Reviewed-by: jwilhelm, jmasa

Summary: Allow G1 to decommit memory of arbitrary regions within the heap and their associated auxiliary data structures card table, BOT, hot card cache, and mark bitmaps.
Reviewed-by: mgerdin, brutisso, jwilhelm

Summary: Let HeapRegionSeq manage the heap region and auxiliary data to decrease the amount of responsibilities of G1CollectedHeap, and encapsulate this work from other code.
Reviewed-by: jwilhelm, jmasa, mgerdin, brutisso

Reviewed-by: tschatzl, jmasa

Summary: Add Resource/HandleMark in the work() method of some AbstractGangTask to reclaim these resources earlier.
Reviewed-by: tschatzl, goetz

Summary: Add Resource/HandleMark in the work() method of some AbstractGangTask to reclaim these resources earlier.
Reviewed-by: tschatzl, goetz

8048085: Aborting marking just before remark results in useless additional clearing of the next mark bitmap
Summary: Skip clearing the next bitmap if we just recently aborted since the full GC already clears this bitmap.
Reviewed-by: brutisso

8048085: Aborting marking just before remark results in useless additional clearing of the next mark bitmap
Summary: Skip clearing the next bitmap if we just recently aborted since the full GC already clears this bitmap.
Reviewed-by: brutisso

Summary: Added -XX:+/-ClassUnloadingWithConcurrentMark
Reviewed-by: jmasa, brutisso, mgerdin

Reviewed-by: tschatzl, ehelin, brutisso, coleenp, roland, iveresov
Contributed-by: stefan.karlsson@oracle.com, mikael.gerdin@oracle.com

Reviewed-by: jmasa, tschatzl, ehelin
Contributed-by: tony.printezis@oracle.com, bengt.rutisson@oracle.com

Summary: Allocate temporary BitMaps in the VMThread's resource area
Reviewed-by: stefank, sjohanss

Summary: Clean up usage of idx_t and uintptr_t when using it in conjunction with BitMap::set_map(), casting to the appropriate type. Fixes compilation on S390.
Reviewed-by: tschatzl
Contributed-by: NDan Horak <dhorak@redhat.com>

Reviewed-by: brutisso, tschatzl

Reviewed-by: brutisso, ehelin

Reviewed-by: twisti, stefank

8043029: Change 8037816 breaks HS build with older GCC versions which don't support diagnostic pragmas
8043164: Format warning in traceStream.hpp
Summary: Backport of main fix + two corrections, enables clang compilation, turns on format attributes, corrects/mutes warnings
Reviewed-by: kvn, coleenp, iveresov, twisti

Reviewed-by: brutisso, tschatzl, mgerdin

Reviewed-by: jwilhelm, ehelin, tschatzl

Reviewed-by: tschatzl, pliden

Reviewed-by: tschatzl, jwilhelm

Summary: Replaced the verification call to a conditional one that only runs verification in debug builds.
Reviewed-by: brutisso, tschatzl

Reviewed-by: brutisso, tschatzl

Summary: The free list is being maintained in a sorted fashion and old and humongous regions are allocated from the bottom of the heap while young regions are allocated at the top.
Reviewed-by: tschatzl, mgerdin
Contributed-by: jesper.wilhelmsson@oracle.com, staffan.friberg@oracle.com

8027454: Do not traverse string table during G1 remark when treating them as strong roots during initial mark
Summary: Do not try to unlink string table entries unconditionally during remark. This is without side effects as the preceding initial mark always uses the string table as strong roots. Needs to be fixed with class unloading during concurrent mark.
Reviewed-by: brutisso, mgerdin

8027455: Improve symbol table scan times during gc pauses
Summary: Parallelize string table and symbol table scan during remark and full GC. Some additional statistics output if the experimental flag G1TraceStringSymbolTableScrubbing is set.
Reviewed-by: mgerdin, coleenp, brutisso

Reviewed-by: brutisso, jmasa, jwilhelm

Summary: Enable CHECK_UNHANDLED_OOPS in fastdebug builds across all supported platforms.
Reviewed-by: coleenp, hseigel, dholmes, stefank, twisti, ihse, rdurbin
Contributed-by: lois.foltan@oracle.com

Summary: Correctly calculate the initialization value for the shift between object start and bitmap bit in the G1 mark bitmaps.
Reviewed-by: tonyp

Summary: Add a list of nmethods to the RSet for a region that contain references into the region. Skip scanning the code cache during root scanning and scan the nmethod lists during RSet scanning instead.
Reviewed-by: tschatzl, brutisso, mgerdin, twisti, kvn

Reviewed-by: acorn, coleenp, sla
Contributed-by: NKaren Kinnear &lt;karen.kinnear@oracle.com&gt;, Bengt Rutisson &lt;bengt.rutisson@oracle.com&gt;, Calvin Cheung &lt;calvin.cheung@oracle.com&gt;, Erik Gahlin &lt;erik.gahlin@oracle.com&gt;, Erik Helin &lt;erik.helin@oracle.com&gt;, Jesper Wilhelmsson &lt;jesper.wilhelmsson@oracle.com&gt;, Keith McGuigan &lt;keith.mcguigan@oracle.com&gt;, Mattias Tobiasson &lt;mattias.tobiasson@oracle.com&gt;, Markus Gronlund &lt;markus.gronlund@oracle.com&gt;, Mikael Auno &lt;mikael.auno@oracle.com&gt;, Nils Eliasson &lt;nils.eliasson@oracle.com&gt;, Nils Loodin &lt;nils.loodin@oracle.com&gt;, Rickard Backman &lt;rickard.backman@oracle.com&gt;, Staffan Larsen &lt;staffan.larsen@oracle.com&gt;, Stefan Karlsson &lt;stefan.karlsson@oracle.com&gt;, Yekaterina Kantserova <yekaterina.kantserova@oracle.com>

Summary: Improve the output of G1PrintRegionLivenessInfo by adding a per-region remembered set size information column
Reviewed-by: jwilhelm, johnc

Reviewed-by: johnc, brutisso

Reviewed-by: brutisso, jmasa

Summary: If the marking stack overflows while the marking tasks are draining the SATB buffers, remark will exit with some SATB buffers left unprocessed. Relax the guarantee to allow for overflow.
Reviewed-by: jmasa, brutisso

Summary: Skip reference processing if the global marking stack overflows during remark. Refactor and rename set_phase(); move code that sets the concurrency level into its own routine. Do not call set_phase() from within parallel reference processing; use the concurrency level routine instead. The marking state should only set reset by CMTask[0] during the concurrent phase of the marking cycle; if an overflow occurs at any stage during the remark, the marking state will be reset after reference processing.
Reviewed-by: brutisso, jmasa

Summary: In CMTask::do_marking_step(), Skip offering termination and entering the first and second synchronization barriers if called from a serial context, i.e. the VM thread.
Reviewed-by: brutisso, tschatzl

Summary: ASSERT and other symbols used incorrectly with #if are supposed to be defined or not.
Reviewed-by: dholmes, mikael

Summary: Update the task local finger to the start of the next object when marking aborts, in order to avoid the redundant scanning of all 0's when the marking task restarts, if otherwise updating to the next word. In addition, reuse the routine nextObject() in routine iterate().
Reviewed-by: johnc, ysr
Contributed-by: Ntamao <tao.mao@oracle.com>

Summary: Reuse the parallel reference processing oop closures during serial reference processing.
Reviewed-by: brutisso