[13] RFR(L) 8220623: [JVMCI] Update JVMCI to support JVMCI based Compiler compiled into shared library

[Robbin Ehn]

Hi,

  434     for (; JavaThread *thr = jtiwh.next(); ) {
  435       if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
  436         num_active++;
  437         if (thr->is_Compiler_thread()) {
  438           CompilerThread* ct = (CompilerThread*) thr;
  439           if (ct->compiler() == NULL || !ct->compiler()->is_jvmci()) {
  440             num_active_compiler_thread++;
  441           } else {
  442             // When using a Java based JVMCI compiler, it's possible
  443             // for one compiler thread to grab a Java lock, enter
  444             // HotSpot and go to sleep on the shutdown safepoint.
  445             // Another JVMCI compiler thread can then attempt grab
  446             // the lock and thus never make progress.
  447           }
  448         }
  449       }
  450     }

We inc num_active on threads in native.
If such thread is a compiler thread we also inc num_active_compiler_thread.
JavaThread blocking on safepoint would be state blocked.
JavaThread waiting on the 'Java lock' would also be blocked.

Why are you not blocked when waiting on that contended Java lock ?

/Robbin

On 3/28/19 8:15 PM, Vladimir Kozlov wrote:
> https://bugs.openjdk.java.net/browse/JDK-8220623
> http://cr.openjdk.java.net/~kvn/8220623/webrev.03/
> 
> Update JVMCI to support pre-compiled as shared library Graal.
> Using aoted Graal can offers benefits including:
>   - fast startup
>   - compile time similar to native JIt compilers (C2)
>   - memory usage disjoint from the application Java heap
>   - no profile pollution of JDK code used by the application
> 
> This is JDK13 port of JVMCI changes done in graal-jvmci-8 [1] up to date.
> Changes were collected in Metropolis repo [2] and tested there.
> 
> Changes we reviewed by Oracle Labs (authors of JVMCI and Graal) and our compiler 
> group.
> Changes in shared code are guarded by #if INCLUDE_JVMCI and JVMCI flags.
> 
> I ran tier1-tier8 (which includes HotSpot and JDK tests) and it was clean. In 
> this set Graal was tested only in tier3.
> 
> And I ran all hs-tier3-graal .. hs-tier8-graal Graal tests available in our 
> system. Several issue were found which were present before these changes.
> 
> Thanks,
> Vladimir
> 
> [1] 
> https://github.com/graalvm/graal-jvmci-8/commit/49ff2045fb603e35516a3a427d8023c00e1607af 
> 
> [2] http://hg.openjdk.java.net/metropolis/dev/