X-Recipient: archive-cygwin AT delorie DOT com
X-Original-To: cygwin AT cygwin DOT com
Delivered-To: cygwin AT cygwin DOT com
DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 5E3BF3861012
Authentication-Results: sourceware.org; dmarc=none (p=none dis=none)
 header.from=SystematicSw.ab.ca
Authentication-Results: sourceware.org;
 spf=none smtp.mailfrom=brian DOT inglis AT systematicsw DOT ab DOT ca
X-Authority-Analysis: v=2.4 cv=NYRYa0P4 c=1 sm=1 tr=0 ts=5ffa0ad4
 a=kiZT5GMN3KAWqtYcXc+/4Q==:117 a=kiZT5GMN3KAWqtYcXc+/4Q==:17
 a=IkcTkHD0fZMA:10 a=CCpqsmhAAAAA:8 a=94nOnFI1EgyDtX4ev68A:9 a=QEXdDO2ut3YA:10
 a=ul9cdbp4aOFLsgKbc677:22
To: cygwin AT cygwin DOT com
References: <657c8576-2715-8c80-a59a-23453306230f AT netcologne DOT de>
From: Brian Inglis <Brian DOT Inglis AT SystematicSw DOT ab DOT ca>
Organization: Systematic Software
Subject: Re: PTHREAD_MUTEX_SHARED on Cygwin
Message-ID: <32467133-a288-b974-4a86-fe17d1ac6a14@SystematicSw.ab.ca>
Date: Sat, 9 Jan 2021 12:58:11 -0700
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
 Thunderbird/78.6.0
MIME-Version: 1.0
In-Reply-To: <657c8576-2715-8c80-a59a-23453306230f@netcologne.de>
Content-Language: en-CA
X-CMAE-Envelope: MS4xfFgy9e8kDjZfcKbnHp8w3Xt0RHPGNUjVld6109qWwgH5mS/soPgnK5q+o9Jh2xUazk9VKJy29n62cfd53Xm/NZoj0Nqbv+5TGBUSfg/XbalkdEbXpv1X
 Mby4WHauXx5EhkSkKo+ebud2OZldTbFJk5MW2YgXYcm/4InxyDEWFrVjDKSsRbNDMomcGrSwvMTJ8L9rIhMeAKvtEmIc27oWT98=
X-Spam-Status: No, score=-5.9 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS,
 KAM_LAZY_DOMAIN_SECURITY, NICE_REPLY_A, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H4,
 RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE,
 TXREP autolearn=ham autolearn_force=no version=3.4.2
X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on
 server2.sourceware.org
X-BeenThere: cygwin AT cygwin DOT com
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Unsubscribe: <https://cygwin.com/mailman/options/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=unsubscribe>
List-Archive: <https://cygwin.com/pipermail/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe: <https://cygwin.com/mailman/listinfo/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
Reply-To: cygwin AT cygwin DOT com
Content-Type: text/plain; charset="utf-8"; Format="flowed"
Errors-To: cygwin-bounces AT cygwin DOT com
Sender: "Cygwin" <cygwin-bounces AT cygwin DOT com>
Content-Transfer-Encoding: 8bit
X-MIME-Autoconverted: from base64 to 8bit by delorie.com id 109JwfEq013914

On 2021-01-09 11:23, Thomas Koenig via Cygwin wrote:
> there is a branch of gfortran for implementing coarrays based on a
> shared memory implementation instead of MPI, the devel_coarray/native
> branch.
> 
> I tried it out on Cygwin, but it doesn't work there (hangs on the
> first sync).
> 
> The branch uses pthread mutexes and condition variables
> with PTHREAD_PROCESS_SHARED for synchronization between processes.
> 
> I also ran the attached test program, which gave the output
> 
> pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED)failed: No error
> 
> 
> Is it correct that PTHREAD_PROCESS_SHARED is not supported on
> Cygwin?  Is it supported for condition variables, or is the fact
> that it is reported as working an oversight?

The function is supported but that parameter is not implemented or tested and 
returns EINVAL:

https://sourceware.org/git?p=newlib-cygwin.git;a=blob;f=winsup/cygwin/thread.cc;hb=HEAD#l16

https://sourceware.org/git?p=newlib-cygwin.git;a=blob;f=winsup/cygwin/thread.cc;hb=HEAD#l1889

> If PTHREAD_PROCESS_SHARED does not work, are there known workarounds?

If you have the ability and time to work on this, one of the Cygwin 
developers/maintainers may be able to assist.

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

This email may be disturbing to some readers as it contains
too much technical detail. Reader discretion is advised.
[Data in binary units and prefixes, physical quantities in SI.]
--
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple