8005602: NPG: classunloading does not happen while CMS GC with -XX:+CMSClassUnloadingEnabled is used
Summary: Call purge() on CLDG after sweep(), reorder purge() call in GenCollectedHeap
Reviewed-by: jmasa, stefank

Summary: Print the concurrent phase start markers for CMS when PrintGCDetails is enabled, not only if both PrintGCDetails and PrintGCTimeStamps are.
Reviewed-by: mgerdin, jmasa

8009723: CMS logs "concurrent mode failure" twice when using (disabling) -XX:-UseCMSCompactAtFullCollection
Reviewed-by: jwilhelm, ehelin, brutisso

Summary: Flags changed to be of uintx type
Reviewed-by: johnc, tamao

Summary: Define jlong as long on all LP64 platforms and add JLONG_FORMAT macro.
Reviewed-by: dholmes, coleenp, mikael, kvn

Reviewed-by: johnc, ysr

Summary: Restore non-silent output of heap verification.
Reviewed-by: ysr, brutisso, jmasa

Summary: support of compress class pointers in the compilers.
Reviewed-by: kvn, twisti

Summary: Removed the unused keep_alive parameter
Reviewed-by: stefank, dholmes, kamg, coleenp

Summary: The warnings associated with the UseMemSetInBOT flag are duplicated in CMS and G1. The separate warnings have been removed and single instance of the warning has been placed in a common location.
Reviewed-by: brutisso, ysr

Reviewed-by: coleenp, stefank, jprovino, ohair

Summary: Move the first part of the GC logging, including timestamp, to the start of the GC
Reviewed-by: johnc, jwilhelm

Summary: Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes
Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland
Contributed-by: Njmasa &lt;jon.masamitsu@oracle.com&gt;, stefank &lt;stefan.karlsson@oracle.com&gt;, mgerdin &lt;mikael.gerdin@oracle.com&gt;, never <tom.rodriguez@oracle.com>

7151532: DCmd for hotspot native memory tracking
Summary: Implementation of native memory tracking phase 1, which tracks VM native memory usage, and related DCmd
Reviewed-by: acorn, coleenp, fparain

Reviewed-by: mgerdin, johnc

Summary: Fix naming style to be consistent with the predominant hotspot style.
Reviewed-by: ysr, brutisso

Summary: removed oop_verify_old_oop and allow_dirty. Also reviewed by: alexlamsl@gmail.com
Reviewed-by: jmasa, jwilhelm

Summary: Make the FreeChunk, FreeList, TreeList, and BinaryTreeDictionary classes usable outside CMS.
Reviewed-by: brutisso, johnc, jwilhelm
Contributed-by: coleen.phillimore@oracle.com

Summary: Temporarily disabled multi-threaded reference discovery when entering a single-threaded remark phase.
Reviewed-by: brutisso, tonyp, jmasa, jcoomes

Summary: Replace calls to os::javaTimeMillis() that are used to update the milliseconds since the last GC to an equivalent that uses a monotonically non-decreasing time source.
Reviewed-by: ysr, jmasa

Summary: Change variables representing the number of GC workers to uint from int and size_t.  Change the parameter in work(int i) to work(uint worker_id).
Reviewed-by: brutisso, tonyp

Summary: Enabled reference processing when work stealing during concurrent marking
Reviewed-by: jmasa, brutisso

Summary: Remove dead code.
Reviewed-by: stefank, ysr

Summary: G1 now uses two reference processors - one is used by concurrent marking and the other is used by STW GCs (both full and incremental evacuation pauses). In an evacuation pause, the reference processor is embedded into the closures used to scan objects. Doing so causes causes reference objects to be 'discovered' by the reference processor. At the end of the evacuation pause, these discovered reference objects are processed - preserving (and copying) referent objects (and their reachable graphs) as appropriate.
Reviewed-by: ysr, jwilhelm, brutisso, stefank, tonyp

