Request for review (M): 7132070: Use a mach_port_t as the OSThread thread_id rather than pthread_t on BSD/OSX

[Paul Hohensee]

Also,

You can move the #include of mach.h into globalDefinitions_gcc.hpp,
in the #ifdef __APPLE__ section.  That way, it won't cause a compile-
time error on non-osx platforms that don't have it.

The declaration of _thread_id, thread_id() and set_thread_id() in 
os_bsd.hpp
can be put under a #ifdef __APPLE__, vis.,

#ifdef _ALLBSD_SOURCE
#ifdef __APPLE__
   thread_t _thread_id;
#else
   pthread_t _thread_id;
#endif
#endif

The uses of mach_thread_self() in os_bsd.cpp can be similarly conditioned.

If there's a thread_t defined by non-osx bsd implementations, then
you don't need predication in os_bsd.hpp, though you'd still need it
in os_bsd.cpp.  I'm assuming there's no mach_thread_self() on non-osx
bsd platforms.

Thanks,

Paul

On 2/15/12 1:33 PM, Paul Hohensee wrote:
> Imo we should at least try to make non-osx bsd builds work, since
> the original code did work for non-osx builds.  This change doesn't
> do that.
>
> In globalDefinitions_gcc.hpp, if you keep the lines
>
> #undef ELF_AC
> #undef EFL_ID
>
> then you don't have to change vm_version_x86.hpp.
>
> Paul
>
> On 2/15/12 10:16 AM, 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>
>> #else
>> <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.
>>
>> Dan
>>
>> 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.
>>>
>>> /Mikael
>>>
>>>
>>> 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.
>>>>
>>>> Thanks,
>>>> /Staffan
>>>