Summary: G1 now uses two reference processors - one is used by concurrent marking and the other is used by STW GCs (both full and incremental evacuation pauses). In an evacuation pause, the reference processor is embedded into the closures used to scan objects. Doing so causes causes reference objects to be 'discovered' by the reference processor. At the end of the evacuation pause, these discovered reference objects are processed - preserving (and copying) referent objects (and their reachable graphs) as appropriate.
Reviewed-by: ysr, jwilhelm, brutisso, stefank, tonyp

Summary: If and when the reference handler thread is able to use the discovered field to link reference objects in its pending list, so will GC. In that case, GC will scan through this field once a reference object has been placed on the pending list, but not scan that field before that stage, as the field is used by the concurrent GC thread to link discovered objects. When ReferenceHandleR thread does not use the discovered field for the purpose of linking the elements in the pending list, as would be the case in older JDKs, the JVM will fall back to the old behaviour of using the next field for that purpose.
Reviewed-by: jcoomes, mchung, stefank

Summary: Remove the sentinelRef and let the last Reference in a discovered chain point back to itself.
Reviewed-by: ysr, jmasa

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: Relaxed the assert by allowing NULL referents when discovery may be concurrent.
Reviewed-by: johnc, jcoomes

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

6934483: GCC 4.5 errors "suggest parentheses around something..." when compiling with -Werror and -Wall
Summary: These are minor changes fixing compile failure when -Wall -Werror flags are used under gcc 4.5.
Reviewed-by: twisti, kvn, rasbold
Contributed-by: NPavel Tisnovsky <ptisnovs@redhat.com>

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

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

Summary: Interval checking is now being performed on the values passed in for these two flags. The current acceptable range for RefDiscoveryPolicy is [0..1], and for TLABWasteTargetPercent it is [1..100].
Reviewed-by: apetrusenko, ysr

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

Summary: Renamed Reference{Policy,Pocessor} methods from snap{,_policy}() to setup{,_policy}()
Reviewed-by: apetrusenko

Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not.
Reviewed-by: jmasa

Summary: Update copyright year for files that have been modified in 2008
Reviewed-by: ohair, tbell

Summary: First mercurial integration of the code for the Garbage-First garbage collector.
Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr

Summary: Compressed oops in instances, arrays, and headers. Code contributors are coleenp, phh, never, swamyv
Reviewed-by: jmasa, kamg, acorn, tbell, kvn, rasbold