Summary: Select number of GC threads dynamically based on heap usage and number of Java threads
Reviewed-by: johnc, ysr, jcoomes

Summary: Avoid overcounting when CMS has concurrent mode failure.
Reviewed-by: ysr
Contributed-by: rednaxelafx@gmail.com

Reviewed-by: dholmes, never, jwilhelm, kvn

Summary: Do a one-step look-ahead, when sweeping free or garbage blocks, to avoid overstepping sweep limit, which may become a non-block-boundary because of a heap expansion delta coalescing with a previously co-terminal free block.
Reviewed-by: brutisso, tonyp

Summary: Add a notification to the GarbageCollectorMXBeans
Reviewed-by: acorn, mchung

Summary: In G1 heap verification, we no longer scan perm to G1-collected heap refs as part of process_strong_roots() but rather in a separate explicit oop iteration over the perm gen. This preserves the original perm card-marks. Added a new assertion in younger_refs_iterate() to catch a simple subcase where the user may have forgotten a prior save_marks() call, as happened in the case of G1's attempt to iterate perm to G1 refs when verifying the heap before exit. The assert was deliberately weakened for ParNew+CMS and will be fixed for that combination in a future CR. Also made some (non-G1) cleanups related to code and comments obsoleted by the migration of Symbols to the native heap.
Reviewed-by: iveresov, jmasa, tonyp

Reviewed-by: never, coleenp, ysr, jwilhelm

Summary: Use _max_num_q = max(discovery_degree, processing_degree), and let balance_queues() redistribute from discovery_degree to processing_degree of queues. This should also allow a more dynamic and flexible parallelism policy in the future.
Reviewed-by: jmasa, johnc

Summary: Count enable_icms() and disable_icms() events so as to prevent inteference between concurrent calls, which can cause the iCMS thread to be left stranded in icms_wait() with an unserviced request and no young allocations to unwedge it.
Reviewed-by: jcoomes, poonam

Summary: Fix block_size_if_printezis_bits() so it does not expect the bits, only uses them when available. Fix block_size_no_stall() so it does not stall when the bits are missing such cases, letting the caller deal with zero size returns. Constant pool cache oops do not need to be unparsable or conc_unsafe after their klass pointer is installed. Some cosmetic clean-ups and some assertion checking for conc-usafety which, in the presence of class file redefinition, has no a-priori time boundedness, so all GCs must be able to safely deal with putatively conc-unsafe objects in a stop-world pause.
Reviewed-by: jmasa, johnc

Summary: move symbols from permgen into C heap and reference count them
Reviewed-by: never, acorn, jmasa, stefank

Summary: Rebuild breakpoint cache at gc_epilogue instead of during oops_do
Reviewed-by: dcubed, ysr, coleenp

Summary: Revert a (relaxed version of the) bounds-check that was incorrectly removed in the fix for 7008136.
Reviewed-by: jmasa, johnc

Summary: Make JvmtiGCMark safe to run non-safepoint and instrument CMS
Reviewed-by: ysr, dcubed

Summary: The recorded _sweep_limit may not necessarily remain a block boundary as the old generation expands during a concurrent cycle. Terminal actions inside the sweep closure need to be aware of this as they cross over the limit.
Reviewed-by: johnc, minqi

7001033: assert(gch->gc_cause() == GCCause::_scavenge_alot || !gch->incremental_collection_failed())
7002546: regression on SpecJbb2005 on 7b118 comparing to 7b117 on small heaps
Summary: Relaxed assertion checking related to incremental_collection_failed flag to allow for ExplicitGCInvokesConcurrent behaviour where we do not want a failing scavenge to bail to a stop-world collection. Parameterized incremental_collection_will_fail() so we can selectively use, or not use, as appropriate, the statistical prediction at specific use sites. This essentially reverts the scavenge bail-out logic to what it was prior to some recent changes that had inadvertently started using the statistical prediction which can be noisy in the presence of bursty loads. Added some associated verbose non-product debugging messages.
Reviewed-by: johnc, tonyp