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

Summary: Replaced MakeDeps and the includeDB files with more standardized solutions.
Reviewed-by: coleenp, kvn, kamg

Summary: Deprecated HandlePromotionFailure, removing the ability to turn off that feature, did away with one epoch look-ahead when deciding if a scavenge is likely to fail, relying on current data.
Reviewed-by: jmasa, johnc, poonam

6692906: CMS: parallel concurrent marking may be prone to hanging or stalling mutators for periods of time
Summary: Inserted missing yield(check)s in closures used during the work-stealing phase of parallel concurrent marking, a missing synchronous yield-request in the cms perm gen allocation path, and a terminator-terminator for the offer_termination invocation that monitors the yield status of the concurrent marking task. Elaborated some documentation comments and made some task queue termination loop flags configurable at start-up to aid debugging in the field.
Reviewed-by: jmasa, johnc, poonam

6942771: SEGV in ParScanThreadState::take_from_overflow_stack
Reviewed-by: apetrusenko, ysr, pbk

Summary: Fixed comment/documentation typos; converted some guarantee()s to assert()s.
Reviewed-by: jmasa

Summary: Associate number of GC workers with the workgang as opposed to the task.
Reviewed-by: johnc, ysr

Summary: Allow for the possibility (when the heap is expanding) that the sweep might skip over and past, rather than necessarily step on, the sweep limit determined at the beginning of a concurrent marking cycle.
Reviewed-by: jmasa, tonyp

Summary: GC workers now recognize an intermediate transient state of blocks which are allocated but have not yet completed initialization. blk_start() calls do not attempt to determine the size of a block in the transient state, rather waiting for the block to become initialized so that it is safe to query its size. Audited and ensured the order of initialization of object fields (klass, free bit and size) to respect block state transition protocol. Also included some new assertion checking code enabled in debug mode.
Reviewed-by: chrisphi, johnc, poonam

Summary: Management code enabled for use by a concurrent collector.
Reviewed-by: mchung, ysr

Reviewed-by: tonyp, ysr

Summary: Change all the Sun copyrights to Oracle copyright
Reviewed-by: ohair

Summary: Added new product ObjectAlignmentInBytes flag to control object alignment.
Reviewed-by: twisti, ysr, iveresov

Summary: Moved PromotionInfo and friends into new files promotionInfo.{h,c}pp from their previous compactibleFreeListSpace.{h,c}pp home.
Reviewed-by: apetrusenko

Summary: GC-locker induced concurrent full gc should be asynchronous; policy now controlled by a separate flag, which defaults to false.
Reviewed-by: jmasa

Summary: On sun4v/CMT avoid use of memset() in BOT updates so as to prevent concurrent BOT readers from seeing the phantom zeros arising from memset()'s use of BIS.
Reviewed-by: jmasa, johnc, minqi, poonam, tonyp

Summary: Ensure a full GC that clears SoftReferences before throwing an out-of-memory
Reviewed-by: ysr, jcoomes

Summary: Calculation of the slicing of survivor spaces for MT was incorrect.
Reviewed-by: ysr

Summary: Rename marking stack sizing flags to be common between G1 and CMS
Reviewed-by: ysr, tonyp

Summary: Adjust assertion checking for ExplicitGCInvokesConcurrentAndUnloadsClasses as a reason for class unloading
Reviewed-by: ysr

Summary: Autonomic per-worker free block cache sizing, tunable coalition policies, fixes to per-size block statistics, retuned gain and bandwidth of some feedback loop filters to allow quicker reactivity to abrupt changes in ambient demand, and other heuristics to reduce fragmentation of the CMS old gen. Also tightened some assertions, including those related to locking.
Reviewed-by: jmasa

Summary: Use CollectorPolicy information instead of MaxNewSize
Reviewed-by: ysr, jcoomes

Summary: After mechanically merging changes, some by-hand adjustments are needed.
Reviewed-by: ysr

Summary: Make a special root-list for those few nmethods which might contain non-perm oops.
Reviewed-by: twisti, kvn, never, jmasa, ysr

Summary: Treat ProfileData in MDO's as a source of weak, not strong, roots. Fixes the bug for stop-world collection -- the case of concurrent collection will be fixed separately.
Reviewed-by: jcoomes, jmasa, kvn, never

Summary: Override should_remember_klasses() and remember_klass() as needed.
Reviewed-by: ysr, jcoomes

Summary: The field is now initialized in the constructor.
Reviewed-by: iveresov, jmasa, johnc

Summary: When using compressed oops, rather than chaining the overflowed grey objects' pre-images through their klass words, we use GC-worker thread-local overflow stacks.
Reviewed-by: jcoomes, jmasa