Merging the MacOS X Port into HotSpot Express 23 (7098194)

[David Holmes]

Hi Dan,

src/cpu/x86/vm/jni_x86.h

I don't understand why this change would be needed:

! #if defined(_LP64) && !defined(__APPLE__)
     typedef long jlong;
   #else
     typedef long long jlong;
   #endif

this is saying that on "apple" under _LP64 a long is not 64-bits. But 
the very definition of LP64 is that longs and pointers are 64-bits. ???

---

src/os/<os>/vm/os_<os>.cpp

+ void os::set_native_thread_name(const char *name) {
+   // Not yet implemented.
+   return;
+ }

I hate seeing "shared" code that is not implemented on 3 out of 4 
supported platforms. Though it seems Linux will also support 
pthread_setname_np as of March 2010 (not sure which kernel or glibc 
versions needed). If not for the fact this also adds an exported JVM 
method to set the native thread name, we could otherwise bury this in 
the platform specific native thread creation code (which might also 
obviate the need for the new _is_attached logic - see next point). I 
also wonder what Java code is using this new JVM API?

Also wondering where the "current thread only" restriction came about?

---

src/share/vm/runtime/thread.hpp

+   //  Remember whether or not we were attached
+   bool _is_attached;

It took me a while to realize that _is_attached really means "was 
attached" ie that the Java thread came about due to a native thread 
attaching to the VM via JNI attachCurrentThread. Could I suggest this is 
renamed to was_attached?

---

src/share/vm/utilities/debug.cpp

Why are we exposing this debug code in a product build?

---

src/share/vm/prims/jni.cpp

The USDT2 ifdef changes are truly ugly especially in this file. Is there 
no way to hide USDT1 vs USDT2 at a lower level so that the top-level 
probe points are not affected? I know this is flagged for "future work" 
but history shows such cleans ups rarely if ever happen - and this 
current code really is pretty awful to look at.

