests for thread attributes API Tyler Retzlaff
2022-06-22 20:26 ` [PATCH v3 6/6] test/threads: remove unit test use of pthread Tyler Retzlaff
2022-06-27 16:56 ` [PATCH v4 0/6] add thread lifetime and attributes API Tyler Retzlaff
2022-06-27 16:56 ` [PATCH v4 1/6] eal: add thread attributes Tyler Retzlaff
2022-06-27 16:56 ` [PATCH v4 2/6] eal: add thread lifetime management Tyler Retzlaff
2022-06-27 16:56 ` [PATCH v4 3/6] eal: add basic rte thread ID equal API Tyler Retzlaff
2022-06-27 16:56 ` [PATCH v4 4/6] test/threads: add tests for thread lifetime API Tyler Retzlaff
2022-06-27 16:56 ` [PATCH v4 5/6] test/threads: add tests for thread attributes API Tyler Retzlaff
2022-06-27 16:56 ` [PATCH v4 6/6] test/threads: remove unit test use of pthread Tyler Retzlaff
2022-07-31 21:16 ` [PATCH v4 0/6] add thread lifetime and attributes API Dmitry Kozlyuk
2022-09-21 8:15 ` David Marchand
2022-09-29 7:02 ` David Marchand
2022-10-05 16:11 ` Tyler Retzlaff
2022-10-05 16:34 ` Tyler Retzlaff
2022-10-06 6:52 ` David Marchand
2022-10-06 15:14 ` Tyler Retzlaff
2022-10-06 13:36 ` Thomas Monjalon
2022-10-06 15:10 ` Tyler Retzlaff
2022-10-06 15:14 ` Thomas Monjalon
2022-10-06 15:20 ` Tyler Retzlaff
2022-10-06 15:26 ` David Marchand
2022-10-06 15:27 ` Tyler Retzlaff
2022-10-05 17:07 ` [PATCH v5 " Tyler Retzlaff
2022-10-05 17:07 ` [PATCH v5 1/6] eal: add thread attributes Tyler Retzlaff
2022-10-06 8:32 ` David Marchand
2022-10-05 17:07 ` [PATCH v5 2/6] eal: add thread lifetime management Tyler Retzlaff
2023-03-01 8:11 ` David Marchand
2023-03-01 20:34 ` Tyler Retzlaff
2022-10-05 17:07 ` [PATCH v5 3/6] eal: add basic rte thread ID equal API Tyler Retzlaff
2022-10-05 17:07 ` [PATCH v5 4/6] test/threads: add tests for thread lifetime API Tyler Retzlaff
2022-10-06 8:32 ` David Marchand
2022-10-06 15:19 ` Tyler Retzlaff
2022-10-05 17:07 ` [PATCH v5 5/6] test/threads: add tests for thread attributes API Tyler Retzlaff
2022-10-05 17:07 ` [PATCH v5 6/6] test/threads: remove unit test use of pthread Tyler Retzlaff
2022-10-06 19:25 ` [PATCH v5 0/6] add thread lifetime and attributes API David Marchand
2022-10-07 19:20 ` Tyler Retzlaff
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