Reviewed-by: brutisso, tschatzl

Reviewed-by: brutisso, jwilhelm

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

Summary: Splitting out a g1 allocator class to simply specialized allocators which can associate each allocation with a given context.
Reviewed-by: mgerdin, brutisso

8055635: Missing include in g1RegionToSpaceMapper.hpp results in unresolved symbol of fastdebug build without precompiled headers
Reviewed-by: mgerdin, ehelin

Summary: If large pages are enabled and configured in Linux, the VM always pre-commits the entire space. The VM fails verification of the commit of the initial heap because some internal data structure marked all memory pages of the heap as committed during initialization. This makes the code think that we attempted a double-commit during first allocation of the heap. Remove the initial marking of memory pages of the heap to committed.
Reviewed-by: mgerdin

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

Summary: The verification code that checked whether no bitmap mark had been found re-read HeapRegion::end() after the check on the bitmap. Concurrent humongous object allocation could have changed HeapRegion::end() in the meantime. Fix this by using the actual end of the region instead of HeapRegion::end() for comparison.
Reviewed-by: brutisso, jmasa

Summary: Enable shrinking within the heap by removing some code added for JDK-8054818. Enable the test case that checks that again too.
Reviewed-by: jwilhelm, jmasa

Reviewed-by: jmasa, jwilhelm

Reviewed-by: jwilhelm, jmasa

Reviewed-by: pliden, jmasa

Summary: Extend the WhiteBox API to provide information about the size and age of objects. Further add a mechanism to trigger a young GC.
Reviewed-by: tschatzl, sjohanss
Contributed-by: NLeonid Mesnik <leonid.mesnik@oracle.com>

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

Reviewed-by: brutisso, tschatzl

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

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

Summary: Do not try to verify timing measures for the redirty logged cards phase when it is not executed.
Reviewed-by: brutisso, jmasa

Summary: Do not try to verify timing measures for the redirty logged cards phase when it is not executed.
Reviewed-by: brutisso, jmasa

Summary: Eager reclaim also needs to clear marks of eagerly reclaimed regions if they have already been marked during concurrent mark.
Reviewed-by: jmasa

Summary: Eager reclaim also needs to clear marks of eagerly reclaimed regions if they have already been marked during concurrent mark.
Reviewed-by: 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

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

Summary: Refactor preparation for compaction during Full GC so that it lazily initializes the first compaction point. This also avoids problems later when the first region may not be committed. Also reviewed by K. Barrett.
Reviewed-by: brutisso

Summary: Refactor preparation for compaction during Full GC so that it lazily initializes the first compaction point. This also avoids problems later when the first region may not be committed. Also reviewed by K. Barrett.
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

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

8049051: Use of during_initial_mark_pause() in G1CollectorPolicy::record_collection_pause_end() prevents use of seperate object copy time prediction during marking
Summary: Replaced use of during_initial_mark_pause() with the variable last_pause_included_initial_mark that holds the real old value of _during_initial_mark_pause.
Reviewed-by: brutisso, ehelin

8049051: Use of during_initial_mark_pause() in G1CollectorPolicy::record_collection_pause_end() prevents use of seperate object copy time prediction during marking
Summary: Replaced use of during_initial_mark_pause() with the variable last_pause_included_initial_mark that holds the real old value of _during_initial_mark_pause.
Reviewed-by: brutisso, ehelin

Reviewed-by: brutisso, sjohanss

Summary: Removed all write barriers during reference processing and added explicit write barriers when iterating through the discovered list.
Reviewed-by: pliden, jmasa, tschatzl

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

Reviewed-by: brutisso, tschatzl, ehelin, jmasa, dfazunen

Reviewed-by: stefank, brutisso

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