Cheers,
David

On 12/10/2011 3:34 AM, Daniel D. Daugherty wrote:
> Greetings,
>
> Tom R shepherded the the BSD Port into HotSpot Express 23 using:
>
> 7089790 integrate bsd-port changes
>
> and I'm following up on that work using the following bug:
>
> 7098194 integrate macosx-port changes
>
> The synopsis is a bit off. In reality, the 7098194changeset will
> include additional changes from the BSD Port in addition the deltas
> made by the MacOS X Port. The bsd-port/hotspot tip changeset for
> this resync is:
>
> changeset: 2729:f1a18ada5853
> tag: tip
> user: Greg Lewis <glewis at eyesbeyond.com>
> date: Wed Sep 21 22:29:10 2011 -0700
> summary: . Finish removing hsearch_r.
>
> The macosx-port/hotspot changeset for this merge is:
>
> changeset: 2756:69de8d34a370
> tag: tip
> user: swingler at apple.com
> date: Thu Sep 29 18:10:16 2011 -0700
> summary: Adding JAVA_LIBRARY_PATH for bundled app launching
> (avoids stomping DYLD_LIBRARY_PATH)
>
> The focus of 7098194 is to get the MacOS X port into HSX-23 without
> regressing the non-MacOS X platforms. In other words, we're trying
> to get HSX-23 caught up with the BSD Port and MacOS X Port projects.
> Shaking out the MacOS X Port itself will be done with other changesets
> on an as needed basis.
>
> Just to be clear, the push target for this changeset is the RT_Baseline
> sub-repo of HotSpot Express (currently HSX-23):
>
> http://hg.openjdk.java.net/hsx/hotspot-rt/hotspot
>
> Like what Tom did for 7089790, I'm posting multiple webrevs so folks
> can review these changes in different ways. My primary focus here is
> the common or shared code so I'm less worried about the BSD or MacOS X
> specific changes. Obviously, if you see something I messed up in those
> files, I'd like to know.
>
> Here's the webrev for all the changes in one shot:
>
> http://cr.openjdk.java.net/~dcubed/mac_os_x_port/7098194-webrev/0-all/
>
> The order of the files in the above webrev is the same as for
> for the subset webrevs below.
>
> Here's the webrevs for the changes in subsets:
>
> http://cr.openjdk.java.net/~dcubed/mac_os_x_port/7098194-webrev/0-bsd-resync/
>
>
> The above webrev has the changes to the bsd-port/hotspot repo made
> after Tom R's work on 7089790 (the 2011.08.02 wiki snapshot).
>
> http://cr.openjdk.java.net/~dcubed/mac_os_x_port/7098194-webrev/0-macosx-other-code/
>
>
> The above webrev has the non-Dtrace and non-infrastructure changes
> made for the MacOS X port. There's a couple of files that also contain
> Dtrace related changes, but I decided it was better to include those
> files in this subset.
>
> http://cr.openjdk.java.net/~dcubed/mac_os_x_port/7098194-webrev/0-macosx-dtrace-code/
>
>
> The above webrev has almost all of the changes to enable Dtrace on
> MacOS X (a couple of files are in the macosx-other-code subset).
> On MacOS X, a newer version of Dtrace is implemented than on Solaris
> which is why the code is #ifdef'ed. I had to change the original
> #ifdef'ing because the original implementation had put some non-Dtrace
> code into #ifdef USDT1 ... #endif blocks so the code didn't build on
> non-Solaris platforms. In order to be more clean with #ifdef'ing, I
> redid all MacOS X Dtrace #ifdef'ing in the following forms:
>
> #ifndef USDT2
> <older Dtrace implementation is in this block>
> <some non-Dtrace code (macros) that call the older Dtrace>
> <implementation are also in this block>
> #else /* USDT2 */
> <new Dtrace implementation for MacOS X in this block>
> #endif /* USDT2 */
>
> #ifndef USDT2
> <older Dtrace implementation is in this block>
> <no #else because the newer Dtrace doesn't need/have the equivalent>
> #endif /* ! USDT2 */
>
> Yes, I realize that the MacOS X Dtrace implementation does not follow
> HotSpot style guidelines very consistently, but I decided not to fix
> that so I could diff against the macosx-port/hotspot more reliably.
>
> I have to consult with Keith McGuigan about how to migrate the Solaris
> Dtrace implementation to the newer version. However, that work will be
> done independently of this bug (7098194).
>
> http://cr.openjdk.java.net/~dcubed/mac_os_x_port/7098194-webrev/0-macosx-infra/
>
>
> The above webrev has all the infrastructure (e.g., Makefile) related
> changes. Many/most folks aren't interested in Makefile stuff so I've
> put these changes in their own subset. Of course, I need Kelly O'Hair
> to bless these changes...
>
> Builds done so far:
>
> - Solaris X86 builds of {Client, Server} VM * {product, fastdebug, jvmg}
> - WinXP builds of {Client, Server} VM * {product, fastdebug, debug}
> - MacOS 10.6.8/Xcode 3.2.6 build of the macosx-port forest with new HSX
> repo
> - MacOS 10.7/Xcode 4.1.1 build of the macosx-port forest with new HSX repo
>
> Testing done so far:
>
> - Serviceability stack (25 subsuites):
> VM/NSK: jvmti, jvmti_unit, jdwp, jdi, sa-jdi, heapdump, hprof, jdb,
> logging, mm
> SDK/JDK: jdi, jdi_closed, jli, logging, mm_csjmx, mm_csm, mm_jlm,
> mm_jlm_closed, mm_jmx, mm_jmx_closed, mm_sm, mm_sm_closed,
> misc_attach, misc_jvmstat, misc_tools
> - Tested configs (8 configs)
> {Solaris X86, WinXP} * {Client, Server} VM * {-Xmixed, -Xcomp}
>
> - MacOS X builds have only had minimal 'java -version' type testing,
> i.e., did the build "work"?
>
> No regressions have been seen in the Solaris X86 testing and WinXP
> testing should be finished later today.
>
> Things still to do (in no particular order):
>
> - gather the list of contributors for the changeset comment
> - JPRT test jobs when the JPRT-hotspotwest queue settles down
> - dtrace testing on Solaris X86
> - code review
> - start bring up of more formal dev testing on MacOS X
>
> Thanks, in advance, for any review comments.
>
> Dan
>