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From: Ross Johnson <>
To: Mark Pizzolato - pthreads - win32
Cc: "" <>
Subject: Re: Issues with struct timespec
Date: Fri, 13 Jan 2012 02:09:00 -0000	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

I've pondered the wisdom of providing the pre-built dlls for many years. 
I see them as a way for new users to get started quickly or for 
evaluation etc, but for more ambitious projects or applications I would 
encourage building the library from source in the same environment as 
the project.

On 13/01/2012 8:06 AM, Mark Pizzolato - pthreads - win32 wrote:
> Hi there,
> In the older versions of pthreads-win32 struct timespec had a tv_sec member which was of type long.
> In the current CVS code base this member has been changed to be of type time_t.
> The only reason struct timespec exists in pthreads-win32 is to support pthread_cond_timedwait().  Pthread.h is providing a definition for struct timespec since, in general there is no other use of that structure in a win32 programming environment.  It is unique to pthreads.
> A problem exists for an application which may use the provided struct timespec definition with pthread_cond_timedwait().  If that application is linking against a prebuilt version of the pthreads code (the most common case), the pthreads library will have been built with a time_t type which is whatever the current compiler/build default size for that type (64bits these days, but 32bits in the past).  Meanwhile, the application using pthreads can have a time_t type which could be 32 or 64 bits completely depending on compile time defines.  Calls to pthread_cond_timedwait() will be passing a struct timespec which may or may not have a time_t element size consistent with the time_t in use when the pthread library was built.
> I would suggest that struct timespec should use a non variable sized type for the tv_sec member.  A type of long should be just fine for normal uses of pthread_cond_timedwait() for most of the next 36 years.  A 64bit type could just as well be used if all of the pthread-win32 target platforms support 64bit numbers, or it could be a fixed size but be specific to the platform as needed.
> While we're here, anyone who uses a struct timespec passed to pthread_cond_timedwait() actually needs to construct the contents of that structure in some way.  We may want to provide a clock_gettime() implementation as part of pthreads-win32 to make the use of this API a little more natural and/or portable.
> I'll be glad to suggest specific code for these ideas depending on what others think of the issue.
> Looking forward to a discussion.
> - Mark Pizzolato

      reply	other threads:[~2012-01-13  2:09 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-12 21:06 Mark Pizzolato - pthreads - win32
2012-01-13  2:09 ` Ross Johnson [this message]

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