Request for review (M): 7132070: Use a mach_port_t as the OSThread thread_id rather than pthread_t on BSD/OSX
Daniel D. Daugherty
daniel.daugherty at oracle.com
Wed Feb 15 12:24:21 PST 2012
The src/os/bsd code was derived from the src/os/linux code.
#ifdef _ALLBSD_SOURCE was used to flag (most) changes relative
to Linux for the BSD port. The #ifdef'ing is not perfect because
the Linux code also evolved as the BSD port was being done and
also because sometimes folks forgot to #ifdef their changes...
Eventually, there is supposed to be a rework/rewrite in this area
where all the "nixes" share code. It won't be under src/os/posix,
but we'll think of some good name if the project ever gets done...
On 2/15/12 12:30 PM, Staffan Larsen wrote:
> Reading this again, I wonder: What is the purpose of _ALLBSD_SOURCE in a file under 'src/os/bsd'? Are there platforms that are 'bad', but do not define _ALLBSD_SOURCE?
> On 15 feb 2012, at 16:16, Daniel D. Daugherty wrote:
>> The _ALLBSD_SOURCE symbol is defined by the HotSpot Makefile infrastructure.
>> It is used to identify code specific to the BSD family of OSes.
>> The __APPLE__ symbol is defined by the Apple compiler(s) and it is used to
>> identify code specific to MacOS X.
>> Typically you'll see something like:
>> #ifdef _ALLBSD_SOURCE
>> <code that works on all BSDs>
>> #ifdef __APPLE__
>> <code specific to MacOS X>
>> <code for other BSDs>
>> #endif // __APPLE__
>> #endif // _ALLBSD_SOURCE
>> As for building on non-MacOS X BSDs, that would be nice, but we
>> don't have the infrastructure to do it.
>> On 2/15/12 6:57 AM, Mikael Gerdin wrote:
>>> Hi Staffan,
>>> It looks like you're adding Mac-specific stuff like thread_t and calls to ::mach_thread_self() inside _ALLBSD_SOURCE #ifdefs, are you sure this won't break BSD builds?
>>> Does the OSX compiler define _ALLBSD_SOURCE or is that for (free|net|open)bsd?
>>> It's too bad we don't do regular builds on any of the BSDs, otherwise this would have been easier to figure out.
>>> On 2012-02-15 11:29, Staffan Larsen wrote:
>>>> Please review the following change:
>>>> Bug: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7132070
>>>> Webrev: http://cr.openjdk.java.net/~sla/7132070/webrev.00/
>>>> This changes the value returned by OSThread::thread_id() and
>>>> os::current_thread_id() on macosx to return the mach thread_t instead of
>>>> pthread_t. There is a separate method OSThread:pthread_id() that returns
>>>> the pthread_t.
>>>> The reason for this change is both that JFR would like a 4 byte value
>>>> for thread id, and that SA requires access to the thread_t.
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