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

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

Reviewed-by: tschatzl, mgerdin, jmasa

Summary: Extract the G1ParScanThreadState class from G1CollectedHeap.?pp into its own files.
Reviewed-by: brutisso, mgerdin

Summary: G1 does not retire allocation buffers after reference processing work when -XX:+ParallelRefProcEnabled is enabled. This causes wrong calculation of PLAB sizes, as the amount of space wasted is not updated correctly.
Reviewed-by: brutisso

Summary: Instead of using a manually managed array for the in_cset_fast_test array, use a G1BiasedArray instance.
Reviewed-by: brutisso, mgerdin

Reviewed-by: brutisso, sjohanss

Reviewed-by: dholmes, kvn, stefank, twisti

Reviewed-by: brutisso, mgerdin

Reviewed-by: tschatzl, pliden

Reviewed-by: tschatzl, jwilhelm

Summary: Revert JDK-6976350 because it does not improve PLAB fragmentation. To the contrary, it tends to increase the amount of wasted space with many threads.
Reviewed-by: brutisso

Summary: Move G1ParCopyClosure::copy_to_survivor_space to decrease code size.
Reviewed-by: stefank, jmasa

Summary: Remove the assumption that G1CollectedHeap::in_cset_fast_test needs to check for NULL references. Most of the time this is not required, making the code doing this check multiple times.
Reviewed-by: stefank, mgerdin, jmasa

Summary: Mentioned closures are actually wrapped methods. This adds confusion to readers, and in this case also increases code size as G1ParScanHeapEvacClosure is part of the oop_oop_iterate() methods. Move them into G1ParScanThreadState as methods.
Reviewed-by: stefank

Summary: Show the time taken by card redirtying during GC in a new "Redirty Cards" line.
Reviewed-by: jwilhelm, brutisso

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

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: 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

Reviewed-by: tschatzl, stefank, jmasa

Summary: Remove the above mentioned template parameter and related unused code. Also remove some classes that are never used.
Reviewed-by: stefank, mgerdin, jwilhelm

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

Summary: Change 8035330: Remove G1ParScanPartialArrayClosure and G1ParScanHeapEvacClosure broke the debug build on AIX. The method do_oop_partial_array() is added in a header, but requires the inline function par_write_ref() through several inlined calls. In some cpp files, like arguments.cpp, par_write_ref() is not defined as the corresponding inline header and is not included. The AIX debug VM does not start because of the missing symbol. This change solves this by cleaning up include dependencies.
Reviewed-by: tschatzl, stefank

Reviewed-by: dholmes, egahlin

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: Move some G1 specific code from CardTableModRefBS to G1SATBCardTableModRefBS.
Reviewed-by: brutisso, tschatzl, ehelin

Summary: Use conservative assumptions of required alignment for the various garbage collector components into account when determining the maximum heap size that supports compressed oops. Using this conservative value avoids several circular dependencies in the calculation.
Reviewed-by: stefank, dholmes

Reviewed-by: tonyp, tschatzl

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

Summary: Remove -Xaprof and Klass::_alloc_count & ArrayKlass::_alloc_size.
Reviewed-by: stefank, coleenp

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: Create G1ParGCAllocBufferContainer to contain two buffers instead of previously using one buffer, in order to hold the first priority buffer longer. Thus, when some large objects hits the value of free space left in the first priority buffer it has an alternative to fit in the second priority buffer while the first priority buffer is given more chances to try allocating smaller objects. Overall, it will improve heap space efficiency.
Reviewed-by: johnc, jmasa, brutisso
Contributed-by: Ntamao <tao.mao@oracle.com>

Reviewed-by: brutisso, tschatzl

Reviewed-by: brutisso, jmasa

Summary: Keep a counter of how many times we were stalled by the GC locker, add a diagnostic flag which sets the limit.
Reviewed-by: brutisso, ehelin, johnc

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

Reviewed-by: tschatzl, jmasa

Summary: Use Stack<> instead of GrowableArray to keep track of preserved marks. Also reviewed by vitalyd@gmail.com.
Reviewed-by: johnc, jcoomes

Summary: Divide by zero error, if ParallelGCThreads is 0, when adjusting the PLAB size.
Reviewed-by: jmasa, jcoomes

Summary: Reset the fields in ParGCAllocBuffer, that are used for accumulating values for the ResizePLAB sensors in PLABStats, to zero after flushing the values to the PLABStats fields. Flush PLABStats values only when retiring the final allocation buffers prior to disposing of a G1ParScanThreadState object, rather than when retiring every allocation buffer.
Reviewed-by: jwilhelm, jmasa, ysr