Summary: Replace G1CodeRootSet with a Hashtable based implementation, merge Code Root Migration phase into Code Root Scanning
Reviewed-by: jmasa, brutisso, tschatzl

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

Reviewed-by: tschatzl, jmasa

Summary: Fixup the remaining variable names.
Reviewed-by: tonyp, jwilhelm

Reviewed-by: jwilhelm, jmasa

Summary: Enhance scalability of native memory tracking
Reviewed-by: coleenp, ctornqvi, gtriantafill

Summary: Try to reclaim humongous objects at every young collection after doing a conservative estimate of its liveness.
Reviewed-by: brutisso, mgerdin

Summary: Try to reclaim humongous objects at every young collection after doing a conservative estimate of its liveness.
Reviewed-by: brutisso, mgerdin

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

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: tschatzl, jwilhelm

Summary: Refactor the From Card Cache into a separate class.
Reviewed-by: jmasa

Summary: Improve fast card cache iteration and avoid taking locks when freeing the collection set.
Reviewed-by: brutisso

Summary: The from card cache is a very frequently accessed data structure. It is essentially a 2d array of per-region values, one row of values for every GC thread. Pad and align the data structure to avoid false sharing.
Reviewed-by: stefank

Summary: Change the code cache remembered sets data structure from a GrowableArray to a chunked list of nmethods. This makes the data structure more amenable to parallelization, and decreases freeing time.
Reviewed-by: mgerdin, brutisso

Summary: A few locations in the code use sizeof(this) which returns the size of the pointer instead of sizeof(classname) which returns the size of the sum of its members. This change fixes these errors and adds a few tests.
Reviewed-by: mgerdin, brutisso

Summary: The mentioned method is never used and out of date. So it is removed.
Reviewed-by: mgerdin, brutisso

Summary: After changes to the PerRegionTable where all these PRTs are linked together in an additional field, simplify iterating over all PRTs by using these links instead of walki
Reviewed-by: mgerdin, jwilhelm, brutisso

Summary: Change checks for isHumongous() to continuesHumongous() as installing a code root for a humongous object is valid, but not for continuations of humongous objects. Cleaned up asserts.
Reviewed-by: jmasa, tamao

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: 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

8014405: G1: PerRegionTable::fl_mem_size() calculates size of the free list using wrong element sizes
Summary: Instead of using a simple sizeof(), ask the PerRegionTable class about its size when iterating over the free list.
Reviewed-by: jwilhelm, brutisso

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

Summary: The fix of 8010992, disable use of global operator new and new[] which caused failure on some tests. This takes two of the bugs also add ALLOW_OPERATOR_NEW_USAGE to prevent crash for third party code calling operator new of jvm on certain platforms.
Reviewed-by: coleenp, dholmes, zgu
Contributed-by: yumin.qi@oracle.com

Reviewed-by: coleenp, zgu, hseigel

Summary: anti-delta fix for 8010992 until 8012902 can be fixed
Reviewed-by: acorn, minqi, rdurbin

Summary: disable use of global operator new and new[] which could cause unexpected exception and escape from NMT tracking.
Reviewed-by: coleenp, dholmes, zgu
Contributed-by: yumin.qi@oracle.com

Summary: Stack allocate instances of HeapRegionRemSetIterator during RSet scanning.
Reviewed-by: brutisso, jwilhelm

Reviewed-by: brutisso, johnc, ysr
Contributed-by: NHal Mo <kungu.mjh@taobao.com>

Summary: Chain the fine grain PerRegionTables in an individual RSet together and free them in bulk using a single operation.
Reviewed-by: johnc, brutisso
Contributed-by: NThomas Schatzl <thomas.schatzl@jku.at>

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

Summary: Remove the per-thread expansion tables (PosParPRT) and associated expansion and compaction from the fine grain RSet entries. This code has been unused for a while.
Reviewed-by: johnc, brutisso
Contributed-by: NThomas Schatzl <thomas.schatzl@jku.at>

Summary: Removed LOG_G and LOG_K. Moved LOG_M to where it is being used.
Reviewed-by: twisti, johnc

Summary: Change the type of fields / variables / etc. that represent region counts and indeces from size_t to uint.
Reviewed-by: iveresov, brutisso, jmasa, jwilhelm

7097516: G1: assert(0<= from_card && from_card<HeapRegion::CardsPerRegion) failed: Must be in range.
Summary: Introduced a version of is_in_reserved() that looks at _orig_end as opposed to _end.
Reviewed-by: tonyp, stefank

Summary: Declare GrainBytes, GrainWords, and CardsPerRegion as size_t.
Reviewed-by: jcoomes, tonyp, jmasa

Summary: Refactor the allocation code during GC to use the G1AllocRegion abstraction. Use separate subclasses of G1AllocRegion for survivor and old regions. Avoid BOT updates and dirty survivor cards incrementally for the former.
Reviewed-by: brutisso, johnc, ysr

Summary: Remove two unnecessary iterations over the collection set which are supposed to prepare the RSet's of the CSet regions for parallel iterations (we'll make sure this is done incrementally). I'll piggyback on this CR the removal of the G1_REM_SET_LOGGING code.
Reviewed-by: brutisso, johnc

7042285: G1: native memory leak during humongous object allocation
6804436: G1: heap region indices should be size_t
Summary: A series of fixes and improvements to the HeapRegionSeq class: a) replace the _regions growable array with a standard C array, b) avoid de-allocating / re-allocating HeapRegion instances when the heap shrinks / grows (fix for 7042285), c) introduce fast method to map address to HeapRegion via a "biased" array pointer, d) embed the _hrs object in G1CollectedHeap, instead of pointing to it via an indirection, e) assume that all the regions added to the HeapRegionSeq instance are contiguous, f) replace int's with size_t's for indexes (and expand that to HeapRegion as part of 6804436), g) remove unnecessary / unused methods, h) rename a couple of fields (_alloc_search_start and _seq_bottom), i) fix iterate_from() not to always start from index 0 irrespective of the region passed to it, j) add a verification method to check the HeapRegionSeq assumptions, k) always call the wrappers for _hrs.iterate(), _hrs_length(), and _hrs.at() from G1CollectedHeap, not those methods directly, and l) unify the code that expands the sequence (by either re-using or creating a new HeapRegion) and make it robust wrt to a HeapRegion allocation failing.
Reviewed-by: stefank, johnc, brutisso

Summary: A race between the concurrent cleanup thread and the VM thread while it is processing the "expanded sparse table list" causes both threads to try to free the same sparse table entry and either causes one of the threads to fail or leaves the entry in an inconsistent state. The solution is purge all entries on the expanded list that correspond go regions that are being cleaned up.
Reviewed-by: brutisso, johnc