Summary: G1 was not handling explicit GCs correctly in many ways. It does now. See the CR for the list of improvements contained in this changeset.
Reviewed-by: iveresov, ysr, johnc

Reviewed-by: ysr, jmasa

Summary: Shrinking of a generation and the corresponding card table was causing part of the card table to be uncommitted.
Reviewed-by: jcoomes

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: Rather than changing the default value of the G1UseFixedWindowMMUTracker, the flag and associated guarantee have been removed.
Reviewed-by: jcoomes, tonyp, ysr

Reviewed-by: kamg, ysr, dholmes, johnc

Summary: When using compressed oops, use compressed promoted pointers in b63:b31 of the mark word, so as not to interfere with the CMS "freeness bit" at b7. Updated mark-word layout documentation.
Reviewed-by: minqi, poonam, jmasa, coleenp

6921317: (partial) G1: assert(top() == bottom() || zfs == Allocated,"Region must be empty, or we must be setting it to
Summary: Extended the failing assertion with the new message format to get more data.
Reviewed-by: tonyp

6951582: Build problems on win64
Summary: Changes to enable building JDK7 with Microsoft Visual Studio 2010
Reviewed-by: ohair, art, ccheung, dcubed

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: Small improvements to G1's PrintGCDetails output. It also includes minor formatting details.
Reviewed-by: ysr, johnc

6949307: G1: raise a vm error, do not core dump, if target pause time and target interval are inconsistent
Summary: First, change the guarantee to raising a vm error. Second, set the interval dynamically, and based on the pause time target, if it is not set explicitly.
Reviewed-by: ysr, johnc

6871109: G1: remove the concept of the scan only prefix
Summary: Removed scan only regions and associated code. The young portion of the collection set is now constructed incrementally - when a young region is retired as the current allocation region it is added to the collection set.
Reviewed-by: apetrusenko, iveresov, tonyp

Summary: ensure_parsability() must be called even if GC_locker prevents GC.
Reviewed-by: ysr, chrisphi

Summary: Replaces the G1-specific parameter with the existing ones that are used by the other GCs (YoungPLABSize and OldPLABSize)
Reviewed-by: tonyp, johnc

Summary: The outgoing region map is not maintained properly and it's causing an assert failure. Given that we don't actually use it, I'm removing it. I'm piggy-backing a small change on this which removes a message that it's printed before a Full GC when DisableExplicitGC is set.
Reviewed-by: apetrusenko, ysr

Summary: The expression that calculates the live bytes for a heap region can overflow for a suitably large humongous region/object. Cache the object size in a suitably sized local variable so that the expression is converted to a wider type.
Reviewed-by: tonyp, jmasa, iveresov, apetrusenko

Summary: Humongous regions may contain multiple objects as a result of being retained as to-space from a previous GC and then re-used as to-space after being tagged as humongous. These changes include a check that causes retained to-space regions that are now tagged as humongous to be disregarded and a new to-space region allocated.
Reviewed-by: tonyp, iveresov

Summary: Make sure that two marking cycles do not overlap, i.e., a new one can only start after the concurrent marking thread finishes all its work. In the fix I piggy-back a couple of minor extra fixes: some general code reformatting for consistency (only around the code I modified), the removal of a field (G1CollectorPolicy::_should_initiate_conc_mark) which doesn't seem to be used at all (it's only set but never read), as well as moving the "is GC locker active" test earlier into the G1 pause / Full GC and using a more appropriate method for it.
Reviewed-by: johnc, jmasa, jcoomes, ysr

Summary: Calling the methods region_stack_push() and region_stack_pop() concurrent is not MT-safe. The assumption is that we will only call region_stack_push() during a GC pause and region_stack_pop() during marking. Unfortunately, we also call region_stack_push() during marking which seems to be introducing subtle marking failures. This change introduces lock-based methods for pushing / popping to be called during marking.
Reviewed-by: iveresov, johnc

Summary: Enable parallel RSet updating and scanning.
Reviewed-by: iveresov, jmasa

Summary: Various fixes to the G1 debugging output.
Reviewed-by: johnc, iveresov

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

Summary: Remove the G1GCPercent parameter, that specifies the desired GC overhead percentage in G1, and observe the GCTimeRatio parameter instead.
Reviewed-by: jmasa, johnc

Summary: process one item at a time from the objarray stack/queue
Reviewed-by: apetrusenko, tonyp

Summary: Newly-created threads always had the active field of their SATB queue initialized to false, even if they were created during marking. As a result, updates from threads created during a marking cycle were never enqueued and never processed. The fix includes remaining a method from active() to is_active() for readability and naming consistency.
Reviewed-by: ysr, johnc

Summary: If CM task was aborted while scanning the last object of the specified region and the size of that object is equal to bitmap's granularity then the next offset would be equal or over the region limit which is exactly what the assertion states.
Reviewed-by: ysr, tonyp, jmasa

Summary: A TLAB became large enough to be considered a humongous object allowing multiple objects to be allocated in a humongous region, which violates a basic assumption about humongous regions. The changes ensure that TLABs cannot be regarded as humongous.
Reviewed-by: iveresov, tonyp

Summary: Use an explicit stack for object arrays and process them in chunks.
Reviewed-by: iveresov, apetrusenko

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

Summary: see synopsis
Reviewed-by: johnc, jmasa

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

Summary: replace the combination of the G1SteadyStateUsed / G1SteadyStateUsedDelta parameteres to decide the marking initiation threshold and instead use InitiatingHeapOccupancyPercent.
Reviewed-by: ysr, johnc

Summary: Rename G1 parameters to make them more consistent.
Reviewed-by: jmasa, johnc

Summary: Implemented block-based work stealing. Moved copying during the rset scanning phase to the main copying phase. Made the size of rset table depend on the region size.
Reviewed-by: apetrusenko, tonyp

Summary: The operations of re-using a RSet component and expanding the same RSet component were not mutually exlusive, and this could lead to RSets getting corrupted and entries being dropped.
Reviewed-by: iveresov, johnc

Summary: Invalid assert. Filter cards evicted from the card count cache instead.
Reviewed-by: apetrusenko, tonyp